diff --git a/README.md b/README.md
index bc026447..51564416 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 % mergerfs(1) mergerfs user manual
 % Antonio SJ Musumeci <trapexit@spawn.link>
-% 2023-02-16
+% 2023-02-19
 
 # NAME
 
@@ -200,6 +200,8 @@ These options are the same regardless of whether you use them with the `mergerfs
   `read-thread-count` refers to the number of threads reading FUSE
   messages which are dispatched to process threads. -1 means disabled
   otherwise acts like `read-thread-count`. (default: -1)
+* **pin-threads=STR**: Selects a strategy to pin threads to CPUs
+  (default: unset)
 * **scheduling-priority=INT**: Set mergerfs' scheduling
   priority. Valid values range from -20 to 19. See `setpriority` man
   page for more details. (default: -10)
@@ -257,7 +259,8 @@ These options are the same regardless of whether you use them with the `mergerfs
 * INT = [MIN_INT,MAX_INT]
 * UINT = [0,MAX_INT]
 * SIZE = 'NNM'; NN = INT, M = 'K' | 'M' | 'G' | 'T'
-* STR = string
+* STR = string (may refer to an enumerated value, see details of
+  argument)
 * FUNC = filesystem function
 * CATEGORY = function category
 * POLICY = mergerfs function policy
@@ -341,6 +344,26 @@ and the kernel use internally (also called the "nodeid").
 As of version 2.35.0 the `use_ino` option has been removed. mergerfs should always be managing inode values.
 
 
+### pin-threads
+
+Simple strategies for pinning read and/or process threads. If process
+threads are not enabled than the strategy simply works on the read
+threads. Invalid values are ignored.
+
+* R1L: All read threads pinned to a single logical CPU.
+* R1P: All read threads pinned to a single physical CPU.
+* RP1L: All read and process threads pinned to a single logical CPU.
+* RP1P: All read and process threads pinned to a single physical CPU.
+* R1LP1L: All read threads pinned to a single logical CPU, all process
+  threads pinned to a (if possible) different logical CPU.
+* R1PP1P: All read threads pinned to a single physical CPU, all
+  process threads pinned to a (if possible) different logical CPU.
+* RPSL: All read and process threads are spread across all logical CPUs.
+* RPSP: All read and process threads are spread across all physical CPUs.
+* R1PPSP: All read threads are pinned to a single physical CPU while
+  process threads are spread across all other phsycial CPUs.
+
+
 ### fuse_msg_size
 
 FUSE applications communicate with the kernel over a special character device: `/dev/fuse`. A large portion of the overhead associated with FUSE is the cost of going back and forth from user space and kernel space over that device. Generally speaking the fewer trips needed the better the performance will be. Reducing the number of trips can be done a number of ways. Kernel level caching and increasing message sizes being two significant ones. When it comes to reads and writes if the message size is doubled the number of trips are approximately halved.
diff --git a/libfuse/Makefile b/libfuse/Makefile
index 35aa96c7..8888d552 100644
--- a/libfuse/Makefile
+++ b/libfuse/Makefile
@@ -46,6 +46,9 @@ SRC_C = \
 	lib/helper.c \
 	lib/mount.c
 SRC_CPP = \
+	lib/format.cpp \
+	lib/os.cpp \
+	lib/cpu.cpp \
 	lib/fuse_loop_mt.cpp \
 	lib/fuse_msgbuf.cpp
 OBJS_C   = $(SRC_C:lib/%.c=build/%.o)
diff --git a/libfuse/include/fuse.h b/libfuse/include/fuse.h
index cb2ec1f0..59354680 100644
--- a/libfuse/include/fuse.h
+++ b/libfuse/include/fuse.h
@@ -629,6 +629,7 @@ void fuse_exit(struct fuse *f);
 
 int fuse_config_read_thread_count(const struct fuse *f);
 int fuse_config_process_thread_count(const struct fuse *f);
+const char* fuse_config_pin_threads(const struct fuse *f);
 
 /**
  * FUSE event loop with multiple threads
diff --git a/libfuse/include/fuse_lowlevel.h b/libfuse/include/fuse_lowlevel.h
index 99524e15..b427638e 100644
--- a/libfuse/include/fuse_lowlevel.h
+++ b/libfuse/include/fuse_lowlevel.h
@@ -1469,7 +1469,8 @@ void fuse_session_process(struct fuse_session *se,
 
 int fuse_session_loop_mt(struct fuse_session *se,
                          const int            read_thread_count,
-                         const int            process_thread_count);
+                         const int            process_thread_count,
+                         const char          *pin_threads_type);
 
 /* ----------------------------------------------------------- *
  * Channel interface					       *
diff --git a/libfuse/lib/cpu.cpp b/libfuse/lib/cpu.cpp
new file mode 100644
index 00000000..31916490
--- /dev/null
+++ b/libfuse/lib/cpu.cpp
@@ -0,0 +1,163 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include "cpu.hpp"
+#include "ghc/filesystem.hpp"
+#include "fmt/core.h"
+
+#include <sched.h>
+
+#include <fstream>
+
+
+int
+CPU::getaffinity(const pthread_t  thread_id_,
+                 cpu_set_t       *cpuset_)
+{
+  CPU_ZERO(cpuset_);
+  return sched_getaffinity(thread_id_,
+                           sizeof(cpu_set_t),
+                           cpuset_);
+}
+
+int
+CPU::setaffinity(const pthread_t  thread_id_,
+                 cpu_set_t       *cpuset_)
+{
+  return pthread_setaffinity_np(thread_id_,
+                                sizeof(cpu_set_t),
+                                cpuset_);
+}
+
+int
+CPU::setaffinity(const pthread_t thread_id_,
+                 const int       cpu_)
+{
+  cpu_set_t cpuset;
+
+  CPU_ZERO(&cpuset);
+  CPU_SET(cpu_,&cpuset);
+
+  return CPU::setaffinity(thread_id_,&cpuset);
+}
+
+int
+CPU::setaffinity(const pthread_t     thread_id_,
+                 const std::set<int> cpus_)
+{
+  cpu_set_t cpuset;
+
+  CPU_ZERO(&cpuset);
+  for(auto const cpu : cpus_)
+    CPU_SET(cpu,&cpuset);
+
+  return CPU::setaffinity(thread_id_,&cpuset);
+}
+
+static
+ghc::filesystem::path
+generate_cpu_core_id_path(const int cpu_id_)
+{
+  const ghc::filesystem::path basepath{"/sys/devices/system/cpu"};
+
+  return basepath / fmt::format("cpu{}",cpu_id_) / "topology" / "core_id";
+}
+
+int
+CPU::count()
+{
+  int rv;
+  cpu_set_t cpuset;
+
+  rv = CPU::getaffinity(0,&cpuset);
+  if(rv < 0)
+    return rv;
+
+  return CPU_COUNT(&cpuset);
+}
+
+CPU::CPUVec
+CPU::cpus()
+{
+  cpu_set_t cpuset;
+  CPU::CPUVec cpuvec;
+
+  CPU::getaffinity(0,&cpuset);
+
+  for(int i = 0; i < CPU_SETSIZE; i++)
+    {
+      if(!CPU_ISSET(i,&cpuset))
+        continue;
+
+      cpuvec.push_back(i);
+    }
+
+  return cpuvec;
+}
+
+CPU::CPU2CoreMap
+CPU::cpu2core()
+{
+  cpu_set_t cpuset;
+  CPU::CPU2CoreMap c2c;
+
+  CPU::getaffinity(0,&cpuset);
+
+  for(int i = 0; i < CPU_SETSIZE; i++)
+    {
+      int core_id;
+      std::ifstream ifs;
+      ghc::filesystem::path path;
+
+      if(!CPU_ISSET(i,&cpuset))
+        continue;
+
+      path = ::generate_cpu_core_id_path(i);
+
+      ifs.open(path);
+      if(!ifs)
+        break;
+
+      ifs >> core_id;
+
+      c2c[i] = core_id;
+
+      ifs.close();
+    }
+
+  return c2c;
+}
+
+CPU::Core2CPUsMap
+CPU::core2cpus()
+{
+  cpu_set_t cpuset;
+  CPU::Core2CPUsMap c2c;
+
+  CPU::getaffinity(0,&cpuset);
+
+  for(int i = 0; i < CPU_SETSIZE; i++)
+    {
+      int core_id;
+      std::ifstream ifs;
+      ghc::filesystem::path path;
+
+      if(!CPU_ISSET(i,&cpuset))
+        continue;
+
+      path = ::generate_cpu_core_id_path(i);
+
+      ifs.open(path);
+      if(!ifs)
+        break;
+
+      ifs >> core_id;
+
+      c2c[core_id].insert(i);
+
+      ifs.close();
+    }
+
+  return c2c;
+}
diff --git a/libfuse/lib/cpu.hpp b/libfuse/lib/cpu.hpp
new file mode 100644
index 00000000..c2d591fe
--- /dev/null
+++ b/libfuse/lib/cpu.hpp
@@ -0,0 +1,33 @@
+#pragma once
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <pthread.h>
+#include <sched.h>
+
+#include <set>
+#include <unordered_map>
+#include <vector>
+
+
+class CPU
+{
+public:
+  typedef std::vector<pthread_t> ThreadIdVec;
+  typedef std::vector<int> CPUVec;
+  typedef std::unordered_map<int,int> CPU2CoreMap;
+  typedef std::unordered_map<int,std::set<int>> Core2CPUsMap;
+
+public:
+  static int count();
+  static int getaffinity(const pthread_t thread_id, cpu_set_t *cpuset);
+  static int setaffinity(const pthread_t thread_id, cpu_set_t *cpuset);
+  static int setaffinity(const pthread_t thread_id, const int cpu);
+  static int setaffinity(const pthread_t thread_id, const std::set<int> cpus);
+
+  static CPU::CPUVec cpus();
+  static CPU::CPU2CoreMap cpu2core();
+  static CPU::Core2CPUsMap core2cpus();
+};
diff --git a/libfuse/lib/fmt/args.h b/libfuse/lib/fmt/args.h
new file mode 100644
index 00000000..a3966d14
--- /dev/null
+++ b/libfuse/lib/fmt/args.h
@@ -0,0 +1,234 @@
+// Formatting library for C++ - dynamic format arguments
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_ARGS_H_
+#define FMT_ARGS_H_
+
+#include <functional>  // std::reference_wrapper
+#include <memory>      // std::unique_ptr
+#include <vector>
+
+#include "core.h"
+
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename T> struct is_reference_wrapper : std::false_type {};
+template <typename T>
+struct is_reference_wrapper<std::reference_wrapper<T>> : std::true_type {};
+
+template <typename T> const T& unwrap(const T& v) { return v; }
+template <typename T> const T& unwrap(const std::reference_wrapper<T>& v) {
+  return static_cast<const T&>(v);
+}
+
+class dynamic_arg_list {
+  // Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
+  // templates it doesn't complain about inability to deduce single translation
+  // unit for placing vtable. So storage_node_base is made a fake template.
+  template <typename = void> struct node {
+    virtual ~node() = default;
+    std::unique_ptr<node<>> next;
+  };
+
+  template <typename T> struct typed_node : node<> {
+    T value;
+
+    template <typename Arg>
+    FMT_CONSTEXPR typed_node(const Arg& arg) : value(arg) {}
+
+    template <typename Char>
+    FMT_CONSTEXPR typed_node(const basic_string_view<Char>& arg)
+        : value(arg.data(), arg.size()) {}
+  };
+
+  std::unique_ptr<node<>> head_;
+
+ public:
+  template <typename T, typename Arg> const T& push(const Arg& arg) {
+    auto new_node = std::unique_ptr<typed_node<T>>(new typed_node<T>(arg));
+    auto& value = new_node->value;
+    new_node->next = std::move(head_);
+    head_ = std::move(new_node);
+    return value;
+  }
+};
+}  // namespace detail
+
+/**
+  \rst
+  A dynamic version of `fmt::format_arg_store`.
+  It's equipped with a storage to potentially temporary objects which lifetimes
+  could be shorter than the format arguments object.
+
+  It can be implicitly converted into `~fmt::basic_format_args` for passing
+  into type-erased formatting functions such as `~fmt::vformat`.
+  \endrst
+ */
+template <typename Context>
+class dynamic_format_arg_store
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+    // Workaround a GCC template argument substitution bug.
+    : public basic_format_args<Context>
+#endif
+{
+ private:
+  using char_type = typename Context::char_type;
+
+  template <typename T> struct need_copy {
+    static constexpr detail::type mapped_type =
+        detail::mapped_type_constant<T, Context>::value;
+
+    enum {
+      value = !(detail::is_reference_wrapper<T>::value ||
+                std::is_same<T, basic_string_view<char_type>>::value ||
+                std::is_same<T, detail::std_string_view<char_type>>::value ||
+                (mapped_type != detail::type::cstring_type &&
+                 mapped_type != detail::type::string_type &&
+                 mapped_type != detail::type::custom_type))
+    };
+  };
+
+  template <typename T>
+  using stored_type = conditional_t<
+      std::is_convertible<T, std::basic_string<char_type>>::value &&
+          !detail::is_reference_wrapper<T>::value,
+      std::basic_string<char_type>, T>;
+
+  // Storage of basic_format_arg must be contiguous.
+  std::vector<basic_format_arg<Context>> data_;
+  std::vector<detail::named_arg_info<char_type>> named_info_;
+
+  // Storage of arguments not fitting into basic_format_arg must grow
+  // without relocation because items in data_ refer to it.
+  detail::dynamic_arg_list dynamic_args_;
+
+  friend class basic_format_args<Context>;
+
+  unsigned long long get_types() const {
+    return detail::is_unpacked_bit | data_.size() |
+           (named_info_.empty()
+                ? 0ULL
+                : static_cast<unsigned long long>(detail::has_named_args_bit));
+  }
+
+  const basic_format_arg<Context>* data() const {
+    return named_info_.empty() ? data_.data() : data_.data() + 1;
+  }
+
+  template <typename T> void emplace_arg(const T& arg) {
+    data_.emplace_back(detail::make_arg<Context>(arg));
+  }
+
+  template <typename T>
+  void emplace_arg(const detail::named_arg<char_type, T>& arg) {
+    if (named_info_.empty()) {
+      constexpr const detail::named_arg_info<char_type>* zero_ptr{nullptr};
+      data_.insert(data_.begin(), {zero_ptr, 0});
+    }
+    data_.emplace_back(detail::make_arg<Context>(detail::unwrap(arg.value)));
+    auto pop_one = [](std::vector<basic_format_arg<Context>>* data) {
+      data->pop_back();
+    };
+    std::unique_ptr<std::vector<basic_format_arg<Context>>, decltype(pop_one)>
+        guard{&data_, pop_one};
+    named_info_.push_back({arg.name, static_cast<int>(data_.size() - 2u)});
+    data_[0].value_.named_args = {named_info_.data(), named_info_.size()};
+    guard.release();
+  }
+
+ public:
+  constexpr dynamic_format_arg_store() = default;
+
+  /**
+    \rst
+    Adds an argument into the dynamic store for later passing to a formatting
+    function.
+
+    Note that custom types and string types (but not string views) are copied
+    into the store dynamically allocating memory if necessary.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      store.push_back(42);
+      store.push_back("abc");
+      store.push_back(1.5f);
+      std::string result = fmt::vformat("{} and {} and {}", store);
+    \endrst
+  */
+  template <typename T> void push_back(const T& arg) {
+    if (detail::const_check(need_copy<T>::value))
+      emplace_arg(dynamic_args_.push<stored_type<T>>(arg));
+    else
+      emplace_arg(detail::unwrap(arg));
+  }
+
+  /**
+    \rst
+    Adds a reference to the argument into the dynamic store for later passing to
+    a formatting function.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      char band[] = "Rolling Stones";
+      store.push_back(std::cref(band));
+      band[9] = 'c'; // Changing str affects the output.
+      std::string result = fmt::vformat("{}", store);
+      // result == "Rolling Scones"
+    \endrst
+  */
+  template <typename T> void push_back(std::reference_wrapper<T> arg) {
+    static_assert(
+        need_copy<T>::value,
+        "objects of built-in types and string views are always copied");
+    emplace_arg(arg.get());
+  }
+
+  /**
+    Adds named argument into the dynamic store for later passing to a formatting
+    function. ``std::reference_wrapper`` is supported to avoid copying of the
+    argument. The name is always copied into the store.
+  */
+  template <typename T>
+  void push_back(const detail::named_arg<char_type, T>& arg) {
+    const char_type* arg_name =
+        dynamic_args_.push<std::basic_string<char_type>>(arg.name).c_str();
+    if (detail::const_check(need_copy<T>::value)) {
+      emplace_arg(
+          fmt::arg(arg_name, dynamic_args_.push<stored_type<T>>(arg.value)));
+    } else {
+      emplace_arg(fmt::arg(arg_name, arg.value));
+    }
+  }
+
+  /** Erase all elements from the store */
+  void clear() {
+    data_.clear();
+    named_info_.clear();
+    dynamic_args_ = detail::dynamic_arg_list();
+  }
+
+  /**
+    \rst
+    Reserves space to store at least *new_cap* arguments including
+    *new_cap_named* named arguments.
+    \endrst
+  */
+  void reserve(size_t new_cap, size_t new_cap_named) {
+    FMT_ASSERT(new_cap >= new_cap_named,
+               "Set of arguments includes set of named arguments");
+    data_.reserve(new_cap);
+    named_info_.reserve(new_cap_named);
+  }
+};
+
+FMT_END_NAMESPACE
+
+#endif  // FMT_ARGS_H_
diff --git a/libfuse/lib/fmt/chrono.h b/libfuse/lib/fmt/chrono.h
new file mode 100644
index 00000000..b112f76e
--- /dev/null
+++ b/libfuse/lib/fmt/chrono.h
@@ -0,0 +1,2069 @@
+// Formatting library for C++ - chrono support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_CHRONO_H_
+#define FMT_CHRONO_H_
+
+#include <algorithm>
+#include <chrono>
+#include <cmath>    // std::isfinite
+#include <cstring>  // std::memcpy
+#include <ctime>
+#include <iterator>
+#include <locale>
+#include <ostream>
+#include <type_traits>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+
+// Enable tzset.
+#ifndef FMT_USE_TZSET
+// UWP doesn't provide _tzset.
+#  if FMT_HAS_INCLUDE("winapifamily.h")
+#    include <winapifamily.h>
+#  endif
+#  if defined(_WIN32) && (!defined(WINAPI_FAMILY) || \
+                          (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+#    define FMT_USE_TZSET 1
+#  else
+#    define FMT_USE_TZSET 0
+#  endif
+#endif
+
+// Enable safe chrono durations, unless explicitly disabled.
+#ifndef FMT_SAFE_DURATION_CAST
+#  define FMT_SAFE_DURATION_CAST 1
+#endif
+#if FMT_SAFE_DURATION_CAST
+
+// For conversion between std::chrono::durations without undefined
+// behaviour or erroneous results.
+// This is a stripped down version of duration_cast, for inclusion in fmt.
+// See https://github.com/pauldreik/safe_duration_cast
+//
+// Copyright Paul Dreik 2019
+namespace safe_duration_cast {
+
+template <typename To, typename From,
+          FMT_ENABLE_IF(!std::is_same<From, To>::value &&
+                        std::numeric_limits<From>::is_signed ==
+                            std::numeric_limits<To>::is_signed)>
+FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
+  ec = 0;
+  using F = std::numeric_limits<From>;
+  using T = std::numeric_limits<To>;
+  static_assert(F::is_integer, "From must be integral");
+  static_assert(T::is_integer, "To must be integral");
+
+  // A and B are both signed, or both unsigned.
+  if (detail::const_check(F::digits <= T::digits)) {
+    // From fits in To without any problem.
+  } else {
+    // From does not always fit in To, resort to a dynamic check.
+    if (from < (T::min)() || from > (T::max)()) {
+      // outside range.
+      ec = 1;
+      return {};
+    }
+  }
+  return static_cast<To>(from);
+}
+
+/**
+ * converts From to To, without loss. If the dynamic value of from
+ * can't be converted to To without loss, ec is set.
+ */
+template <typename To, typename From,
+          FMT_ENABLE_IF(!std::is_same<From, To>::value &&
+                        std::numeric_limits<From>::is_signed !=
+                            std::numeric_limits<To>::is_signed)>
+FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
+  ec = 0;
+  using F = std::numeric_limits<From>;
+  using T = std::numeric_limits<To>;
+  static_assert(F::is_integer, "From must be integral");
+  static_assert(T::is_integer, "To must be integral");
+
+  if (detail::const_check(F::is_signed && !T::is_signed)) {
+    // From may be negative, not allowed!
+    if (fmt::detail::is_negative(from)) {
+      ec = 1;
+      return {};
+    }
+    // From is positive. Can it always fit in To?
+    if (detail::const_check(F::digits > T::digits) &&
+        from > static_cast<From>(detail::max_value<To>())) {
+      ec = 1;
+      return {};
+    }
+  }
+
+  if (detail::const_check(!F::is_signed && T::is_signed &&
+                          F::digits >= T::digits) &&
+      from > static_cast<From>(detail::max_value<To>())) {
+    ec = 1;
+    return {};
+  }
+  return static_cast<To>(from);  // Lossless conversion.
+}
+
+template <typename To, typename From,
+          FMT_ENABLE_IF(std::is_same<From, To>::value)>
+FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
+  ec = 0;
+  return from;
+}  // function
+
+// clang-format off
+/**
+ * converts From to To if possible, otherwise ec is set.
+ *
+ * input                            |    output
+ * ---------------------------------|---------------
+ * NaN                              | NaN
+ * Inf                              | Inf
+ * normal, fits in output           | converted (possibly lossy)
+ * normal, does not fit in output   | ec is set
+ * subnormal                        | best effort
+ * -Inf                             | -Inf
+ */
+// clang-format on
+template <typename To, typename From,
+          FMT_ENABLE_IF(!std::is_same<From, To>::value)>
+FMT_CONSTEXPR To safe_float_conversion(const From from, int& ec) {
+  ec = 0;
+  using T = std::numeric_limits<To>;
+  static_assert(std::is_floating_point<From>::value, "From must be floating");
+  static_assert(std::is_floating_point<To>::value, "To must be floating");
+
+  // catch the only happy case
+  if (std::isfinite(from)) {
+    if (from >= T::lowest() && from <= (T::max)()) {
+      return static_cast<To>(from);
+    }
+    // not within range.
+    ec = 1;
+    return {};
+  }
+
+  // nan and inf will be preserved
+  return static_cast<To>(from);
+}  // function
+
+template <typename To, typename From,
+          FMT_ENABLE_IF(std::is_same<From, To>::value)>
+FMT_CONSTEXPR To safe_float_conversion(const From from, int& ec) {
+  ec = 0;
+  static_assert(std::is_floating_point<From>::value, "From must be floating");
+  return from;
+}
+
+/**
+ * safe duration cast between integral durations
+ */
+template <typename To, typename FromRep, typename FromPeriod,
+          FMT_ENABLE_IF(std::is_integral<FromRep>::value),
+          FMT_ENABLE_IF(std::is_integral<typename To::rep>::value)>
+To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
+                      int& ec) {
+  using From = std::chrono::duration<FromRep, FromPeriod>;
+  ec = 0;
+  // the basic idea is that we need to convert from count() in the from type
+  // to count() in the To type, by multiplying it with this:
+  struct Factor
+      : std::ratio_divide<typename From::period, typename To::period> {};
+
+  static_assert(Factor::num > 0, "num must be positive");
+  static_assert(Factor::den > 0, "den must be positive");
+
+  // the conversion is like this: multiply from.count() with Factor::num
+  // /Factor::den and convert it to To::rep, all this without
+  // overflow/underflow. let's start by finding a suitable type that can hold
+  // both To, From and Factor::num
+  using IntermediateRep =
+      typename std::common_type<typename From::rep, typename To::rep,
+                                decltype(Factor::num)>::type;
+
+  // safe conversion to IntermediateRep
+  IntermediateRep count =
+      lossless_integral_conversion<IntermediateRep>(from.count(), ec);
+  if (ec) return {};
+  // multiply with Factor::num without overflow or underflow
+  if (detail::const_check(Factor::num != 1)) {
+    const auto max1 = detail::max_value<IntermediateRep>() / Factor::num;
+    if (count > max1) {
+      ec = 1;
+      return {};
+    }
+    const auto min1 =
+        (std::numeric_limits<IntermediateRep>::min)() / Factor::num;
+    if (!std::is_unsigned<IntermediateRep>::value && count < min1) {
+      ec = 1;
+      return {};
+    }
+    count *= Factor::num;
+  }
+
+  if (detail::const_check(Factor::den != 1)) count /= Factor::den;
+  auto tocount = lossless_integral_conversion<typename To::rep>(count, ec);
+  return ec ? To() : To(tocount);
+}
+
+/**
+ * safe duration_cast between floating point durations
+ */
+template <typename To, typename FromRep, typename FromPeriod,
+          FMT_ENABLE_IF(std::is_floating_point<FromRep>::value),
+          FMT_ENABLE_IF(std::is_floating_point<typename To::rep>::value)>
+To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
+                      int& ec) {
+  using From = std::chrono::duration<FromRep, FromPeriod>;
+  ec = 0;
+  if (std::isnan(from.count())) {
+    // nan in, gives nan out. easy.
+    return To{std::numeric_limits<typename To::rep>::quiet_NaN()};
+  }
+  // maybe we should also check if from is denormal, and decide what to do about
+  // it.
+
+  // +-inf should be preserved.
+  if (std::isinf(from.count())) {
+    return To{from.count()};
+  }
+
+  // the basic idea is that we need to convert from count() in the from type
+  // to count() in the To type, by multiplying it with this:
+  struct Factor
+      : std::ratio_divide<typename From::period, typename To::period> {};
+
+  static_assert(Factor::num > 0, "num must be positive");
+  static_assert(Factor::den > 0, "den must be positive");
+
+  // the conversion is like this: multiply from.count() with Factor::num
+  // /Factor::den and convert it to To::rep, all this without
+  // overflow/underflow. let's start by finding a suitable type that can hold
+  // both To, From and Factor::num
+  using IntermediateRep =
+      typename std::common_type<typename From::rep, typename To::rep,
+                                decltype(Factor::num)>::type;
+
+  // force conversion of From::rep -> IntermediateRep to be safe,
+  // even if it will never happen be narrowing in this context.
+  IntermediateRep count =
+      safe_float_conversion<IntermediateRep>(from.count(), ec);
+  if (ec) {
+    return {};
+  }
+
+  // multiply with Factor::num without overflow or underflow
+  if (detail::const_check(Factor::num != 1)) {
+    constexpr auto max1 = detail::max_value<IntermediateRep>() /
+                          static_cast<IntermediateRep>(Factor::num);
+    if (count > max1) {
+      ec = 1;
+      return {};
+    }
+    constexpr auto min1 = std::numeric_limits<IntermediateRep>::lowest() /
+                          static_cast<IntermediateRep>(Factor::num);
+    if (count < min1) {
+      ec = 1;
+      return {};
+    }
+    count *= static_cast<IntermediateRep>(Factor::num);
+  }
+
+  // this can't go wrong, right? den>0 is checked earlier.
+  if (detail::const_check(Factor::den != 1)) {
+    using common_t = typename std::common_type<IntermediateRep, intmax_t>::type;
+    count /= static_cast<common_t>(Factor::den);
+  }
+
+  // convert to the to type, safely
+  using ToRep = typename To::rep;
+
+  const ToRep tocount = safe_float_conversion<ToRep>(count, ec);
+  if (ec) {
+    return {};
+  }
+  return To{tocount};
+}
+}  // namespace safe_duration_cast
+#endif
+
+// Prevents expansion of a preceding token as a function-style macro.
+// Usage: f FMT_NOMACRO()
+#define FMT_NOMACRO
+
+namespace detail {
+template <typename T = void> struct null {};
+inline null<> localtime_r FMT_NOMACRO(...) { return null<>(); }
+inline null<> localtime_s(...) { return null<>(); }
+inline null<> gmtime_r(...) { return null<>(); }
+inline null<> gmtime_s(...) { return null<>(); }
+
+inline const std::locale& get_classic_locale() {
+  static const auto& locale = std::locale::classic();
+  return locale;
+}
+
+template <typename CodeUnit> struct codecvt_result {
+  static constexpr const size_t max_size = 32;
+  CodeUnit buf[max_size];
+  CodeUnit* end;
+};
+template <typename CodeUnit>
+constexpr const size_t codecvt_result<CodeUnit>::max_size;
+
+template <typename CodeUnit>
+void write_codecvt(codecvt_result<CodeUnit>& out, string_view in_buf,
+                   const std::locale& loc) {
+#if FMT_CLANG_VERSION
+#  pragma clang diagnostic push
+#  pragma clang diagnostic ignored "-Wdeprecated"
+  auto& f = std::use_facet<std::codecvt<CodeUnit, char, std::mbstate_t>>(loc);
+#  pragma clang diagnostic pop
+#else
+  auto& f = std::use_facet<std::codecvt<CodeUnit, char, std::mbstate_t>>(loc);
+#endif
+  auto mb = std::mbstate_t();
+  const char* from_next = nullptr;
+  auto result = f.in(mb, in_buf.begin(), in_buf.end(), from_next,
+                     std::begin(out.buf), std::end(out.buf), out.end);
+  if (result != std::codecvt_base::ok)
+    FMT_THROW(format_error("failed to format time"));
+}
+
+template <typename OutputIt>
+auto write_encoded_tm_str(OutputIt out, string_view in, const std::locale& loc)
+    -> OutputIt {
+  if (detail::is_utf8() && loc != get_classic_locale()) {
+    // char16_t and char32_t codecvts are broken in MSVC (linkage errors) and
+    // gcc-4.
+#if FMT_MSC_VERSION != 0 || \
+    (defined(__GLIBCXX__) && !defined(_GLIBCXX_USE_DUAL_ABI))
+    // The _GLIBCXX_USE_DUAL_ABI macro is always defined in libstdc++ from gcc-5
+    // and newer.
+    using code_unit = wchar_t;
+#else
+    using code_unit = char32_t;
+#endif
+
+    using unit_t = codecvt_result<code_unit>;
+    unit_t unit;
+    write_codecvt(unit, in, loc);
+    // In UTF-8 is used one to four one-byte code units.
+    auto&& buf = basic_memory_buffer<char, unit_t::max_size * 4>();
+    for (code_unit* p = unit.buf; p != unit.end; ++p) {
+      uint32_t c = static_cast<uint32_t>(*p);
+      if (sizeof(code_unit) == 2 && c >= 0xd800 && c <= 0xdfff) {
+        // surrogate pair
+        ++p;
+        if (p == unit.end || (c & 0xfc00) != 0xd800 ||
+            (*p & 0xfc00) != 0xdc00) {
+          FMT_THROW(format_error("failed to format time"));
+        }
+        c = (c << 10) + static_cast<uint32_t>(*p) - 0x35fdc00;
+      }
+      if (c < 0x80) {
+        buf.push_back(static_cast<char>(c));
+      } else if (c < 0x800) {
+        buf.push_back(static_cast<char>(0xc0 | (c >> 6)));
+        buf.push_back(static_cast<char>(0x80 | (c & 0x3f)));
+      } else if ((c >= 0x800 && c <= 0xd7ff) || (c >= 0xe000 && c <= 0xffff)) {
+        buf.push_back(static_cast<char>(0xe0 | (c >> 12)));
+        buf.push_back(static_cast<char>(0x80 | ((c & 0xfff) >> 6)));
+        buf.push_back(static_cast<char>(0x80 | (c & 0x3f)));
+      } else if (c >= 0x10000 && c <= 0x10ffff) {
+        buf.push_back(static_cast<char>(0xf0 | (c >> 18)));
+        buf.push_back(static_cast<char>(0x80 | ((c & 0x3ffff) >> 12)));
+        buf.push_back(static_cast<char>(0x80 | ((c & 0xfff) >> 6)));
+        buf.push_back(static_cast<char>(0x80 | (c & 0x3f)));
+      } else {
+        FMT_THROW(format_error("failed to format time"));
+      }
+    }
+    return copy_str<char>(buf.data(), buf.data() + buf.size(), out);
+  }
+  return copy_str<char>(in.data(), in.data() + in.size(), out);
+}
+
+template <typename Char, typename OutputIt,
+          FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto write_tm_str(OutputIt out, string_view sv, const std::locale& loc)
+    -> OutputIt {
+  codecvt_result<Char> unit;
+  write_codecvt(unit, sv, loc);
+  return copy_str<Char>(unit.buf, unit.end, out);
+}
+
+template <typename Char, typename OutputIt,
+          FMT_ENABLE_IF(std::is_same<Char, char>::value)>
+auto write_tm_str(OutputIt out, string_view sv, const std::locale& loc)
+    -> OutputIt {
+  return write_encoded_tm_str(out, sv, loc);
+}
+
+template <typename Char>
+inline void do_write(buffer<Char>& buf, const std::tm& time,
+                     const std::locale& loc, char format, char modifier) {
+  auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
+  auto&& os = std::basic_ostream<Char>(&format_buf);
+  os.imbue(loc);
+  using iterator = std::ostreambuf_iterator<Char>;
+  const auto& facet = std::use_facet<std::time_put<Char, iterator>>(loc);
+  auto end = facet.put(os, os, Char(' '), &time, format, modifier);
+  if (end.failed()) FMT_THROW(format_error("failed to format time"));
+}
+
+template <typename Char, typename OutputIt,
+          FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto write(OutputIt out, const std::tm& time, const std::locale& loc,
+           char format, char modifier = 0) -> OutputIt {
+  auto&& buf = get_buffer<Char>(out);
+  do_write<Char>(buf, time, loc, format, modifier);
+  return buf.out();
+}
+
+template <typename Char, typename OutputIt,
+          FMT_ENABLE_IF(std::is_same<Char, char>::value)>
+auto write(OutputIt out, const std::tm& time, const std::locale& loc,
+           char format, char modifier = 0) -> OutputIt {
+  auto&& buf = basic_memory_buffer<Char>();
+  do_write<char>(buf, time, loc, format, modifier);
+  return write_encoded_tm_str(out, string_view(buf.data(), buf.size()), loc);
+}
+
+}  // namespace detail
+
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  Converts given time since epoch as ``std::time_t`` value into calendar time,
+  expressed in local time. Unlike ``std::localtime``, this function is
+  thread-safe on most platforms.
+ */
+inline std::tm localtime(std::time_t time) {
+  struct dispatcher {
+    std::time_t time_;
+    std::tm tm_;
+
+    dispatcher(std::time_t t) : time_(t) {}
+
+    bool run() {
+      using namespace fmt::detail;
+      return handle(localtime_r(&time_, &tm_));
+    }
+
+    bool handle(std::tm* tm) { return tm != nullptr; }
+
+    bool handle(detail::null<>) {
+      using namespace fmt::detail;
+      return fallback(localtime_s(&tm_, &time_));
+    }
+
+    bool fallback(int res) { return res == 0; }
+
+#if !FMT_MSC_VERSION
+    bool fallback(detail::null<>) {
+      using namespace fmt::detail;
+      std::tm* tm = std::localtime(&time_);
+      if (tm) tm_ = *tm;
+      return tm != nullptr;
+    }
+#endif
+  };
+  dispatcher lt(time);
+  // Too big time values may be unsupported.
+  if (!lt.run()) FMT_THROW(format_error("time_t value out of range"));
+  return lt.tm_;
+}
+
+inline std::tm localtime(
+    std::chrono::time_point<std::chrono::system_clock> time_point) {
+  return localtime(std::chrono::system_clock::to_time_t(time_point));
+}
+
+/**
+  Converts given time since epoch as ``std::time_t`` value into calendar time,
+  expressed in Coordinated Universal Time (UTC). Unlike ``std::gmtime``, this
+  function is thread-safe on most platforms.
+ */
+inline std::tm gmtime(std::time_t time) {
+  struct dispatcher {
+    std::time_t time_;
+    std::tm tm_;
+
+    dispatcher(std::time_t t) : time_(t) {}
+
+    bool run() {
+      using namespace fmt::detail;
+      return handle(gmtime_r(&time_, &tm_));
+    }
+
+    bool handle(std::tm* tm) { return tm != nullptr; }
+
+    bool handle(detail::null<>) {
+      using namespace fmt::detail;
+      return fallback(gmtime_s(&tm_, &time_));
+    }
+
+    bool fallback(int res) { return res == 0; }
+
+#if !FMT_MSC_VERSION
+    bool fallback(detail::null<>) {
+      std::tm* tm = std::gmtime(&time_);
+      if (tm) tm_ = *tm;
+      return tm != nullptr;
+    }
+#endif
+  };
+  dispatcher gt(time);
+  // Too big time values may be unsupported.
+  if (!gt.run()) FMT_THROW(format_error("time_t value out of range"));
+  return gt.tm_;
+}
+
+inline std::tm gmtime(
+    std::chrono::time_point<std::chrono::system_clock> time_point) {
+  return gmtime(std::chrono::system_clock::to_time_t(time_point));
+}
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+// Writes two-digit numbers a, b and c separated by sep to buf.
+// The method by Pavel Novikov based on
+// https://johnnylee-sde.github.io/Fast-unsigned-integer-to-time-string/.
+inline void write_digit2_separated(char* buf, unsigned a, unsigned b,
+                                   unsigned c, char sep) {
+  unsigned long long digits =
+      a | (b << 24) | (static_cast<unsigned long long>(c) << 48);
+  // Convert each value to BCD.
+  // We have x = a * 10 + b and we want to convert it to BCD y = a * 16 + b.
+  // The difference is
+  //   y - x = a * 6
+  // a can be found from x:
+  //   a = floor(x / 10)
+  // then
+  //   y = x + a * 6 = x + floor(x / 10) * 6
+  // floor(x / 10) is (x * 205) >> 11 (needs 16 bits).
+  digits += (((digits * 205) >> 11) & 0x000f00000f00000f) * 6;
+  // Put low nibbles to high bytes and high nibbles to low bytes.
+  digits = ((digits & 0x00f00000f00000f0) >> 4) |
+           ((digits & 0x000f00000f00000f) << 8);
+  auto usep = static_cast<unsigned long long>(sep);
+  // Add ASCII '0' to each digit byte and insert separators.
+  digits |= 0x3030003030003030 | (usep << 16) | (usep << 40);
+
+  constexpr const size_t len = 8;
+  if (const_check(is_big_endian())) {
+    char tmp[len];
+    std::memcpy(tmp, &digits, len);
+    std::reverse_copy(tmp, tmp + len, buf);
+  } else {
+    std::memcpy(buf, &digits, len);
+  }
+}
+
+template <typename Period> FMT_CONSTEXPR inline const char* get_units() {
+  if (std::is_same<Period, std::atto>::value) return "as";
+  if (std::is_same<Period, std::femto>::value) return "fs";
+  if (std::is_same<Period, std::pico>::value) return "ps";
+  if (std::is_same<Period, std::nano>::value) return "ns";
+  if (std::is_same<Period, std::micro>::value) return "µs";
+  if (std::is_same<Period, std::milli>::value) return "ms";
+  if (std::is_same<Period, std::centi>::value) return "cs";
+  if (std::is_same<Period, std::deci>::value) return "ds";
+  if (std::is_same<Period, std::ratio<1>>::value) return "s";
+  if (std::is_same<Period, std::deca>::value) return "das";
+  if (std::is_same<Period, std::hecto>::value) return "hs";
+  if (std::is_same<Period, std::kilo>::value) return "ks";
+  if (std::is_same<Period, std::mega>::value) return "Ms";
+  if (std::is_same<Period, std::giga>::value) return "Gs";
+  if (std::is_same<Period, std::tera>::value) return "Ts";
+  if (std::is_same<Period, std::peta>::value) return "Ps";
+  if (std::is_same<Period, std::exa>::value) return "Es";
+  if (std::is_same<Period, std::ratio<60>>::value) return "m";
+  if (std::is_same<Period, std::ratio<3600>>::value) return "h";
+  return nullptr;
+}
+
+enum class numeric_system {
+  standard,
+  // Alternative numeric system, e.g. 十二 instead of 12 in ja_JP locale.
+  alternative
+};
+
+// Parses a put_time-like format string and invokes handler actions.
+template <typename Char, typename Handler>
+FMT_CONSTEXPR const Char* parse_chrono_format(const Char* begin,
+                                              const Char* end,
+                                              Handler&& handler) {
+  auto ptr = begin;
+  while (ptr != end) {
+    auto c = *ptr;
+    if (c == '}') break;
+    if (c != '%') {
+      ++ptr;
+      continue;
+    }
+    if (begin != ptr) handler.on_text(begin, ptr);
+    ++ptr;  // consume '%'
+    if (ptr == end) FMT_THROW(format_error("invalid format"));
+    c = *ptr++;
+    switch (c) {
+    case '%':
+      handler.on_text(ptr - 1, ptr);
+      break;
+    case 'n': {
+      const Char newline[] = {'\n'};
+      handler.on_text(newline, newline + 1);
+      break;
+    }
+    case 't': {
+      const Char tab[] = {'\t'};
+      handler.on_text(tab, tab + 1);
+      break;
+    }
+    // Year:
+    case 'Y':
+      handler.on_year(numeric_system::standard);
+      break;
+    case 'y':
+      handler.on_short_year(numeric_system::standard);
+      break;
+    case 'C':
+      handler.on_century(numeric_system::standard);
+      break;
+    case 'G':
+      handler.on_iso_week_based_year();
+      break;
+    case 'g':
+      handler.on_iso_week_based_short_year();
+      break;
+    // Day of the week:
+    case 'a':
+      handler.on_abbr_weekday();
+      break;
+    case 'A':
+      handler.on_full_weekday();
+      break;
+    case 'w':
+      handler.on_dec0_weekday(numeric_system::standard);
+      break;
+    case 'u':
+      handler.on_dec1_weekday(numeric_system::standard);
+      break;
+    // Month:
+    case 'b':
+    case 'h':
+      handler.on_abbr_month();
+      break;
+    case 'B':
+      handler.on_full_month();
+      break;
+    case 'm':
+      handler.on_dec_month(numeric_system::standard);
+      break;
+    // Day of the year/month:
+    case 'U':
+      handler.on_dec0_week_of_year(numeric_system::standard);
+      break;
+    case 'W':
+      handler.on_dec1_week_of_year(numeric_system::standard);
+      break;
+    case 'V':
+      handler.on_iso_week_of_year(numeric_system::standard);
+      break;
+    case 'j':
+      handler.on_day_of_year();
+      break;
+    case 'd':
+      handler.on_day_of_month(numeric_system::standard);
+      break;
+    case 'e':
+      handler.on_day_of_month_space(numeric_system::standard);
+      break;
+    // Hour, minute, second:
+    case 'H':
+      handler.on_24_hour(numeric_system::standard);
+      break;
+    case 'I':
+      handler.on_12_hour(numeric_system::standard);
+      break;
+    case 'M':
+      handler.on_minute(numeric_system::standard);
+      break;
+    case 'S':
+      handler.on_second(numeric_system::standard);
+      break;
+    // Other:
+    case 'c':
+      handler.on_datetime(numeric_system::standard);
+      break;
+    case 'x':
+      handler.on_loc_date(numeric_system::standard);
+      break;
+    case 'X':
+      handler.on_loc_time(numeric_system::standard);
+      break;
+    case 'D':
+      handler.on_us_date();
+      break;
+    case 'F':
+      handler.on_iso_date();
+      break;
+    case 'r':
+      handler.on_12_hour_time();
+      break;
+    case 'R':
+      handler.on_24_hour_time();
+      break;
+    case 'T':
+      handler.on_iso_time();
+      break;
+    case 'p':
+      handler.on_am_pm();
+      break;
+    case 'Q':
+      handler.on_duration_value();
+      break;
+    case 'q':
+      handler.on_duration_unit();
+      break;
+    case 'z':
+      handler.on_utc_offset();
+      break;
+    case 'Z':
+      handler.on_tz_name();
+      break;
+    // Alternative representation:
+    case 'E': {
+      if (ptr == end) FMT_THROW(format_error("invalid format"));
+      c = *ptr++;
+      switch (c) {
+      case 'Y':
+        handler.on_year(numeric_system::alternative);
+        break;
+      case 'y':
+        handler.on_offset_year();
+        break;
+      case 'C':
+        handler.on_century(numeric_system::alternative);
+        break;
+      case 'c':
+        handler.on_datetime(numeric_system::alternative);
+        break;
+      case 'x':
+        handler.on_loc_date(numeric_system::alternative);
+        break;
+      case 'X':
+        handler.on_loc_time(numeric_system::alternative);
+        break;
+      default:
+        FMT_THROW(format_error("invalid format"));
+      }
+      break;
+    }
+    case 'O':
+      if (ptr == end) FMT_THROW(format_error("invalid format"));
+      c = *ptr++;
+      switch (c) {
+      case 'y':
+        handler.on_short_year(numeric_system::alternative);
+        break;
+      case 'm':
+        handler.on_dec_month(numeric_system::alternative);
+        break;
+      case 'U':
+        handler.on_dec0_week_of_year(numeric_system::alternative);
+        break;
+      case 'W':
+        handler.on_dec1_week_of_year(numeric_system::alternative);
+        break;
+      case 'V':
+        handler.on_iso_week_of_year(numeric_system::alternative);
+        break;
+      case 'd':
+        handler.on_day_of_month(numeric_system::alternative);
+        break;
+      case 'e':
+        handler.on_day_of_month_space(numeric_system::alternative);
+        break;
+      case 'w':
+        handler.on_dec0_weekday(numeric_system::alternative);
+        break;
+      case 'u':
+        handler.on_dec1_weekday(numeric_system::alternative);
+        break;
+      case 'H':
+        handler.on_24_hour(numeric_system::alternative);
+        break;
+      case 'I':
+        handler.on_12_hour(numeric_system::alternative);
+        break;
+      case 'M':
+        handler.on_minute(numeric_system::alternative);
+        break;
+      case 'S':
+        handler.on_second(numeric_system::alternative);
+        break;
+      default:
+        FMT_THROW(format_error("invalid format"));
+      }
+      break;
+    default:
+      FMT_THROW(format_error("invalid format"));
+    }
+    begin = ptr;
+  }
+  if (begin != ptr) handler.on_text(begin, ptr);
+  return ptr;
+}
+
+template <typename Derived> struct null_chrono_spec_handler {
+  FMT_CONSTEXPR void unsupported() {
+    static_cast<Derived*>(this)->unsupported();
+  }
+  FMT_CONSTEXPR void on_year(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_short_year(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_offset_year() { unsupported(); }
+  FMT_CONSTEXPR void on_century(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_iso_week_based_year() { unsupported(); }
+  FMT_CONSTEXPR void on_iso_week_based_short_year() { unsupported(); }
+  FMT_CONSTEXPR void on_abbr_weekday() { unsupported(); }
+  FMT_CONSTEXPR void on_full_weekday() { unsupported(); }
+  FMT_CONSTEXPR void on_dec0_weekday(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_dec1_weekday(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_abbr_month() { unsupported(); }
+  FMT_CONSTEXPR void on_full_month() { unsupported(); }
+  FMT_CONSTEXPR void on_dec_month(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_dec0_week_of_year(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_dec1_week_of_year(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_iso_week_of_year(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_day_of_year() { unsupported(); }
+  FMT_CONSTEXPR void on_day_of_month(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_day_of_month_space(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_24_hour(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_12_hour(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_minute(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_second(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_datetime(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_loc_date(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_loc_time(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_us_date() { unsupported(); }
+  FMT_CONSTEXPR void on_iso_date() { unsupported(); }
+  FMT_CONSTEXPR void on_12_hour_time() { unsupported(); }
+  FMT_CONSTEXPR void on_24_hour_time() { unsupported(); }
+  FMT_CONSTEXPR void on_iso_time() { unsupported(); }
+  FMT_CONSTEXPR void on_am_pm() { unsupported(); }
+  FMT_CONSTEXPR void on_duration_value() { unsupported(); }
+  FMT_CONSTEXPR void on_duration_unit() { unsupported(); }
+  FMT_CONSTEXPR void on_utc_offset() { unsupported(); }
+  FMT_CONSTEXPR void on_tz_name() { unsupported(); }
+};
+
+struct tm_format_checker : null_chrono_spec_handler<tm_format_checker> {
+  FMT_NORETURN void unsupported() { FMT_THROW(format_error("no format")); }
+
+  template <typename Char>
+  FMT_CONSTEXPR void on_text(const Char*, const Char*) {}
+  FMT_CONSTEXPR void on_year(numeric_system) {}
+  FMT_CONSTEXPR void on_short_year(numeric_system) {}
+  FMT_CONSTEXPR void on_offset_year() {}
+  FMT_CONSTEXPR void on_century(numeric_system) {}
+  FMT_CONSTEXPR void on_iso_week_based_year() {}
+  FMT_CONSTEXPR void on_iso_week_based_short_year() {}
+  FMT_CONSTEXPR void on_abbr_weekday() {}
+  FMT_CONSTEXPR void on_full_weekday() {}
+  FMT_CONSTEXPR void on_dec0_weekday(numeric_system) {}
+  FMT_CONSTEXPR void on_dec1_weekday(numeric_system) {}
+  FMT_CONSTEXPR void on_abbr_month() {}
+  FMT_CONSTEXPR void on_full_month() {}
+  FMT_CONSTEXPR void on_dec_month(numeric_system) {}
+  FMT_CONSTEXPR void on_dec0_week_of_year(numeric_system) {}
+  FMT_CONSTEXPR void on_dec1_week_of_year(numeric_system) {}
+  FMT_CONSTEXPR void on_iso_week_of_year(numeric_system) {}
+  FMT_CONSTEXPR void on_day_of_year() {}
+  FMT_CONSTEXPR void on_day_of_month(numeric_system) {}
+  FMT_CONSTEXPR void on_day_of_month_space(numeric_system) {}
+  FMT_CONSTEXPR void on_24_hour(numeric_system) {}
+  FMT_CONSTEXPR void on_12_hour(numeric_system) {}
+  FMT_CONSTEXPR void on_minute(numeric_system) {}
+  FMT_CONSTEXPR void on_second(numeric_system) {}
+  FMT_CONSTEXPR void on_datetime(numeric_system) {}
+  FMT_CONSTEXPR void on_loc_date(numeric_system) {}
+  FMT_CONSTEXPR void on_loc_time(numeric_system) {}
+  FMT_CONSTEXPR void on_us_date() {}
+  FMT_CONSTEXPR void on_iso_date() {}
+  FMT_CONSTEXPR void on_12_hour_time() {}
+  FMT_CONSTEXPR void on_24_hour_time() {}
+  FMT_CONSTEXPR void on_iso_time() {}
+  FMT_CONSTEXPR void on_am_pm() {}
+  FMT_CONSTEXPR void on_utc_offset() {}
+  FMT_CONSTEXPR void on_tz_name() {}
+};
+
+inline const char* tm_wday_full_name(int wday) {
+  static constexpr const char* full_name_list[] = {
+      "Sunday",   "Monday", "Tuesday", "Wednesday",
+      "Thursday", "Friday", "Saturday"};
+  return wday >= 0 && wday <= 6 ? full_name_list[wday] : "?";
+}
+inline const char* tm_wday_short_name(int wday) {
+  static constexpr const char* short_name_list[] = {"Sun", "Mon", "Tue", "Wed",
+                                                    "Thu", "Fri", "Sat"};
+  return wday >= 0 && wday <= 6 ? short_name_list[wday] : "???";
+}
+
+inline const char* tm_mon_full_name(int mon) {
+  static constexpr const char* full_name_list[] = {
+      "January", "February", "March",     "April",   "May",      "June",
+      "July",    "August",   "September", "October", "November", "December"};
+  return mon >= 0 && mon <= 11 ? full_name_list[mon] : "?";
+}
+inline const char* tm_mon_short_name(int mon) {
+  static constexpr const char* short_name_list[] = {
+      "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+      "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
+  };
+  return mon >= 0 && mon <= 11 ? short_name_list[mon] : "???";
+}
+
+template <typename T, typename = void>
+struct has_member_data_tm_gmtoff : std::false_type {};
+template <typename T>
+struct has_member_data_tm_gmtoff<T, void_t<decltype(T::tm_gmtoff)>>
+    : std::true_type {};
+
+template <typename T, typename = void>
+struct has_member_data_tm_zone : std::false_type {};
+template <typename T>
+struct has_member_data_tm_zone<T, void_t<decltype(T::tm_zone)>>
+    : std::true_type {};
+
+#if FMT_USE_TZSET
+inline void tzset_once() {
+  static bool init = []() -> bool {
+    _tzset();
+    return true;
+  }();
+  ignore_unused(init);
+}
+#endif
+
+template <typename OutputIt, typename Char> class tm_writer {
+ private:
+  static constexpr int days_per_week = 7;
+
+  const std::locale& loc_;
+  const bool is_classic_;
+  OutputIt out_;
+  const std::tm& tm_;
+
+  auto tm_sec() const noexcept -> int {
+    FMT_ASSERT(tm_.tm_sec >= 0 && tm_.tm_sec <= 61, "");
+    return tm_.tm_sec;
+  }
+  auto tm_min() const noexcept -> int {
+    FMT_ASSERT(tm_.tm_min >= 0 && tm_.tm_min <= 59, "");
+    return tm_.tm_min;
+  }
+  auto tm_hour() const noexcept -> int {
+    FMT_ASSERT(tm_.tm_hour >= 0 && tm_.tm_hour <= 23, "");
+    return tm_.tm_hour;
+  }
+  auto tm_mday() const noexcept -> int {
+    FMT_ASSERT(tm_.tm_mday >= 1 && tm_.tm_mday <= 31, "");
+    return tm_.tm_mday;
+  }
+  auto tm_mon() const noexcept -> int {
+    FMT_ASSERT(tm_.tm_mon >= 0 && tm_.tm_mon <= 11, "");
+    return tm_.tm_mon;
+  }
+  auto tm_year() const noexcept -> long long { return 1900ll + tm_.tm_year; }
+  auto tm_wday() const noexcept -> int {
+    FMT_ASSERT(tm_.tm_wday >= 0 && tm_.tm_wday <= 6, "");
+    return tm_.tm_wday;
+  }
+  auto tm_yday() const noexcept -> int {
+    FMT_ASSERT(tm_.tm_yday >= 0 && tm_.tm_yday <= 365, "");
+    return tm_.tm_yday;
+  }
+
+  auto tm_hour12() const noexcept -> int {
+    const auto h = tm_hour();
+    const auto z = h < 12 ? h : h - 12;
+    return z == 0 ? 12 : z;
+  }
+
+  // POSIX and the C Standard are unclear or inconsistent about what %C and %y
+  // do if the year is negative or exceeds 9999. Use the convention that %C
+  // concatenated with %y yields the same output as %Y, and that %Y contains at
+  // least 4 characters, with more only if necessary.
+  auto split_year_lower(long long year) const noexcept -> int {
+    auto l = year % 100;
+    if (l < 0) l = -l;  // l in [0, 99]
+    return static_cast<int>(l);
+  }
+
+  // Algorithm:
+  // https://en.wikipedia.org/wiki/ISO_week_date#Calculating_the_week_number_from_a_month_and_day_of_the_month_or_ordinal_date
+  auto iso_year_weeks(long long curr_year) const noexcept -> int {
+    const auto prev_year = curr_year - 1;
+    const auto curr_p =
+        (curr_year + curr_year / 4 - curr_year / 100 + curr_year / 400) %
+        days_per_week;
+    const auto prev_p =
+        (prev_year + prev_year / 4 - prev_year / 100 + prev_year / 400) %
+        days_per_week;
+    return 52 + ((curr_p == 4 || prev_p == 3) ? 1 : 0);
+  }
+  auto iso_week_num(int tm_yday, int tm_wday) const noexcept -> int {
+    return (tm_yday + 11 - (tm_wday == 0 ? days_per_week : tm_wday)) /
+           days_per_week;
+  }
+  auto tm_iso_week_year() const noexcept -> long long {
+    const auto year = tm_year();
+    const auto w = iso_week_num(tm_yday(), tm_wday());
+    if (w < 1) return year - 1;
+    if (w > iso_year_weeks(year)) return year + 1;
+    return year;
+  }
+  auto tm_iso_week_of_year() const noexcept -> int {
+    const auto year = tm_year();
+    const auto w = iso_week_num(tm_yday(), tm_wday());
+    if (w < 1) return iso_year_weeks(year - 1);
+    if (w > iso_year_weeks(year)) return 1;
+    return w;
+  }
+
+  void write1(int value) {
+    *out_++ = static_cast<char>('0' + to_unsigned(value) % 10);
+  }
+  void write2(int value) {
+    const char* d = digits2(to_unsigned(value) % 100);
+    *out_++ = *d++;
+    *out_++ = *d;
+  }
+
+  void write_year_extended(long long year) {
+    // At least 4 characters.
+    int width = 4;
+    if (year < 0) {
+      *out_++ = '-';
+      year = 0 - year;
+      --width;
+    }
+    uint32_or_64_or_128_t<long long> n = to_unsigned(year);
+    const int num_digits = count_digits(n);
+    if (width > num_digits) out_ = std::fill_n(out_, width - num_digits, '0');
+    out_ = format_decimal<Char>(out_, n, num_digits).end;
+  }
+  void write_year(long long year) {
+    if (year >= 0 && year < 10000) {
+      write2(static_cast<int>(year / 100));
+      write2(static_cast<int>(year % 100));
+    } else {
+      write_year_extended(year);
+    }
+  }
+
+  void write_utc_offset(long offset) {
+    if (offset < 0) {
+      *out_++ = '-';
+      offset = -offset;
+    } else {
+      *out_++ = '+';
+    }
+    offset /= 60;
+    write2(static_cast<int>(offset / 60));
+    write2(static_cast<int>(offset % 60));
+  }
+  template <typename T, FMT_ENABLE_IF(has_member_data_tm_gmtoff<T>::value)>
+  void format_utc_offset_impl(const T& tm) {
+    write_utc_offset(tm.tm_gmtoff);
+  }
+  template <typename T, FMT_ENABLE_IF(!has_member_data_tm_gmtoff<T>::value)>
+  void format_utc_offset_impl(const T& tm) {
+#if defined(_WIN32) && defined(_UCRT)
+#  if FMT_USE_TZSET
+    tzset_once();
+#  endif
+    long offset = 0;
+    _get_timezone(&offset);
+    if (tm.tm_isdst) {
+      long dstbias = 0;
+      _get_dstbias(&dstbias);
+      offset += dstbias;
+    }
+    write_utc_offset(-offset);
+#else
+    ignore_unused(tm);
+    format_localized('z');
+#endif
+  }
+
+  template <typename T, FMT_ENABLE_IF(has_member_data_tm_zone<T>::value)>
+  void format_tz_name_impl(const T& tm) {
+    if (is_classic_)
+      out_ = write_tm_str<Char>(out_, tm.tm_zone, loc_);
+    else
+      format_localized('Z');
+  }
+  template <typename T, FMT_ENABLE_IF(!has_member_data_tm_zone<T>::value)>
+  void format_tz_name_impl(const T&) {
+    format_localized('Z');
+  }
+
+  void format_localized(char format, char modifier = 0) {
+    out_ = write<Char>(out_, tm_, loc_, format, modifier);
+  }
+
+ public:
+  tm_writer(const std::locale& loc, OutputIt out, const std::tm& tm)
+      : loc_(loc),
+        is_classic_(loc_ == get_classic_locale()),
+        out_(out),
+        tm_(tm) {}
+
+  OutputIt out() const { return out_; }
+
+  FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
+    out_ = copy_str<Char>(begin, end, out_);
+  }
+
+  void on_abbr_weekday() {
+    if (is_classic_)
+      out_ = write(out_, tm_wday_short_name(tm_wday()));
+    else
+      format_localized('a');
+  }
+  void on_full_weekday() {
+    if (is_classic_)
+      out_ = write(out_, tm_wday_full_name(tm_wday()));
+    else
+      format_localized('A');
+  }
+  void on_dec0_weekday(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard) return write1(tm_wday());
+    format_localized('w', 'O');
+  }
+  void on_dec1_weekday(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard) {
+      auto wday = tm_wday();
+      write1(wday == 0 ? days_per_week : wday);
+    } else {
+      format_localized('u', 'O');
+    }
+  }
+
+  void on_abbr_month() {
+    if (is_classic_)
+      out_ = write(out_, tm_mon_short_name(tm_mon()));
+    else
+      format_localized('b');
+  }
+  void on_full_month() {
+    if (is_classic_)
+      out_ = write(out_, tm_mon_full_name(tm_mon()));
+    else
+      format_localized('B');
+  }
+
+  void on_datetime(numeric_system ns) {
+    if (is_classic_) {
+      on_abbr_weekday();
+      *out_++ = ' ';
+      on_abbr_month();
+      *out_++ = ' ';
+      on_day_of_month_space(numeric_system::standard);
+      *out_++ = ' ';
+      on_iso_time();
+      *out_++ = ' ';
+      on_year(numeric_system::standard);
+    } else {
+      format_localized('c', ns == numeric_system::standard ? '\0' : 'E');
+    }
+  }
+  void on_loc_date(numeric_system ns) {
+    if (is_classic_)
+      on_us_date();
+    else
+      format_localized('x', ns == numeric_system::standard ? '\0' : 'E');
+  }
+  void on_loc_time(numeric_system ns) {
+    if (is_classic_)
+      on_iso_time();
+    else
+      format_localized('X', ns == numeric_system::standard ? '\0' : 'E');
+  }
+  void on_us_date() {
+    char buf[8];
+    write_digit2_separated(buf, to_unsigned(tm_mon() + 1),
+                           to_unsigned(tm_mday()),
+                           to_unsigned(split_year_lower(tm_year())), '/');
+    out_ = copy_str<Char>(std::begin(buf), std::end(buf), out_);
+  }
+  void on_iso_date() {
+    auto year = tm_year();
+    char buf[10];
+    size_t offset = 0;
+    if (year >= 0 && year < 10000) {
+      copy2(buf, digits2(static_cast<size_t>(year / 100)));
+    } else {
+      offset = 4;
+      write_year_extended(year);
+      year = 0;
+    }
+    write_digit2_separated(buf + 2, static_cast<unsigned>(year % 100),
+                           to_unsigned(tm_mon() + 1), to_unsigned(tm_mday()),
+                           '-');
+    out_ = copy_str<Char>(std::begin(buf) + offset, std::end(buf), out_);
+  }
+
+  void on_utc_offset() { format_utc_offset_impl(tm_); }
+  void on_tz_name() { format_tz_name_impl(tm_); }
+
+  void on_year(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard)
+      return write_year(tm_year());
+    format_localized('Y', 'E');
+  }
+  void on_short_year(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard)
+      return write2(split_year_lower(tm_year()));
+    format_localized('y', 'O');
+  }
+  void on_offset_year() {
+    if (is_classic_) return write2(split_year_lower(tm_year()));
+    format_localized('y', 'E');
+  }
+
+  void on_century(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard) {
+      auto year = tm_year();
+      auto upper = year / 100;
+      if (year >= -99 && year < 0) {
+        // Zero upper on negative year.
+        *out_++ = '-';
+        *out_++ = '0';
+      } else if (upper >= 0 && upper < 100) {
+        write2(static_cast<int>(upper));
+      } else {
+        out_ = write<Char>(out_, upper);
+      }
+    } else {
+      format_localized('C', 'E');
+    }
+  }
+
+  void on_dec_month(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard)
+      return write2(tm_mon() + 1);
+    format_localized('m', 'O');
+  }
+
+  void on_dec0_week_of_year(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard)
+      return write2((tm_yday() + days_per_week - tm_wday()) / days_per_week);
+    format_localized('U', 'O');
+  }
+  void on_dec1_week_of_year(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard) {
+      auto wday = tm_wday();
+      write2((tm_yday() + days_per_week -
+              (wday == 0 ? (days_per_week - 1) : (wday - 1))) /
+             days_per_week);
+    } else {
+      format_localized('W', 'O');
+    }
+  }
+  void on_iso_week_of_year(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard)
+      return write2(tm_iso_week_of_year());
+    format_localized('V', 'O');
+  }
+
+  void on_iso_week_based_year() { write_year(tm_iso_week_year()); }
+  void on_iso_week_based_short_year() {
+    write2(split_year_lower(tm_iso_week_year()));
+  }
+
+  void on_day_of_year() {
+    auto yday = tm_yday() + 1;
+    write1(yday / 100);
+    write2(yday % 100);
+  }
+  void on_day_of_month(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard) return write2(tm_mday());
+    format_localized('d', 'O');
+  }
+  void on_day_of_month_space(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard) {
+      auto mday = to_unsigned(tm_mday()) % 100;
+      const char* d2 = digits2(mday);
+      *out_++ = mday < 10 ? ' ' : d2[0];
+      *out_++ = d2[1];
+    } else {
+      format_localized('e', 'O');
+    }
+  }
+
+  void on_24_hour(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard) return write2(tm_hour());
+    format_localized('H', 'O');
+  }
+  void on_12_hour(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard)
+      return write2(tm_hour12());
+    format_localized('I', 'O');
+  }
+  void on_minute(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard) return write2(tm_min());
+    format_localized('M', 'O');
+  }
+  void on_second(numeric_system ns) {
+    if (is_classic_ || ns == numeric_system::standard) return write2(tm_sec());
+    format_localized('S', 'O');
+  }
+
+  void on_12_hour_time() {
+    if (is_classic_) {
+      char buf[8];
+      write_digit2_separated(buf, to_unsigned(tm_hour12()),
+                             to_unsigned(tm_min()), to_unsigned(tm_sec()), ':');
+      out_ = copy_str<Char>(std::begin(buf), std::end(buf), out_);
+      *out_++ = ' ';
+      on_am_pm();
+    } else {
+      format_localized('r');
+    }
+  }
+  void on_24_hour_time() {
+    write2(tm_hour());
+    *out_++ = ':';
+    write2(tm_min());
+  }
+  void on_iso_time() {
+    char buf[8];
+    write_digit2_separated(buf, to_unsigned(tm_hour()), to_unsigned(tm_min()),
+                           to_unsigned(tm_sec()), ':');
+    out_ = copy_str<Char>(std::begin(buf), std::end(buf), out_);
+  }
+
+  void on_am_pm() {
+    if (is_classic_) {
+      *out_++ = tm_hour() < 12 ? 'A' : 'P';
+      *out_++ = 'M';
+    } else {
+      format_localized('p');
+    }
+  }
+
+  // These apply to chrono durations but not tm.
+  void on_duration_value() {}
+  void on_duration_unit() {}
+};
+
+struct chrono_format_checker : null_chrono_spec_handler<chrono_format_checker> {
+  FMT_NORETURN void unsupported() { FMT_THROW(format_error("no date")); }
+
+  template <typename Char>
+  FMT_CONSTEXPR void on_text(const Char*, const Char*) {}
+  FMT_CONSTEXPR void on_24_hour(numeric_system) {}
+  FMT_CONSTEXPR void on_12_hour(numeric_system) {}
+  FMT_CONSTEXPR void on_minute(numeric_system) {}
+  FMT_CONSTEXPR void on_second(numeric_system) {}
+  FMT_CONSTEXPR void on_12_hour_time() {}
+  FMT_CONSTEXPR void on_24_hour_time() {}
+  FMT_CONSTEXPR void on_iso_time() {}
+  FMT_CONSTEXPR void on_am_pm() {}
+  FMT_CONSTEXPR void on_duration_value() {}
+  FMT_CONSTEXPR void on_duration_unit() {}
+};
+
+template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+inline bool isfinite(T) {
+  return true;
+}
+
+// Converts value to Int and checks that it's in the range [0, upper).
+template <typename T, typename Int, FMT_ENABLE_IF(std::is_integral<T>::value)>
+inline Int to_nonnegative_int(T value, Int upper) {
+  FMT_ASSERT(std::is_unsigned<Int>::value ||
+             (value >= 0 && to_unsigned(value) <= to_unsigned(upper)),
+             "invalid value");
+  (void)upper;
+  return static_cast<Int>(value);
+}
+template <typename T, typename Int, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+inline Int to_nonnegative_int(T value, Int upper) {
+  if (value < 0 || value > static_cast<T>(upper))
+    FMT_THROW(format_error("invalid value"));
+  return static_cast<Int>(value);
+}
+
+template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+inline T mod(T x, int y) {
+  return x % static_cast<T>(y);
+}
+template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
+inline T mod(T x, int y) {
+  return std::fmod(x, static_cast<T>(y));
+}
+
+// If T is an integral type, maps T to its unsigned counterpart, otherwise
+// leaves it unchanged (unlike std::make_unsigned).
+template <typename T, bool INTEGRAL = std::is_integral<T>::value>
+struct make_unsigned_or_unchanged {
+  using type = T;
+};
+
+template <typename T> struct make_unsigned_or_unchanged<T, true> {
+  using type = typename std::make_unsigned<T>::type;
+};
+
+#if FMT_SAFE_DURATION_CAST
+// throwing version of safe_duration_cast
+template <typename To, typename FromRep, typename FromPeriod>
+To fmt_safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from) {
+  int ec;
+  To to = safe_duration_cast::safe_duration_cast<To>(from, ec);
+  if (ec) FMT_THROW(format_error("cannot format duration"));
+  return to;
+}
+#endif
+
+template <typename Rep, typename Period,
+          FMT_ENABLE_IF(std::is_integral<Rep>::value)>
+inline std::chrono::duration<Rep, std::milli> get_milliseconds(
+    std::chrono::duration<Rep, Period> d) {
+  // this may overflow and/or the result may not fit in the
+  // target type.
+#if FMT_SAFE_DURATION_CAST
+  using CommonSecondsType =
+      typename std::common_type<decltype(d), std::chrono::seconds>::type;
+  const auto d_as_common = fmt_safe_duration_cast<CommonSecondsType>(d);
+  const auto d_as_whole_seconds =
+      fmt_safe_duration_cast<std::chrono::seconds>(d_as_common);
+  // this conversion should be nonproblematic
+  const auto diff = d_as_common - d_as_whole_seconds;
+  const auto ms =
+      fmt_safe_duration_cast<std::chrono::duration<Rep, std::milli>>(diff);
+  return ms;
+#else
+  auto s = std::chrono::duration_cast<std::chrono::seconds>(d);
+  return std::chrono::duration_cast<std::chrono::milliseconds>(d - s);
+#endif
+}
+
+// Counts the number of fractional digits in the range [0, 18] according to the
+// C++20 spec. If more than 18 fractional digits are required then returns 6 for
+// microseconds precision.
+template <long long Num, long long Den, int N = 0,
+          bool Enabled = (N < 19) && (Num <= max_value<long long>() / 10)>
+struct count_fractional_digits {
+  static constexpr int value =
+      Num % Den == 0 ? N : count_fractional_digits<Num * 10, Den, N + 1>::value;
+};
+
+// Base case that doesn't instantiate any more templates
+// in order to avoid overflow.
+template <long long Num, long long Den, int N>
+struct count_fractional_digits<Num, Den, N, false> {
+  static constexpr int value = (Num % Den == 0) ? N : 6;
+};
+
+constexpr long long pow10(std::uint32_t n) {
+  return n == 0 ? 1 : 10 * pow10(n - 1);
+}
+
+template <class Rep, class Period,
+          FMT_ENABLE_IF(std::numeric_limits<Rep>::is_signed)>
+constexpr std::chrono::duration<Rep, Period> abs(
+    std::chrono::duration<Rep, Period> d) {
+  // We need to compare the duration using the count() method directly
+  // due to a compiler bug in clang-11 regarding the spaceship operator,
+  // when -Wzero-as-null-pointer-constant is enabled.
+  // In clang-12 the bug has been fixed. See
+  // https://bugs.llvm.org/show_bug.cgi?id=46235 and the reproducible example:
+  // https://www.godbolt.org/z/Knbb5joYx.
+  return d.count() >= d.zero().count() ? d : -d;
+}
+
+template <class Rep, class Period,
+          FMT_ENABLE_IF(!std::numeric_limits<Rep>::is_signed)>
+constexpr std::chrono::duration<Rep, Period> abs(
+    std::chrono::duration<Rep, Period> d) {
+  return d;
+}
+
+template <typename Char, typename Rep, typename OutputIt,
+          FMT_ENABLE_IF(std::is_integral<Rep>::value)>
+OutputIt format_duration_value(OutputIt out, Rep val, int) {
+  return write<Char>(out, val);
+}
+
+template <typename Char, typename Rep, typename OutputIt,
+          FMT_ENABLE_IF(std::is_floating_point<Rep>::value)>
+OutputIt format_duration_value(OutputIt out, Rep val, int precision) {
+  auto specs = basic_format_specs<Char>();
+  specs.precision = precision;
+  specs.type = precision >= 0 ? presentation_type::fixed_lower
+                              : presentation_type::general_lower;
+  return write<Char>(out, val, specs);
+}
+
+template <typename Char, typename OutputIt>
+OutputIt copy_unit(string_view unit, OutputIt out, Char) {
+  return std::copy(unit.begin(), unit.end(), out);
+}
+
+template <typename OutputIt>
+OutputIt copy_unit(string_view unit, OutputIt out, wchar_t) {
+  // This works when wchar_t is UTF-32 because units only contain characters
+  // that have the same representation in UTF-16 and UTF-32.
+  utf8_to_utf16 u(unit);
+  return std::copy(u.c_str(), u.c_str() + u.size(), out);
+}
+
+template <typename Char, typename Period, typename OutputIt>
+OutputIt format_duration_unit(OutputIt out) {
+  if (const char* unit = get_units<Period>())
+    return copy_unit(string_view(unit), out, Char());
+  *out++ = '[';
+  out = write<Char>(out, Period::num);
+  if (const_check(Period::den != 1)) {
+    *out++ = '/';
+    out = write<Char>(out, Period::den);
+  }
+  *out++ = ']';
+  *out++ = 's';
+  return out;
+}
+
+class get_locale {
+ private:
+  union {
+    std::locale locale_;
+  };
+  bool has_locale_ = false;
+
+ public:
+  get_locale(bool localized, locale_ref loc) : has_locale_(localized) {
+    if (localized)
+      ::new (&locale_) std::locale(loc.template get<std::locale>());
+  }
+  ~get_locale() {
+    if (has_locale_) locale_.~locale();
+  }
+  operator const std::locale&() const {
+    return has_locale_ ? locale_ : get_classic_locale();
+  }
+};
+
+template <typename FormatContext, typename OutputIt, typename Rep,
+          typename Period>
+struct chrono_formatter {
+  FormatContext& context;
+  OutputIt out;
+  int precision;
+  bool localized = false;
+  // rep is unsigned to avoid overflow.
+  using rep =
+      conditional_t<std::is_integral<Rep>::value && sizeof(Rep) < sizeof(int),
+                    unsigned, typename make_unsigned_or_unchanged<Rep>::type>;
+  rep val;
+  using seconds = std::chrono::duration<rep>;
+  seconds s;
+  using milliseconds = std::chrono::duration<rep, std::milli>;
+  bool negative;
+
+  using char_type = typename FormatContext::char_type;
+  using tm_writer_type = tm_writer<OutputIt, char_type>;
+
+  chrono_formatter(FormatContext& ctx, OutputIt o,
+                   std::chrono::duration<Rep, Period> d)
+      : context(ctx),
+        out(o),
+        val(static_cast<rep>(d.count())),
+        negative(false) {
+    if (d.count() < 0) {
+      val = 0 - val;
+      negative = true;
+    }
+
+    // this may overflow and/or the result may not fit in the
+    // target type.
+#if FMT_SAFE_DURATION_CAST
+    // might need checked conversion (rep!=Rep)
+    auto tmpval = std::chrono::duration<rep, Period>(val);
+    s = fmt_safe_duration_cast<seconds>(tmpval);
+#else
+    s = std::chrono::duration_cast<seconds>(
+        std::chrono::duration<rep, Period>(val));
+#endif
+  }
+
+  // returns true if nan or inf, writes to out.
+  bool handle_nan_inf() {
+    if (isfinite(val)) {
+      return false;
+    }
+    if (isnan(val)) {
+      write_nan();
+      return true;
+    }
+    // must be +-inf
+    if (val > 0) {
+      write_pinf();
+    } else {
+      write_ninf();
+    }
+    return true;
+  }
+
+  Rep hour() const { return static_cast<Rep>(mod((s.count() / 3600), 24)); }
+
+  Rep hour12() const {
+    Rep hour = static_cast<Rep>(mod((s.count() / 3600), 12));
+    return hour <= 0 ? 12 : hour;
+  }
+
+  Rep minute() const { return static_cast<Rep>(mod((s.count() / 60), 60)); }
+  Rep second() const { return static_cast<Rep>(mod(s.count(), 60)); }
+
+  std::tm time() const {
+    auto time = std::tm();
+    time.tm_hour = to_nonnegative_int(hour(), 24);
+    time.tm_min = to_nonnegative_int(minute(), 60);
+    time.tm_sec = to_nonnegative_int(second(), 60);
+    return time;
+  }
+
+  void write_sign() {
+    if (negative) {
+      *out++ = '-';
+      negative = false;
+    }
+  }
+
+  void write(Rep value, int width) {
+    write_sign();
+    if (isnan(value)) return write_nan();
+    uint32_or_64_or_128_t<int> n =
+        to_unsigned(to_nonnegative_int(value, max_value<int>()));
+    int num_digits = detail::count_digits(n);
+    if (width > num_digits) out = std::fill_n(out, width - num_digits, '0');
+    out = format_decimal<char_type>(out, n, num_digits).end;
+  }
+
+  template <typename Duration> void write_fractional_seconds(Duration d) {
+    FMT_ASSERT(!std::is_floating_point<typename Duration::rep>::value, "");
+    constexpr auto num_fractional_digits =
+        count_fractional_digits<Duration::period::num,
+                                Duration::period::den>::value;
+
+    using subsecond_precision = std::chrono::duration<
+        typename std::common_type<typename Duration::rep,
+                                  std::chrono::seconds::rep>::type,
+        std::ratio<1, detail::pow10(num_fractional_digits)>>;
+    if (std::ratio_less<typename subsecond_precision::period,
+                        std::chrono::seconds::period>::value) {
+      *out++ = '.';
+      auto fractional =
+          detail::abs(d) - std::chrono::duration_cast<std::chrono::seconds>(d);
+      auto subseconds =
+          std::chrono::treat_as_floating_point<
+              typename subsecond_precision::rep>::value
+              ? fractional.count()
+              : std::chrono::duration_cast<subsecond_precision>(fractional)
+                    .count();
+      uint32_or_64_or_128_t<long long> n =
+          to_unsigned(to_nonnegative_int(subseconds, max_value<long long>()));
+      int num_digits = detail::count_digits(n);
+      if (num_fractional_digits > num_digits)
+        out = std::fill_n(out, num_fractional_digits - num_digits, '0');
+      out = format_decimal<char_type>(out, n, num_digits).end;
+    }
+  }
+
+  void write_nan() { std::copy_n("nan", 3, out); }
+  void write_pinf() { std::copy_n("inf", 3, out); }
+  void write_ninf() { std::copy_n("-inf", 4, out); }
+
+  template <typename Callback, typename... Args>
+  void format_tm(const tm& time, Callback cb, Args... args) {
+    if (isnan(val)) return write_nan();
+    get_locale loc(localized, context.locale());
+    auto w = tm_writer_type(loc, out, time);
+    (w.*cb)(args...);
+    out = w.out();
+  }
+
+  void on_text(const char_type* begin, const char_type* end) {
+    std::copy(begin, end, out);
+  }
+
+  // These are not implemented because durations don't have date information.
+  void on_abbr_weekday() {}
+  void on_full_weekday() {}
+  void on_dec0_weekday(numeric_system) {}
+  void on_dec1_weekday(numeric_system) {}
+  void on_abbr_month() {}
+  void on_full_month() {}
+  void on_datetime(numeric_system) {}
+  void on_loc_date(numeric_system) {}
+  void on_loc_time(numeric_system) {}
+  void on_us_date() {}
+  void on_iso_date() {}
+  void on_utc_offset() {}
+  void on_tz_name() {}
+  void on_year(numeric_system) {}
+  void on_short_year(numeric_system) {}
+  void on_offset_year() {}
+  void on_century(numeric_system) {}
+  void on_iso_week_based_year() {}
+  void on_iso_week_based_short_year() {}
+  void on_dec_month(numeric_system) {}
+  void on_dec0_week_of_year(numeric_system) {}
+  void on_dec1_week_of_year(numeric_system) {}
+  void on_iso_week_of_year(numeric_system) {}
+  void on_day_of_year() {}
+  void on_day_of_month(numeric_system) {}
+  void on_day_of_month_space(numeric_system) {}
+
+  void on_24_hour(numeric_system ns) {
+    if (handle_nan_inf()) return;
+
+    if (ns == numeric_system::standard) return write(hour(), 2);
+    auto time = tm();
+    time.tm_hour = to_nonnegative_int(hour(), 24);
+    format_tm(time, &tm_writer_type::on_24_hour, ns);
+  }
+
+  void on_12_hour(numeric_system ns) {
+    if (handle_nan_inf()) return;
+
+    if (ns == numeric_system::standard) return write(hour12(), 2);
+    auto time = tm();
+    time.tm_hour = to_nonnegative_int(hour12(), 12);
+    format_tm(time, &tm_writer_type::on_12_hour, ns);
+  }
+
+  void on_minute(numeric_system ns) {
+    if (handle_nan_inf()) return;
+
+    if (ns == numeric_system::standard) return write(minute(), 2);
+    auto time = tm();
+    time.tm_min = to_nonnegative_int(minute(), 60);
+    format_tm(time, &tm_writer_type::on_minute, ns);
+  }
+
+  void on_second(numeric_system ns) {
+    if (handle_nan_inf()) return;
+
+    if (ns == numeric_system::standard) {
+      if (std::is_floating_point<rep>::value) {
+        constexpr auto num_fractional_digits =
+            count_fractional_digits<Period::num, Period::den>::value;
+        auto buf = memory_buffer();
+        format_to(std::back_inserter(buf), runtime("{:.{}f}"),
+                  std::fmod(val * static_cast<rep>(Period::num) /
+                                static_cast<rep>(Period::den),
+                            static_cast<rep>(60)),
+                  num_fractional_digits);
+        if (negative) *out++ = '-';
+        if (buf.size() < 2 || buf[1] == '.') *out++ = '0';
+        out = std::copy(buf.begin(), buf.end(), out);
+      } else {
+        write(second(), 2);
+        write_fractional_seconds(std::chrono::duration<rep, Period>(val));
+      }
+      return;
+    }
+    auto time = tm();
+    time.tm_sec = to_nonnegative_int(second(), 60);
+    format_tm(time, &tm_writer_type::on_second, ns);
+  }
+
+  void on_12_hour_time() {
+    if (handle_nan_inf()) return;
+    format_tm(time(), &tm_writer_type::on_12_hour_time);
+  }
+
+  void on_24_hour_time() {
+    if (handle_nan_inf()) {
+      *out++ = ':';
+      handle_nan_inf();
+      return;
+    }
+
+    write(hour(), 2);
+    *out++ = ':';
+    write(minute(), 2);
+  }
+
+  void on_iso_time() {
+    on_24_hour_time();
+    *out++ = ':';
+    if (handle_nan_inf()) return;
+    on_second(numeric_system::standard);
+  }
+
+  void on_am_pm() {
+    if (handle_nan_inf()) return;
+    format_tm(time(), &tm_writer_type::on_am_pm);
+  }
+
+  void on_duration_value() {
+    if (handle_nan_inf()) return;
+    write_sign();
+    out = format_duration_value<char_type>(out, val, precision);
+  }
+
+  void on_duration_unit() {
+    out = format_duration_unit<char_type, Period>(out);
+  }
+};
+
+FMT_END_DETAIL_NAMESPACE
+
+#if defined(__cpp_lib_chrono) && __cpp_lib_chrono >= 201907
+using weekday = std::chrono::weekday;
+#else
+// A fallback version of weekday.
+class weekday {
+ private:
+  unsigned char value;
+
+ public:
+  weekday() = default;
+  explicit constexpr weekday(unsigned wd) noexcept
+      : value(static_cast<unsigned char>(wd != 7 ? wd : 0)) {}
+  constexpr unsigned c_encoding() const noexcept { return value; }
+};
+
+class year_month_day {};
+#endif
+
+// A rudimentary weekday formatter.
+template <typename Char> struct formatter<weekday, Char> {
+ private:
+  bool localized = false;
+
+ public:
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+      -> decltype(ctx.begin()) {
+    auto begin = ctx.begin(), end = ctx.end();
+    if (begin != end && *begin == 'L') {
+      ++begin;
+      localized = true;
+    }
+    return begin;
+  }
+
+  template <typename FormatContext>
+  auto format(weekday wd, FormatContext& ctx) const -> decltype(ctx.out()) {
+    auto time = std::tm();
+    time.tm_wday = static_cast<int>(wd.c_encoding());
+    detail::get_locale loc(localized, ctx.locale());
+    auto w = detail::tm_writer<decltype(ctx.out()), Char>(loc, ctx.out(), time);
+    w.on_abbr_weekday();
+    return w.out();
+  }
+};
+
+template <typename Rep, typename Period, typename Char>
+struct formatter<std::chrono::duration<Rep, Period>, Char> {
+ private:
+  basic_format_specs<Char> specs;
+  int precision = -1;
+  using arg_ref_type = detail::arg_ref<Char>;
+  arg_ref_type width_ref;
+  arg_ref_type precision_ref;
+  bool localized = false;
+  basic_string_view<Char> format_str;
+  using duration = std::chrono::duration<Rep, Period>;
+
+  struct spec_handler {
+    formatter& f;
+    basic_format_parse_context<Char>& context;
+    basic_string_view<Char> format_str;
+
+    template <typename Id> FMT_CONSTEXPR arg_ref_type make_arg_ref(Id arg_id) {
+      context.check_arg_id(arg_id);
+      return arg_ref_type(arg_id);
+    }
+
+    FMT_CONSTEXPR arg_ref_type make_arg_ref(basic_string_view<Char> arg_id) {
+      context.check_arg_id(arg_id);
+      return arg_ref_type(arg_id);
+    }
+
+    FMT_CONSTEXPR arg_ref_type make_arg_ref(detail::auto_id) {
+      return arg_ref_type(context.next_arg_id());
+    }
+
+    void on_error(const char* msg) { FMT_THROW(format_error(msg)); }
+    FMT_CONSTEXPR void on_fill(basic_string_view<Char> fill) {
+      f.specs.fill = fill;
+    }
+    FMT_CONSTEXPR void on_align(align_t align) { f.specs.align = align; }
+    FMT_CONSTEXPR void on_width(int width) { f.specs.width = width; }
+    FMT_CONSTEXPR void on_precision(int _precision) {
+      f.precision = _precision;
+    }
+    FMT_CONSTEXPR void end_precision() {}
+
+    template <typename Id> FMT_CONSTEXPR void on_dynamic_width(Id arg_id) {
+      f.width_ref = make_arg_ref(arg_id);
+    }
+
+    template <typename Id> FMT_CONSTEXPR void on_dynamic_precision(Id arg_id) {
+      f.precision_ref = make_arg_ref(arg_id);
+    }
+  };
+
+  using iterator = typename basic_format_parse_context<Char>::iterator;
+  struct parse_range {
+    iterator begin;
+    iterator end;
+  };
+
+  FMT_CONSTEXPR parse_range do_parse(basic_format_parse_context<Char>& ctx) {
+    auto begin = ctx.begin(), end = ctx.end();
+    if (begin == end || *begin == '}') return {begin, begin};
+    spec_handler handler{*this, ctx, format_str};
+    begin = detail::parse_align(begin, end, handler);
+    if (begin == end) return {begin, begin};
+    begin = detail::parse_width(begin, end, handler);
+    if (begin == end) return {begin, begin};
+    if (*begin == '.') {
+      if (std::is_floating_point<Rep>::value)
+        begin = detail::parse_precision(begin, end, handler);
+      else
+        handler.on_error("precision not allowed for this argument type");
+    }
+    if (begin != end && *begin == 'L') {
+      ++begin;
+      localized = true;
+    }
+    end = detail::parse_chrono_format(begin, end,
+                                      detail::chrono_format_checker());
+    return {begin, end};
+  }
+
+ public:
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+      -> decltype(ctx.begin()) {
+    auto range = do_parse(ctx);
+    format_str = basic_string_view<Char>(
+        &*range.begin, detail::to_unsigned(range.end - range.begin));
+    return range.end;
+  }
+
+  template <typename FormatContext>
+  auto format(const duration& d, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto specs_copy = specs;
+    auto precision_copy = precision;
+    auto begin = format_str.begin(), end = format_str.end();
+    // As a possible future optimization, we could avoid extra copying if width
+    // is not specified.
+    basic_memory_buffer<Char> buf;
+    auto out = std::back_inserter(buf);
+    detail::handle_dynamic_spec<detail::width_checker>(specs_copy.width,
+                                                       width_ref, ctx);
+    detail::handle_dynamic_spec<detail::precision_checker>(precision_copy,
+                                                           precision_ref, ctx);
+    if (begin == end || *begin == '}') {
+      out = detail::format_duration_value<Char>(out, d.count(), precision_copy);
+      detail::format_duration_unit<Char, Period>(out);
+    } else {
+      detail::chrono_formatter<FormatContext, decltype(out), Rep, Period> f(
+          ctx, out, d);
+      f.precision = precision_copy;
+      f.localized = localized;
+      detail::parse_chrono_format(begin, end, f);
+    }
+    return detail::write(
+        ctx.out(), basic_string_view<Char>(buf.data(), buf.size()), specs_copy);
+  }
+};
+
+template <typename Char, typename Duration>
+struct formatter<std::chrono::time_point<std::chrono::system_clock, Duration>,
+                 Char> : formatter<std::tm, Char> {
+  FMT_CONSTEXPR formatter() {
+    basic_string_view<Char> default_specs =
+        detail::string_literal<Char, '%', 'F', ' ', '%', 'T'>{};
+    this->do_parse(default_specs.begin(), default_specs.end());
+  }
+
+  template <typename FormatContext>
+  auto format(std::chrono::time_point<std::chrono::system_clock> val,
+              FormatContext& ctx) const -> decltype(ctx.out()) {
+    return formatter<std::tm, Char>::format(localtime(val), ctx);
+  }
+};
+
+template <typename Char> struct formatter<std::tm, Char> {
+ private:
+  enum class spec {
+    unknown,
+    year_month_day,
+    hh_mm_ss,
+  };
+  spec spec_ = spec::unknown;
+  basic_string_view<Char> specs;
+
+ protected:
+  template <typename It> FMT_CONSTEXPR auto do_parse(It begin, It end) -> It {
+    if (begin != end && *begin == ':') ++begin;
+    end = detail::parse_chrono_format(begin, end, detail::tm_format_checker());
+    // Replace default spec only if the new spec is not empty.
+    if (end != begin) specs = {begin, detail::to_unsigned(end - begin)};
+    return end;
+  }
+
+ public:
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+      -> decltype(ctx.begin()) {
+    auto end = this->do_parse(ctx.begin(), ctx.end());
+    // basic_string_view<>::compare isn't constexpr before C++17.
+    if (specs.size() == 2 && specs[0] == Char('%')) {
+      if (specs[1] == Char('F'))
+        spec_ = spec::year_month_day;
+      else if (specs[1] == Char('T'))
+        spec_ = spec::hh_mm_ss;
+    }
+    return end;
+  }
+
+  template <typename FormatContext>
+  auto format(const std::tm& tm, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    const auto loc_ref = ctx.locale();
+    detail::get_locale loc(static_cast<bool>(loc_ref), loc_ref);
+    auto w = detail::tm_writer<decltype(ctx.out()), Char>(loc, ctx.out(), tm);
+    if (spec_ == spec::year_month_day)
+      w.on_iso_date();
+    else if (spec_ == spec::hh_mm_ss)
+      w.on_iso_time();
+    else
+      detail::parse_chrono_format(specs.begin(), specs.end(), w);
+    return w.out();
+  }
+};
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_CHRONO_H_
diff --git a/libfuse/lib/fmt/color.h b/libfuse/lib/fmt/color.h
new file mode 100644
index 00000000..4c163277
--- /dev/null
+++ b/libfuse/lib/fmt/color.h
@@ -0,0 +1,651 @@
+// Formatting library for C++ - color support
+//
+// Copyright (c) 2018 - present, Victor Zverovich and fmt contributors
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_COLOR_H_
+#define FMT_COLOR_H_
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+enum class color : uint32_t {
+  alice_blue = 0xF0F8FF,               // rgb(240,248,255)
+  antique_white = 0xFAEBD7,            // rgb(250,235,215)
+  aqua = 0x00FFFF,                     // rgb(0,255,255)
+  aquamarine = 0x7FFFD4,               // rgb(127,255,212)
+  azure = 0xF0FFFF,                    // rgb(240,255,255)
+  beige = 0xF5F5DC,                    // rgb(245,245,220)
+  bisque = 0xFFE4C4,                   // rgb(255,228,196)
+  black = 0x000000,                    // rgb(0,0,0)
+  blanched_almond = 0xFFEBCD,          // rgb(255,235,205)
+  blue = 0x0000FF,                     // rgb(0,0,255)
+  blue_violet = 0x8A2BE2,              // rgb(138,43,226)
+  brown = 0xA52A2A,                    // rgb(165,42,42)
+  burly_wood = 0xDEB887,               // rgb(222,184,135)
+  cadet_blue = 0x5F9EA0,               // rgb(95,158,160)
+  chartreuse = 0x7FFF00,               // rgb(127,255,0)
+  chocolate = 0xD2691E,                // rgb(210,105,30)
+  coral = 0xFF7F50,                    // rgb(255,127,80)
+  cornflower_blue = 0x6495ED,          // rgb(100,149,237)
+  cornsilk = 0xFFF8DC,                 // rgb(255,248,220)
+  crimson = 0xDC143C,                  // rgb(220,20,60)
+  cyan = 0x00FFFF,                     // rgb(0,255,255)
+  dark_blue = 0x00008B,                // rgb(0,0,139)
+  dark_cyan = 0x008B8B,                // rgb(0,139,139)
+  dark_golden_rod = 0xB8860B,          // rgb(184,134,11)
+  dark_gray = 0xA9A9A9,                // rgb(169,169,169)
+  dark_green = 0x006400,               // rgb(0,100,0)
+  dark_khaki = 0xBDB76B,               // rgb(189,183,107)
+  dark_magenta = 0x8B008B,             // rgb(139,0,139)
+  dark_olive_green = 0x556B2F,         // rgb(85,107,47)
+  dark_orange = 0xFF8C00,              // rgb(255,140,0)
+  dark_orchid = 0x9932CC,              // rgb(153,50,204)
+  dark_red = 0x8B0000,                 // rgb(139,0,0)
+  dark_salmon = 0xE9967A,              // rgb(233,150,122)
+  dark_sea_green = 0x8FBC8F,           // rgb(143,188,143)
+  dark_slate_blue = 0x483D8B,          // rgb(72,61,139)
+  dark_slate_gray = 0x2F4F4F,          // rgb(47,79,79)
+  dark_turquoise = 0x00CED1,           // rgb(0,206,209)
+  dark_violet = 0x9400D3,              // rgb(148,0,211)
+  deep_pink = 0xFF1493,                // rgb(255,20,147)
+  deep_sky_blue = 0x00BFFF,            // rgb(0,191,255)
+  dim_gray = 0x696969,                 // rgb(105,105,105)
+  dodger_blue = 0x1E90FF,              // rgb(30,144,255)
+  fire_brick = 0xB22222,               // rgb(178,34,34)
+  floral_white = 0xFFFAF0,             // rgb(255,250,240)
+  forest_green = 0x228B22,             // rgb(34,139,34)
+  fuchsia = 0xFF00FF,                  // rgb(255,0,255)
+  gainsboro = 0xDCDCDC,                // rgb(220,220,220)
+  ghost_white = 0xF8F8FF,              // rgb(248,248,255)
+  gold = 0xFFD700,                     // rgb(255,215,0)
+  golden_rod = 0xDAA520,               // rgb(218,165,32)
+  gray = 0x808080,                     // rgb(128,128,128)
+  green = 0x008000,                    // rgb(0,128,0)
+  green_yellow = 0xADFF2F,             // rgb(173,255,47)
+  honey_dew = 0xF0FFF0,                // rgb(240,255,240)
+  hot_pink = 0xFF69B4,                 // rgb(255,105,180)
+  indian_red = 0xCD5C5C,               // rgb(205,92,92)
+  indigo = 0x4B0082,                   // rgb(75,0,130)
+  ivory = 0xFFFFF0,                    // rgb(255,255,240)
+  khaki = 0xF0E68C,                    // rgb(240,230,140)
+  lavender = 0xE6E6FA,                 // rgb(230,230,250)
+  lavender_blush = 0xFFF0F5,           // rgb(255,240,245)
+  lawn_green = 0x7CFC00,               // rgb(124,252,0)
+  lemon_chiffon = 0xFFFACD,            // rgb(255,250,205)
+  light_blue = 0xADD8E6,               // rgb(173,216,230)
+  light_coral = 0xF08080,              // rgb(240,128,128)
+  light_cyan = 0xE0FFFF,               // rgb(224,255,255)
+  light_golden_rod_yellow = 0xFAFAD2,  // rgb(250,250,210)
+  light_gray = 0xD3D3D3,               // rgb(211,211,211)
+  light_green = 0x90EE90,              // rgb(144,238,144)
+  light_pink = 0xFFB6C1,               // rgb(255,182,193)
+  light_salmon = 0xFFA07A,             // rgb(255,160,122)
+  light_sea_green = 0x20B2AA,          // rgb(32,178,170)
+  light_sky_blue = 0x87CEFA,           // rgb(135,206,250)
+  light_slate_gray = 0x778899,         // rgb(119,136,153)
+  light_steel_blue = 0xB0C4DE,         // rgb(176,196,222)
+  light_yellow = 0xFFFFE0,             // rgb(255,255,224)
+  lime = 0x00FF00,                     // rgb(0,255,0)
+  lime_green = 0x32CD32,               // rgb(50,205,50)
+  linen = 0xFAF0E6,                    // rgb(250,240,230)
+  magenta = 0xFF00FF,                  // rgb(255,0,255)
+  maroon = 0x800000,                   // rgb(128,0,0)
+  medium_aquamarine = 0x66CDAA,        // rgb(102,205,170)
+  medium_blue = 0x0000CD,              // rgb(0,0,205)
+  medium_orchid = 0xBA55D3,            // rgb(186,85,211)
+  medium_purple = 0x9370DB,            // rgb(147,112,219)
+  medium_sea_green = 0x3CB371,         // rgb(60,179,113)
+  medium_slate_blue = 0x7B68EE,        // rgb(123,104,238)
+  medium_spring_green = 0x00FA9A,      // rgb(0,250,154)
+  medium_turquoise = 0x48D1CC,         // rgb(72,209,204)
+  medium_violet_red = 0xC71585,        // rgb(199,21,133)
+  midnight_blue = 0x191970,            // rgb(25,25,112)
+  mint_cream = 0xF5FFFA,               // rgb(245,255,250)
+  misty_rose = 0xFFE4E1,               // rgb(255,228,225)
+  moccasin = 0xFFE4B5,                 // rgb(255,228,181)
+  navajo_white = 0xFFDEAD,             // rgb(255,222,173)
+  navy = 0x000080,                     // rgb(0,0,128)
+  old_lace = 0xFDF5E6,                 // rgb(253,245,230)
+  olive = 0x808000,                    // rgb(128,128,0)
+  olive_drab = 0x6B8E23,               // rgb(107,142,35)
+  orange = 0xFFA500,                   // rgb(255,165,0)
+  orange_red = 0xFF4500,               // rgb(255,69,0)
+  orchid = 0xDA70D6,                   // rgb(218,112,214)
+  pale_golden_rod = 0xEEE8AA,          // rgb(238,232,170)
+  pale_green = 0x98FB98,               // rgb(152,251,152)
+  pale_turquoise = 0xAFEEEE,           // rgb(175,238,238)
+  pale_violet_red = 0xDB7093,          // rgb(219,112,147)
+  papaya_whip = 0xFFEFD5,              // rgb(255,239,213)
+  peach_puff = 0xFFDAB9,               // rgb(255,218,185)
+  peru = 0xCD853F,                     // rgb(205,133,63)
+  pink = 0xFFC0CB,                     // rgb(255,192,203)
+  plum = 0xDDA0DD,                     // rgb(221,160,221)
+  powder_blue = 0xB0E0E6,              // rgb(176,224,230)
+  purple = 0x800080,                   // rgb(128,0,128)
+  rebecca_purple = 0x663399,           // rgb(102,51,153)
+  red = 0xFF0000,                      // rgb(255,0,0)
+  rosy_brown = 0xBC8F8F,               // rgb(188,143,143)
+  royal_blue = 0x4169E1,               // rgb(65,105,225)
+  saddle_brown = 0x8B4513,             // rgb(139,69,19)
+  salmon = 0xFA8072,                   // rgb(250,128,114)
+  sandy_brown = 0xF4A460,              // rgb(244,164,96)
+  sea_green = 0x2E8B57,                // rgb(46,139,87)
+  sea_shell = 0xFFF5EE,                // rgb(255,245,238)
+  sienna = 0xA0522D,                   // rgb(160,82,45)
+  silver = 0xC0C0C0,                   // rgb(192,192,192)
+  sky_blue = 0x87CEEB,                 // rgb(135,206,235)
+  slate_blue = 0x6A5ACD,               // rgb(106,90,205)
+  slate_gray = 0x708090,               // rgb(112,128,144)
+  snow = 0xFFFAFA,                     // rgb(255,250,250)
+  spring_green = 0x00FF7F,             // rgb(0,255,127)
+  steel_blue = 0x4682B4,               // rgb(70,130,180)
+  tan = 0xD2B48C,                      // rgb(210,180,140)
+  teal = 0x008080,                     // rgb(0,128,128)
+  thistle = 0xD8BFD8,                  // rgb(216,191,216)
+  tomato = 0xFF6347,                   // rgb(255,99,71)
+  turquoise = 0x40E0D0,                // rgb(64,224,208)
+  violet = 0xEE82EE,                   // rgb(238,130,238)
+  wheat = 0xF5DEB3,                    // rgb(245,222,179)
+  white = 0xFFFFFF,                    // rgb(255,255,255)
+  white_smoke = 0xF5F5F5,              // rgb(245,245,245)
+  yellow = 0xFFFF00,                   // rgb(255,255,0)
+  yellow_green = 0x9ACD32              // rgb(154,205,50)
+};                                     // enum class color
+
+enum class terminal_color : uint8_t {
+  black = 30,
+  red,
+  green,
+  yellow,
+  blue,
+  magenta,
+  cyan,
+  white,
+  bright_black = 90,
+  bright_red,
+  bright_green,
+  bright_yellow,
+  bright_blue,
+  bright_magenta,
+  bright_cyan,
+  bright_white
+};
+
+enum class emphasis : uint8_t {
+  bold = 1,
+  faint = 1 << 1,
+  italic = 1 << 2,
+  underline = 1 << 3,
+  blink = 1 << 4,
+  reverse = 1 << 5,
+  conceal = 1 << 6,
+  strikethrough = 1 << 7,
+};
+
+// rgb is a struct for red, green and blue colors.
+// Using the name "rgb" makes some editors show the color in a tooltip.
+struct rgb {
+  FMT_CONSTEXPR rgb() : r(0), g(0), b(0) {}
+  FMT_CONSTEXPR rgb(uint8_t r_, uint8_t g_, uint8_t b_) : r(r_), g(g_), b(b_) {}
+  FMT_CONSTEXPR rgb(uint32_t hex)
+      : r((hex >> 16) & 0xFF), g((hex >> 8) & 0xFF), b(hex & 0xFF) {}
+  FMT_CONSTEXPR rgb(color hex)
+      : r((uint32_t(hex) >> 16) & 0xFF),
+        g((uint32_t(hex) >> 8) & 0xFF),
+        b(uint32_t(hex) & 0xFF) {}
+  uint8_t r;
+  uint8_t g;
+  uint8_t b;
+};
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+// color is a struct of either a rgb color or a terminal color.
+struct color_type {
+  FMT_CONSTEXPR color_type() noexcept : is_rgb(), value{} {}
+  FMT_CONSTEXPR color_type(color rgb_color) noexcept : is_rgb(true), value{} {
+    value.rgb_color = static_cast<uint32_t>(rgb_color);
+  }
+  FMT_CONSTEXPR color_type(rgb rgb_color) noexcept : is_rgb(true), value{} {
+    value.rgb_color = (static_cast<uint32_t>(rgb_color.r) << 16) |
+                      (static_cast<uint32_t>(rgb_color.g) << 8) | rgb_color.b;
+  }
+  FMT_CONSTEXPR color_type(terminal_color term_color) noexcept
+      : is_rgb(), value{} {
+    value.term_color = static_cast<uint8_t>(term_color);
+  }
+  bool is_rgb;
+  union color_union {
+    uint8_t term_color;
+    uint32_t rgb_color;
+  } value;
+};
+
+FMT_END_DETAIL_NAMESPACE
+
+/** A text style consisting of foreground and background colors and emphasis. */
+class text_style {
+ public:
+  FMT_CONSTEXPR text_style(emphasis em = emphasis()) noexcept
+      : set_foreground_color(), set_background_color(), ems(em) {}
+
+  FMT_CONSTEXPR text_style& operator|=(const text_style& rhs) {
+    if (!set_foreground_color) {
+      set_foreground_color = rhs.set_foreground_color;
+      foreground_color = rhs.foreground_color;
+    } else if (rhs.set_foreground_color) {
+      if (!foreground_color.is_rgb || !rhs.foreground_color.is_rgb)
+        FMT_THROW(format_error("can't OR a terminal color"));
+      foreground_color.value.rgb_color |= rhs.foreground_color.value.rgb_color;
+    }
+
+    if (!set_background_color) {
+      set_background_color = rhs.set_background_color;
+      background_color = rhs.background_color;
+    } else if (rhs.set_background_color) {
+      if (!background_color.is_rgb || !rhs.background_color.is_rgb)
+        FMT_THROW(format_error("can't OR a terminal color"));
+      background_color.value.rgb_color |= rhs.background_color.value.rgb_color;
+    }
+
+    ems = static_cast<emphasis>(static_cast<uint8_t>(ems) |
+                                static_cast<uint8_t>(rhs.ems));
+    return *this;
+  }
+
+  friend FMT_CONSTEXPR text_style operator|(text_style lhs,
+                                            const text_style& rhs) {
+    return lhs |= rhs;
+  }
+
+  FMT_CONSTEXPR bool has_foreground() const noexcept {
+    return set_foreground_color;
+  }
+  FMT_CONSTEXPR bool has_background() const noexcept {
+    return set_background_color;
+  }
+  FMT_CONSTEXPR bool has_emphasis() const noexcept {
+    return static_cast<uint8_t>(ems) != 0;
+  }
+  FMT_CONSTEXPR detail::color_type get_foreground() const noexcept {
+    FMT_ASSERT(has_foreground(), "no foreground specified for this style");
+    return foreground_color;
+  }
+  FMT_CONSTEXPR detail::color_type get_background() const noexcept {
+    FMT_ASSERT(has_background(), "no background specified for this style");
+    return background_color;
+  }
+  FMT_CONSTEXPR emphasis get_emphasis() const noexcept {
+    FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
+    return ems;
+  }
+
+ private:
+  FMT_CONSTEXPR text_style(bool is_foreground,
+                           detail::color_type text_color) noexcept
+      : set_foreground_color(), set_background_color(), ems() {
+    if (is_foreground) {
+      foreground_color = text_color;
+      set_foreground_color = true;
+    } else {
+      background_color = text_color;
+      set_background_color = true;
+    }
+  }
+
+  friend FMT_CONSTEXPR text_style fg(detail::color_type foreground) noexcept;
+
+  friend FMT_CONSTEXPR text_style bg(detail::color_type background) noexcept;
+
+  detail::color_type foreground_color;
+  detail::color_type background_color;
+  bool set_foreground_color;
+  bool set_background_color;
+  emphasis ems;
+};
+
+/** Creates a text style from the foreground (text) color. */
+FMT_CONSTEXPR inline text_style fg(detail::color_type foreground) noexcept {
+  return text_style(true, foreground);
+}
+
+/** Creates a text style from the background color. */
+FMT_CONSTEXPR inline text_style bg(detail::color_type background) noexcept {
+  return text_style(false, background);
+}
+
+FMT_CONSTEXPR inline text_style operator|(emphasis lhs, emphasis rhs) noexcept {
+  return text_style(lhs) | rhs;
+}
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+template <typename Char> struct ansi_color_escape {
+  FMT_CONSTEXPR ansi_color_escape(detail::color_type text_color,
+                                  const char* esc) noexcept {
+    // If we have a terminal color, we need to output another escape code
+    // sequence.
+    if (!text_color.is_rgb) {
+      bool is_background = esc == string_view("\x1b[48;2;");
+      uint32_t value = text_color.value.term_color;
+      // Background ASCII codes are the same as the foreground ones but with
+      // 10 more.
+      if (is_background) value += 10u;
+
+      size_t index = 0;
+      buffer[index++] = static_cast<Char>('\x1b');
+      buffer[index++] = static_cast<Char>('[');
+
+      if (value >= 100u) {
+        buffer[index++] = static_cast<Char>('1');
+        value %= 100u;
+      }
+      buffer[index++] = static_cast<Char>('0' + value / 10u);
+      buffer[index++] = static_cast<Char>('0' + value % 10u);
+
+      buffer[index++] = static_cast<Char>('m');
+      buffer[index++] = static_cast<Char>('\0');
+      return;
+    }
+
+    for (int i = 0; i < 7; i++) {
+      buffer[i] = static_cast<Char>(esc[i]);
+    }
+    rgb color(text_color.value.rgb_color);
+    to_esc(color.r, buffer + 7, ';');
+    to_esc(color.g, buffer + 11, ';');
+    to_esc(color.b, buffer + 15, 'm');
+    buffer[19] = static_cast<Char>(0);
+  }
+  FMT_CONSTEXPR ansi_color_escape(emphasis em) noexcept {
+    uint8_t em_codes[num_emphases] = {};
+    if (has_emphasis(em, emphasis::bold)) em_codes[0] = 1;
+    if (has_emphasis(em, emphasis::faint)) em_codes[1] = 2;
+    if (has_emphasis(em, emphasis::italic)) em_codes[2] = 3;
+    if (has_emphasis(em, emphasis::underline)) em_codes[3] = 4;
+    if (has_emphasis(em, emphasis::blink)) em_codes[4] = 5;
+    if (has_emphasis(em, emphasis::reverse)) em_codes[5] = 7;
+    if (has_emphasis(em, emphasis::conceal)) em_codes[6] = 8;
+    if (has_emphasis(em, emphasis::strikethrough)) em_codes[7] = 9;
+
+    size_t index = 0;
+    for (size_t i = 0; i < num_emphases; ++i) {
+      if (!em_codes[i]) continue;
+      buffer[index++] = static_cast<Char>('\x1b');
+      buffer[index++] = static_cast<Char>('[');
+      buffer[index++] = static_cast<Char>('0' + em_codes[i]);
+      buffer[index++] = static_cast<Char>('m');
+    }
+    buffer[index++] = static_cast<Char>(0);
+  }
+  FMT_CONSTEXPR operator const Char*() const noexcept { return buffer; }
+
+  FMT_CONSTEXPR const Char* begin() const noexcept { return buffer; }
+  FMT_CONSTEXPR_CHAR_TRAITS const Char* end() const noexcept {
+    return buffer + std::char_traits<Char>::length(buffer);
+  }
+
+ private:
+  static constexpr size_t num_emphases = 8;
+  Char buffer[7u + 3u * num_emphases + 1u];
+
+  static FMT_CONSTEXPR void to_esc(uint8_t c, Char* out,
+                                   char delimiter) noexcept {
+    out[0] = static_cast<Char>('0' + c / 100);
+    out[1] = static_cast<Char>('0' + c / 10 % 10);
+    out[2] = static_cast<Char>('0' + c % 10);
+    out[3] = static_cast<Char>(delimiter);
+  }
+  static FMT_CONSTEXPR bool has_emphasis(emphasis em, emphasis mask) noexcept {
+    return static_cast<uint8_t>(em) & static_cast<uint8_t>(mask);
+  }
+};
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_foreground_color(
+    detail::color_type foreground) noexcept {
+  return ansi_color_escape<Char>(foreground, "\x1b[38;2;");
+}
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_background_color(
+    detail::color_type background) noexcept {
+  return ansi_color_escape<Char>(background, "\x1b[48;2;");
+}
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_emphasis(emphasis em) noexcept {
+  return ansi_color_escape<Char>(em);
+}
+
+template <typename Char> inline void fputs(const Char* chars, FILE* stream) {
+  int result = std::fputs(chars, stream);
+  if (result < 0)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+template <> inline void fputs<wchar_t>(const wchar_t* chars, FILE* stream) {
+  int result = std::fputws(chars, stream);
+  if (result < 0)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+template <typename Char> inline void reset_color(FILE* stream) {
+  fputs("\x1b[0m", stream);
+}
+
+template <> inline void reset_color<wchar_t>(FILE* stream) {
+  fputs(L"\x1b[0m", stream);
+}
+
+template <typename Char> inline void reset_color(buffer<Char>& buffer) {
+  auto reset_color = string_view("\x1b[0m");
+  buffer.append(reset_color.begin(), reset_color.end());
+}
+
+template <typename T> struct styled_arg {
+  const T& value;
+  text_style style;
+};
+
+template <typename Char>
+void vformat_to(buffer<Char>& buf, const text_style& ts,
+                basic_string_view<Char> format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  bool has_style = false;
+  if (ts.has_emphasis()) {
+    has_style = true;
+    auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
+    buf.append(emphasis.begin(), emphasis.end());
+  }
+  if (ts.has_foreground()) {
+    has_style = true;
+    auto foreground = detail::make_foreground_color<Char>(ts.get_foreground());
+    buf.append(foreground.begin(), foreground.end());
+  }
+  if (ts.has_background()) {
+    has_style = true;
+    auto background = detail::make_background_color<Char>(ts.get_background());
+    buf.append(background.begin(), background.end());
+  }
+  detail::vformat_to(buf, format_str, args, {});
+  if (has_style) detail::reset_color<Char>(buf);
+}
+
+FMT_END_DETAIL_NAMESPACE
+
+template <typename S, typename Char = char_t<S>>
+void vprint(std::FILE* f, const text_style& ts, const S& format,
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  basic_memory_buffer<Char> buf;
+  detail::vformat_to(buf, ts, detail::to_string_view(format), args);
+  if (detail::is_utf8()) {
+    detail::print(f, basic_string_view<Char>(buf.begin(), buf.size()));
+  } else {
+    buf.push_back(Char(0));
+    detail::fputs(buf.data(), f);
+  }
+}
+
+/**
+  \rst
+  Formats a string and prints it to the specified file stream using ANSI
+  escape sequences to specify text formatting.
+
+  **Example**::
+
+    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
+               "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
+ */
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(std::FILE* f, const text_style& ts, const S& format_str,
+           const Args&... args) {
+  vprint(f, ts, format_str,
+         fmt::make_format_args<buffer_context<char_t<S>>>(args...));
+}
+
+/**
+  \rst
+  Formats a string and prints it to stdout using ANSI escape sequences to
+  specify text formatting.
+
+  **Example**::
+
+    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
+               "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
+ */
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(const text_style& ts, const S& format_str, const Args&... args) {
+  return print(stdout, ts, format_str, args...);
+}
+
+template <typename S, typename Char = char_t<S>>
+inline std::basic_string<Char> vformat(
+    const text_style& ts, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  basic_memory_buffer<Char> buf;
+  detail::vformat_to(buf, ts, detail::to_string_view(format_str), args);
+  return fmt::to_string(buf);
+}
+
+/**
+  \rst
+  Formats arguments and returns the result as a string using ANSI
+  escape sequences to specify text formatting.
+
+  **Example**::
+
+    #include <fmt/color.h>
+    std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red),
+                                      "The answer is {}", 42);
+  \endrst
+*/
+template <typename S, typename... Args, typename Char = char_t<S>>
+inline std::basic_string<Char> format(const text_style& ts, const S& format_str,
+                                      const Args&... args) {
+  return fmt::vformat(ts, detail::to_string_view(format_str),
+                      fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+/**
+  Formats a string with the given text_style and writes the output to ``out``.
+ */
+template <typename OutputIt, typename Char,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
+OutputIt vformat_to(
+    OutputIt out, const text_style& ts, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, ts, format_str, args);
+  return detail::get_iterator(buf);
+}
+
+/**
+  \rst
+  Formats arguments with the given text_style, writes the result to the output
+  iterator ``out`` and returns the iterator past the end of the output range.
+
+  **Example**::
+
+    std::vector<char> out;
+    fmt::format_to(std::back_inserter(out),
+                   fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
+  \endrst
+*/
+template <typename OutputIt, typename S, typename... Args,
+          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value&&
+              detail::is_string<S>::value>
+inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  return vformat_to(out, ts, detail::to_string_view(format_str),
+                    fmt::make_format_args<buffer_context<char_t<S>>>(args...));
+}
+
+template <typename T, typename Char>
+struct formatter<detail::styled_arg<T>, Char> : formatter<T, Char> {
+  template <typename FormatContext>
+  auto format(const detail::styled_arg<T>& arg, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    const auto& ts = arg.style;
+    const auto& value = arg.value;
+    auto out = ctx.out();
+
+    bool has_style = false;
+    if (ts.has_emphasis()) {
+      has_style = true;
+      auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
+      out = std::copy(emphasis.begin(), emphasis.end(), out);
+    }
+    if (ts.has_foreground()) {
+      has_style = true;
+      auto foreground =
+          detail::make_foreground_color<Char>(ts.get_foreground());
+      out = std::copy(foreground.begin(), foreground.end(), out);
+    }
+    if (ts.has_background()) {
+      has_style = true;
+      auto background =
+          detail::make_background_color<Char>(ts.get_background());
+      out = std::copy(background.begin(), background.end(), out);
+    }
+    out = formatter<T, Char>::format(value, ctx);
+    if (has_style) {
+      auto reset_color = string_view("\x1b[0m");
+      out = std::copy(reset_color.begin(), reset_color.end(), out);
+    }
+    return out;
+  }
+};
+
+/**
+  \rst
+  Returns an argument that will be formatted using ANSI escape sequences,
+  to be used in a formatting function.
+
+  **Example**::
+
+    fmt::print("Elapsed time: {0:.2f} seconds",
+               fmt::styled(1.23, fmt::fg(fmt::color::green) |
+                                 fmt::bg(fmt::color::blue)));
+  \endrst
+ */
+template <typename T>
+FMT_CONSTEXPR auto styled(const T& value, text_style ts)
+    -> detail::styled_arg<remove_cvref_t<T>> {
+  return detail::styled_arg<remove_cvref_t<T>>{value, ts};
+}
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_COLOR_H_
diff --git a/libfuse/lib/fmt/compile.h b/libfuse/lib/fmt/compile.h
new file mode 100644
index 00000000..933668c4
--- /dev/null
+++ b/libfuse/lib/fmt/compile.h
@@ -0,0 +1,611 @@
+// Formatting library for C++ - experimental format string compilation
+//
+// Copyright (c) 2012 - present, Victor Zverovich and fmt contributors
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_COMPILE_H_
+#define FMT_COMPILE_H_
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+
+template <typename Char, typename InputIt>
+FMT_CONSTEXPR inline counting_iterator copy_str(InputIt begin, InputIt end,
+                                                counting_iterator it) {
+  return it + (end - begin);
+}
+
+template <typename OutputIt> class truncating_iterator_base {
+ protected:
+  OutputIt out_;
+  size_t limit_;
+  size_t count_ = 0;
+
+  truncating_iterator_base() : out_(), limit_(0) {}
+
+  truncating_iterator_base(OutputIt out, size_t limit)
+      : out_(out), limit_(limit) {}
+
+ public:
+  using iterator_category = std::output_iterator_tag;
+  using value_type = typename std::iterator_traits<OutputIt>::value_type;
+  using difference_type = std::ptrdiff_t;
+  using pointer = void;
+  using reference = void;
+  FMT_UNCHECKED_ITERATOR(truncating_iterator_base);
+
+  OutputIt base() const { return out_; }
+  size_t count() const { return count_; }
+};
+
+// An output iterator that truncates the output and counts the number of objects
+// written to it.
+template <typename OutputIt,
+          typename Enable = typename std::is_void<
+              typename std::iterator_traits<OutputIt>::value_type>::type>
+class truncating_iterator;
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::false_type>
+    : public truncating_iterator_base<OutputIt> {
+  mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_;
+
+ public:
+  using value_type = typename truncating_iterator_base<OutputIt>::value_type;
+
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  truncating_iterator& operator++() {
+    if (this->count_++ < this->limit_) ++this->out_;
+    return *this;
+  }
+
+  truncating_iterator operator++(int) {
+    auto it = *this;
+    ++*this;
+    return it;
+  }
+
+  value_type& operator*() const {
+    return this->count_ < this->limit_ ? *this->out_ : blackhole_;
+  }
+};
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::true_type>
+    : public truncating_iterator_base<OutputIt> {
+ public:
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  template <typename T> truncating_iterator& operator=(T val) {
+    if (this->count_++ < this->limit_) *this->out_++ = val;
+    return *this;
+  }
+
+  truncating_iterator& operator++() { return *this; }
+  truncating_iterator& operator++(int) { return *this; }
+  truncating_iterator& operator*() { return *this; }
+};
+
+// A compile-time string which is compiled into fast formatting code.
+class compiled_string {};
+
+template <typename S>
+struct is_compiled_string : std::is_base_of<compiled_string, S> {};
+
+/**
+  \rst
+  Converts a string literal *s* into a format string that will be parsed at
+  compile time and converted into efficient formatting code. Requires C++17
+  ``constexpr if`` compiler support.
+
+  **Example**::
+
+    // Converts 42 into std::string using the most efficient method and no
+    // runtime format string processing.
+    std::string s = fmt::format(FMT_COMPILE("{}"), 42);
+  \endrst
+ */
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+#  define FMT_COMPILE(s) \
+    FMT_STRING_IMPL(s, fmt::detail::compiled_string, explicit)
+#else
+#  define FMT_COMPILE(s) FMT_STRING(s)
+#endif
+
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+template <typename Char, size_t N,
+          fmt::detail_exported::fixed_string<Char, N> Str>
+struct udl_compiled_string : compiled_string {
+  using char_type = Char;
+  explicit constexpr operator basic_string_view<char_type>() const {
+    return {Str.data, N - 1};
+  }
+};
+#endif
+
+template <typename T, typename... Tail>
+const T& first(const T& value, const Tail&...) {
+  return value;
+}
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+template <typename... Args> struct type_list {};
+
+// Returns a reference to the argument at index N from [first, rest...].
+template <int N, typename T, typename... Args>
+constexpr const auto& get([[maybe_unused]] const T& first,
+                          [[maybe_unused]] const Args&... rest) {
+  static_assert(N < 1 + sizeof...(Args), "index is out of bounds");
+  if constexpr (N == 0)
+    return first;
+  else
+    return detail::get<N - 1>(rest...);
+}
+
+template <typename Char, typename... Args>
+constexpr int get_arg_index_by_name(basic_string_view<Char> name,
+                                    type_list<Args...>) {
+  return get_arg_index_by_name<Args...>(name);
+}
+
+template <int N, typename> struct get_type_impl;
+
+template <int N, typename... Args> struct get_type_impl<N, type_list<Args...>> {
+  using type =
+      remove_cvref_t<decltype(detail::get<N>(std::declval<Args>()...))>;
+};
+
+template <int N, typename T>
+using get_type = typename get_type_impl<N, T>::type;
+
+template <typename T> struct is_compiled_format : std::false_type {};
+
+template <typename Char> struct text {
+  basic_string_view<Char> data;
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
+    return write<Char>(out, data);
+  }
+};
+
+template <typename Char>
+struct is_compiled_format<text<Char>> : std::true_type {};
+
+template <typename Char>
+constexpr text<Char> make_text(basic_string_view<Char> s, size_t pos,
+                               size_t size) {
+  return {{&s[pos], size}};
+}
+
+template <typename Char> struct code_unit {
+  Char value;
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
+    return write<Char>(out, value);
+  }
+};
+
+// This ensures that the argument type is convertible to `const T&`.
+template <typename T, int N, typename... Args>
+constexpr const T& get_arg_checked(const Args&... args) {
+  const auto& arg = detail::get<N>(args...);
+  if constexpr (detail::is_named_arg<remove_cvref_t<decltype(arg)>>()) {
+    return arg.value;
+  } else {
+    return arg;
+  }
+}
+
+template <typename Char>
+struct is_compiled_format<code_unit<Char>> : std::true_type {};
+
+// A replacement field that refers to argument N.
+template <typename Char, typename T, int N> struct field {
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    return write<Char>(out, get_arg_checked<T, N>(args...));
+  }
+};
+
+template <typename Char, typename T, int N>
+struct is_compiled_format<field<Char, T, N>> : std::true_type {};
+
+// A replacement field that refers to argument with name.
+template <typename Char> struct runtime_named_field {
+  using char_type = Char;
+  basic_string_view<Char> name;
+
+  template <typename OutputIt, typename T>
+  constexpr static bool try_format_argument(
+      OutputIt& out,
+      // [[maybe_unused]] due to unused-but-set-parameter warning in GCC 7,8,9
+      [[maybe_unused]] basic_string_view<Char> arg_name, const T& arg) {
+    if constexpr (is_named_arg<typename std::remove_cv<T>::type>::value) {
+      if (arg_name == arg.name) {
+        out = write<Char>(out, arg.value);
+        return true;
+      }
+    }
+    return false;
+  }
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    bool found = (try_format_argument(out, name, args) || ...);
+    if (!found) {
+      FMT_THROW(format_error("argument with specified name is not found"));
+    }
+    return out;
+  }
+};
+
+template <typename Char>
+struct is_compiled_format<runtime_named_field<Char>> : std::true_type {};
+
+// A replacement field that refers to argument N and has format specifiers.
+template <typename Char, typename T, int N> struct spec_field {
+  using char_type = Char;
+  formatter<T, Char> fmt;
+
+  template <typename OutputIt, typename... Args>
+  constexpr FMT_INLINE OutputIt format(OutputIt out,
+                                       const Args&... args) const {
+    const auto& vargs =
+        fmt::make_format_args<basic_format_context<OutputIt, Char>>(args...);
+    basic_format_context<OutputIt, Char> ctx(out, vargs);
+    return fmt.format(get_arg_checked<T, N>(args...), ctx);
+  }
+};
+
+template <typename Char, typename T, int N>
+struct is_compiled_format<spec_field<Char, T, N>> : std::true_type {};
+
+template <typename L, typename R> struct concat {
+  L lhs;
+  R rhs;
+  using char_type = typename L::char_type;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    out = lhs.format(out, args...);
+    return rhs.format(out, args...);
+  }
+};
+
+template <typename L, typename R>
+struct is_compiled_format<concat<L, R>> : std::true_type {};
+
+template <typename L, typename R>
+constexpr concat<L, R> make_concat(L lhs, R rhs) {
+  return {lhs, rhs};
+}
+
+struct unknown_format {};
+
+template <typename Char>
+constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {
+  for (size_t size = str.size(); pos != size; ++pos) {
+    if (str[pos] == '{' || str[pos] == '}') break;
+  }
+  return pos;
+}
+
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str);
+
+template <typename Args, size_t POS, int ID, typename T, typename S>
+constexpr auto parse_tail(T head, S format_str) {
+  if constexpr (POS !=
+                basic_string_view<typename S::char_type>(format_str).size()) {
+    constexpr auto tail = compile_format_string<Args, POS, ID>(format_str);
+    if constexpr (std::is_same<remove_cvref_t<decltype(tail)>,
+                               unknown_format>())
+      return tail;
+    else
+      return make_concat(head, tail);
+  } else {
+    return head;
+  }
+}
+
+template <typename T, typename Char> struct parse_specs_result {
+  formatter<T, Char> fmt;
+  size_t end;
+  int next_arg_id;
+};
+
+constexpr int manual_indexing_id = -1;
+
+template <typename T, typename Char>
+constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
+                                                  size_t pos, int next_arg_id) {
+  str.remove_prefix(pos);
+  auto ctx = compile_parse_context<Char>(str, max_value<int>(), nullptr, {},
+                                         next_arg_id);
+  auto f = formatter<T, Char>();
+  auto end = f.parse(ctx);
+  return {f, pos + fmt::detail::to_unsigned(end - str.data()),
+          next_arg_id == 0 ? manual_indexing_id : ctx.next_arg_id()};
+}
+
+template <typename Char> struct arg_id_handler {
+  arg_ref<Char> arg_id;
+
+  constexpr int operator()() {
+    FMT_ASSERT(false, "handler cannot be used with automatic indexing");
+    return 0;
+  }
+  constexpr int operator()(int id) {
+    arg_id = arg_ref<Char>(id);
+    return 0;
+  }
+  constexpr int operator()(basic_string_view<Char> id) {
+    arg_id = arg_ref<Char>(id);
+    return 0;
+  }
+
+  constexpr void on_error(const char* message) {
+    FMT_THROW(format_error(message));
+  }
+};
+
+template <typename Char> struct parse_arg_id_result {
+  arg_ref<Char> arg_id;
+  const Char* arg_id_end;
+};
+
+template <int ID, typename Char>
+constexpr auto parse_arg_id(const Char* begin, const Char* end) {
+  auto handler = arg_id_handler<Char>{arg_ref<Char>{}};
+  auto arg_id_end = parse_arg_id(begin, end, handler);
+  return parse_arg_id_result<Char>{handler.arg_id, arg_id_end};
+}
+
+template <typename T, typename Enable = void> struct field_type {
+  using type = remove_cvref_t<T>;
+};
+
+template <typename T>
+struct field_type<T, enable_if_t<detail::is_named_arg<T>::value>> {
+  using type = remove_cvref_t<decltype(T::value)>;
+};
+
+template <typename T, typename Args, size_t END_POS, int ARG_INDEX, int NEXT_ID,
+          typename S>
+constexpr auto parse_replacement_field_then_tail(S format_str) {
+  using char_type = typename S::char_type;
+  constexpr auto str = basic_string_view<char_type>(format_str);
+  constexpr char_type c = END_POS != str.size() ? str[END_POS] : char_type();
+  if constexpr (c == '}') {
+    return parse_tail<Args, END_POS + 1, NEXT_ID>(
+        field<char_type, typename field_type<T>::type, ARG_INDEX>(),
+        format_str);
+  } else if constexpr (c != ':') {
+    FMT_THROW(format_error("expected ':'"));
+  } else {
+    constexpr auto result = parse_specs<typename field_type<T>::type>(
+        str, END_POS + 1, NEXT_ID == manual_indexing_id ? 0 : NEXT_ID);
+    if constexpr (result.end >= str.size() || str[result.end] != '}') {
+      FMT_THROW(format_error("expected '}'"));
+      return 0;
+    } else {
+      return parse_tail<Args, result.end + 1, result.next_arg_id>(
+          spec_field<char_type, typename field_type<T>::type, ARG_INDEX>{
+              result.fmt},
+          format_str);
+    }
+  }
+}
+
+// Compiles a non-empty format string and returns the compiled representation
+// or unknown_format() on unrecognized input.
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str) {
+  using char_type = typename S::char_type;
+  constexpr auto str = basic_string_view<char_type>(format_str);
+  if constexpr (str[POS] == '{') {
+    if constexpr (POS + 1 == str.size())
+      FMT_THROW(format_error("unmatched '{' in format string"));
+    if constexpr (str[POS + 1] == '{') {
+      return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+    } else if constexpr (str[POS + 1] == '}' || str[POS + 1] == ':') {
+      static_assert(ID != manual_indexing_id,
+                    "cannot switch from manual to automatic argument indexing");
+      constexpr auto next_id =
+          ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+      return parse_replacement_field_then_tail<get_type<ID, Args>, Args,
+                                               POS + 1, ID, next_id>(
+          format_str);
+    } else {
+      constexpr auto arg_id_result =
+          parse_arg_id<ID>(str.data() + POS + 1, str.data() + str.size());
+      constexpr auto arg_id_end_pos = arg_id_result.arg_id_end - str.data();
+      constexpr char_type c =
+          arg_id_end_pos != str.size() ? str[arg_id_end_pos] : char_type();
+      static_assert(c == '}' || c == ':', "missing '}' in format string");
+      if constexpr (arg_id_result.arg_id.kind == arg_id_kind::index) {
+        static_assert(
+            ID == manual_indexing_id || ID == 0,
+            "cannot switch from automatic to manual argument indexing");
+        constexpr auto arg_index = arg_id_result.arg_id.val.index;
+        return parse_replacement_field_then_tail<get_type<arg_index, Args>,
+                                                 Args, arg_id_end_pos,
+                                                 arg_index, manual_indexing_id>(
+            format_str);
+      } else if constexpr (arg_id_result.arg_id.kind == arg_id_kind::name) {
+        constexpr auto arg_index =
+            get_arg_index_by_name(arg_id_result.arg_id.val.name, Args{});
+        if constexpr (arg_index != invalid_arg_index) {
+          constexpr auto next_id =
+              ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+          return parse_replacement_field_then_tail<
+              decltype(get_type<arg_index, Args>::value), Args, arg_id_end_pos,
+              arg_index, next_id>(format_str);
+        } else {
+          if constexpr (c == '}') {
+            return parse_tail<Args, arg_id_end_pos + 1, ID>(
+                runtime_named_field<char_type>{arg_id_result.arg_id.val.name},
+                format_str);
+          } else if constexpr (c == ':') {
+            return unknown_format();  // no type info for specs parsing
+          }
+        }
+      }
+    }
+  } else if constexpr (str[POS] == '}') {
+    if constexpr (POS + 1 == str.size())
+      FMT_THROW(format_error("unmatched '}' in format string"));
+    return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+  } else {
+    constexpr auto end = parse_text(str, POS + 1);
+    if constexpr (end - POS > 1) {
+      return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
+                                       format_str);
+    } else {
+      return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]},
+                                       format_str);
+    }
+  }
+}
+
+template <typename... Args, typename S,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+constexpr auto compile(S format_str) {
+  constexpr auto str = basic_string_view<typename S::char_type>(format_str);
+  if constexpr (str.size() == 0) {
+    return detail::make_text(str, 0, 0);
+  } else {
+    constexpr auto result =
+        detail::compile_format_string<detail::type_list<Args...>, 0, 0>(
+            format_str);
+    return result;
+  }
+}
+#endif  // defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+}  // namespace detail
+
+FMT_MODULE_EXPORT_BEGIN
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+
+template <typename CompiledFormat, typename... Args,
+          typename Char = typename CompiledFormat::char_type,
+          FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
+FMT_INLINE std::basic_string<Char> format(const CompiledFormat& cf,
+                                          const Args&... args) {
+  auto s = std::basic_string<Char>();
+  cf.format(std::back_inserter(s), args...);
+  return s;
+}
+
+template <typename OutputIt, typename CompiledFormat, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
+constexpr FMT_INLINE OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+                                        const Args&... args) {
+  return cf.format(out, args...);
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_INLINE std::basic_string<typename S::char_type> format(const S&,
+                                                           Args&&... args) {
+  if constexpr (std::is_same<typename S::char_type, char>::value) {
+    constexpr auto str = basic_string_view<typename S::char_type>(S());
+    if constexpr (str.size() == 2 && str[0] == '{' && str[1] == '}') {
+      const auto& first = detail::first(args...);
+      if constexpr (detail::is_named_arg<
+                        remove_cvref_t<decltype(first)>>::value) {
+        return fmt::to_string(first.value);
+      } else {
+        return fmt::to_string(first);
+      }
+    }
+  }
+  constexpr auto compiled = detail::compile<Args...>(S());
+  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+                             detail::unknown_format>()) {
+    return fmt::format(
+        static_cast<basic_string_view<typename S::char_type>>(S()),
+        std::forward<Args>(args)...);
+  } else {
+    return fmt::format(compiled, std::forward<Args>(args)...);
+  }
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_CONSTEXPR OutputIt format_to(OutputIt out, const S&, Args&&... args) {
+  constexpr auto compiled = detail::compile<Args...>(S());
+  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+                             detail::unknown_format>()) {
+    return fmt::format_to(
+        out, static_cast<basic_string_view<typename S::char_type>>(S()),
+        std::forward<Args>(args)...);
+  } else {
+    return fmt::format_to(out, compiled, std::forward<Args>(args)...);
+  }
+}
+#endif
+
+template <typename OutputIt, typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
+                                         const S& format_str, Args&&... args) {
+  auto it = fmt::format_to(detail::truncating_iterator<OutputIt>(out, n),
+                           format_str, std::forward<Args>(args)...);
+  return {it.base(), it.count()};
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_CONSTEXPR20 size_t formatted_size(const S& format_str,
+                                      const Args&... args) {
+  return fmt::format_to(detail::counting_iterator(), format_str, args...)
+      .count();
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(std::FILE* f, const S& format_str, const Args&... args) {
+  memory_buffer buffer;
+  fmt::format_to(std::back_inserter(buffer), format_str, args...);
+  detail::print(f, {buffer.data(), buffer.size()});
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(const S& format_str, const Args&... args) {
+  print(stdout, format_str, args...);
+}
+
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+inline namespace literals {
+template <detail_exported::fixed_string Str> constexpr auto operator""_cf() {
+  using char_t = remove_cvref_t<decltype(Str.data[0])>;
+  return detail::udl_compiled_string<char_t, sizeof(Str.data) / sizeof(char_t),
+                                     Str>();
+}
+}  // namespace literals
+#endif
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_COMPILE_H_
diff --git a/libfuse/lib/fmt/core.h b/libfuse/lib/fmt/core.h
new file mode 100644
index 00000000..f6a37af9
--- /dev/null
+++ b/libfuse/lib/fmt/core.h
@@ -0,0 +1,3323 @@
+// Formatting library for C++ - the core API for char/UTF-8
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_CORE_H_
+#define FMT_CORE_H_
+
+#include <cstddef>  // std::byte
+#include <cstdio>   // std::FILE
+#include <cstring>  // std::strlen
+#include <iterator>
+#include <limits>
+#include <string>
+#include <type_traits>
+
+// The fmt library version in the form major * 10000 + minor * 100 + patch.
+#define FMT_VERSION 90100
+
+#if defined(__clang__) && !defined(__ibmxl__)
+#  define FMT_CLANG_VERSION (__clang_major__ * 100 + __clang_minor__)
+#else
+#  define FMT_CLANG_VERSION 0
+#endif
+
+#if defined(__GNUC__) && !defined(__clang__) && !defined(__INTEL_COMPILER) && \
+    !defined(__NVCOMPILER)
+#  define FMT_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
+#else
+#  define FMT_GCC_VERSION 0
+#endif
+
+#ifndef FMT_GCC_PRAGMA
+// Workaround _Pragma bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59884.
+#  if FMT_GCC_VERSION >= 504
+#    define FMT_GCC_PRAGMA(arg) _Pragma(arg)
+#  else
+#    define FMT_GCC_PRAGMA(arg)
+#  endif
+#endif
+
+#ifdef __ICL
+#  define FMT_ICC_VERSION __ICL
+#elif defined(__INTEL_COMPILER)
+#  define FMT_ICC_VERSION __INTEL_COMPILER
+#else
+#  define FMT_ICC_VERSION 0
+#endif
+
+#ifdef _MSC_VER
+#  define FMT_MSC_VERSION _MSC_VER
+#  define FMT_MSC_WARNING(...) __pragma(warning(__VA_ARGS__))
+#else
+#  define FMT_MSC_VERSION 0
+#  define FMT_MSC_WARNING(...)
+#endif
+
+#ifdef _MSVC_LANG
+#  define FMT_CPLUSPLUS _MSVC_LANG
+#else
+#  define FMT_CPLUSPLUS __cplusplus
+#endif
+
+#ifdef __has_feature
+#  define FMT_HAS_FEATURE(x) __has_feature(x)
+#else
+#  define FMT_HAS_FEATURE(x) 0
+#endif
+
+#if (defined(__has_include) || FMT_ICC_VERSION >= 1600 || \
+     FMT_MSC_VERSION > 1900) &&                           \
+    !defined(__INTELLISENSE__)
+#  define FMT_HAS_INCLUDE(x) __has_include(x)
+#else
+#  define FMT_HAS_INCLUDE(x) 0
+#endif
+
+#ifdef __has_cpp_attribute
+#  define FMT_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
+#else
+#  define FMT_HAS_CPP_ATTRIBUTE(x) 0
+#endif
+
+#define FMT_HAS_CPP14_ATTRIBUTE(attribute) \
+  (FMT_CPLUSPLUS >= 201402L && FMT_HAS_CPP_ATTRIBUTE(attribute))
+
+#define FMT_HAS_CPP17_ATTRIBUTE(attribute) \
+  (FMT_CPLUSPLUS >= 201703L && FMT_HAS_CPP_ATTRIBUTE(attribute))
+
+// Check if relaxed C++14 constexpr is supported.
+// GCC doesn't allow throw in constexpr until version 6 (bug 67371).
+#ifndef FMT_USE_CONSTEXPR
+#  if (FMT_HAS_FEATURE(cxx_relaxed_constexpr) || FMT_MSC_VERSION >= 1912 || \
+       (FMT_GCC_VERSION >= 600 && FMT_CPLUSPLUS >= 201402L)) &&             \
+      !FMT_ICC_VERSION && !defined(__NVCC__)
+#    define FMT_USE_CONSTEXPR 1
+#  else
+#    define FMT_USE_CONSTEXPR 0
+#  endif
+#endif
+#if FMT_USE_CONSTEXPR
+#  define FMT_CONSTEXPR constexpr
+#else
+#  define FMT_CONSTEXPR
+#endif
+
+#if ((FMT_CPLUSPLUS >= 202002L) &&                            \
+     (!defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE > 9)) || \
+    (FMT_CPLUSPLUS >= 201709L && FMT_GCC_VERSION >= 1002)
+#  define FMT_CONSTEXPR20 constexpr
+#else
+#  define FMT_CONSTEXPR20
+#endif
+
+// Check if constexpr std::char_traits<>::{compare,length} are supported.
+#if defined(__GLIBCXX__)
+#  if FMT_CPLUSPLUS >= 201703L && defined(_GLIBCXX_RELEASE) && \
+      _GLIBCXX_RELEASE >= 7  // GCC 7+ libstdc++ has _GLIBCXX_RELEASE.
+#    define FMT_CONSTEXPR_CHAR_TRAITS constexpr
+#  endif
+#elif defined(_LIBCPP_VERSION) && FMT_CPLUSPLUS >= 201703L && \
+    _LIBCPP_VERSION >= 4000
+#  define FMT_CONSTEXPR_CHAR_TRAITS constexpr
+#elif FMT_MSC_VERSION >= 1914 && FMT_CPLUSPLUS >= 201703L
+#  define FMT_CONSTEXPR_CHAR_TRAITS constexpr
+#endif
+#ifndef FMT_CONSTEXPR_CHAR_TRAITS
+#  define FMT_CONSTEXPR_CHAR_TRAITS
+#endif
+
+// Check if exceptions are disabled.
+#ifndef FMT_EXCEPTIONS
+#  if (defined(__GNUC__) && !defined(__EXCEPTIONS)) || \
+      (FMT_MSC_VERSION && !_HAS_EXCEPTIONS)
+#    define FMT_EXCEPTIONS 0
+#  else
+#    define FMT_EXCEPTIONS 1
+#  endif
+#endif
+
+#ifndef FMT_DEPRECATED
+#  if FMT_HAS_CPP14_ATTRIBUTE(deprecated) || FMT_MSC_VERSION >= 1900
+#    define FMT_DEPRECATED [[deprecated]]
+#  else
+#    if (defined(__GNUC__) && !defined(__LCC__)) || defined(__clang__)
+#      define FMT_DEPRECATED __attribute__((deprecated))
+#    elif FMT_MSC_VERSION
+#      define FMT_DEPRECATED __declspec(deprecated)
+#    else
+#      define FMT_DEPRECATED /* deprecated */
+#    endif
+#  endif
+#endif
+
+// [[noreturn]] is disabled on MSVC and NVCC because of bogus unreachable code
+// warnings.
+#if FMT_EXCEPTIONS && FMT_HAS_CPP_ATTRIBUTE(noreturn) && !FMT_MSC_VERSION && \
+    !defined(__NVCC__)
+#  define FMT_NORETURN [[noreturn]]
+#else
+#  define FMT_NORETURN
+#endif
+
+#if FMT_HAS_CPP17_ATTRIBUTE(fallthrough)
+#  define FMT_FALLTHROUGH [[fallthrough]]
+#elif defined(__clang__)
+#  define FMT_FALLTHROUGH [[clang::fallthrough]]
+#elif FMT_GCC_VERSION >= 700 && \
+    (!defined(__EDG_VERSION__) || __EDG_VERSION__ >= 520)
+#  define FMT_FALLTHROUGH [[gnu::fallthrough]]
+#else
+#  define FMT_FALLTHROUGH
+#endif
+
+#ifndef FMT_NODISCARD
+#  if FMT_HAS_CPP17_ATTRIBUTE(nodiscard)
+#    define FMT_NODISCARD [[nodiscard]]
+#  else
+#    define FMT_NODISCARD
+#  endif
+#endif
+
+#ifndef FMT_USE_FLOAT
+#  define FMT_USE_FLOAT 1
+#endif
+#ifndef FMT_USE_DOUBLE
+#  define FMT_USE_DOUBLE 1
+#endif
+#ifndef FMT_USE_LONG_DOUBLE
+#  define FMT_USE_LONG_DOUBLE 1
+#endif
+
+#ifndef FMT_INLINE
+#  if FMT_GCC_VERSION || FMT_CLANG_VERSION
+#    define FMT_INLINE inline __attribute__((always_inline))
+#  else
+#    define FMT_INLINE inline
+#  endif
+#endif
+
+// An inline std::forward replacement.
+#define FMT_FORWARD(...) static_cast<decltype(__VA_ARGS__)&&>(__VA_ARGS__)
+
+#ifdef _MSC_VER
+#  define FMT_UNCHECKED_ITERATOR(It) \
+    using _Unchecked_type = It  // Mark iterator as checked.
+#else
+#  define FMT_UNCHECKED_ITERATOR(It) using unchecked_type = It
+#endif
+
+#ifndef FMT_BEGIN_NAMESPACE
+#  define FMT_BEGIN_NAMESPACE \
+    namespace fmt {           \
+    inline namespace v9 {
+#  define FMT_END_NAMESPACE \
+    }                       \
+    }
+#endif
+
+#ifndef FMT_MODULE_EXPORT
+#  define FMT_MODULE_EXPORT
+#  define FMT_MODULE_EXPORT_BEGIN
+#  define FMT_MODULE_EXPORT_END
+#  define FMT_BEGIN_DETAIL_NAMESPACE namespace detail {
+#  define FMT_END_DETAIL_NAMESPACE }
+#endif
+
+#if !defined(FMT_HEADER_ONLY) && defined(_WIN32)
+#  define FMT_CLASS_API FMT_MSC_WARNING(suppress : 4275)
+#  ifdef FMT_EXPORT
+#    define FMT_API __declspec(dllexport)
+#  elif defined(FMT_SHARED)
+#    define FMT_API __declspec(dllimport)
+#  endif
+#else
+#  define FMT_CLASS_API
+#  if defined(FMT_EXPORT) || defined(FMT_SHARED)
+#    if defined(__GNUC__) || defined(__clang__)
+#      define FMT_API __attribute__((visibility("default")))
+#    endif
+#  endif
+#endif
+#ifndef FMT_API
+#  define FMT_API
+#endif
+
+// libc++ supports string_view in pre-c++17.
+#if FMT_HAS_INCLUDE(<string_view>) && \
+    (FMT_CPLUSPLUS >= 201703L || defined(_LIBCPP_VERSION))
+#  include <string_view>
+#  define FMT_USE_STRING_VIEW
+#elif FMT_HAS_INCLUDE("experimental/string_view") && FMT_CPLUSPLUS >= 201402L
+#  include <experimental/string_view>
+#  define FMT_USE_EXPERIMENTAL_STRING_VIEW
+#endif
+
+#ifndef FMT_UNICODE
+#  define FMT_UNICODE !FMT_MSC_VERSION
+#endif
+
+#ifndef FMT_CONSTEVAL
+#  if ((FMT_GCC_VERSION >= 1000 || FMT_CLANG_VERSION >= 1101) &&         \
+       FMT_CPLUSPLUS >= 202002L && !defined(__apple_build_version__)) || \
+      (defined(__cpp_consteval) &&                                       \
+       (!FMT_MSC_VERSION || _MSC_FULL_VER >= 193030704))
+// consteval is broken in MSVC before VS2022 and Apple clang 13.
+#    define FMT_CONSTEVAL consteval
+#    define FMT_HAS_CONSTEVAL
+#  else
+#    define FMT_CONSTEVAL
+#  endif
+#endif
+
+#ifndef FMT_USE_NONTYPE_TEMPLATE_ARGS
+#  if defined(__cpp_nontype_template_args) &&                  \
+      ((FMT_GCC_VERSION >= 903 && FMT_CPLUSPLUS >= 201709L) || \
+       __cpp_nontype_template_args >= 201911L) &&              \
+      !defined(__NVCOMPILER)
+#    define FMT_USE_NONTYPE_TEMPLATE_ARGS 1
+#  else
+#    define FMT_USE_NONTYPE_TEMPLATE_ARGS 0
+#  endif
+#endif
+
+// Enable minimal optimizations for more compact code in debug mode.
+FMT_GCC_PRAGMA("GCC push_options")
+#if !defined(__OPTIMIZE__) && !defined(__NVCOMPILER)
+FMT_GCC_PRAGMA("GCC optimize(\"Og\")")
+#endif
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+// Implementations of enable_if_t and other metafunctions for older systems.
+template <bool B, typename T = void>
+using enable_if_t = typename std::enable_if<B, T>::type;
+template <bool B, typename T, typename F>
+using conditional_t = typename std::conditional<B, T, F>::type;
+template <bool B> using bool_constant = std::integral_constant<bool, B>;
+template <typename T>
+using remove_reference_t = typename std::remove_reference<T>::type;
+template <typename T>
+using remove_const_t = typename std::remove_const<T>::type;
+template <typename T>
+using remove_cvref_t = typename std::remove_cv<remove_reference_t<T>>::type;
+template <typename T> struct type_identity { using type = T; };
+template <typename T> using type_identity_t = typename type_identity<T>::type;
+template <typename T>
+using underlying_t = typename std::underlying_type<T>::type;
+
+template <typename...> struct disjunction : std::false_type {};
+template <typename P> struct disjunction<P> : P {};
+template <typename P1, typename... Pn>
+struct disjunction<P1, Pn...>
+    : conditional_t<bool(P1::value), P1, disjunction<Pn...>> {};
+
+template <typename...> struct conjunction : std::true_type {};
+template <typename P> struct conjunction<P> : P {};
+template <typename P1, typename... Pn>
+struct conjunction<P1, Pn...>
+    : conditional_t<bool(P1::value), conjunction<Pn...>, P1> {};
+
+struct monostate {
+  constexpr monostate() {}
+};
+
+// An enable_if helper to be used in template parameters which results in much
+// shorter symbols: https://godbolt.org/z/sWw4vP. Extra parentheses are needed
+// to workaround a bug in MSVC 2019 (see #1140 and #1186).
+#ifdef FMT_DOC
+#  define FMT_ENABLE_IF(...)
+#else
+#  define FMT_ENABLE_IF(...) enable_if_t<(__VA_ARGS__), int> = 0
+#endif
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+// Suppresses "unused variable" warnings with the method described in
+// https://herbsutter.com/2009/10/18/mailbag-shutting-up-compiler-warnings/.
+// (void)var does not work on many Intel compilers.
+template <typename... T> FMT_CONSTEXPR void ignore_unused(const T&...) {}
+
+constexpr FMT_INLINE auto is_constant_evaluated(
+    bool default_value = false) noexcept -> bool {
+#ifdef __cpp_lib_is_constant_evaluated
+  ignore_unused(default_value);
+  return std::is_constant_evaluated();
+#else
+  return default_value;
+#endif
+}
+
+// Suppresses "conditional expression is constant" warnings.
+template <typename T> constexpr FMT_INLINE auto const_check(T value) -> T {
+  return value;
+}
+
+FMT_NORETURN FMT_API void assert_fail(const char* file, int line,
+                                      const char* message);
+
+#ifndef FMT_ASSERT
+#  ifdef NDEBUG
+// FMT_ASSERT is not empty to avoid -Wempty-body.
+#    define FMT_ASSERT(condition, message) \
+      ::fmt::detail::ignore_unused((condition), (message))
+#  else
+#    define FMT_ASSERT(condition, message)                                    \
+      ((condition) /* void() fails with -Winvalid-constexpr on clang 4.0.1 */ \
+           ? (void)0                                                          \
+           : ::fmt::detail::assert_fail(__FILE__, __LINE__, (message)))
+#  endif
+#endif
+
+#if defined(FMT_USE_STRING_VIEW)
+template <typename Char> using std_string_view = std::basic_string_view<Char>;
+#elif defined(FMT_USE_EXPERIMENTAL_STRING_VIEW)
+template <typename Char>
+using std_string_view = std::experimental::basic_string_view<Char>;
+#else
+template <typename T> struct std_string_view {};
+#endif
+
+#ifdef FMT_USE_INT128
+// Do nothing.
+#elif defined(__SIZEOF_INT128__) && !defined(__NVCC__) && \
+    !(FMT_CLANG_VERSION && FMT_MSC_VERSION)
+#  define FMT_USE_INT128 1
+using int128_opt = __int128_t;  // An optional native 128-bit integer.
+using uint128_opt = __uint128_t;
+template <typename T> inline auto convert_for_visit(T value) -> T {
+  return value;
+}
+#else
+#  define FMT_USE_INT128 0
+#endif
+#if !FMT_USE_INT128
+enum class int128_opt {};
+enum class uint128_opt {};
+// Reduce template instantiations.
+template <typename T> auto convert_for_visit(T) -> monostate { return {}; }
+#endif
+
+// Casts a nonnegative integer to unsigned.
+template <typename Int>
+FMT_CONSTEXPR auto to_unsigned(Int value) ->
+    typename std::make_unsigned<Int>::type {
+  FMT_ASSERT(std::is_unsigned<Int>::value || value >= 0, "negative value");
+  return static_cast<typename std::make_unsigned<Int>::type>(value);
+}
+
+FMT_MSC_WARNING(suppress : 4566) constexpr unsigned char micro[] = "\u00B5";
+
+constexpr auto is_utf8() -> bool {
+  // Avoid buggy sign extensions in MSVC's constant evaluation mode (#2297).
+  using uchar = unsigned char;
+  return FMT_UNICODE || (sizeof(micro) == 3 && uchar(micro[0]) == 0xC2 &&
+                         uchar(micro[1]) == 0xB5);
+}
+FMT_END_DETAIL_NAMESPACE
+
+/**
+  An implementation of ``std::basic_string_view`` for pre-C++17. It provides a
+  subset of the API. ``fmt::basic_string_view`` is used for format strings even
+  if ``std::string_view`` is available to prevent issues when a library is
+  compiled with a different ``-std`` option than the client code (which is not
+  recommended).
+ */
+template <typename Char> class basic_string_view {
+ private:
+  const Char* data_;
+  size_t size_;
+
+ public:
+  using value_type = Char;
+  using iterator = const Char*;
+
+  constexpr basic_string_view() noexcept : data_(nullptr), size_(0) {}
+
+  /** Constructs a string reference object from a C string and a size. */
+  constexpr basic_string_view(const Char* s, size_t count) noexcept
+      : data_(s), size_(count) {}
+
+  /**
+    \rst
+    Constructs a string reference object from a C string computing
+    the size with ``std::char_traits<Char>::length``.
+    \endrst
+   */
+  FMT_CONSTEXPR_CHAR_TRAITS
+  FMT_INLINE
+  basic_string_view(const Char* s)
+      : data_(s),
+        size_(detail::const_check(std::is_same<Char, char>::value &&
+                                  !detail::is_constant_evaluated(true))
+                  ? std::strlen(reinterpret_cast<const char*>(s))
+                  : std::char_traits<Char>::length(s)) {}
+
+  /** Constructs a string reference from a ``std::basic_string`` object. */
+  template <typename Traits, typename Alloc>
+  FMT_CONSTEXPR basic_string_view(
+      const std::basic_string<Char, Traits, Alloc>& s) noexcept
+      : data_(s.data()), size_(s.size()) {}
+
+  template <typename S, FMT_ENABLE_IF(std::is_same<
+                                      S, detail::std_string_view<Char>>::value)>
+  FMT_CONSTEXPR basic_string_view(S s) noexcept
+      : data_(s.data()), size_(s.size()) {}
+
+  /** Returns a pointer to the string data. */
+  constexpr auto data() const noexcept -> const Char* { return data_; }
+
+  /** Returns the string size. */
+  constexpr auto size() const noexcept -> size_t { return size_; }
+
+  constexpr auto begin() const noexcept -> iterator { return data_; }
+  constexpr auto end() const noexcept -> iterator { return data_ + size_; }
+
+  constexpr auto operator[](size_t pos) const noexcept -> const Char& {
+    return data_[pos];
+  }
+
+  FMT_CONSTEXPR void remove_prefix(size_t n) noexcept {
+    data_ += n;
+    size_ -= n;
+  }
+
+  // Lexicographically compare this string reference to other.
+  FMT_CONSTEXPR_CHAR_TRAITS auto compare(basic_string_view other) const -> int {
+    size_t str_size = size_ < other.size_ ? size_ : other.size_;
+    int result = std::char_traits<Char>::compare(data_, other.data_, str_size);
+    if (result == 0)
+      result = size_ == other.size_ ? 0 : (size_ < other.size_ ? -1 : 1);
+    return result;
+  }
+
+  FMT_CONSTEXPR_CHAR_TRAITS friend auto operator==(basic_string_view lhs,
+                                                   basic_string_view rhs)
+      -> bool {
+    return lhs.compare(rhs) == 0;
+  }
+  friend auto operator!=(basic_string_view lhs, basic_string_view rhs) -> bool {
+    return lhs.compare(rhs) != 0;
+  }
+  friend auto operator<(basic_string_view lhs, basic_string_view rhs) -> bool {
+    return lhs.compare(rhs) < 0;
+  }
+  friend auto operator<=(basic_string_view lhs, basic_string_view rhs) -> bool {
+    return lhs.compare(rhs) <= 0;
+  }
+  friend auto operator>(basic_string_view lhs, basic_string_view rhs) -> bool {
+    return lhs.compare(rhs) > 0;
+  }
+  friend auto operator>=(basic_string_view lhs, basic_string_view rhs) -> bool {
+    return lhs.compare(rhs) >= 0;
+  }
+};
+
+using string_view = basic_string_view<char>;
+
+/** Specifies if ``T`` is a character type. Can be specialized by users. */
+template <typename T> struct is_char : std::false_type {};
+template <> struct is_char<char> : std::true_type {};
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+// A base class for compile-time strings.
+struct compile_string {};
+
+template <typename S>
+struct is_compile_string : std::is_base_of<compile_string, S> {};
+
+// Returns a string view of `s`.
+template <typename Char, FMT_ENABLE_IF(is_char<Char>::value)>
+FMT_INLINE auto to_string_view(const Char* s) -> basic_string_view<Char> {
+  return s;
+}
+template <typename Char, typename Traits, typename Alloc>
+inline auto to_string_view(const std::basic_string<Char, Traits, Alloc>& s)
+    -> basic_string_view<Char> {
+  return s;
+}
+template <typename Char>
+constexpr auto to_string_view(basic_string_view<Char> s)
+    -> basic_string_view<Char> {
+  return s;
+}
+template <typename Char,
+          FMT_ENABLE_IF(!std::is_empty<std_string_view<Char>>::value)>
+inline auto to_string_view(std_string_view<Char> s) -> basic_string_view<Char> {
+  return s;
+}
+template <typename S, FMT_ENABLE_IF(is_compile_string<S>::value)>
+constexpr auto to_string_view(const S& s)
+    -> basic_string_view<typename S::char_type> {
+  return basic_string_view<typename S::char_type>(s);
+}
+void to_string_view(...);
+
+// Specifies whether S is a string type convertible to fmt::basic_string_view.
+// It should be a constexpr function but MSVC 2017 fails to compile it in
+// enable_if and MSVC 2015 fails to compile it as an alias template.
+// ADL invocation of to_string_view is DEPRECATED!
+template <typename S>
+struct is_string : std::is_class<decltype(to_string_view(std::declval<S>()))> {
+};
+
+template <typename S, typename = void> struct char_t_impl {};
+template <typename S> struct char_t_impl<S, enable_if_t<is_string<S>::value>> {
+  using result = decltype(to_string_view(std::declval<S>()));
+  using type = typename result::value_type;
+};
+
+enum class type {
+  none_type,
+  // Integer types should go first,
+  int_type,
+  uint_type,
+  long_long_type,
+  ulong_long_type,
+  int128_type,
+  uint128_type,
+  bool_type,
+  char_type,
+  last_integer_type = char_type,
+  // followed by floating-point types.
+  float_type,
+  double_type,
+  long_double_type,
+  last_numeric_type = long_double_type,
+  cstring_type,
+  string_type,
+  pointer_type,
+  custom_type
+};
+
+// Maps core type T to the corresponding type enum constant.
+template <typename T, typename Char>
+struct type_constant : std::integral_constant<type, type::custom_type> {};
+
+#define FMT_TYPE_CONSTANT(Type, constant) \
+  template <typename Char>                \
+  struct type_constant<Type, Char>        \
+      : std::integral_constant<type, type::constant> {}
+
+FMT_TYPE_CONSTANT(int, int_type);
+FMT_TYPE_CONSTANT(unsigned, uint_type);
+FMT_TYPE_CONSTANT(long long, long_long_type);
+FMT_TYPE_CONSTANT(unsigned long long, ulong_long_type);
+FMT_TYPE_CONSTANT(int128_opt, int128_type);
+FMT_TYPE_CONSTANT(uint128_opt, uint128_type);
+FMT_TYPE_CONSTANT(bool, bool_type);
+FMT_TYPE_CONSTANT(Char, char_type);
+FMT_TYPE_CONSTANT(float, float_type);
+FMT_TYPE_CONSTANT(double, double_type);
+FMT_TYPE_CONSTANT(long double, long_double_type);
+FMT_TYPE_CONSTANT(const Char*, cstring_type);
+FMT_TYPE_CONSTANT(basic_string_view<Char>, string_type);
+FMT_TYPE_CONSTANT(const void*, pointer_type);
+
+constexpr bool is_integral_type(type t) {
+  return t > type::none_type && t <= type::last_integer_type;
+}
+
+constexpr bool is_arithmetic_type(type t) {
+  return t > type::none_type && t <= type::last_numeric_type;
+}
+
+FMT_NORETURN FMT_API void throw_format_error(const char* message);
+
+struct error_handler {
+  constexpr error_handler() = default;
+  constexpr error_handler(const error_handler&) = default;
+
+  // This function is intentionally not constexpr to give a compile-time error.
+  FMT_NORETURN void on_error(const char* message) {
+    throw_format_error(message);
+  }
+};
+FMT_END_DETAIL_NAMESPACE
+
+/** String's character type. */
+template <typename S> using char_t = typename detail::char_t_impl<S>::type;
+
+/**
+  \rst
+  Parsing context consisting of a format string range being parsed and an
+  argument counter for automatic indexing.
+  You can use the ``format_parse_context`` type alias for ``char`` instead.
+  \endrst
+ */
+template <typename Char, typename ErrorHandler = detail::error_handler>
+class basic_format_parse_context : private ErrorHandler {
+ private:
+  basic_string_view<Char> format_str_;
+  int next_arg_id_;
+
+  FMT_CONSTEXPR void do_check_arg_id(int id);
+
+ public:
+  using char_type = Char;
+  using iterator = typename basic_string_view<Char>::iterator;
+
+  explicit constexpr basic_format_parse_context(
+      basic_string_view<Char> format_str, ErrorHandler eh = {},
+      int next_arg_id = 0)
+      : ErrorHandler(eh), format_str_(format_str), next_arg_id_(next_arg_id) {}
+
+  /**
+    Returns an iterator to the beginning of the format string range being
+    parsed.
+   */
+  constexpr auto begin() const noexcept -> iterator {
+    return format_str_.begin();
+  }
+
+  /**
+    Returns an iterator past the end of the format string range being parsed.
+   */
+  constexpr auto end() const noexcept -> iterator { return format_str_.end(); }
+
+  /** Advances the begin iterator to ``it``. */
+  FMT_CONSTEXPR void advance_to(iterator it) {
+    format_str_.remove_prefix(detail::to_unsigned(it - begin()));
+  }
+
+  /**
+    Reports an error if using the manual argument indexing; otherwise returns
+    the next argument index and switches to the automatic indexing.
+   */
+  FMT_CONSTEXPR auto next_arg_id() -> int {
+    if (next_arg_id_ < 0) {
+      on_error("cannot switch from manual to automatic argument indexing");
+      return 0;
+    }
+    int id = next_arg_id_++;
+    do_check_arg_id(id);
+    return id;
+  }
+
+  /**
+    Reports an error if using the automatic argument indexing; otherwise
+    switches to the manual indexing.
+   */
+  FMT_CONSTEXPR void check_arg_id(int id) {
+    if (next_arg_id_ > 0) {
+      on_error("cannot switch from automatic to manual argument indexing");
+      return;
+    }
+    next_arg_id_ = -1;
+    do_check_arg_id(id);
+  }
+  FMT_CONSTEXPR void check_arg_id(basic_string_view<Char>) {}
+  FMT_CONSTEXPR void check_dynamic_spec(int arg_id);
+
+  FMT_CONSTEXPR void on_error(const char* message) {
+    ErrorHandler::on_error(message);
+  }
+
+  constexpr auto error_handler() const -> ErrorHandler { return *this; }
+};
+
+using format_parse_context = basic_format_parse_context<char>;
+
+FMT_BEGIN_DETAIL_NAMESPACE
+// A parse context with extra data used only in compile-time checks.
+template <typename Char, typename ErrorHandler = detail::error_handler>
+class compile_parse_context
+    : public basic_format_parse_context<Char, ErrorHandler> {
+ private:
+  int num_args_;
+  const type* types_;
+  using base = basic_format_parse_context<Char, ErrorHandler>;
+
+ public:
+  explicit FMT_CONSTEXPR compile_parse_context(
+      basic_string_view<Char> format_str, int num_args, const type* types,
+      ErrorHandler eh = {}, int next_arg_id = 0)
+      : base(format_str, eh, next_arg_id), num_args_(num_args), types_(types) {}
+
+  constexpr auto num_args() const -> int { return num_args_; }
+  constexpr auto arg_type(int id) const -> type { return types_[id]; }
+
+  FMT_CONSTEXPR auto next_arg_id() -> int {
+    int id = base::next_arg_id();
+    if (id >= num_args_) this->on_error("argument not found");
+    return id;
+  }
+
+  FMT_CONSTEXPR void check_arg_id(int id) {
+    base::check_arg_id(id);
+    if (id >= num_args_) this->on_error("argument not found");
+  }
+  using base::check_arg_id;
+
+  FMT_CONSTEXPR void check_dynamic_spec(int arg_id) {
+    if (arg_id < num_args_ && types_ && !is_integral_type(types_[arg_id]))
+      this->on_error("width/precision is not integer");
+  }
+};
+FMT_END_DETAIL_NAMESPACE
+
+template <typename Char, typename ErrorHandler>
+FMT_CONSTEXPR void
+basic_format_parse_context<Char, ErrorHandler>::do_check_arg_id(int id) {
+  // Argument id is only checked at compile-time during parsing because
+  // formatting has its own validation.
+  if (detail::is_constant_evaluated() && FMT_GCC_VERSION >= 1200) {
+    using context = detail::compile_parse_context<Char, ErrorHandler>;
+    if (id >= static_cast<context*>(this)->num_args())
+      on_error("argument not found");
+  }
+}
+
+template <typename Char, typename ErrorHandler>
+FMT_CONSTEXPR void
+basic_format_parse_context<Char, ErrorHandler>::check_dynamic_spec(int arg_id) {
+  if (detail::is_constant_evaluated()) {
+    using context = detail::compile_parse_context<Char, ErrorHandler>;
+    static_cast<context*>(this)->check_dynamic_spec(arg_id);
+  }
+}
+
+template <typename Context> class basic_format_arg;
+template <typename Context> class basic_format_args;
+template <typename Context> class dynamic_format_arg_store;
+
+// A formatter for objects of type T.
+template <typename T, typename Char = char, typename Enable = void>
+struct formatter {
+  // A deleted default constructor indicates a disabled formatter.
+  formatter() = delete;
+};
+
+// Specifies if T has an enabled formatter specialization. A type can be
+// formattable even if it doesn't have a formatter e.g. via a conversion.
+template <typename T, typename Context>
+using has_formatter =
+    std::is_constructible<typename Context::template formatter_type<T>>;
+
+// Checks whether T is a container with contiguous storage.
+template <typename T> struct is_contiguous : std::false_type {};
+template <typename Char>
+struct is_contiguous<std::basic_string<Char>> : std::true_type {};
+
+class appender;
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+template <typename Context, typename T>
+constexpr auto has_const_formatter_impl(T*)
+    -> decltype(typename Context::template formatter_type<T>().format(
+                    std::declval<const T&>(), std::declval<Context&>()),
+                true) {
+  return true;
+}
+template <typename Context>
+constexpr auto has_const_formatter_impl(...) -> bool {
+  return false;
+}
+template <typename T, typename Context>
+constexpr auto has_const_formatter() -> bool {
+  return has_const_formatter_impl<Context>(static_cast<T*>(nullptr));
+}
+
+// Extracts a reference to the container from back_insert_iterator.
+template <typename Container>
+inline auto get_container(std::back_insert_iterator<Container> it)
+    -> Container& {
+  using base = std::back_insert_iterator<Container>;
+  struct accessor : base {
+    accessor(base b) : base(b) {}
+    using base::container;
+  };
+  return *accessor(it).container;
+}
+
+template <typename Char, typename InputIt, typename OutputIt>
+FMT_CONSTEXPR auto copy_str(InputIt begin, InputIt end, OutputIt out)
+    -> OutputIt {
+  while (begin != end) *out++ = static_cast<Char>(*begin++);
+  return out;
+}
+
+template <typename Char, typename T, typename U,
+          FMT_ENABLE_IF(
+              std::is_same<remove_const_t<T>, U>::value&& is_char<U>::value)>
+FMT_CONSTEXPR auto copy_str(T* begin, T* end, U* out) -> U* {
+  if (is_constant_evaluated()) return copy_str<Char, T*, U*>(begin, end, out);
+  auto size = to_unsigned(end - begin);
+  memcpy(out, begin, size * sizeof(U));
+  return out + size;
+}
+
+/**
+  \rst
+  A contiguous memory buffer with an optional growing ability. It is an internal
+  class and shouldn't be used directly, only via `~fmt::basic_memory_buffer`.
+  \endrst
+ */
+template <typename T> class buffer {
+ private:
+  T* ptr_;
+  size_t size_;
+  size_t capacity_;
+
+ protected:
+  // Don't initialize ptr_ since it is not accessed to save a few cycles.
+  FMT_MSC_WARNING(suppress : 26495)
+  buffer(size_t sz) noexcept : size_(sz), capacity_(sz) {}
+
+  FMT_CONSTEXPR20 buffer(T* p = nullptr, size_t sz = 0, size_t cap = 0) noexcept
+      : ptr_(p), size_(sz), capacity_(cap) {}
+
+  FMT_CONSTEXPR20 ~buffer() = default;
+  buffer(buffer&&) = default;
+
+  /** Sets the buffer data and capacity. */
+  FMT_CONSTEXPR void set(T* buf_data, size_t buf_capacity) noexcept {
+    ptr_ = buf_data;
+    capacity_ = buf_capacity;
+  }
+
+  /** Increases the buffer capacity to hold at least *capacity* elements. */
+  virtual FMT_CONSTEXPR20 void grow(size_t capacity) = 0;
+
+ public:
+  using value_type = T;
+  using const_reference = const T&;
+
+  buffer(const buffer&) = delete;
+  void operator=(const buffer&) = delete;
+
+  auto begin() noexcept -> T* { return ptr_; }
+  auto end() noexcept -> T* { return ptr_ + size_; }
+
+  auto begin() const noexcept -> const T* { return ptr_; }
+  auto end() const noexcept -> const T* { return ptr_ + size_; }
+
+  /** Returns the size of this buffer. */
+  constexpr auto size() const noexcept -> size_t { return size_; }
+
+  /** Returns the capacity of this buffer. */
+  constexpr auto capacity() const noexcept -> size_t { return capacity_; }
+
+  /** Returns a pointer to the buffer data. */
+  FMT_CONSTEXPR auto data() noexcept -> T* { return ptr_; }
+
+  /** Returns a pointer to the buffer data. */
+  FMT_CONSTEXPR auto data() const noexcept -> const T* { return ptr_; }
+
+  /** Clears this buffer. */
+  void clear() { size_ = 0; }
+
+  // Tries resizing the buffer to contain *count* elements. If T is a POD type
+  // the new elements may not be initialized.
+  FMT_CONSTEXPR20 void try_resize(size_t count) {
+    try_reserve(count);
+    size_ = count <= capacity_ ? count : capacity_;
+  }
+
+  // Tries increasing the buffer capacity to *new_capacity*. It can increase the
+  // capacity by a smaller amount than requested but guarantees there is space
+  // for at least one additional element either by increasing the capacity or by
+  // flushing the buffer if it is full.
+  FMT_CONSTEXPR20 void try_reserve(size_t new_capacity) {
+    if (new_capacity > capacity_) grow(new_capacity);
+  }
+
+  FMT_CONSTEXPR20 void push_back(const T& value) {
+    try_reserve(size_ + 1);
+    ptr_[size_++] = value;
+  }
+
+  /** Appends data to the end of the buffer. */
+  template <typename U> void append(const U* begin, const U* end);
+
+  template <typename Idx> FMT_CONSTEXPR auto operator[](Idx index) -> T& {
+    return ptr_[index];
+  }
+  template <typename Idx>
+  FMT_CONSTEXPR auto operator[](Idx index) const -> const T& {
+    return ptr_[index];
+  }
+};
+
+struct buffer_traits {
+  explicit buffer_traits(size_t) {}
+  auto count() const -> size_t { return 0; }
+  auto limit(size_t size) -> size_t { return size; }
+};
+
+class fixed_buffer_traits {
+ private:
+  size_t count_ = 0;
+  size_t limit_;
+
+ public:
+  explicit fixed_buffer_traits(size_t limit) : limit_(limit) {}
+  auto count() const -> size_t { return count_; }
+  auto limit(size_t size) -> size_t {
+    size_t n = limit_ > count_ ? limit_ - count_ : 0;
+    count_ += size;
+    return size < n ? size : n;
+  }
+};
+
+// A buffer that writes to an output iterator when flushed.
+template <typename OutputIt, typename T, typename Traits = buffer_traits>
+class iterator_buffer final : public Traits, public buffer<T> {
+ private:
+  OutputIt out_;
+  enum { buffer_size = 256 };
+  T data_[buffer_size];
+
+ protected:
+  FMT_CONSTEXPR20 void grow(size_t) override {
+    if (this->size() == buffer_size) flush();
+  }
+
+  void flush() {
+    auto size = this->size();
+    this->clear();
+    out_ = copy_str<T>(data_, data_ + this->limit(size), out_);
+  }
+
+ public:
+  explicit iterator_buffer(OutputIt out, size_t n = buffer_size)
+      : Traits(n), buffer<T>(data_, 0, buffer_size), out_(out) {}
+  iterator_buffer(iterator_buffer&& other)
+      : Traits(other), buffer<T>(data_, 0, buffer_size), out_(other.out_) {}
+  ~iterator_buffer() { flush(); }
+
+  auto out() -> OutputIt {
+    flush();
+    return out_;
+  }
+  auto count() const -> size_t { return Traits::count() + this->size(); }
+};
+
+template <typename T>
+class iterator_buffer<T*, T, fixed_buffer_traits> final
+    : public fixed_buffer_traits,
+      public buffer<T> {
+ private:
+  T* out_;
+  enum { buffer_size = 256 };
+  T data_[buffer_size];
+
+ protected:
+  FMT_CONSTEXPR20 void grow(size_t) override {
+    if (this->size() == this->capacity()) flush();
+  }
+
+  void flush() {
+    size_t n = this->limit(this->size());
+    if (this->data() == out_) {
+      out_ += n;
+      this->set(data_, buffer_size);
+    }
+    this->clear();
+  }
+
+ public:
+  explicit iterator_buffer(T* out, size_t n = buffer_size)
+      : fixed_buffer_traits(n), buffer<T>(out, 0, n), out_(out) {}
+  iterator_buffer(iterator_buffer&& other)
+      : fixed_buffer_traits(other),
+        buffer<T>(std::move(other)),
+        out_(other.out_) {
+    if (this->data() != out_) {
+      this->set(data_, buffer_size);
+      this->clear();
+    }
+  }
+  ~iterator_buffer() { flush(); }
+
+  auto out() -> T* {
+    flush();
+    return out_;
+  }
+  auto count() const -> size_t {
+    return fixed_buffer_traits::count() + this->size();
+  }
+};
+
+template <typename T> class iterator_buffer<T*, T> final : public buffer<T> {
+ protected:
+  FMT_CONSTEXPR20 void grow(size_t) override {}
+
+ public:
+  explicit iterator_buffer(T* out, size_t = 0) : buffer<T>(out, 0, ~size_t()) {}
+
+  auto out() -> T* { return &*this->end(); }
+};
+
+// A buffer that writes to a container with the contiguous storage.
+template <typename Container>
+class iterator_buffer<std::back_insert_iterator<Container>,
+                      enable_if_t<is_contiguous<Container>::value,
+                                  typename Container::value_type>>
+    final : public buffer<typename Container::value_type> {
+ private:
+  Container& container_;
+
+ protected:
+  FMT_CONSTEXPR20 void grow(size_t capacity) override {
+    container_.resize(capacity);
+    this->set(&container_[0], capacity);
+  }
+
+ public:
+  explicit iterator_buffer(Container& c)
+      : buffer<typename Container::value_type>(c.size()), container_(c) {}
+  explicit iterator_buffer(std::back_insert_iterator<Container> out, size_t = 0)
+      : iterator_buffer(get_container(out)) {}
+
+  auto out() -> std::back_insert_iterator<Container> {
+    return std::back_inserter(container_);
+  }
+};
+
+// A buffer that counts the number of code units written discarding the output.
+template <typename T = char> class counting_buffer final : public buffer<T> {
+ private:
+  enum { buffer_size = 256 };
+  T data_[buffer_size];
+  size_t count_ = 0;
+
+ protected:
+  FMT_CONSTEXPR20 void grow(size_t) override {
+    if (this->size() != buffer_size) return;
+    count_ += this->size();
+    this->clear();
+  }
+
+ public:
+  counting_buffer() : buffer<T>(data_, 0, buffer_size) {}
+
+  auto count() -> size_t { return count_ + this->size(); }
+};
+
+template <typename T>
+using buffer_appender = conditional_t<std::is_same<T, char>::value, appender,
+                                      std::back_insert_iterator<buffer<T>>>;
+
+// Maps an output iterator to a buffer.
+template <typename T, typename OutputIt>
+auto get_buffer(OutputIt out) -> iterator_buffer<OutputIt, T> {
+  return iterator_buffer<OutputIt, T>(out);
+}
+
+template <typename Buffer>
+auto get_iterator(Buffer& buf) -> decltype(buf.out()) {
+  return buf.out();
+}
+template <typename T> auto get_iterator(buffer<T>& buf) -> buffer_appender<T> {
+  return buffer_appender<T>(buf);
+}
+
+template <typename T, typename Char = char, typename Enable = void>
+struct fallback_formatter {
+  fallback_formatter() = delete;
+};
+
+// Specifies if T has an enabled fallback_formatter specialization.
+template <typename T, typename Char>
+using has_fallback_formatter =
+#ifdef FMT_DEPRECATED_OSTREAM
+    std::is_constructible<fallback_formatter<T, Char>>;
+#else
+    std::false_type;
+#endif
+
+struct view {};
+
+template <typename Char, typename T> struct named_arg : view {
+  const Char* name;
+  const T& value;
+  named_arg(const Char* n, const T& v) : name(n), value(v) {}
+};
+
+template <typename Char> struct named_arg_info {
+  const Char* name;
+  int id;
+};
+
+template <typename T, typename Char, size_t NUM_ARGS, size_t NUM_NAMED_ARGS>
+struct arg_data {
+  // args_[0].named_args points to named_args_ to avoid bloating format_args.
+  // +1 to workaround a bug in gcc 7.5 that causes duplicated-branches warning.
+  T args_[1 + (NUM_ARGS != 0 ? NUM_ARGS : +1)];
+  named_arg_info<Char> named_args_[NUM_NAMED_ARGS];
+
+  template <typename... U>
+  arg_data(const U&... init) : args_{T(named_args_, NUM_NAMED_ARGS), init...} {}
+  arg_data(const arg_data& other) = delete;
+  auto args() const -> const T* { return args_ + 1; }
+  auto named_args() -> named_arg_info<Char>* { return named_args_; }
+};
+
+template <typename T, typename Char, size_t NUM_ARGS>
+struct arg_data<T, Char, NUM_ARGS, 0> {
+  // +1 to workaround a bug in gcc 7.5 that causes duplicated-branches warning.
+  T args_[NUM_ARGS != 0 ? NUM_ARGS : +1];
+
+  template <typename... U>
+  FMT_CONSTEXPR FMT_INLINE arg_data(const U&... init) : args_{init...} {}
+  FMT_CONSTEXPR FMT_INLINE auto args() const -> const T* { return args_; }
+  FMT_CONSTEXPR FMT_INLINE auto named_args() -> std::nullptr_t {
+    return nullptr;
+  }
+};
+
+template <typename Char>
+inline void init_named_args(named_arg_info<Char>*, int, int) {}
+
+template <typename T> struct is_named_arg : std::false_type {};
+template <typename T> struct is_statically_named_arg : std::false_type {};
+
+template <typename T, typename Char>
+struct is_named_arg<named_arg<Char, T>> : std::true_type {};
+
+template <typename Char, typename T, typename... Tail,
+          FMT_ENABLE_IF(!is_named_arg<T>::value)>
+void init_named_args(named_arg_info<Char>* named_args, int arg_count,
+                     int named_arg_count, const T&, const Tail&... args) {
+  init_named_args(named_args, arg_count + 1, named_arg_count, args...);
+}
+
+template <typename Char, typename T, typename... Tail,
+          FMT_ENABLE_IF(is_named_arg<T>::value)>
+void init_named_args(named_arg_info<Char>* named_args, int arg_count,
+                     int named_arg_count, const T& arg, const Tail&... args) {
+  named_args[named_arg_count++] = {arg.name, arg_count};
+  init_named_args(named_args, arg_count + 1, named_arg_count, args...);
+}
+
+template <typename... Args>
+FMT_CONSTEXPR FMT_INLINE void init_named_args(std::nullptr_t, int, int,
+                                              const Args&...) {}
+
+template <bool B = false> constexpr auto count() -> size_t { return B ? 1 : 0; }
+template <bool B1, bool B2, bool... Tail> constexpr auto count() -> size_t {
+  return (B1 ? 1 : 0) + count<B2, Tail...>();
+}
+
+template <typename... Args> constexpr auto count_named_args() -> size_t {
+  return count<is_named_arg<Args>::value...>();
+}
+
+template <typename... Args>
+constexpr auto count_statically_named_args() -> size_t {
+  return count<is_statically_named_arg<Args>::value...>();
+}
+
+struct unformattable {};
+struct unformattable_char : unformattable {};
+struct unformattable_const : unformattable {};
+struct unformattable_pointer : unformattable {};
+
+template <typename Char> struct string_value {
+  const Char* data;
+  size_t size;
+};
+
+template <typename Char> struct named_arg_value {
+  const named_arg_info<Char>* data;
+  size_t size;
+};
+
+template <typename Context> struct custom_value {
+  using parse_context = typename Context::parse_context_type;
+  void* value;
+  void (*format)(void* arg, parse_context& parse_ctx, Context& ctx);
+};
+
+// A formatting argument value.
+template <typename Context> class value {
+ public:
+  using char_type = typename Context::char_type;
+
+  union {
+    monostate no_value;
+    int int_value;
+    unsigned uint_value;
+    long long long_long_value;
+    unsigned long long ulong_long_value;
+    int128_opt int128_value;
+    uint128_opt uint128_value;
+    bool bool_value;
+    char_type char_value;
+    float float_value;
+    double double_value;
+    long double long_double_value;
+    const void* pointer;
+    string_value<char_type> string;
+    custom_value<Context> custom;
+    named_arg_value<char_type> named_args;
+  };
+
+  constexpr FMT_INLINE value() : no_value() {}
+  constexpr FMT_INLINE value(int val) : int_value(val) {}
+  constexpr FMT_INLINE value(unsigned val) : uint_value(val) {}
+  constexpr FMT_INLINE value(long long val) : long_long_value(val) {}
+  constexpr FMT_INLINE value(unsigned long long val) : ulong_long_value(val) {}
+  FMT_INLINE value(int128_opt val) : int128_value(val) {}
+  FMT_INLINE value(uint128_opt val) : uint128_value(val) {}
+  constexpr FMT_INLINE value(float val) : float_value(val) {}
+  constexpr FMT_INLINE value(double val) : double_value(val) {}
+  FMT_INLINE value(long double val) : long_double_value(val) {}
+  constexpr FMT_INLINE value(bool val) : bool_value(val) {}
+  constexpr FMT_INLINE value(char_type val) : char_value(val) {}
+  FMT_CONSTEXPR FMT_INLINE value(const char_type* val) {
+    string.data = val;
+    if (is_constant_evaluated()) string.size = {};
+  }
+  FMT_CONSTEXPR FMT_INLINE value(basic_string_view<char_type> val) {
+    string.data = val.data();
+    string.size = val.size();
+  }
+  FMT_INLINE value(const void* val) : pointer(val) {}
+  FMT_INLINE value(const named_arg_info<char_type>* args, size_t size)
+      : named_args{args, size} {}
+
+  template <typename T> FMT_CONSTEXPR FMT_INLINE value(T& val) {
+    using value_type = remove_cvref_t<T>;
+    custom.value = const_cast<value_type*>(&val);
+    // Get the formatter type through the context to allow different contexts
+    // have different extension points, e.g. `formatter<T>` for `format` and
+    // `printf_formatter<T>` for `printf`.
+    custom.format = format_custom_arg<
+        value_type,
+        conditional_t<has_formatter<value_type, Context>::value,
+                      typename Context::template formatter_type<value_type>,
+                      fallback_formatter<value_type, char_type>>>;
+  }
+  value(unformattable);
+  value(unformattable_char);
+  value(unformattable_const);
+  value(unformattable_pointer);
+
+ private:
+  // Formats an argument of a custom type, such as a user-defined class.
+  template <typename T, typename Formatter>
+  static void format_custom_arg(void* arg,
+                                typename Context::parse_context_type& parse_ctx,
+                                Context& ctx) {
+    auto f = Formatter();
+    parse_ctx.advance_to(f.parse(parse_ctx));
+    using qualified_type =
+        conditional_t<has_const_formatter<T, Context>(), const T, T>;
+    ctx.advance_to(f.format(*static_cast<qualified_type*>(arg), ctx));
+  }
+};
+
+template <typename Context, typename T>
+FMT_CONSTEXPR auto make_arg(T&& value) -> basic_format_arg<Context>;
+
+// To minimize the number of types we need to deal with, long is translated
+// either to int or to long long depending on its size.
+enum { long_short = sizeof(long) == sizeof(int) };
+using long_type = conditional_t<long_short, int, long long>;
+using ulong_type = conditional_t<long_short, unsigned, unsigned long long>;
+
+#ifdef __cpp_lib_byte
+inline auto format_as(std::byte b) -> unsigned char {
+  return static_cast<unsigned char>(b);
+}
+#endif
+
+template <typename T> struct has_format_as {
+  template <typename U, typename V = decltype(format_as(U())),
+            FMT_ENABLE_IF(std::is_enum<U>::value&& std::is_integral<V>::value)>
+  static auto check(U*) -> std::true_type;
+  static auto check(...) -> std::false_type;
+
+  enum { value = decltype(check(static_cast<T*>(nullptr)))::value };
+};
+
+// Maps formatting arguments to core types.
+// arg_mapper reports errors by returning unformattable instead of using
+// static_assert because it's used in the is_formattable trait.
+template <typename Context> struct arg_mapper {
+  using char_type = typename Context::char_type;
+
+  FMT_CONSTEXPR FMT_INLINE auto map(signed char val) -> int { return val; }
+  FMT_CONSTEXPR FMT_INLINE auto map(unsigned char val) -> unsigned {
+    return val;
+  }
+  FMT_CONSTEXPR FMT_INLINE auto map(short val) -> int { return val; }
+  FMT_CONSTEXPR FMT_INLINE auto map(unsigned short val) -> unsigned {
+    return val;
+  }
+  FMT_CONSTEXPR FMT_INLINE auto map(int val) -> int { return val; }
+  FMT_CONSTEXPR FMT_INLINE auto map(unsigned val) -> unsigned { return val; }
+  FMT_CONSTEXPR FMT_INLINE auto map(long val) -> long_type { return val; }
+  FMT_CONSTEXPR FMT_INLINE auto map(unsigned long val) -> ulong_type {
+    return val;
+  }
+  FMT_CONSTEXPR FMT_INLINE auto map(long long val) -> long long { return val; }
+  FMT_CONSTEXPR FMT_INLINE auto map(unsigned long long val)
+      -> unsigned long long {
+    return val;
+  }
+  FMT_CONSTEXPR FMT_INLINE auto map(int128_opt val) -> int128_opt {
+    return val;
+  }
+  FMT_CONSTEXPR FMT_INLINE auto map(uint128_opt val) -> uint128_opt {
+    return val;
+  }
+  FMT_CONSTEXPR FMT_INLINE auto map(bool val) -> bool { return val; }
+
+  template <typename T, FMT_ENABLE_IF(std::is_same<T, char>::value ||
+                                      std::is_same<T, char_type>::value)>
+  FMT_CONSTEXPR FMT_INLINE auto map(T val) -> char_type {
+    return val;
+  }
+  template <typename T, enable_if_t<(std::is_same<T, wchar_t>::value ||
+#ifdef __cpp_char8_t
+                                     std::is_same<T, char8_t>::value ||
+#endif
+                                     std::is_same<T, char16_t>::value ||
+                                     std::is_same<T, char32_t>::value) &&
+                                        !std::is_same<T, char_type>::value,
+                                    int> = 0>
+  FMT_CONSTEXPR FMT_INLINE auto map(T) -> unformattable_char {
+    return {};
+  }
+
+  FMT_CONSTEXPR FMT_INLINE auto map(float val) -> float { return val; }
+  FMT_CONSTEXPR FMT_INLINE auto map(double val) -> double { return val; }
+  FMT_CONSTEXPR FMT_INLINE auto map(long double val) -> long double {
+    return val;
+  }
+
+  FMT_CONSTEXPR FMT_INLINE auto map(char_type* val) -> const char_type* {
+    return val;
+  }
+  FMT_CONSTEXPR FMT_INLINE auto map(const char_type* val) -> const char_type* {
+    return val;
+  }
+  template <typename T,
+            FMT_ENABLE_IF(is_string<T>::value && !std::is_pointer<T>::value &&
+                          std::is_same<char_type, char_t<T>>::value)>
+  FMT_CONSTEXPR FMT_INLINE auto map(const T& val)
+      -> basic_string_view<char_type> {
+    return to_string_view(val);
+  }
+  template <typename T,
+            FMT_ENABLE_IF(is_string<T>::value && !std::is_pointer<T>::value &&
+                          !std::is_same<char_type, char_t<T>>::value)>
+  FMT_CONSTEXPR FMT_INLINE auto map(const T&) -> unformattable_char {
+    return {};
+  }
+  template <typename T,
+            FMT_ENABLE_IF(
+                std::is_convertible<T, basic_string_view<char_type>>::value &&
+                !is_string<T>::value && !has_formatter<T, Context>::value &&
+                !has_fallback_formatter<T, char_type>::value)>
+  FMT_CONSTEXPR FMT_INLINE auto map(const T& val)
+      -> basic_string_view<char_type> {
+    return basic_string_view<char_type>(val);
+  }
+  template <typename T,
+            FMT_ENABLE_IF(
+                std::is_convertible<T, std_string_view<char_type>>::value &&
+                !std::is_convertible<T, basic_string_view<char_type>>::value &&
+                !is_string<T>::value && !has_formatter<T, Context>::value &&
+                !has_fallback_formatter<T, char_type>::value)>
+  FMT_CONSTEXPR FMT_INLINE auto map(const T& val)
+      -> basic_string_view<char_type> {
+    return std_string_view<char_type>(val);
+  }
+
+  FMT_CONSTEXPR FMT_INLINE auto map(void* val) -> const void* { return val; }
+  FMT_CONSTEXPR FMT_INLINE auto map(const void* val) -> const void* {
+    return val;
+  }
+  FMT_CONSTEXPR FMT_INLINE auto map(std::nullptr_t val) -> const void* {
+    return val;
+  }
+
+  // We use SFINAE instead of a const T* parameter to avoid conflicting with
+  // the C array overload.
+  template <
+      typename T,
+      FMT_ENABLE_IF(
+          std::is_pointer<T>::value || std::is_member_pointer<T>::value ||
+          std::is_function<typename std::remove_pointer<T>::type>::value ||
+          (std::is_convertible<const T&, const void*>::value &&
+           !std::is_convertible<const T&, const char_type*>::value &&
+           !has_formatter<T, Context>::value))>
+  FMT_CONSTEXPR auto map(const T&) -> unformattable_pointer {
+    return {};
+  }
+
+  template <typename T, std::size_t N,
+            FMT_ENABLE_IF(!std::is_same<T, wchar_t>::value)>
+  FMT_CONSTEXPR FMT_INLINE auto map(const T (&values)[N]) -> const T (&)[N] {
+    return values;
+  }
+
+  template <typename T,
+            FMT_ENABLE_IF(
+                std::is_enum<T>::value&& std::is_convertible<T, int>::value &&
+                !has_format_as<T>::value && !has_formatter<T, Context>::value &&
+                !has_fallback_formatter<T, char_type>::value)>
+  FMT_DEPRECATED FMT_CONSTEXPR FMT_INLINE auto map(const T& val)
+      -> decltype(std::declval<arg_mapper>().map(
+          static_cast<underlying_t<T>>(val))) {
+    return map(static_cast<underlying_t<T>>(val));
+  }
+
+  template <typename T, FMT_ENABLE_IF(has_format_as<T>::value &&
+                                      !has_formatter<T, Context>::value)>
+  FMT_CONSTEXPR FMT_INLINE auto map(const T& val)
+      -> decltype(std::declval<arg_mapper>().map(format_as(T()))) {
+    return map(format_as(val));
+  }
+
+  template <typename T, typename U = remove_cvref_t<T>>
+  struct formattable
+      : bool_constant<has_const_formatter<U, Context>() ||
+                      !std::is_const<remove_reference_t<T>>::value ||
+                      has_fallback_formatter<U, char_type>::value> {};
+
+#if (FMT_MSC_VERSION != 0 && FMT_MSC_VERSION < 1910) || \
+    FMT_ICC_VERSION != 0 || defined(__NVCC__)
+  // Workaround a bug in MSVC and Intel (Issue 2746).
+  template <typename T> FMT_CONSTEXPR FMT_INLINE auto do_map(T&& val) -> T& {
+    return val;
+  }
+#else
+  template <typename T, FMT_ENABLE_IF(formattable<T>::value)>
+  FMT_CONSTEXPR FMT_INLINE auto do_map(T&& val) -> T& {
+    return val;
+  }
+  template <typename T, FMT_ENABLE_IF(!formattable<T>::value)>
+  FMT_CONSTEXPR FMT_INLINE auto do_map(T&&) -> unformattable_const {
+    return {};
+  }
+#endif
+
+  template <typename T, typename U = remove_cvref_t<T>,
+            FMT_ENABLE_IF(!is_string<U>::value && !is_char<U>::value &&
+                          !std::is_array<U>::value &&
+                          !std::is_pointer<U>::value &&
+                          !has_format_as<U>::value &&
+                          (has_formatter<U, Context>::value ||
+                           has_fallback_formatter<U, char_type>::value))>
+  FMT_CONSTEXPR FMT_INLINE auto map(T&& val)
+      -> decltype(this->do_map(std::forward<T>(val))) {
+    return do_map(std::forward<T>(val));
+  }
+
+  template <typename T, FMT_ENABLE_IF(is_named_arg<T>::value)>
+  FMT_CONSTEXPR FMT_INLINE auto map(const T& named_arg)
+      -> decltype(std::declval<arg_mapper>().map(named_arg.value)) {
+    return map(named_arg.value);
+  }
+
+  auto map(...) -> unformattable { return {}; }
+};
+
+// A type constant after applying arg_mapper<Context>.
+template <typename T, typename Context>
+using mapped_type_constant =
+    type_constant<decltype(arg_mapper<Context>().map(std::declval<const T&>())),
+                  typename Context::char_type>;
+
+enum { packed_arg_bits = 4 };
+// Maximum number of arguments with packed types.
+enum { max_packed_args = 62 / packed_arg_bits };
+enum : unsigned long long { is_unpacked_bit = 1ULL << 63 };
+enum : unsigned long long { has_named_args_bit = 1ULL << 62 };
+
+FMT_END_DETAIL_NAMESPACE
+
+// An output iterator that appends to a buffer.
+// It is used to reduce symbol sizes for the common case.
+class appender : public std::back_insert_iterator<detail::buffer<char>> {
+  using base = std::back_insert_iterator<detail::buffer<char>>;
+
+  template <typename T>
+  friend auto get_buffer(appender out) -> detail::buffer<char>& {
+    return detail::get_container(out);
+  }
+
+ public:
+  using std::back_insert_iterator<detail::buffer<char>>::back_insert_iterator;
+  appender(base it) noexcept : base(it) {}
+  FMT_UNCHECKED_ITERATOR(appender);
+
+  auto operator++() noexcept -> appender& { return *this; }
+  auto operator++(int) noexcept -> appender { return *this; }
+};
+
+// A formatting argument. It is a trivially copyable/constructible type to
+// allow storage in basic_memory_buffer.
+template <typename Context> class basic_format_arg {
+ private:
+  detail::value<Context> value_;
+  detail::type type_;
+
+  template <typename ContextType, typename T>
+  friend FMT_CONSTEXPR auto detail::make_arg(T&& value)
+      -> basic_format_arg<ContextType>;
+
+  template <typename Visitor, typename Ctx>
+  friend FMT_CONSTEXPR auto visit_format_arg(Visitor&& vis,
+                                             const basic_format_arg<Ctx>& arg)
+      -> decltype(vis(0));
+
+  friend class basic_format_args<Context>;
+  friend class dynamic_format_arg_store<Context>;
+
+  using char_type = typename Context::char_type;
+
+  template <typename T, typename Char, size_t NUM_ARGS, size_t NUM_NAMED_ARGS>
+  friend struct detail::arg_data;
+
+  basic_format_arg(const detail::named_arg_info<char_type>* args, size_t size)
+      : value_(args, size) {}
+
+ public:
+  class handle {
+   public:
+    explicit handle(detail::custom_value<Context> custom) : custom_(custom) {}
+
+    void format(typename Context::parse_context_type& parse_ctx,
+                Context& ctx) const {
+      custom_.format(custom_.value, parse_ctx, ctx);
+    }
+
+   private:
+    detail::custom_value<Context> custom_;
+  };
+
+  constexpr basic_format_arg() : type_(detail::type::none_type) {}
+
+  constexpr explicit operator bool() const noexcept {
+    return type_ != detail::type::none_type;
+  }
+
+  auto type() const -> detail::type { return type_; }
+
+  auto is_integral() const -> bool { return detail::is_integral_type(type_); }
+  auto is_arithmetic() const -> bool {
+    return detail::is_arithmetic_type(type_);
+  }
+};
+
+/**
+  \rst
+  Visits an argument dispatching to the appropriate visit method based on
+  the argument type. For example, if the argument type is ``double`` then
+  ``vis(value)`` will be called with the value of type ``double``.
+  \endrst
+ */
+template <typename Visitor, typename Context>
+FMT_CONSTEXPR FMT_INLINE auto visit_format_arg(
+    Visitor&& vis, const basic_format_arg<Context>& arg) -> decltype(vis(0)) {
+  switch (arg.type_) {
+  case detail::type::none_type:
+    break;
+  case detail::type::int_type:
+    return vis(arg.value_.int_value);
+  case detail::type::uint_type:
+    return vis(arg.value_.uint_value);
+  case detail::type::long_long_type:
+    return vis(arg.value_.long_long_value);
+  case detail::type::ulong_long_type:
+    return vis(arg.value_.ulong_long_value);
+  case detail::type::int128_type:
+    return vis(detail::convert_for_visit(arg.value_.int128_value));
+  case detail::type::uint128_type:
+    return vis(detail::convert_for_visit(arg.value_.uint128_value));
+  case detail::type::bool_type:
+    return vis(arg.value_.bool_value);
+  case detail::type::char_type:
+    return vis(arg.value_.char_value);
+  case detail::type::float_type:
+    return vis(arg.value_.float_value);
+  case detail::type::double_type:
+    return vis(arg.value_.double_value);
+  case detail::type::long_double_type:
+    return vis(arg.value_.long_double_value);
+  case detail::type::cstring_type:
+    return vis(arg.value_.string.data);
+  case detail::type::string_type:
+    using sv = basic_string_view<typename Context::char_type>;
+    return vis(sv(arg.value_.string.data, arg.value_.string.size));
+  case detail::type::pointer_type:
+    return vis(arg.value_.pointer);
+  case detail::type::custom_type:
+    return vis(typename basic_format_arg<Context>::handle(arg.value_.custom));
+  }
+  return vis(monostate());
+}
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+template <typename Char, typename InputIt>
+auto copy_str(InputIt begin, InputIt end, appender out) -> appender {
+  get_container(out).append(begin, end);
+  return out;
+}
+
+template <typename Char, typename R, typename OutputIt>
+FMT_CONSTEXPR auto copy_str(R&& rng, OutputIt out) -> OutputIt {
+  return detail::copy_str<Char>(rng.begin(), rng.end(), out);
+}
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 500
+// A workaround for gcc 4.8 to make void_t work in a SFINAE context.
+template <typename... Ts> struct void_t_impl { using type = void; };
+template <typename... Ts>
+using void_t = typename detail::void_t_impl<Ts...>::type;
+#else
+template <typename...> using void_t = void;
+#endif
+
+template <typename It, typename T, typename Enable = void>
+struct is_output_iterator : std::false_type {};
+
+template <typename It, typename T>
+struct is_output_iterator<
+    It, T,
+    void_t<typename std::iterator_traits<It>::iterator_category,
+           decltype(*std::declval<It>() = std::declval<T>())>>
+    : std::true_type {};
+
+template <typename OutputIt>
+struct is_back_insert_iterator : std::false_type {};
+template <typename Container>
+struct is_back_insert_iterator<std::back_insert_iterator<Container>>
+    : std::true_type {};
+
+template <typename OutputIt>
+struct is_contiguous_back_insert_iterator : std::false_type {};
+template <typename Container>
+struct is_contiguous_back_insert_iterator<std::back_insert_iterator<Container>>
+    : is_contiguous<Container> {};
+template <>
+struct is_contiguous_back_insert_iterator<appender> : std::true_type {};
+
+// A type-erased reference to an std::locale to avoid a heavy <locale> include.
+class locale_ref {
+ private:
+  const void* locale_;  // A type-erased pointer to std::locale.
+
+ public:
+  constexpr locale_ref() : locale_(nullptr) {}
+  template <typename Locale> explicit locale_ref(const Locale& loc);
+
+  explicit operator bool() const noexcept { return locale_ != nullptr; }
+
+  template <typename Locale> auto get() const -> Locale;
+};
+
+template <typename> constexpr auto encode_types() -> unsigned long long {
+  return 0;
+}
+
+template <typename Context, typename Arg, typename... Args>
+constexpr auto encode_types() -> unsigned long long {
+  return static_cast<unsigned>(mapped_type_constant<Arg, Context>::value) |
+         (encode_types<Context, Args...>() << packed_arg_bits);
+}
+
+template <typename Context, typename T>
+FMT_CONSTEXPR FMT_INLINE auto make_value(T&& val) -> value<Context> {
+  const auto& arg = arg_mapper<Context>().map(FMT_FORWARD(val));
+
+  constexpr bool formattable_char =
+      !std::is_same<decltype(arg), const unformattable_char&>::value;
+  static_assert(formattable_char, "Mixing character types is disallowed.");
+
+  constexpr bool formattable_const =
+      !std::is_same<decltype(arg), const unformattable_const&>::value;
+  static_assert(formattable_const, "Cannot format a const argument.");
+
+  // Formatting of arbitrary pointers is disallowed. If you want to output
+  // a pointer cast it to "void *" or "const void *". In particular, this
+  // forbids formatting of "[const] volatile char *" which is printed as bool
+  // by iostreams.
+  constexpr bool formattable_pointer =
+      !std::is_same<decltype(arg), const unformattable_pointer&>::value;
+  static_assert(formattable_pointer,
+                "Formatting of non-void pointers is disallowed.");
+
+  constexpr bool formattable =
+      !std::is_same<decltype(arg), const unformattable&>::value;
+  static_assert(
+      formattable,
+      "Cannot format an argument. To make type T formattable provide a "
+      "formatter<T> specialization: https://fmt.dev/latest/api.html#udt");
+  return {arg};
+}
+
+template <typename Context, typename T>
+FMT_CONSTEXPR auto make_arg(T&& value) -> basic_format_arg<Context> {
+  basic_format_arg<Context> arg;
+  arg.type_ = mapped_type_constant<T, Context>::value;
+  arg.value_ = make_value<Context>(value);
+  return arg;
+}
+
+// The type template parameter is there to avoid an ODR violation when using
+// a fallback formatter in one translation unit and an implicit conversion in
+// another (not recommended).
+template <bool IS_PACKED, typename Context, type, typename T,
+          FMT_ENABLE_IF(IS_PACKED)>
+FMT_CONSTEXPR FMT_INLINE auto make_arg(T&& val) -> value<Context> {
+  return make_value<Context>(val);
+}
+
+template <bool IS_PACKED, typename Context, type, typename T,
+          FMT_ENABLE_IF(!IS_PACKED)>
+FMT_CONSTEXPR inline auto make_arg(T&& value) -> basic_format_arg<Context> {
+  return make_arg<Context>(value);
+}
+FMT_END_DETAIL_NAMESPACE
+
+// Formatting context.
+template <typename OutputIt, typename Char> class basic_format_context {
+ public:
+  /** The character type for the output. */
+  using char_type = Char;
+
+ private:
+  OutputIt out_;
+  basic_format_args<basic_format_context> args_;
+  detail::locale_ref loc_;
+
+ public:
+  using iterator = OutputIt;
+  using format_arg = basic_format_arg<basic_format_context>;
+  using parse_context_type = basic_format_parse_context<Char>;
+  template <typename T> using formatter_type = formatter<T, char_type>;
+
+  basic_format_context(basic_format_context&&) = default;
+  basic_format_context(const basic_format_context&) = delete;
+  void operator=(const basic_format_context&) = delete;
+  /**
+   Constructs a ``basic_format_context`` object. References to the arguments are
+   stored in the object so make sure they have appropriate lifetimes.
+   */
+  constexpr basic_format_context(
+      OutputIt out, basic_format_args<basic_format_context> ctx_args,
+      detail::locale_ref loc = detail::locale_ref())
+      : out_(out), args_(ctx_args), loc_(loc) {}
+
+  constexpr auto arg(int id) const -> format_arg { return args_.get(id); }
+  FMT_CONSTEXPR auto arg(basic_string_view<char_type> name) -> format_arg {
+    return args_.get(name);
+  }
+  FMT_CONSTEXPR auto arg_id(basic_string_view<char_type> name) -> int {
+    return args_.get_id(name);
+  }
+  auto args() const -> const basic_format_args<basic_format_context>& {
+    return args_;
+  }
+
+  FMT_CONSTEXPR auto error_handler() -> detail::error_handler { return {}; }
+  void on_error(const char* message) { error_handler().on_error(message); }
+
+  // Returns an iterator to the beginning of the output range.
+  FMT_CONSTEXPR auto out() -> iterator { return out_; }
+
+  // Advances the begin iterator to ``it``.
+  void advance_to(iterator it) {
+    if (!detail::is_back_insert_iterator<iterator>()) out_ = it;
+  }
+
+  FMT_CONSTEXPR auto locale() -> detail::locale_ref { return loc_; }
+};
+
+template <typename Char>
+using buffer_context =
+    basic_format_context<detail::buffer_appender<Char>, Char>;
+using format_context = buffer_context<char>;
+
+// Workaround an alias issue: https://stackoverflow.com/q/62767544/471164.
+#define FMT_BUFFER_CONTEXT(Char) \
+  basic_format_context<detail::buffer_appender<Char>, Char>
+
+template <typename T, typename Char = char>
+using is_formattable = bool_constant<
+    !std::is_base_of<detail::unformattable,
+                     decltype(detail::arg_mapper<buffer_context<Char>>().map(
+                         std::declval<T>()))>::value &&
+    !detail::has_fallback_formatter<T, Char>::value>;
+
+/**
+  \rst
+  An array of references to arguments. It can be implicitly converted into
+  `~fmt::basic_format_args` for passing into type-erased formatting functions
+  such as `~fmt::vformat`.
+  \endrst
+ */
+template <typename Context, typename... Args>
+class format_arg_store
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+    // Workaround a GCC template argument substitution bug.
+    : public basic_format_args<Context>
+#endif
+{
+ private:
+  static const size_t num_args = sizeof...(Args);
+  static const size_t num_named_args = detail::count_named_args<Args...>();
+  static const bool is_packed = num_args <= detail::max_packed_args;
+
+  using value_type = conditional_t<is_packed, detail::value<Context>,
+                                   basic_format_arg<Context>>;
+
+  detail::arg_data<value_type, typename Context::char_type, num_args,
+                   num_named_args>
+      data_;
+
+  friend class basic_format_args<Context>;
+
+  static constexpr unsigned long long desc =
+      (is_packed ? detail::encode_types<Context, Args...>()
+                 : detail::is_unpacked_bit | num_args) |
+      (num_named_args != 0
+           ? static_cast<unsigned long long>(detail::has_named_args_bit)
+           : 0);
+
+ public:
+  template <typename... T>
+  FMT_CONSTEXPR FMT_INLINE format_arg_store(T&&... args)
+      :
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+        basic_format_args<Context>(*this),
+#endif
+        data_{detail::make_arg<
+            is_packed, Context,
+            detail::mapped_type_constant<remove_cvref_t<T>, Context>::value>(
+            FMT_FORWARD(args))...} {
+    detail::init_named_args(data_.named_args(), 0, 0, args...);
+  }
+};
+
+/**
+  \rst
+  Constructs a `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::format_args`. `Context`
+  can be omitted in which case it defaults to `~fmt::context`.
+  See `~fmt::arg` for lifetime considerations.
+  \endrst
+ */
+template <typename Context = format_context, typename... Args>
+constexpr auto make_format_args(Args&&... args)
+    -> format_arg_store<Context, remove_cvref_t<Args>...> {
+  return {FMT_FORWARD(args)...};
+}
+
+/**
+  \rst
+  Returns a named argument to be used in a formatting function.
+  It should only be used in a call to a formatting function or
+  `dynamic_format_arg_store::push_back`.
+
+  **Example**::
+
+    fmt::print("Elapsed time: {s:.2f} seconds", fmt::arg("s", 1.23));
+  \endrst
+ */
+template <typename Char, typename T>
+inline auto arg(const Char* name, const T& arg) -> detail::named_arg<Char, T> {
+  static_assert(!detail::is_named_arg<T>(), "nested named arguments");
+  return {name, arg};
+}
+
+/**
+  \rst
+  A view of a collection of formatting arguments. To avoid lifetime issues it
+  should only be used as a parameter type in type-erased functions such as
+  ``vformat``::
+
+    void vlog(string_view format_str, format_args args);  // OK
+    format_args args = make_format_args(42);  // Error: dangling reference
+  \endrst
+ */
+template <typename Context> class basic_format_args {
+ public:
+  using size_type = int;
+  using format_arg = basic_format_arg<Context>;
+
+ private:
+  // A descriptor that contains information about formatting arguments.
+  // If the number of arguments is less or equal to max_packed_args then
+  // argument types are passed in the descriptor. This reduces binary code size
+  // per formatting function call.
+  unsigned long long desc_;
+  union {
+    // If is_packed() returns true then argument values are stored in values_;
+    // otherwise they are stored in args_. This is done to improve cache
+    // locality and reduce compiled code size since storing larger objects
+    // may require more code (at least on x86-64) even if the same amount of
+    // data is actually copied to stack. It saves ~10% on the bloat test.
+    const detail::value<Context>* values_;
+    const format_arg* args_;
+  };
+
+  constexpr auto is_packed() const -> bool {
+    return (desc_ & detail::is_unpacked_bit) == 0;
+  }
+  auto has_named_args() const -> bool {
+    return (desc_ & detail::has_named_args_bit) != 0;
+  }
+
+  FMT_CONSTEXPR auto type(int index) const -> detail::type {
+    int shift = index * detail::packed_arg_bits;
+    unsigned int mask = (1 << detail::packed_arg_bits) - 1;
+    return static_cast<detail::type>((desc_ >> shift) & mask);
+  }
+
+  constexpr FMT_INLINE basic_format_args(unsigned long long desc,
+                                         const detail::value<Context>* values)
+      : desc_(desc), values_(values) {}
+  constexpr basic_format_args(unsigned long long desc, const format_arg* args)
+      : desc_(desc), args_(args) {}
+
+ public:
+  constexpr basic_format_args() : desc_(0), args_(nullptr) {}
+
+  /**
+   \rst
+   Constructs a `basic_format_args` object from `~fmt::format_arg_store`.
+   \endrst
+   */
+  template <typename... Args>
+  constexpr FMT_INLINE basic_format_args(
+      const format_arg_store<Context, Args...>& store)
+      : basic_format_args(format_arg_store<Context, Args...>::desc,
+                          store.data_.args()) {}
+
+  /**
+   \rst
+   Constructs a `basic_format_args` object from
+   `~fmt::dynamic_format_arg_store`.
+   \endrst
+   */
+  constexpr FMT_INLINE basic_format_args(
+      const dynamic_format_arg_store<Context>& store)
+      : basic_format_args(store.get_types(), store.data()) {}
+
+  /**
+   \rst
+   Constructs a `basic_format_args` object from a dynamic set of arguments.
+   \endrst
+   */
+  constexpr basic_format_args(const format_arg* args, int count)
+      : basic_format_args(detail::is_unpacked_bit | detail::to_unsigned(count),
+                          args) {}
+
+  /** Returns the argument with the specified id. */
+  FMT_CONSTEXPR auto get(int id) const -> format_arg {
+    format_arg arg;
+    if (!is_packed()) {
+      if (id < max_size()) arg = args_[id];
+      return arg;
+    }
+    if (id >= detail::max_packed_args) return arg;
+    arg.type_ = type(id);
+    if (arg.type_ == detail::type::none_type) return arg;
+    arg.value_ = values_[id];
+    return arg;
+  }
+
+  template <typename Char>
+  auto get(basic_string_view<Char> name) const -> format_arg {
+    int id = get_id(name);
+    return id >= 0 ? get(id) : format_arg();
+  }
+
+  template <typename Char>
+  auto get_id(basic_string_view<Char> name) const -> int {
+    if (!has_named_args()) return -1;
+    const auto& named_args =
+        (is_packed() ? values_[-1] : args_[-1].value_).named_args;
+    for (size_t i = 0; i < named_args.size; ++i) {
+      if (named_args.data[i].name == name) return named_args.data[i].id;
+    }
+    return -1;
+  }
+
+  auto max_size() const -> int {
+    unsigned long long max_packed = detail::max_packed_args;
+    return static_cast<int>(is_packed() ? max_packed
+                                        : desc_ & ~detail::is_unpacked_bit);
+  }
+};
+
+/** An alias to ``basic_format_args<format_context>``. */
+// A separate type would result in shorter symbols but break ABI compatibility
+// between clang and gcc on ARM (#1919).
+using format_args = basic_format_args<format_context>;
+
+// We cannot use enum classes as bit fields because of a gcc bug, so we put them
+// in namespaces instead (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61414).
+// Additionally, if an underlying type is specified, older gcc incorrectly warns
+// that the type is too small. Both bugs are fixed in gcc 9.3.
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 903
+#  define FMT_ENUM_UNDERLYING_TYPE(type)
+#else
+#  define FMT_ENUM_UNDERLYING_TYPE(type) : type
+#endif
+namespace align {
+enum type FMT_ENUM_UNDERLYING_TYPE(unsigned char){none, left, right, center,
+                                                  numeric};
+}
+using align_t = align::type;
+namespace sign {
+enum type FMT_ENUM_UNDERLYING_TYPE(unsigned char){none, minus, plus, space};
+}
+using sign_t = sign::type;
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+// Workaround an array initialization issue in gcc 4.8.
+template <typename Char> struct fill_t {
+ private:
+  enum { max_size = 4 };
+  Char data_[max_size] = {Char(' '), Char(0), Char(0), Char(0)};
+  unsigned char size_ = 1;
+
+ public:
+  FMT_CONSTEXPR void operator=(basic_string_view<Char> s) {
+    auto size = s.size();
+    if (size > max_size) return throw_format_error("invalid fill");
+    for (size_t i = 0; i < size; ++i) data_[i] = s[i];
+    size_ = static_cast<unsigned char>(size);
+  }
+
+  constexpr auto size() const -> size_t { return size_; }
+  constexpr auto data() const -> const Char* { return data_; }
+
+  FMT_CONSTEXPR auto operator[](size_t index) -> Char& { return data_[index]; }
+  FMT_CONSTEXPR auto operator[](size_t index) const -> const Char& {
+    return data_[index];
+  }
+};
+FMT_END_DETAIL_NAMESPACE
+
+enum class presentation_type : unsigned char {
+  none,
+  // Integer types should go first,
+  dec,             // 'd'
+  oct,             // 'o'
+  hex_lower,       // 'x'
+  hex_upper,       // 'X'
+  bin_lower,       // 'b'
+  bin_upper,       // 'B'
+  hexfloat_lower,  // 'a'
+  hexfloat_upper,  // 'A'
+  exp_lower,       // 'e'
+  exp_upper,       // 'E'
+  fixed_lower,     // 'f'
+  fixed_upper,     // 'F'
+  general_lower,   // 'g'
+  general_upper,   // 'G'
+  chr,             // 'c'
+  string,          // 's'
+  pointer,         // 'p'
+  debug            // '?'
+};
+
+// Format specifiers for built-in and string types.
+template <typename Char> struct basic_format_specs {
+  int width;
+  int precision;
+  presentation_type type;
+  align_t align : 4;
+  sign_t sign : 3;
+  bool alt : 1;  // Alternate form ('#').
+  bool localized : 1;
+  detail::fill_t<Char> fill;
+
+  constexpr basic_format_specs()
+      : width(0),
+        precision(-1),
+        type(presentation_type::none),
+        align(align::none),
+        sign(sign::none),
+        alt(false),
+        localized(false) {}
+};
+
+using format_specs = basic_format_specs<char>;
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+enum class arg_id_kind { none, index, name };
+
+// An argument reference.
+template <typename Char> struct arg_ref {
+  FMT_CONSTEXPR arg_ref() : kind(arg_id_kind::none), val() {}
+
+  FMT_CONSTEXPR explicit arg_ref(int index)
+      : kind(arg_id_kind::index), val(index) {}
+  FMT_CONSTEXPR explicit arg_ref(basic_string_view<Char> name)
+      : kind(arg_id_kind::name), val(name) {}
+
+  FMT_CONSTEXPR auto operator=(int idx) -> arg_ref& {
+    kind = arg_id_kind::index;
+    val.index = idx;
+    return *this;
+  }
+
+  arg_id_kind kind;
+  union value {
+    FMT_CONSTEXPR value(int id = 0) : index{id} {}
+    FMT_CONSTEXPR value(basic_string_view<Char> n) : name(n) {}
+
+    int index;
+    basic_string_view<Char> name;
+  } val;
+};
+
+// Format specifiers with width and precision resolved at formatting rather
+// than parsing time to allow re-using the same parsed specifiers with
+// different sets of arguments (precompilation of format strings).
+template <typename Char>
+struct dynamic_format_specs : basic_format_specs<Char> {
+  arg_ref<Char> width_ref;
+  arg_ref<Char> precision_ref;
+};
+
+struct auto_id {};
+
+// A format specifier handler that sets fields in basic_format_specs.
+template <typename Char> class specs_setter {
+ protected:
+  basic_format_specs<Char>& specs_;
+
+ public:
+  explicit FMT_CONSTEXPR specs_setter(basic_format_specs<Char>& specs)
+      : specs_(specs) {}
+
+  FMT_CONSTEXPR specs_setter(const specs_setter& other)
+      : specs_(other.specs_) {}
+
+  FMT_CONSTEXPR void on_align(align_t align) { specs_.align = align; }
+  FMT_CONSTEXPR void on_fill(basic_string_view<Char> fill) {
+    specs_.fill = fill;
+  }
+  FMT_CONSTEXPR void on_sign(sign_t s) { specs_.sign = s; }
+  FMT_CONSTEXPR void on_hash() { specs_.alt = true; }
+  FMT_CONSTEXPR void on_localized() { specs_.localized = true; }
+
+  FMT_CONSTEXPR void on_zero() {
+    if (specs_.align == align::none) specs_.align = align::numeric;
+    specs_.fill[0] = Char('0');
+  }
+
+  FMT_CONSTEXPR void on_width(int width) { specs_.width = width; }
+  FMT_CONSTEXPR void on_precision(int precision) {
+    specs_.precision = precision;
+  }
+  FMT_CONSTEXPR void end_precision() {}
+
+  FMT_CONSTEXPR void on_type(presentation_type type) { specs_.type = type; }
+};
+
+// Format spec handler that saves references to arguments representing dynamic
+// width and precision to be resolved at formatting time.
+template <typename ParseContext>
+class dynamic_specs_handler
+    : public specs_setter<typename ParseContext::char_type> {
+ public:
+  using char_type = typename ParseContext::char_type;
+
+  FMT_CONSTEXPR dynamic_specs_handler(dynamic_format_specs<char_type>& specs,
+                                      ParseContext& ctx)
+      : specs_setter<char_type>(specs), specs_(specs), context_(ctx) {}
+
+  FMT_CONSTEXPR dynamic_specs_handler(const dynamic_specs_handler& other)
+      : specs_setter<char_type>(other),
+        specs_(other.specs_),
+        context_(other.context_) {}
+
+  template <typename Id> FMT_CONSTEXPR void on_dynamic_width(Id arg_id) {
+    specs_.width_ref = make_arg_ref(arg_id);
+  }
+
+  template <typename Id> FMT_CONSTEXPR void on_dynamic_precision(Id arg_id) {
+    specs_.precision_ref = make_arg_ref(arg_id);
+  }
+
+  FMT_CONSTEXPR void on_error(const char* message) {
+    context_.on_error(message);
+  }
+
+ private:
+  dynamic_format_specs<char_type>& specs_;
+  ParseContext& context_;
+
+  using arg_ref_type = arg_ref<char_type>;
+
+  FMT_CONSTEXPR auto make_arg_ref(int arg_id) -> arg_ref_type {
+    context_.check_arg_id(arg_id);
+    context_.check_dynamic_spec(arg_id);
+    return arg_ref_type(arg_id);
+  }
+
+  FMT_CONSTEXPR auto make_arg_ref(auto_id) -> arg_ref_type {
+    int arg_id = context_.next_arg_id();
+    context_.check_dynamic_spec(arg_id);
+    return arg_ref_type(arg_id);
+  }
+
+  FMT_CONSTEXPR auto make_arg_ref(basic_string_view<char_type> arg_id)
+      -> arg_ref_type {
+    context_.check_arg_id(arg_id);
+    basic_string_view<char_type> format_str(
+        context_.begin(), to_unsigned(context_.end() - context_.begin()));
+    return arg_ref_type(arg_id);
+  }
+};
+
+template <typename Char> constexpr bool is_ascii_letter(Char c) {
+  return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
+}
+
+// Converts a character to ASCII. Returns a number > 127 on conversion failure.
+template <typename Char, FMT_ENABLE_IF(std::is_integral<Char>::value)>
+constexpr auto to_ascii(Char c) -> Char {
+  return c;
+}
+template <typename Char, FMT_ENABLE_IF(std::is_enum<Char>::value)>
+constexpr auto to_ascii(Char c) -> underlying_t<Char> {
+  return c;
+}
+
+FMT_CONSTEXPR inline auto code_point_length_impl(char c) -> int {
+  return "\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\0\0\0\0\0\0\0\0\2\2\2\2\3\3\4"
+      [static_cast<unsigned char>(c) >> 3];
+}
+
+template <typename Char>
+FMT_CONSTEXPR auto code_point_length(const Char* begin) -> int {
+  if (const_check(sizeof(Char) != 1)) return 1;
+  int len = code_point_length_impl(static_cast<char>(*begin));
+
+  // Compute the pointer to the next character early so that the next
+  // iteration can start working on the next character. Neither Clang
+  // nor GCC figure out this reordering on their own.
+  return len + !len;
+}
+
+// Return the result via the out param to workaround gcc bug 77539.
+template <bool IS_CONSTEXPR, typename T, typename Ptr = const T*>
+FMT_CONSTEXPR auto find(Ptr first, Ptr last, T value, Ptr& out) -> bool {
+  for (out = first; out != last; ++out) {
+    if (*out == value) return true;
+  }
+  return false;
+}
+
+template <>
+inline auto find<false, char>(const char* first, const char* last, char value,
+                              const char*& out) -> bool {
+  out = static_cast<const char*>(
+      std::memchr(first, value, to_unsigned(last - first)));
+  return out != nullptr;
+}
+
+// Parses the range [begin, end) as an unsigned integer. This function assumes
+// that the range is non-empty and the first character is a digit.
+template <typename Char>
+FMT_CONSTEXPR auto parse_nonnegative_int(const Char*& begin, const Char* end,
+                                         int error_value) noexcept -> int {
+  FMT_ASSERT(begin != end && '0' <= *begin && *begin <= '9', "");
+  unsigned value = 0, prev = 0;
+  auto p = begin;
+  do {
+    prev = value;
+    value = value * 10 + unsigned(*p - '0');
+    ++p;
+  } while (p != end && '0' <= *p && *p <= '9');
+  auto num_digits = p - begin;
+  begin = p;
+  if (num_digits <= std::numeric_limits<int>::digits10)
+    return static_cast<int>(value);
+  // Check for overflow.
+  const unsigned max = to_unsigned((std::numeric_limits<int>::max)());
+  return num_digits == std::numeric_limits<int>::digits10 + 1 &&
+                 prev * 10ull + unsigned(p[-1] - '0') <= max
+             ? static_cast<int>(value)
+             : error_value;
+}
+
+// Parses fill and alignment.
+template <typename Char, typename Handler>
+FMT_CONSTEXPR auto parse_align(const Char* begin, const Char* end,
+                               Handler&& handler) -> const Char* {
+  FMT_ASSERT(begin != end, "");
+  auto align = align::none;
+  auto p = begin + code_point_length(begin);
+  if (end - p <= 0) p = begin;
+  for (;;) {
+    switch (to_ascii(*p)) {
+    case '<':
+      align = align::left;
+      break;
+    case '>':
+      align = align::right;
+      break;
+    case '^':
+      align = align::center;
+      break;
+    default:
+      break;
+    }
+    if (align != align::none) {
+      if (p != begin) {
+        auto c = *begin;
+        if (c == '{')
+          return handler.on_error("invalid fill character '{'"), begin;
+        handler.on_fill(basic_string_view<Char>(begin, to_unsigned(p - begin)));
+        begin = p + 1;
+      } else
+        ++begin;
+      handler.on_align(align);
+      break;
+    } else if (p == begin) {
+      break;
+    }
+    p = begin;
+  }
+  return begin;
+}
+
+template <typename Char> FMT_CONSTEXPR bool is_name_start(Char c) {
+  return ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') || '_' == c;
+}
+
+template <typename Char, typename IDHandler>
+FMT_CONSTEXPR auto do_parse_arg_id(const Char* begin, const Char* end,
+                                   IDHandler&& handler) -> const Char* {
+  FMT_ASSERT(begin != end, "");
+  Char c = *begin;
+  if (c >= '0' && c <= '9') {
+    int index = 0;
+    if (c != '0')
+      index =
+          parse_nonnegative_int(begin, end, (std::numeric_limits<int>::max)());
+    else
+      ++begin;
+    if (begin == end || (*begin != '}' && *begin != ':'))
+      handler.on_error("invalid format string");
+    else
+      handler(index);
+    return begin;
+  }
+  if (!is_name_start(c)) {
+    handler.on_error("invalid format string");
+    return begin;
+  }
+  auto it = begin;
+  do {
+    ++it;
+  } while (it != end && (is_name_start(c = *it) || ('0' <= c && c <= '9')));
+  handler(basic_string_view<Char>(begin, to_unsigned(it - begin)));
+  return it;
+}
+
+template <typename Char, typename IDHandler>
+FMT_CONSTEXPR FMT_INLINE auto parse_arg_id(const Char* begin, const Char* end,
+                                           IDHandler&& handler) -> const Char* {
+  Char c = *begin;
+  if (c != '}' && c != ':') return do_parse_arg_id(begin, end, handler);
+  handler();
+  return begin;
+}
+
+template <typename Char, typename Handler>
+FMT_CONSTEXPR auto parse_width(const Char* begin, const Char* end,
+                               Handler&& handler) -> const Char* {
+  using detail::auto_id;
+  struct width_adapter {
+    Handler& handler;
+
+    FMT_CONSTEXPR void operator()() { handler.on_dynamic_width(auto_id()); }
+    FMT_CONSTEXPR void operator()(int id) { handler.on_dynamic_width(id); }
+    FMT_CONSTEXPR void operator()(basic_string_view<Char> id) {
+      handler.on_dynamic_width(id);
+    }
+    FMT_CONSTEXPR void on_error(const char* message) {
+      if (message) handler.on_error(message);
+    }
+  };
+
+  FMT_ASSERT(begin != end, "");
+  if ('0' <= *begin && *begin <= '9') {
+    int width = parse_nonnegative_int(begin, end, -1);
+    if (width != -1)
+      handler.on_width(width);
+    else
+      handler.on_error("number is too big");
+  } else if (*begin == '{') {
+    ++begin;
+    if (begin != end) begin = parse_arg_id(begin, end, width_adapter{handler});
+    if (begin == end || *begin != '}')
+      return handler.on_error("invalid format string"), begin;
+    ++begin;
+  }
+  return begin;
+}
+
+template <typename Char, typename Handler>
+FMT_CONSTEXPR auto parse_precision(const Char* begin, const Char* end,
+                                   Handler&& handler) -> const Char* {
+  using detail::auto_id;
+  struct precision_adapter {
+    Handler& handler;
+
+    FMT_CONSTEXPR void operator()() { handler.on_dynamic_precision(auto_id()); }
+    FMT_CONSTEXPR void operator()(int id) { handler.on_dynamic_precision(id); }
+    FMT_CONSTEXPR void operator()(basic_string_view<Char> id) {
+      handler.on_dynamic_precision(id);
+    }
+    FMT_CONSTEXPR void on_error(const char* message) {
+      if (message) handler.on_error(message);
+    }
+  };
+
+  ++begin;
+  auto c = begin != end ? *begin : Char();
+  if ('0' <= c && c <= '9') {
+    auto precision = parse_nonnegative_int(begin, end, -1);
+    if (precision != -1)
+      handler.on_precision(precision);
+    else
+      handler.on_error("number is too big");
+  } else if (c == '{') {
+    ++begin;
+    if (begin != end)
+      begin = parse_arg_id(begin, end, precision_adapter{handler});
+    if (begin == end || *begin++ != '}')
+      return handler.on_error("invalid format string"), begin;
+  } else {
+    return handler.on_error("missing precision specifier"), begin;
+  }
+  handler.end_precision();
+  return begin;
+}
+
+template <typename Char>
+FMT_CONSTEXPR auto parse_presentation_type(Char type) -> presentation_type {
+  switch (to_ascii(type)) {
+  case 'd':
+    return presentation_type::dec;
+  case 'o':
+    return presentation_type::oct;
+  case 'x':
+    return presentation_type::hex_lower;
+  case 'X':
+    return presentation_type::hex_upper;
+  case 'b':
+    return presentation_type::bin_lower;
+  case 'B':
+    return presentation_type::bin_upper;
+  case 'a':
+    return presentation_type::hexfloat_lower;
+  case 'A':
+    return presentation_type::hexfloat_upper;
+  case 'e':
+    return presentation_type::exp_lower;
+  case 'E':
+    return presentation_type::exp_upper;
+  case 'f':
+    return presentation_type::fixed_lower;
+  case 'F':
+    return presentation_type::fixed_upper;
+  case 'g':
+    return presentation_type::general_lower;
+  case 'G':
+    return presentation_type::general_upper;
+  case 'c':
+    return presentation_type::chr;
+  case 's':
+    return presentation_type::string;
+  case 'p':
+    return presentation_type::pointer;
+  case '?':
+    return presentation_type::debug;
+  default:
+    return presentation_type::none;
+  }
+}
+
+// Parses standard format specifiers and sends notifications about parsed
+// components to handler.
+template <typename Char, typename SpecHandler>
+FMT_CONSTEXPR FMT_INLINE auto parse_format_specs(const Char* begin,
+                                                 const Char* end,
+                                                 SpecHandler&& handler)
+    -> const Char* {
+  if (1 < end - begin && begin[1] == '}' && is_ascii_letter(*begin) &&
+      *begin != 'L') {
+    presentation_type type = parse_presentation_type(*begin++);
+    if (type == presentation_type::none)
+      handler.on_error("invalid type specifier");
+    handler.on_type(type);
+    return begin;
+  }
+
+  if (begin == end) return begin;
+
+  begin = parse_align(begin, end, handler);
+  if (begin == end) return begin;
+
+  // Parse sign.
+  switch (to_ascii(*begin)) {
+  case '+':
+    handler.on_sign(sign::plus);
+    ++begin;
+    break;
+  case '-':
+    handler.on_sign(sign::minus);
+    ++begin;
+    break;
+  case ' ':
+    handler.on_sign(sign::space);
+    ++begin;
+    break;
+  default:
+    break;
+  }
+  if (begin == end) return begin;
+
+  if (*begin == '#') {
+    handler.on_hash();
+    if (++begin == end) return begin;
+  }
+
+  // Parse zero flag.
+  if (*begin == '0') {
+    handler.on_zero();
+    if (++begin == end) return begin;
+  }
+
+  begin = parse_width(begin, end, handler);
+  if (begin == end) return begin;
+
+  // Parse precision.
+  if (*begin == '.') {
+    begin = parse_precision(begin, end, handler);
+    if (begin == end) return begin;
+  }
+
+  if (*begin == 'L') {
+    handler.on_localized();
+    ++begin;
+  }
+
+  // Parse type.
+  if (begin != end && *begin != '}') {
+    presentation_type type = parse_presentation_type(*begin++);
+    if (type == presentation_type::none)
+      handler.on_error("invalid type specifier");
+    handler.on_type(type);
+  }
+  return begin;
+}
+
+template <typename Char, typename Handler>
+FMT_CONSTEXPR auto parse_replacement_field(const Char* begin, const Char* end,
+                                           Handler&& handler) -> const Char* {
+  struct id_adapter {
+    Handler& handler;
+    int arg_id;
+
+    FMT_CONSTEXPR void operator()() { arg_id = handler.on_arg_id(); }
+    FMT_CONSTEXPR void operator()(int id) { arg_id = handler.on_arg_id(id); }
+    FMT_CONSTEXPR void operator()(basic_string_view<Char> id) {
+      arg_id = handler.on_arg_id(id);
+    }
+    FMT_CONSTEXPR void on_error(const char* message) {
+      if (message) handler.on_error(message);
+    }
+  };
+
+  ++begin;
+  if (begin == end) return handler.on_error("invalid format string"), end;
+  if (*begin == '}') {
+    handler.on_replacement_field(handler.on_arg_id(), begin);
+  } else if (*begin == '{') {
+    handler.on_text(begin, begin + 1);
+  } else {
+    auto adapter = id_adapter{handler, 0};
+    begin = parse_arg_id(begin, end, adapter);
+    Char c = begin != end ? *begin : Char();
+    if (c == '}') {
+      handler.on_replacement_field(adapter.arg_id, begin);
+    } else if (c == ':') {
+      begin = handler.on_format_specs(adapter.arg_id, begin + 1, end);
+      if (begin == end || *begin != '}')
+        return handler.on_error("unknown format specifier"), end;
+    } else {
+      return handler.on_error("missing '}' in format string"), end;
+    }
+  }
+  return begin + 1;
+}
+
+template <bool IS_CONSTEXPR, typename Char, typename Handler>
+FMT_CONSTEXPR FMT_INLINE void parse_format_string(
+    basic_string_view<Char> format_str, Handler&& handler) {
+  // Workaround a name-lookup bug in MSVC's modules implementation.
+  using detail::find;
+
+  auto begin = format_str.data();
+  auto end = begin + format_str.size();
+  if (end - begin < 32) {
+    // Use a simple loop instead of memchr for small strings.
+    const Char* p = begin;
+    while (p != end) {
+      auto c = *p++;
+      if (c == '{') {
+        handler.on_text(begin, p - 1);
+        begin = p = parse_replacement_field(p - 1, end, handler);
+      } else if (c == '}') {
+        if (p == end || *p != '}')
+          return handler.on_error("unmatched '}' in format string");
+        handler.on_text(begin, p);
+        begin = ++p;
+      }
+    }
+    handler.on_text(begin, end);
+    return;
+  }
+  struct writer {
+    FMT_CONSTEXPR void operator()(const Char* from, const Char* to) {
+      if (from == to) return;
+      for (;;) {
+        const Char* p = nullptr;
+        if (!find<IS_CONSTEXPR>(from, to, Char('}'), p))
+          return handler_.on_text(from, to);
+        ++p;
+        if (p == to || *p != '}')
+          return handler_.on_error("unmatched '}' in format string");
+        handler_.on_text(from, p);
+        from = p + 1;
+      }
+    }
+    Handler& handler_;
+  } write = {handler};
+  while (begin != end) {
+    // Doing two passes with memchr (one for '{' and another for '}') is up to
+    // 2.5x faster than the naive one-pass implementation on big format strings.
+    const Char* p = begin;
+    if (*begin != '{' && !find<IS_CONSTEXPR>(begin + 1, end, Char('{'), p))
+      return write(begin, end);
+    write(begin, p);
+    begin = parse_replacement_field(p, end, handler);
+  }
+}
+
+template <typename T, bool = is_named_arg<T>::value> struct strip_named_arg {
+  using type = T;
+};
+template <typename T> struct strip_named_arg<T, true> {
+  using type = remove_cvref_t<decltype(T::value)>;
+};
+
+template <typename T, typename ParseContext>
+FMT_CONSTEXPR auto parse_format_specs(ParseContext& ctx)
+    -> decltype(ctx.begin()) {
+  using char_type = typename ParseContext::char_type;
+  using context = buffer_context<char_type>;
+  using stripped_type = typename strip_named_arg<T>::type;
+  using mapped_type = conditional_t<
+      mapped_type_constant<T, context>::value != type::custom_type,
+      decltype(arg_mapper<context>().map(std::declval<const T&>())),
+      stripped_type>;
+  auto f = conditional_t<has_formatter<mapped_type, context>::value,
+                         formatter<mapped_type, char_type>,
+                         fallback_formatter<stripped_type, char_type>>();
+  return f.parse(ctx);
+}
+
+template <typename ErrorHandler>
+FMT_CONSTEXPR void check_int_type_spec(presentation_type type,
+                                       ErrorHandler&& eh) {
+  if (type > presentation_type::bin_upper && type != presentation_type::chr)
+    eh.on_error("invalid type specifier");
+}
+
+// Checks char specs and returns true if the type spec is char (and not int).
+template <typename Char, typename ErrorHandler = error_handler>
+FMT_CONSTEXPR auto check_char_specs(const basic_format_specs<Char>& specs,
+                                    ErrorHandler&& eh = {}) -> bool {
+  if (specs.type != presentation_type::none &&
+      specs.type != presentation_type::chr &&
+      specs.type != presentation_type::debug) {
+    check_int_type_spec(specs.type, eh);
+    return false;
+  }
+  if (specs.align == align::numeric || specs.sign != sign::none || specs.alt)
+    eh.on_error("invalid format specifier for char");
+  return true;
+}
+
+// A floating-point presentation format.
+enum class float_format : unsigned char {
+  general,  // General: exponent notation or fixed point based on magnitude.
+  exp,      // Exponent notation with the default precision of 6, e.g. 1.2e-3.
+  fixed,    // Fixed point with the default precision of 6, e.g. 0.0012.
+  hex
+};
+
+struct float_specs {
+  int precision;
+  float_format format : 8;
+  sign_t sign : 8;
+  bool upper : 1;
+  bool locale : 1;
+  bool binary32 : 1;
+  bool showpoint : 1;
+};
+
+template <typename ErrorHandler = error_handler, typename Char>
+FMT_CONSTEXPR auto parse_float_type_spec(const basic_format_specs<Char>& specs,
+                                         ErrorHandler&& eh = {})
+    -> float_specs {
+  auto result = float_specs();
+  result.showpoint = specs.alt;
+  result.locale = specs.localized;
+  switch (specs.type) {
+  case presentation_type::none:
+    result.format = float_format::general;
+    break;
+  case presentation_type::general_upper:
+    result.upper = true;
+    FMT_FALLTHROUGH;
+  case presentation_type::general_lower:
+    result.format = float_format::general;
+    break;
+  case presentation_type::exp_upper:
+    result.upper = true;
+    FMT_FALLTHROUGH;
+  case presentation_type::exp_lower:
+    result.format = float_format::exp;
+    result.showpoint |= specs.precision != 0;
+    break;
+  case presentation_type::fixed_upper:
+    result.upper = true;
+    FMT_FALLTHROUGH;
+  case presentation_type::fixed_lower:
+    result.format = float_format::fixed;
+    result.showpoint |= specs.precision != 0;
+    break;
+  case presentation_type::hexfloat_upper:
+    result.upper = true;
+    FMT_FALLTHROUGH;
+  case presentation_type::hexfloat_lower:
+    result.format = float_format::hex;
+    break;
+  default:
+    eh.on_error("invalid type specifier");
+    break;
+  }
+  return result;
+}
+
+template <typename ErrorHandler = error_handler>
+FMT_CONSTEXPR auto check_cstring_type_spec(presentation_type type,
+                                           ErrorHandler&& eh = {}) -> bool {
+  if (type == presentation_type::none || type == presentation_type::string ||
+      type == presentation_type::debug)
+    return true;
+  if (type != presentation_type::pointer) eh.on_error("invalid type specifier");
+  return false;
+}
+
+template <typename ErrorHandler = error_handler>
+FMT_CONSTEXPR void check_string_type_spec(presentation_type type,
+                                          ErrorHandler&& eh = {}) {
+  if (type != presentation_type::none && type != presentation_type::string &&
+      type != presentation_type::debug)
+    eh.on_error("invalid type specifier");
+}
+
+template <typename ErrorHandler>
+FMT_CONSTEXPR void check_pointer_type_spec(presentation_type type,
+                                           ErrorHandler&& eh) {
+  if (type != presentation_type::none && type != presentation_type::pointer)
+    eh.on_error("invalid type specifier");
+}
+
+// A parse_format_specs handler that checks if specifiers are consistent with
+// the argument type.
+template <typename Handler> class specs_checker : public Handler {
+ private:
+  detail::type arg_type_;
+
+  FMT_CONSTEXPR void require_numeric_argument() {
+    if (!is_arithmetic_type(arg_type_))
+      this->on_error("format specifier requires numeric argument");
+  }
+
+ public:
+  FMT_CONSTEXPR specs_checker(const Handler& handler, detail::type arg_type)
+      : Handler(handler), arg_type_(arg_type) {}
+
+  FMT_CONSTEXPR void on_align(align_t align) {
+    if (align == align::numeric) require_numeric_argument();
+    Handler::on_align(align);
+  }
+
+  FMT_CONSTEXPR void on_sign(sign_t s) {
+    require_numeric_argument();
+    if (is_integral_type(arg_type_) && arg_type_ != type::int_type &&
+        arg_type_ != type::long_long_type && arg_type_ != type::int128_type &&
+        arg_type_ != type::char_type) {
+      this->on_error("format specifier requires signed argument");
+    }
+    Handler::on_sign(s);
+  }
+
+  FMT_CONSTEXPR void on_hash() {
+    require_numeric_argument();
+    Handler::on_hash();
+  }
+
+  FMT_CONSTEXPR void on_localized() {
+    require_numeric_argument();
+    Handler::on_localized();
+  }
+
+  FMT_CONSTEXPR void on_zero() {
+    require_numeric_argument();
+    Handler::on_zero();
+  }
+
+  FMT_CONSTEXPR void end_precision() {
+    if (is_integral_type(arg_type_) || arg_type_ == type::pointer_type)
+      this->on_error("precision not allowed for this argument type");
+  }
+};
+
+constexpr int invalid_arg_index = -1;
+
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+template <int N, typename T, typename... Args, typename Char>
+constexpr auto get_arg_index_by_name(basic_string_view<Char> name) -> int {
+  if constexpr (detail::is_statically_named_arg<T>()) {
+    if (name == T::name) return N;
+  }
+  if constexpr (sizeof...(Args) > 0)
+    return get_arg_index_by_name<N + 1, Args...>(name);
+  (void)name;  // Workaround an MSVC bug about "unused" parameter.
+  return invalid_arg_index;
+}
+#endif
+
+template <typename... Args, typename Char>
+FMT_CONSTEXPR auto get_arg_index_by_name(basic_string_view<Char> name) -> int {
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+  if constexpr (sizeof...(Args) > 0)
+    return get_arg_index_by_name<0, Args...>(name);
+#endif
+  (void)name;
+  return invalid_arg_index;
+}
+
+template <typename Char, typename ErrorHandler, typename... Args>
+class format_string_checker {
+ private:
+  // In the future basic_format_parse_context will replace compile_parse_context
+  // here and will use is_constant_evaluated and downcasting to access the data
+  // needed for compile-time checks: https://godbolt.org/z/GvWzcTjh1.
+  using parse_context_type = compile_parse_context<Char, ErrorHandler>;
+  static constexpr int num_args = sizeof...(Args);
+
+  // Format specifier parsing function.
+  using parse_func = const Char* (*)(parse_context_type&);
+
+  parse_context_type context_;
+  parse_func parse_funcs_[num_args > 0 ? static_cast<size_t>(num_args) : 1];
+  type types_[num_args > 0 ? static_cast<size_t>(num_args) : 1];
+
+ public:
+  explicit FMT_CONSTEXPR format_string_checker(
+      basic_string_view<Char> format_str, ErrorHandler eh)
+      : context_(format_str, num_args, types_, eh),
+        parse_funcs_{&parse_format_specs<Args, parse_context_type>...},
+        types_{
+            mapped_type_constant<Args,
+                                 basic_format_context<Char*, Char>>::value...} {
+  }
+
+  FMT_CONSTEXPR void on_text(const Char*, const Char*) {}
+
+  FMT_CONSTEXPR auto on_arg_id() -> int { return context_.next_arg_id(); }
+  FMT_CONSTEXPR auto on_arg_id(int id) -> int {
+    return context_.check_arg_id(id), id;
+  }
+  FMT_CONSTEXPR auto on_arg_id(basic_string_view<Char> id) -> int {
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+    auto index = get_arg_index_by_name<Args...>(id);
+    if (index == invalid_arg_index) on_error("named argument is not found");
+    return context_.check_arg_id(index), index;
+#else
+    (void)id;
+    on_error("compile-time checks for named arguments require C++20 support");
+    return 0;
+#endif
+  }
+
+  FMT_CONSTEXPR void on_replacement_field(int, const Char*) {}
+
+  FMT_CONSTEXPR auto on_format_specs(int id, const Char* begin, const Char*)
+      -> const Char* {
+    context_.advance_to(context_.begin() + (begin - &*context_.begin()));
+    // id >= 0 check is a workaround for gcc 10 bug (#2065).
+    return id >= 0 && id < num_args ? parse_funcs_[id](context_) : begin;
+  }
+
+  FMT_CONSTEXPR void on_error(const char* message) {
+    context_.on_error(message);
+  }
+};
+
+// Reports a compile-time error if S is not a valid format string.
+template <typename..., typename S, FMT_ENABLE_IF(!is_compile_string<S>::value)>
+FMT_INLINE void check_format_string(const S&) {
+#ifdef FMT_ENFORCE_COMPILE_STRING
+  static_assert(is_compile_string<S>::value,
+                "FMT_ENFORCE_COMPILE_STRING requires all format strings to use "
+                "FMT_STRING.");
+#endif
+}
+template <typename... Args, typename S,
+          FMT_ENABLE_IF(is_compile_string<S>::value)>
+void check_format_string(S format_str) {
+  FMT_CONSTEXPR auto s = basic_string_view<typename S::char_type>(format_str);
+  using checker = format_string_checker<typename S::char_type, error_handler,
+                                        remove_cvref_t<Args>...>;
+  FMT_CONSTEXPR bool invalid_format =
+      (parse_format_string<true>(s, checker(s, {})), true);
+  ignore_unused(invalid_format);
+}
+
+template <typename Char>
+void vformat_to(
+    buffer<Char>& buf, basic_string_view<Char> fmt,
+    basic_format_args<FMT_BUFFER_CONTEXT(type_identity_t<Char>)> args,
+    locale_ref loc = {});
+
+FMT_API void vprint_mojibake(std::FILE*, string_view, format_args);
+#ifndef _WIN32
+inline void vprint_mojibake(std::FILE*, string_view, format_args) {}
+#endif
+FMT_END_DETAIL_NAMESPACE
+
+// A formatter specialization for the core types corresponding to detail::type
+// constants.
+template <typename T, typename Char>
+struct formatter<T, Char,
+                 enable_if_t<detail::type_constant<T, Char>::value !=
+                             detail::type::custom_type>> {
+ private:
+  detail::dynamic_format_specs<Char> specs_;
+
+ public:
+  // Parses format specifiers stopping either at the end of the range or at the
+  // terminating '}'.
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    auto begin = ctx.begin(), end = ctx.end();
+    if (begin == end) return begin;
+    using handler_type = detail::dynamic_specs_handler<ParseContext>;
+    auto type = detail::type_constant<T, Char>::value;
+    auto checker =
+        detail::specs_checker<handler_type>(handler_type(specs_, ctx), type);
+    auto it = detail::parse_format_specs(begin, end, checker);
+    auto eh = ctx.error_handler();
+    switch (type) {
+    case detail::type::none_type:
+      FMT_ASSERT(false, "invalid argument type");
+      break;
+    case detail::type::bool_type:
+      if (specs_.type == presentation_type::none ||
+          specs_.type == presentation_type::string) {
+        break;
+      }
+      FMT_FALLTHROUGH;
+    case detail::type::int_type:
+    case detail::type::uint_type:
+    case detail::type::long_long_type:
+    case detail::type::ulong_long_type:
+    case detail::type::int128_type:
+    case detail::type::uint128_type:
+      detail::check_int_type_spec(specs_.type, eh);
+      break;
+    case detail::type::char_type:
+      detail::check_char_specs(specs_, eh);
+      break;
+    case detail::type::float_type:
+      if (detail::const_check(FMT_USE_FLOAT))
+        detail::parse_float_type_spec(specs_, eh);
+      else
+        FMT_ASSERT(false, "float support disabled");
+      break;
+    case detail::type::double_type:
+      if (detail::const_check(FMT_USE_DOUBLE))
+        detail::parse_float_type_spec(specs_, eh);
+      else
+        FMT_ASSERT(false, "double support disabled");
+      break;
+    case detail::type::long_double_type:
+      if (detail::const_check(FMT_USE_LONG_DOUBLE))
+        detail::parse_float_type_spec(specs_, eh);
+      else
+        FMT_ASSERT(false, "long double support disabled");
+      break;
+    case detail::type::cstring_type:
+      detail::check_cstring_type_spec(specs_.type, eh);
+      break;
+    case detail::type::string_type:
+      detail::check_string_type_spec(specs_.type, eh);
+      break;
+    case detail::type::pointer_type:
+      detail::check_pointer_type_spec(specs_.type, eh);
+      break;
+    case detail::type::custom_type:
+      // Custom format specifiers are checked in parse functions of
+      // formatter specializations.
+      break;
+    }
+    return it;
+  }
+
+  template <detail::type U = detail::type_constant<T, Char>::value,
+            enable_if_t<(U == detail::type::string_type ||
+                         U == detail::type::cstring_type ||
+                         U == detail::type::char_type),
+                        int> = 0>
+  FMT_CONSTEXPR void set_debug_format() {
+    specs_.type = presentation_type::debug;
+  }
+
+  template <typename FormatContext>
+  FMT_CONSTEXPR auto format(const T& val, FormatContext& ctx) const
+      -> decltype(ctx.out());
+};
+
+#define FMT_FORMAT_AS(Type, Base)                                        \
+  template <typename Char>                                               \
+  struct formatter<Type, Char> : formatter<Base, Char> {                 \
+    template <typename FormatContext>                                    \
+    auto format(Type const& val, FormatContext& ctx) const               \
+        -> decltype(ctx.out()) {                                         \
+      return formatter<Base, Char>::format(static_cast<Base>(val), ctx); \
+    }                                                                    \
+  }
+
+FMT_FORMAT_AS(signed char, int);
+FMT_FORMAT_AS(unsigned char, unsigned);
+FMT_FORMAT_AS(short, int);
+FMT_FORMAT_AS(unsigned short, unsigned);
+FMT_FORMAT_AS(long, long long);
+FMT_FORMAT_AS(unsigned long, unsigned long long);
+FMT_FORMAT_AS(Char*, const Char*);
+FMT_FORMAT_AS(std::basic_string<Char>, basic_string_view<Char>);
+FMT_FORMAT_AS(std::nullptr_t, const void*);
+FMT_FORMAT_AS(detail::std_string_view<Char>, basic_string_view<Char>);
+
+template <typename Char> struct basic_runtime { basic_string_view<Char> str; };
+
+/** A compile-time format string. */
+template <typename Char, typename... Args> class basic_format_string {
+ private:
+  basic_string_view<Char> str_;
+
+ public:
+  template <typename S,
+            FMT_ENABLE_IF(
+                std::is_convertible<const S&, basic_string_view<Char>>::value)>
+  FMT_CONSTEVAL FMT_INLINE basic_format_string(const S& s) : str_(s) {
+    static_assert(
+        detail::count<
+            (std::is_base_of<detail::view, remove_reference_t<Args>>::value &&
+             std::is_reference<Args>::value)...>() == 0,
+        "passing views as lvalues is disallowed");
+#ifdef FMT_HAS_CONSTEVAL
+    if constexpr (detail::count_named_args<Args...>() ==
+                  detail::count_statically_named_args<Args...>()) {
+      using checker = detail::format_string_checker<Char, detail::error_handler,
+                                                    remove_cvref_t<Args>...>;
+      detail::parse_format_string<true>(str_, checker(s, {}));
+    }
+#else
+    detail::check_format_string<Args...>(s);
+#endif
+  }
+  basic_format_string(basic_runtime<Char> r) : str_(r.str) {}
+
+  FMT_INLINE operator basic_string_view<Char>() const { return str_; }
+};
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+// Workaround broken conversion on older gcc.
+template <typename...> using format_string = string_view;
+inline auto runtime(string_view s) -> string_view { return s; }
+#else
+template <typename... Args>
+using format_string = basic_format_string<char, type_identity_t<Args>...>;
+/**
+  \rst
+  Creates a runtime format string.
+
+  **Example**::
+
+    // Check format string at runtime instead of compile-time.
+    fmt::print(fmt::runtime("{:d}"), "I am not a number");
+  \endrst
+ */
+inline auto runtime(string_view s) -> basic_runtime<char> { return {{s}}; }
+#endif
+
+FMT_API auto vformat(string_view fmt, format_args args) -> std::string;
+
+/**
+  \rst
+  Formats ``args`` according to specifications in ``fmt`` and returns the result
+  as a string.
+
+  **Example**::
+
+    #include <fmt/core.h>
+    std::string message = fmt::format("The answer is {}.", 42);
+  \endrst
+*/
+template <typename... T>
+FMT_NODISCARD FMT_INLINE auto format(format_string<T...> fmt, T&&... args)
+    -> std::string {
+  return vformat(fmt, fmt::make_format_args(args...));
+}
+
+/** Formats a string and writes the output to ``out``. */
+template <typename OutputIt,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value)>
+auto vformat_to(OutputIt out, string_view fmt, format_args args) -> OutputIt {
+  using detail::get_buffer;
+  auto&& buf = get_buffer<char>(out);
+  detail::vformat_to(buf, fmt, args, {});
+  return detail::get_iterator(buf);
+}
+
+/**
+ \rst
+ Formats ``args`` according to specifications in ``fmt``, writes the result to
+ the output iterator ``out`` and returns the iterator past the end of the output
+ range. `format_to` does not append a terminating null character.
+
+ **Example**::
+
+   auto out = std::vector<char>();
+   fmt::format_to(std::back_inserter(out), "{}", 42);
+ \endrst
+ */
+template <typename OutputIt, typename... T,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value)>
+FMT_INLINE auto format_to(OutputIt out, format_string<T...> fmt, T&&... args)
+    -> OutputIt {
+  return vformat_to(out, fmt, fmt::make_format_args(args...));
+}
+
+template <typename OutputIt> struct format_to_n_result {
+  /** Iterator past the end of the output range. */
+  OutputIt out;
+  /** Total (not truncated) output size. */
+  size_t size;
+};
+
+template <typename OutputIt, typename... T,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value)>
+auto vformat_to_n(OutputIt out, size_t n, string_view fmt, format_args args)
+    -> format_to_n_result<OutputIt> {
+  using traits = detail::fixed_buffer_traits;
+  auto buf = detail::iterator_buffer<OutputIt, char, traits>(out, n);
+  detail::vformat_to(buf, fmt, args, {});
+  return {buf.out(), buf.count()};
+}
+
+/**
+  \rst
+  Formats ``args`` according to specifications in ``fmt``, writes up to ``n``
+  characters of the result to the output iterator ``out`` and returns the total
+  (not truncated) output size and the iterator past the end of the output range.
+  `format_to_n` does not append a terminating null character.
+  \endrst
+ */
+template <typename OutputIt, typename... T,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value)>
+FMT_INLINE auto format_to_n(OutputIt out, size_t n, format_string<T...> fmt,
+                            T&&... args) -> format_to_n_result<OutputIt> {
+  return vformat_to_n(out, n, fmt, fmt::make_format_args(args...));
+}
+
+/** Returns the number of chars in the output of ``format(fmt, args...)``. */
+template <typename... T>
+FMT_NODISCARD FMT_INLINE auto formatted_size(format_string<T...> fmt,
+                                             T&&... args) -> size_t {
+  auto buf = detail::counting_buffer<>();
+  detail::vformat_to(buf, string_view(fmt), fmt::make_format_args(args...), {});
+  return buf.count();
+}
+
+FMT_API void vprint(string_view fmt, format_args args);
+FMT_API void vprint(std::FILE* f, string_view fmt, format_args args);
+
+/**
+  \rst
+  Formats ``args`` according to specifications in ``fmt`` and writes the output
+  to ``stdout``.
+
+  **Example**::
+
+    fmt::print("Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
+ */
+template <typename... T>
+FMT_INLINE void print(format_string<T...> fmt, T&&... args) {
+  const auto& vargs = fmt::make_format_args(args...);
+  return detail::is_utf8() ? vprint(fmt, vargs)
+                           : detail::vprint_mojibake(stdout, fmt, vargs);
+}
+
+/**
+  \rst
+  Formats ``args`` according to specifications in ``fmt`` and writes the
+  output to the file ``f``.
+
+  **Example**::
+
+    fmt::print(stderr, "Don't {}!", "panic");
+  \endrst
+ */
+template <typename... T>
+FMT_INLINE void print(std::FILE* f, format_string<T...> fmt, T&&... args) {
+  const auto& vargs = fmt::make_format_args(args...);
+  return detail::is_utf8() ? vprint(f, fmt, vargs)
+                           : detail::vprint_mojibake(f, fmt, vargs);
+}
+
+FMT_MODULE_EXPORT_END
+FMT_GCC_PRAGMA("GCC pop_options")
+FMT_END_NAMESPACE
+
+#ifdef FMT_HEADER_ONLY
+#  include "format.h"
+#endif
+#endif  // FMT_CORE_H_
diff --git a/libfuse/lib/fmt/format-inl.h b/libfuse/lib/fmt/format-inl.h
new file mode 100644
index 00000000..22b1ec8d
--- /dev/null
+++ b/libfuse/lib/fmt/format-inl.h
@@ -0,0 +1,1723 @@
+// Formatting library for C++ - implementation
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_FORMAT_INL_H_
+#define FMT_FORMAT_INL_H_
+
+#include <algorithm>
+#include <cctype>
+#include <cerrno>  // errno
+#include <climits>
+#include <cmath>
+#include <cstdarg>
+#include <cstring>  // std::memmove
+#include <cwchar>
+#include <exception>
+
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+#  include <locale>
+#endif
+
+#ifdef _WIN32
+#  include <io.h>  // _isatty
+#endif
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+
+FMT_FUNC void assert_fail(const char* file, int line, const char* message) {
+  // Use unchecked std::fprintf to avoid triggering another assertion when
+  // writing to stderr fails
+  std::fprintf(stderr, "%s:%d: assertion failed: %s", file, line, message);
+  // Chosen instead of std::abort to satisfy Clang in CUDA mode during device
+  // code pass.
+  std::terminate();
+}
+
+FMT_FUNC void throw_format_error(const char* message) {
+  FMT_THROW(format_error(message));
+}
+
+FMT_FUNC void format_error_code(detail::buffer<char>& out, int error_code,
+                                string_view message) noexcept {
+  // Report error code making sure that the output fits into
+  // inline_buffer_size to avoid dynamic memory allocation and potential
+  // bad_alloc.
+  out.try_resize(0);
+  static const char SEP[] = ": ";
+  static const char ERROR_STR[] = "error ";
+  // Subtract 2 to account for terminating null characters in SEP and ERROR_STR.
+  size_t error_code_size = sizeof(SEP) + sizeof(ERROR_STR) - 2;
+  auto abs_value = static_cast<uint32_or_64_or_128_t<int>>(error_code);
+  if (detail::is_negative(error_code)) {
+    abs_value = 0 - abs_value;
+    ++error_code_size;
+  }
+  error_code_size += detail::to_unsigned(detail::count_digits(abs_value));
+  auto it = buffer_appender<char>(out);
+  if (message.size() <= inline_buffer_size - error_code_size)
+    format_to(it, FMT_STRING("{}{}"), message, SEP);
+  format_to(it, FMT_STRING("{}{}"), ERROR_STR, error_code);
+  FMT_ASSERT(out.size() <= inline_buffer_size, "");
+}
+
+FMT_FUNC void report_error(format_func func, int error_code,
+                           const char* message) noexcept {
+  memory_buffer full_message;
+  func(full_message, error_code, message);
+  // Don't use fwrite_fully because the latter may throw.
+  if (std::fwrite(full_message.data(), full_message.size(), 1, stderr) > 0)
+    std::fputc('\n', stderr);
+}
+
+// A wrapper around fwrite that throws on error.
+inline void fwrite_fully(const void* ptr, size_t size, size_t count,
+                         FILE* stream) {
+  size_t written = std::fwrite(ptr, size, count, stream);
+  if (written < count)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+template <typename Locale>
+locale_ref::locale_ref(const Locale& loc) : locale_(&loc) {
+  static_assert(std::is_same<Locale, std::locale>::value, "");
+}
+
+template <typename Locale> Locale locale_ref::get() const {
+  static_assert(std::is_same<Locale, std::locale>::value, "");
+  return locale_ ? *static_cast<const std::locale*>(locale_) : std::locale();
+}
+
+template <typename Char>
+FMT_FUNC auto thousands_sep_impl(locale_ref loc) -> thousands_sep_result<Char> {
+  auto& facet = std::use_facet<std::numpunct<Char>>(loc.get<std::locale>());
+  auto grouping = facet.grouping();
+  auto thousands_sep = grouping.empty() ? Char() : facet.thousands_sep();
+  return {std::move(grouping), thousands_sep};
+}
+template <typename Char> FMT_FUNC Char decimal_point_impl(locale_ref loc) {
+  return std::use_facet<std::numpunct<Char>>(loc.get<std::locale>())
+      .decimal_point();
+}
+#else
+template <typename Char>
+FMT_FUNC auto thousands_sep_impl(locale_ref) -> thousands_sep_result<Char> {
+  return {"\03", FMT_STATIC_THOUSANDS_SEPARATOR};
+}
+template <typename Char> FMT_FUNC Char decimal_point_impl(locale_ref) {
+  return '.';
+}
+#endif
+}  // namespace detail
+
+#if !FMT_MSC_VERSION
+FMT_API FMT_FUNC format_error::~format_error() noexcept = default;
+#endif
+
+FMT_FUNC std::system_error vsystem_error(int error_code, string_view format_str,
+                                         format_args args) {
+  auto ec = std::error_code(error_code, std::generic_category());
+  return std::system_error(ec, vformat(format_str, args));
+}
+
+namespace detail {
+
+template <typename F> inline bool operator==(basic_fp<F> x, basic_fp<F> y) {
+  return x.f == y.f && x.e == y.e;
+}
+
+// Compilers should be able to optimize this into the ror instruction.
+FMT_CONSTEXPR inline uint32_t rotr(uint32_t n, uint32_t r) noexcept {
+  r &= 31;
+  return (n >> r) | (n << (32 - r));
+}
+FMT_CONSTEXPR inline uint64_t rotr(uint64_t n, uint32_t r) noexcept {
+  r &= 63;
+  return (n >> r) | (n << (64 - r));
+}
+
+// Computes 128-bit result of multiplication of two 64-bit unsigned integers.
+inline uint128_fallback umul128(uint64_t x, uint64_t y) noexcept {
+#if FMT_USE_INT128
+  auto p = static_cast<uint128_opt>(x) * static_cast<uint128_opt>(y);
+  return {static_cast<uint64_t>(p >> 64), static_cast<uint64_t>(p)};
+#elif defined(_MSC_VER) && defined(_M_X64)
+  auto result = uint128_fallback();
+  result.lo_ = _umul128(x, y, &result.hi_);
+  return result;
+#else
+  const uint64_t mask = static_cast<uint64_t>(max_value<uint32_t>());
+
+  uint64_t a = x >> 32;
+  uint64_t b = x & mask;
+  uint64_t c = y >> 32;
+  uint64_t d = y & mask;
+
+  uint64_t ac = a * c;
+  uint64_t bc = b * c;
+  uint64_t ad = a * d;
+  uint64_t bd = b * d;
+
+  uint64_t intermediate = (bd >> 32) + (ad & mask) + (bc & mask);
+
+  return {ac + (intermediate >> 32) + (ad >> 32) + (bc >> 32),
+          (intermediate << 32) + (bd & mask)};
+#endif
+}
+
+// Implementation of Dragonbox algorithm: https://github.com/jk-jeon/dragonbox.
+namespace dragonbox {
+// Computes upper 64 bits of multiplication of two 64-bit unsigned integers.
+inline uint64_t umul128_upper64(uint64_t x, uint64_t y) noexcept {
+#if FMT_USE_INT128
+  auto p = static_cast<uint128_opt>(x) * static_cast<uint128_opt>(y);
+  return static_cast<uint64_t>(p >> 64);
+#elif defined(_MSC_VER) && defined(_M_X64)
+  return __umulh(x, y);
+#else
+  return umul128(x, y).high();
+#endif
+}
+
+// Computes upper 128 bits of multiplication of a 64-bit unsigned integer and a
+// 128-bit unsigned integer.
+inline uint128_fallback umul192_upper128(uint64_t x,
+                                         uint128_fallback y) noexcept {
+  uint128_fallback r = umul128(x, y.high());
+  r += umul128_upper64(x, y.low());
+  return r;
+}
+
+// Computes upper 64 bits of multiplication of a 32-bit unsigned integer and a
+// 64-bit unsigned integer.
+inline uint64_t umul96_upper64(uint32_t x, uint64_t y) noexcept {
+  return umul128_upper64(static_cast<uint64_t>(x) << 32, y);
+}
+
+// Computes lower 128 bits of multiplication of a 64-bit unsigned integer and a
+// 128-bit unsigned integer.
+inline uint128_fallback umul192_lower128(uint64_t x,
+                                         uint128_fallback y) noexcept {
+  uint64_t high = x * y.high();
+  uint128_fallback high_low = umul128(x, y.low());
+  return {high + high_low.high(), high_low.low()};
+}
+
+// Computes lower 64 bits of multiplication of a 32-bit unsigned integer and a
+// 64-bit unsigned integer.
+inline uint64_t umul96_lower64(uint32_t x, uint64_t y) noexcept {
+  return x * y;
+}
+
+// Computes floor(log10(pow(2, e))) for e in [-2620, 2620] using the method from
+// https://fmt.dev/papers/Dragonbox.pdf#page=28, section 6.1.
+inline int floor_log10_pow2(int e) noexcept {
+  FMT_ASSERT(e <= 2620 && e >= -2620, "too large exponent");
+  static_assert((-1 >> 1) == -1, "right shift is not arithmetic");
+  return (e * 315653) >> 20;
+}
+
+// Various fast log computations.
+inline int floor_log2_pow10(int e) noexcept {
+  FMT_ASSERT(e <= 1233 && e >= -1233, "too large exponent");
+  return (e * 1741647) >> 19;
+}
+inline int floor_log10_pow2_minus_log10_4_over_3(int e) noexcept {
+  FMT_ASSERT(e <= 2936 && e >= -2985, "too large exponent");
+  return (e * 631305 - 261663) >> 21;
+}
+
+static constexpr struct {
+  uint32_t divisor;
+  int shift_amount;
+} div_small_pow10_infos[] = {{10, 16}, {100, 16}};
+
+// Replaces n by floor(n / pow(10, N)) returning true if and only if n is
+// divisible by pow(10, N).
+// Precondition: n <= pow(10, N + 1).
+template <int N>
+bool check_divisibility_and_divide_by_pow10(uint32_t& n) noexcept {
+  // The numbers below are chosen such that:
+  //   1. floor(n/d) = floor(nm / 2^k) where d=10 or d=100,
+  //   2. nm mod 2^k < m if and only if n is divisible by d,
+  // where m is magic_number, k is shift_amount
+  // and d is divisor.
+  //
+  // Item 1 is a common technique of replacing division by a constant with
+  // multiplication, see e.g. "Division by Invariant Integers Using
+  // Multiplication" by Granlund and Montgomery (1994). magic_number (m) is set
+  // to ceil(2^k/d) for large enough k.
+  // The idea for item 2 originates from Schubfach.
+  constexpr auto info = div_small_pow10_infos[N - 1];
+  FMT_ASSERT(n <= info.divisor * 10, "n is too large");
+  constexpr uint32_t magic_number =
+      (1u << info.shift_amount) / info.divisor + 1;
+  n *= magic_number;
+  const uint32_t comparison_mask = (1u << info.shift_amount) - 1;
+  bool result = (n & comparison_mask) < magic_number;
+  n >>= info.shift_amount;
+  return result;
+}
+
+// Computes floor(n / pow(10, N)) for small n and N.
+// Precondition: n <= pow(10, N + 1).
+template <int N> uint32_t small_division_by_pow10(uint32_t n) noexcept {
+  constexpr auto info = div_small_pow10_infos[N - 1];
+  FMT_ASSERT(n <= info.divisor * 10, "n is too large");
+  constexpr uint32_t magic_number =
+      (1u << info.shift_amount) / info.divisor + 1;
+  return (n * magic_number) >> info.shift_amount;
+}
+
+// Computes floor(n / 10^(kappa + 1)) (float)
+inline uint32_t divide_by_10_to_kappa_plus_1(uint32_t n) noexcept {
+  // 1374389535 = ceil(2^37/100)
+  return static_cast<uint32_t>((static_cast<uint64_t>(n) * 1374389535) >> 37);
+}
+// Computes floor(n / 10^(kappa + 1)) (double)
+inline uint64_t divide_by_10_to_kappa_plus_1(uint64_t n) noexcept {
+  // 2361183241434822607 = ceil(2^(64+7)/1000)
+  return umul128_upper64(n, 2361183241434822607ull) >> 7;
+}
+
+// Various subroutines using pow10 cache
+template <class T> struct cache_accessor;
+
+template <> struct cache_accessor<float> {
+  using carrier_uint = float_info<float>::carrier_uint;
+  using cache_entry_type = uint64_t;
+
+  static uint64_t get_cached_power(int k) noexcept {
+    FMT_ASSERT(k >= float_info<float>::min_k && k <= float_info<float>::max_k,
+               "k is out of range");
+    static constexpr const uint64_t pow10_significands[] = {
+        0x81ceb32c4b43fcf5, 0xa2425ff75e14fc32, 0xcad2f7f5359a3b3f,
+        0xfd87b5f28300ca0e, 0x9e74d1b791e07e49, 0xc612062576589ddb,
+        0xf79687aed3eec552, 0x9abe14cd44753b53, 0xc16d9a0095928a28,
+        0xf1c90080baf72cb2, 0x971da05074da7bef, 0xbce5086492111aeb,
+        0xec1e4a7db69561a6, 0x9392ee8e921d5d08, 0xb877aa3236a4b44a,
+        0xe69594bec44de15c, 0x901d7cf73ab0acda, 0xb424dc35095cd810,
+        0xe12e13424bb40e14, 0x8cbccc096f5088cc, 0xafebff0bcb24aaff,
+        0xdbe6fecebdedd5bf, 0x89705f4136b4a598, 0xabcc77118461cefd,
+        0xd6bf94d5e57a42bd, 0x8637bd05af6c69b6, 0xa7c5ac471b478424,
+        0xd1b71758e219652c, 0x83126e978d4fdf3c, 0xa3d70a3d70a3d70b,
+        0xcccccccccccccccd, 0x8000000000000000, 0xa000000000000000,
+        0xc800000000000000, 0xfa00000000000000, 0x9c40000000000000,
+        0xc350000000000000, 0xf424000000000000, 0x9896800000000000,
+        0xbebc200000000000, 0xee6b280000000000, 0x9502f90000000000,
+        0xba43b74000000000, 0xe8d4a51000000000, 0x9184e72a00000000,
+        0xb5e620f480000000, 0xe35fa931a0000000, 0x8e1bc9bf04000000,
+        0xb1a2bc2ec5000000, 0xde0b6b3a76400000, 0x8ac7230489e80000,
+        0xad78ebc5ac620000, 0xd8d726b7177a8000, 0x878678326eac9000,
+        0xa968163f0a57b400, 0xd3c21bcecceda100, 0x84595161401484a0,
+        0xa56fa5b99019a5c8, 0xcecb8f27f4200f3a, 0x813f3978f8940985,
+        0xa18f07d736b90be6, 0xc9f2c9cd04674edf, 0xfc6f7c4045812297,
+        0x9dc5ada82b70b59e, 0xc5371912364ce306, 0xf684df56c3e01bc7,
+        0x9a130b963a6c115d, 0xc097ce7bc90715b4, 0xf0bdc21abb48db21,
+        0x96769950b50d88f5, 0xbc143fa4e250eb32, 0xeb194f8e1ae525fe,
+        0x92efd1b8d0cf37bf, 0xb7abc627050305ae, 0xe596b7b0c643c71a,
+        0x8f7e32ce7bea5c70, 0xb35dbf821ae4f38c, 0xe0352f62a19e306f};
+    return pow10_significands[k - float_info<float>::min_k];
+  }
+
+  struct compute_mul_result {
+    carrier_uint result;
+    bool is_integer;
+  };
+  struct compute_mul_parity_result {
+    bool parity;
+    bool is_integer;
+  };
+
+  static compute_mul_result compute_mul(
+      carrier_uint u, const cache_entry_type& cache) noexcept {
+    auto r = umul96_upper64(u, cache);
+    return {static_cast<carrier_uint>(r >> 32),
+            static_cast<carrier_uint>(r) == 0};
+  }
+
+  static uint32_t compute_delta(const cache_entry_type& cache,
+                                int beta) noexcept {
+    return static_cast<uint32_t>(cache >> (64 - 1 - beta));
+  }
+
+  static compute_mul_parity_result compute_mul_parity(
+      carrier_uint two_f, const cache_entry_type& cache, int beta) noexcept {
+    FMT_ASSERT(beta >= 1, "");
+    FMT_ASSERT(beta < 64, "");
+
+    auto r = umul96_lower64(two_f, cache);
+    return {((r >> (64 - beta)) & 1) != 0,
+            static_cast<uint32_t>(r >> (32 - beta)) == 0};
+  }
+
+  static carrier_uint compute_left_endpoint_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept {
+    return static_cast<carrier_uint>(
+        (cache - (cache >> (num_significand_bits<float>() + 2))) >>
+        (64 - num_significand_bits<float>() - 1 - beta));
+  }
+
+  static carrier_uint compute_right_endpoint_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept {
+    return static_cast<carrier_uint>(
+        (cache + (cache >> (num_significand_bits<float>() + 1))) >>
+        (64 - num_significand_bits<float>() - 1 - beta));
+  }
+
+  static carrier_uint compute_round_up_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept {
+    return (static_cast<carrier_uint>(
+                cache >> (64 - num_significand_bits<float>() - 2 - beta)) +
+            1) /
+           2;
+  }
+};
+
+template <> struct cache_accessor<double> {
+  using carrier_uint = float_info<double>::carrier_uint;
+  using cache_entry_type = uint128_fallback;
+
+  static uint128_fallback get_cached_power(int k) noexcept {
+    FMT_ASSERT(k >= float_info<double>::min_k && k <= float_info<double>::max_k,
+               "k is out of range");
+
+    static constexpr const uint128_fallback pow10_significands[] = {
+#if FMT_USE_FULL_CACHE_DRAGONBOX
+      {0xff77b1fcbebcdc4f, 0x25e8e89c13bb0f7b},
+      {0x9faacf3df73609b1, 0x77b191618c54e9ad},
+      {0xc795830d75038c1d, 0xd59df5b9ef6a2418},
+      {0xf97ae3d0d2446f25, 0x4b0573286b44ad1e},
+      {0x9becce62836ac577, 0x4ee367f9430aec33},
+      {0xc2e801fb244576d5, 0x229c41f793cda740},
+      {0xf3a20279ed56d48a, 0x6b43527578c11110},
+      {0x9845418c345644d6, 0x830a13896b78aaaa},
+      {0xbe5691ef416bd60c, 0x23cc986bc656d554},
+      {0xedec366b11c6cb8f, 0x2cbfbe86b7ec8aa9},
+      {0x94b3a202eb1c3f39, 0x7bf7d71432f3d6aa},
+      {0xb9e08a83a5e34f07, 0xdaf5ccd93fb0cc54},
+      {0xe858ad248f5c22c9, 0xd1b3400f8f9cff69},
+      {0x91376c36d99995be, 0x23100809b9c21fa2},
+      {0xb58547448ffffb2d, 0xabd40a0c2832a78b},
+      {0xe2e69915b3fff9f9, 0x16c90c8f323f516d},
+      {0x8dd01fad907ffc3b, 0xae3da7d97f6792e4},
+      {0xb1442798f49ffb4a, 0x99cd11cfdf41779d},
+      {0xdd95317f31c7fa1d, 0x40405643d711d584},
+      {0x8a7d3eef7f1cfc52, 0x482835ea666b2573},
+      {0xad1c8eab5ee43b66, 0xda3243650005eed0},
+      {0xd863b256369d4a40, 0x90bed43e40076a83},
+      {0x873e4f75e2224e68, 0x5a7744a6e804a292},
+      {0xa90de3535aaae202, 0x711515d0a205cb37},
+      {0xd3515c2831559a83, 0x0d5a5b44ca873e04},
+      {0x8412d9991ed58091, 0xe858790afe9486c3},
+      {0xa5178fff668ae0b6, 0x626e974dbe39a873},
+      {0xce5d73ff402d98e3, 0xfb0a3d212dc81290},
+      {0x80fa687f881c7f8e, 0x7ce66634bc9d0b9a},
+      {0xa139029f6a239f72, 0x1c1fffc1ebc44e81},
+      {0xc987434744ac874e, 0xa327ffb266b56221},
+      {0xfbe9141915d7a922, 0x4bf1ff9f0062baa9},
+      {0x9d71ac8fada6c9b5, 0x6f773fc3603db4aa},
+      {0xc4ce17b399107c22, 0xcb550fb4384d21d4},
+      {0xf6019da07f549b2b, 0x7e2a53a146606a49},
+      {0x99c102844f94e0fb, 0x2eda7444cbfc426e},
+      {0xc0314325637a1939, 0xfa911155fefb5309},
+      {0xf03d93eebc589f88, 0x793555ab7eba27cb},
+      {0x96267c7535b763b5, 0x4bc1558b2f3458df},
+      {0xbbb01b9283253ca2, 0x9eb1aaedfb016f17},
+      {0xea9c227723ee8bcb, 0x465e15a979c1cadd},
+      {0x92a1958a7675175f, 0x0bfacd89ec191eca},
+      {0xb749faed14125d36, 0xcef980ec671f667c},
+      {0xe51c79a85916f484, 0x82b7e12780e7401b},
+      {0x8f31cc0937ae58d2, 0xd1b2ecb8b0908811},
+      {0xb2fe3f0b8599ef07, 0x861fa7e6dcb4aa16},
+      {0xdfbdcece67006ac9, 0x67a791e093e1d49b},
+      {0x8bd6a141006042bd, 0xe0c8bb2c5c6d24e1},
+      {0xaecc49914078536d, 0x58fae9f773886e19},
+      {0xda7f5bf590966848, 0xaf39a475506a899f},
+      {0x888f99797a5e012d, 0x6d8406c952429604},
+      {0xaab37fd7d8f58178, 0xc8e5087ba6d33b84},
+      {0xd5605fcdcf32e1d6, 0xfb1e4a9a90880a65},
+      {0x855c3be0a17fcd26, 0x5cf2eea09a550680},
+      {0xa6b34ad8c9dfc06f, 0xf42faa48c0ea481f},
+      {0xd0601d8efc57b08b, 0xf13b94daf124da27},
+      {0x823c12795db6ce57, 0x76c53d08d6b70859},
+      {0xa2cb1717b52481ed, 0x54768c4b0c64ca6f},
+      {0xcb7ddcdda26da268, 0xa9942f5dcf7dfd0a},
+      {0xfe5d54150b090b02, 0xd3f93b35435d7c4d},
+      {0x9efa548d26e5a6e1, 0xc47bc5014a1a6db0},
+      {0xc6b8e9b0709f109a, 0x359ab6419ca1091c},
+      {0xf867241c8cc6d4c0, 0xc30163d203c94b63},
+      {0x9b407691d7fc44f8, 0x79e0de63425dcf1e},
+      {0xc21094364dfb5636, 0x985915fc12f542e5},
+      {0xf294b943e17a2bc4, 0x3e6f5b7b17b2939e},
+      {0x979cf3ca6cec5b5a, 0xa705992ceecf9c43},
+      {0xbd8430bd08277231, 0x50c6ff782a838354},
+      {0xece53cec4a314ebd, 0xa4f8bf5635246429},
+      {0x940f4613ae5ed136, 0x871b7795e136be9a},
+      {0xb913179899f68584, 0x28e2557b59846e40},
+      {0xe757dd7ec07426e5, 0x331aeada2fe589d0},
+      {0x9096ea6f3848984f, 0x3ff0d2c85def7622},
+      {0xb4bca50b065abe63, 0x0fed077a756b53aa},
+      {0xe1ebce4dc7f16dfb, 0xd3e8495912c62895},
+      {0x8d3360f09cf6e4bd, 0x64712dd7abbbd95d},
+      {0xb080392cc4349dec, 0xbd8d794d96aacfb4},
+      {0xdca04777f541c567, 0xecf0d7a0fc5583a1},
+      {0x89e42caaf9491b60, 0xf41686c49db57245},
+      {0xac5d37d5b79b6239, 0x311c2875c522ced6},
+      {0xd77485cb25823ac7, 0x7d633293366b828c},
+      {0x86a8d39ef77164bc, 0xae5dff9c02033198},
+      {0xa8530886b54dbdeb, 0xd9f57f830283fdfd},
+      {0xd267caa862a12d66, 0xd072df63c324fd7c},
+      {0x8380dea93da4bc60, 0x4247cb9e59f71e6e},
+      {0xa46116538d0deb78, 0x52d9be85f074e609},
+      {0xcd795be870516656, 0x67902e276c921f8c},
+      {0x806bd9714632dff6, 0x00ba1cd8a3db53b7},
+      {0xa086cfcd97bf97f3, 0x80e8a40eccd228a5},
+      {0xc8a883c0fdaf7df0, 0x6122cd128006b2ce},
+      {0xfad2a4b13d1b5d6c, 0x796b805720085f82},
+      {0x9cc3a6eec6311a63, 0xcbe3303674053bb1},
+      {0xc3f490aa77bd60fc, 0xbedbfc4411068a9d},
+      {0xf4f1b4d515acb93b, 0xee92fb5515482d45},
+      {0x991711052d8bf3c5, 0x751bdd152d4d1c4b},
+      {0xbf5cd54678eef0b6, 0xd262d45a78a0635e},
+      {0xef340a98172aace4, 0x86fb897116c87c35},
+      {0x9580869f0e7aac0e, 0xd45d35e6ae3d4da1},
+      {0xbae0a846d2195712, 0x8974836059cca10a},
+      {0xe998d258869facd7, 0x2bd1a438703fc94c},
+      {0x91ff83775423cc06, 0x7b6306a34627ddd0},
+      {0xb67f6455292cbf08, 0x1a3bc84c17b1d543},
+      {0xe41f3d6a7377eeca, 0x20caba5f1d9e4a94},
+      {0x8e938662882af53e, 0x547eb47b7282ee9d},
+      {0xb23867fb2a35b28d, 0xe99e619a4f23aa44},
+      {0xdec681f9f4c31f31, 0x6405fa00e2ec94d5},
+      {0x8b3c113c38f9f37e, 0xde83bc408dd3dd05},
+      {0xae0b158b4738705e, 0x9624ab50b148d446},
+      {0xd98ddaee19068c76, 0x3badd624dd9b0958},
+      {0x87f8a8d4cfa417c9, 0xe54ca5d70a80e5d7},
+      {0xa9f6d30a038d1dbc, 0x5e9fcf4ccd211f4d},
+      {0xd47487cc8470652b, 0x7647c32000696720},
+      {0x84c8d4dfd2c63f3b, 0x29ecd9f40041e074},
+      {0xa5fb0a17c777cf09, 0xf468107100525891},
+      {0xcf79cc9db955c2cc, 0x7182148d4066eeb5},
+      {0x81ac1fe293d599bf, 0xc6f14cd848405531},
+      {0xa21727db38cb002f, 0xb8ada00e5a506a7d},
+      {0xca9cf1d206fdc03b, 0xa6d90811f0e4851d},
+      {0xfd442e4688bd304a, 0x908f4a166d1da664},
+      {0x9e4a9cec15763e2e, 0x9a598e4e043287ff},
+      {0xc5dd44271ad3cdba, 0x40eff1e1853f29fe},
+      {0xf7549530e188c128, 0xd12bee59e68ef47d},
+      {0x9a94dd3e8cf578b9, 0x82bb74f8301958cf},
+      {0xc13a148e3032d6e7, 0xe36a52363c1faf02},
+      {0xf18899b1bc3f8ca1, 0xdc44e6c3cb279ac2},
+      {0x96f5600f15a7b7e5, 0x29ab103a5ef8c0ba},
+      {0xbcb2b812db11a5de, 0x7415d448f6b6f0e8},
+      {0xebdf661791d60f56, 0x111b495b3464ad22},
+      {0x936b9fcebb25c995, 0xcab10dd900beec35},
+      {0xb84687c269ef3bfb, 0x3d5d514f40eea743},
+      {0xe65829b3046b0afa, 0x0cb4a5a3112a5113},
+      {0x8ff71a0fe2c2e6dc, 0x47f0e785eaba72ac},
+      {0xb3f4e093db73a093, 0x59ed216765690f57},
+      {0xe0f218b8d25088b8, 0x306869c13ec3532d},
+      {0x8c974f7383725573, 0x1e414218c73a13fc},
+      {0xafbd2350644eeacf, 0xe5d1929ef90898fb},
+      {0xdbac6c247d62a583, 0xdf45f746b74abf3a},
+      {0x894bc396ce5da772, 0x6b8bba8c328eb784},
+      {0xab9eb47c81f5114f, 0x066ea92f3f326565},
+      {0xd686619ba27255a2, 0xc80a537b0efefebe},
+      {0x8613fd0145877585, 0xbd06742ce95f5f37},
+      {0xa798fc4196e952e7, 0x2c48113823b73705},
+      {0xd17f3b51fca3a7a0, 0xf75a15862ca504c6},
+      {0x82ef85133de648c4, 0x9a984d73dbe722fc},
+      {0xa3ab66580d5fdaf5, 0xc13e60d0d2e0ebbb},
+      {0xcc963fee10b7d1b3, 0x318df905079926a9},
+      {0xffbbcfe994e5c61f, 0xfdf17746497f7053},
+      {0x9fd561f1fd0f9bd3, 0xfeb6ea8bedefa634},
+      {0xc7caba6e7c5382c8, 0xfe64a52ee96b8fc1},
+      {0xf9bd690a1b68637b, 0x3dfdce7aa3c673b1},
+      {0x9c1661a651213e2d, 0x06bea10ca65c084f},
+      {0xc31bfa0fe5698db8, 0x486e494fcff30a63},
+      {0xf3e2f893dec3f126, 0x5a89dba3c3efccfb},
+      {0x986ddb5c6b3a76b7, 0xf89629465a75e01d},
+      {0xbe89523386091465, 0xf6bbb397f1135824},
+      {0xee2ba6c0678b597f, 0x746aa07ded582e2d},
+      {0x94db483840b717ef, 0xa8c2a44eb4571cdd},
+      {0xba121a4650e4ddeb, 0x92f34d62616ce414},
+      {0xe896a0d7e51e1566, 0x77b020baf9c81d18},
+      {0x915e2486ef32cd60, 0x0ace1474dc1d122f},
+      {0xb5b5ada8aaff80b8, 0x0d819992132456bb},
+      {0xe3231912d5bf60e6, 0x10e1fff697ed6c6a},
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+      {0xbeeefb584aff8603, 0xaafb550ffacfd8fb},
+      {0xeeaaba2e5dbf6784, 0x95ba2a53f983cf39},
+      {0x952ab45cfa97a0b2, 0xdd945a747bf26184},
+      {0xba756174393d88df, 0x94f971119aeef9e5},
+      {0xe912b9d1478ceb17, 0x7a37cd5601aab85e},
+      {0x91abb422ccb812ee, 0xac62e055c10ab33b},
+      {0xb616a12b7fe617aa, 0x577b986b314d600a},
+      {0xe39c49765fdf9d94, 0xed5a7e85fda0b80c},
+      {0x8e41ade9fbebc27d, 0x14588f13be847308},
+      {0xb1d219647ae6b31c, 0x596eb2d8ae258fc9},
+      {0xde469fbd99a05fe3, 0x6fca5f8ed9aef3bc},
+      {0x8aec23d680043bee, 0x25de7bb9480d5855},
+      {0xada72ccc20054ae9, 0xaf561aa79a10ae6b},
+      {0xd910f7ff28069da4, 0x1b2ba1518094da05},
+      {0x87aa9aff79042286, 0x90fb44d2f05d0843},
+      {0xa99541bf57452b28, 0x353a1607ac744a54},
+      {0xd3fa922f2d1675f2, 0x42889b8997915ce9},
+      {0x847c9b5d7c2e09b7, 0x69956135febada12},
+      {0xa59bc234db398c25, 0x43fab9837e699096},
+      {0xcf02b2c21207ef2e, 0x94f967e45e03f4bc},
+      {0x8161afb94b44f57d, 0x1d1be0eebac278f6},
+      {0xa1ba1ba79e1632dc, 0x6462d92a69731733},
+      {0xca28a291859bbf93, 0x7d7b8f7503cfdcff},
+      {0xfcb2cb35e702af78, 0x5cda735244c3d43f},
+      {0x9defbf01b061adab, 0x3a0888136afa64a8},
+      {0xc56baec21c7a1916, 0x088aaa1845b8fdd1},
+      {0xf6c69a72a3989f5b, 0x8aad549e57273d46},
+      {0x9a3c2087a63f6399, 0x36ac54e2f678864c},
+      {0xc0cb28a98fcf3c7f, 0x84576a1bb416a7de},
+      {0xf0fdf2d3f3c30b9f, 0x656d44a2a11c51d6},
+      {0x969eb7c47859e743, 0x9f644ae5a4b1b326},
+      {0xbc4665b596706114, 0x873d5d9f0dde1fef},
+      {0xeb57ff22fc0c7959, 0xa90cb506d155a7eb},
+      {0x9316ff75dd87cbd8, 0x09a7f12442d588f3},
+      {0xb7dcbf5354e9bece, 0x0c11ed6d538aeb30},
+      {0xe5d3ef282a242e81, 0x8f1668c8a86da5fb},
+      {0x8fa475791a569d10, 0xf96e017d694487bd},
+      {0xb38d92d760ec4455, 0x37c981dcc395a9ad},
+      {0xe070f78d3927556a, 0x85bbe253f47b1418},
+      {0x8c469ab843b89562, 0x93956d7478ccec8f},
+      {0xaf58416654a6babb, 0x387ac8d1970027b3},
+      {0xdb2e51bfe9d0696a, 0x06997b05fcc0319f},
+      {0x88fcf317f22241e2, 0x441fece3bdf81f04},
+      {0xab3c2fddeeaad25a, 0xd527e81cad7626c4},
+      {0xd60b3bd56a5586f1, 0x8a71e223d8d3b075},
+      {0x85c7056562757456, 0xf6872d5667844e4a},
+      {0xa738c6bebb12d16c, 0xb428f8ac016561dc},
+      {0xd106f86e69d785c7, 0xe13336d701beba53},
+      {0x82a45b450226b39c, 0xecc0024661173474},
+      {0xa34d721642b06084, 0x27f002d7f95d0191},
+      {0xcc20ce9bd35c78a5, 0x31ec038df7b441f5},
+      {0xff290242c83396ce, 0x7e67047175a15272},
+      {0x9f79a169bd203e41, 0x0f0062c6e984d387},
+      {0xc75809c42c684dd1, 0x52c07b78a3e60869},
+      {0xf92e0c3537826145, 0xa7709a56ccdf8a83},
+      {0x9bbcc7a142b17ccb, 0x88a66076400bb692},
+      {0xc2abf989935ddbfe, 0x6acff893d00ea436},
+      {0xf356f7ebf83552fe, 0x0583f6b8c4124d44},
+      {0x98165af37b2153de, 0xc3727a337a8b704b},
+      {0xbe1bf1b059e9a8d6, 0x744f18c0592e4c5d},
+      {0xeda2ee1c7064130c, 0x1162def06f79df74},
+      {0x9485d4d1c63e8be7, 0x8addcb5645ac2ba9},
+      {0xb9a74a0637ce2ee1, 0x6d953e2bd7173693},
+      {0xe8111c87c5c1ba99, 0xc8fa8db6ccdd0438},
+      {0x910ab1d4db9914a0, 0x1d9c9892400a22a3},
+      {0xb54d5e4a127f59c8, 0x2503beb6d00cab4c},
+      {0xe2a0b5dc971f303a, 0x2e44ae64840fd61e},
+      {0x8da471a9de737e24, 0x5ceaecfed289e5d3},
+      {0xb10d8e1456105dad, 0x7425a83e872c5f48},
+      {0xdd50f1996b947518, 0xd12f124e28f7771a},
+      {0x8a5296ffe33cc92f, 0x82bd6b70d99aaa70},
+      {0xace73cbfdc0bfb7b, 0x636cc64d1001550c},
+      {0xd8210befd30efa5a, 0x3c47f7e05401aa4f},
+      {0x8714a775e3e95c78, 0x65acfaec34810a72},
+      {0xa8d9d1535ce3b396, 0x7f1839a741a14d0e},
+      {0xd31045a8341ca07c, 0x1ede48111209a051},
+      {0x83ea2b892091e44d, 0x934aed0aab460433},
+      {0xa4e4b66b68b65d60, 0xf81da84d56178540},
+      {0xce1de40642e3f4b9, 0x36251260ab9d668f},
+      {0x80d2ae83e9ce78f3, 0xc1d72b7c6b42601a},
+      {0xa1075a24e4421730, 0xb24cf65b8612f820},
+      {0xc94930ae1d529cfc, 0xdee033f26797b628},
+      {0xfb9b7cd9a4a7443c, 0x169840ef017da3b2},
+      {0x9d412e0806e88aa5, 0x8e1f289560ee864f},
+      {0xc491798a08a2ad4e, 0xf1a6f2bab92a27e3},
+      {0xf5b5d7ec8acb58a2, 0xae10af696774b1dc},
+      {0x9991a6f3d6bf1765, 0xacca6da1e0a8ef2a},
+      {0xbff610b0cc6edd3f, 0x17fd090a58d32af4},
+      {0xeff394dcff8a948e, 0xddfc4b4cef07f5b1},
+      {0x95f83d0a1fb69cd9, 0x4abdaf101564f98f},
+      {0xbb764c4ca7a4440f, 0x9d6d1ad41abe37f2},
+      {0xea53df5fd18d5513, 0x84c86189216dc5ee},
+      {0x92746b9be2f8552c, 0x32fd3cf5b4e49bb5},
+      {0xb7118682dbb66a77, 0x3fbc8c33221dc2a2},
+      {0xe4d5e82392a40515, 0x0fabaf3feaa5334b},
+      {0x8f05b1163ba6832d, 0x29cb4d87f2a7400f},
+      {0xb2c71d5bca9023f8, 0x743e20e9ef511013},
+      {0xdf78e4b2bd342cf6, 0x914da9246b255417},
+      {0x8bab8eefb6409c1a, 0x1ad089b6c2f7548f},
+      {0xae9672aba3d0c320, 0xa184ac2473b529b2},
+      {0xda3c0f568cc4f3e8, 0xc9e5d72d90a2741f},
+      {0x8865899617fb1871, 0x7e2fa67c7a658893},
+      {0xaa7eebfb9df9de8d, 0xddbb901b98feeab8},
+      {0xd51ea6fa85785631, 0x552a74227f3ea566},
+      {0x8533285c936b35de, 0xd53a88958f872760},
+      {0xa67ff273b8460356, 0x8a892abaf368f138},
+      {0xd01fef10a657842c, 0x2d2b7569b0432d86},
+      {0x8213f56a67f6b29b, 0x9c3b29620e29fc74},
+      {0xa298f2c501f45f42, 0x8349f3ba91b47b90},
+      {0xcb3f2f7642717713, 0x241c70a936219a74},
+      {0xfe0efb53d30dd4d7, 0xed238cd383aa0111},
+      {0x9ec95d1463e8a506, 0xf4363804324a40ab},
+      {0xc67bb4597ce2ce48, 0xb143c6053edcd0d6},
+      {0xf81aa16fdc1b81da, 0xdd94b7868e94050b},
+      {0x9b10a4e5e9913128, 0xca7cf2b4191c8327},
+      {0xc1d4ce1f63f57d72, 0xfd1c2f611f63a3f1},
+      {0xf24a01a73cf2dccf, 0xbc633b39673c8ced},
+      {0x976e41088617ca01, 0xd5be0503e085d814},
+      {0xbd49d14aa79dbc82, 0x4b2d8644d8a74e19},
+      {0xec9c459d51852ba2, 0xddf8e7d60ed1219f},
+      {0x93e1ab8252f33b45, 0xcabb90e5c942b504},
+      {0xb8da1662e7b00a17, 0x3d6a751f3b936244},
+      {0xe7109bfba19c0c9d, 0x0cc512670a783ad5},
+      {0x906a617d450187e2, 0x27fb2b80668b24c6},
+      {0xb484f9dc9641e9da, 0xb1f9f660802dedf7},
+      {0xe1a63853bbd26451, 0x5e7873f8a0396974},
+      {0x8d07e33455637eb2, 0xdb0b487b6423e1e9},
+      {0xb049dc016abc5e5f, 0x91ce1a9a3d2cda63},
+      {0xdc5c5301c56b75f7, 0x7641a140cc7810fc},
+      {0x89b9b3e11b6329ba, 0xa9e904c87fcb0a9e},
+      {0xac2820d9623bf429, 0x546345fa9fbdcd45},
+      {0xd732290fbacaf133, 0xa97c177947ad4096},
+      {0x867f59a9d4bed6c0, 0x49ed8eabcccc485e},
+      {0xa81f301449ee8c70, 0x5c68f256bfff5a75},
+      {0xd226fc195c6a2f8c, 0x73832eec6fff3112},
+      {0x83585d8fd9c25db7, 0xc831fd53c5ff7eac},
+      {0xa42e74f3d032f525, 0xba3e7ca8b77f5e56},
+      {0xcd3a1230c43fb26f, 0x28ce1bd2e55f35ec},
+      {0x80444b5e7aa7cf85, 0x7980d163cf5b81b4},
+      {0xa0555e361951c366, 0xd7e105bcc3326220},
+      {0xc86ab5c39fa63440, 0x8dd9472bf3fefaa8},
+      {0xfa856334878fc150, 0xb14f98f6f0feb952},
+      {0x9c935e00d4b9d8d2, 0x6ed1bf9a569f33d4},
+      {0xc3b8358109e84f07, 0x0a862f80ec4700c9},
+      {0xf4a642e14c6262c8, 0xcd27bb612758c0fb},
+      {0x98e7e9cccfbd7dbd, 0x8038d51cb897789d},
+      {0xbf21e44003acdd2c, 0xe0470a63e6bd56c4},
+      {0xeeea5d5004981478, 0x1858ccfce06cac75},
+      {0x95527a5202df0ccb, 0x0f37801e0c43ebc9},
+      {0xbaa718e68396cffd, 0xd30560258f54e6bb},
+      {0xe950df20247c83fd, 0x47c6b82ef32a206a},
+      {0x91d28b7416cdd27e, 0x4cdc331d57fa5442},
+      {0xb6472e511c81471d, 0xe0133fe4adf8e953},
+      {0xe3d8f9e563a198e5, 0x58180fddd97723a7},
+      {0x8e679c2f5e44ff8f, 0x570f09eaa7ea7649},
+      {0xb201833b35d63f73, 0x2cd2cc6551e513db},
+      {0xde81e40a034bcf4f, 0xf8077f7ea65e58d2},
+      {0x8b112e86420f6191, 0xfb04afaf27faf783},
+      {0xadd57a27d29339f6, 0x79c5db9af1f9b564},
+      {0xd94ad8b1c7380874, 0x18375281ae7822bd},
+      {0x87cec76f1c830548, 0x8f2293910d0b15b6},
+      {0xa9c2794ae3a3c69a, 0xb2eb3875504ddb23},
+      {0xd433179d9c8cb841, 0x5fa60692a46151ec},
+      {0x849feec281d7f328, 0xdbc7c41ba6bcd334},
+      {0xa5c7ea73224deff3, 0x12b9b522906c0801},
+      {0xcf39e50feae16bef, 0xd768226b34870a01},
+      {0x81842f29f2cce375, 0xe6a1158300d46641},
+      {0xa1e53af46f801c53, 0x60495ae3c1097fd1},
+      {0xca5e89b18b602368, 0x385bb19cb14bdfc5},
+      {0xfcf62c1dee382c42, 0x46729e03dd9ed7b6},
+      {0x9e19db92b4e31ba9, 0x6c07a2c26a8346d2},
+      {0xc5a05277621be293, 0xc7098b7305241886},
+      { 0xf70867153aa2db38,
+        0xb8cbee4fc66d1ea8 }
+#else
+      {0xff77b1fcbebcdc4f, 0x25e8e89c13bb0f7b},
+      {0xce5d73ff402d98e3, 0xfb0a3d212dc81290},
+      {0xa6b34ad8c9dfc06f, 0xf42faa48c0ea481f},
+      {0x86a8d39ef77164bc, 0xae5dff9c02033198},
+      {0xd98ddaee19068c76, 0x3badd624dd9b0958},
+      {0xafbd2350644eeacf, 0xe5d1929ef90898fb},
+      {0x8df5efabc5979c8f, 0xca8d3ffa1ef463c2},
+      {0xe55990879ddcaabd, 0xcc420a6a101d0516},
+      {0xb94470938fa89bce, 0xf808e40e8d5b3e6a},
+      {0x95a8637627989aad, 0xdde7001379a44aa9},
+      {0xf1c90080baf72cb1, 0x5324c68b12dd6339},
+      {0xc350000000000000, 0x0000000000000000},
+      {0x9dc5ada82b70b59d, 0xf020000000000000},
+      {0xfee50b7025c36a08, 0x02f236d04753d5b5},
+      {0xcde6fd5e09abcf26, 0xed4c0226b55e6f87},
+      {0xa6539930bf6bff45, 0x84db8346b786151d},
+      {0x865b86925b9bc5c2, 0x0b8a2392ba45a9b3},
+      {0xd910f7ff28069da4, 0x1b2ba1518094da05},
+      {0xaf58416654a6babb, 0x387ac8d1970027b3},
+      {0x8da471a9de737e24, 0x5ceaecfed289e5d3},
+      {0xe4d5e82392a40515, 0x0fabaf3feaa5334b},
+      {0xb8da1662e7b00a17, 0x3d6a751f3b936244},
+      { 0x95527a5202df0ccb,
+        0x0f37801e0c43ebc9 }
+#endif
+    };
+
+#if FMT_USE_FULL_CACHE_DRAGONBOX
+    return pow10_significands[k - float_info<double>::min_k];
+#else
+    static constexpr const uint64_t powers_of_5_64[] = {
+        0x0000000000000001, 0x0000000000000005, 0x0000000000000019,
+        0x000000000000007d, 0x0000000000000271, 0x0000000000000c35,
+        0x0000000000003d09, 0x000000000001312d, 0x000000000005f5e1,
+        0x00000000001dcd65, 0x00000000009502f9, 0x0000000002e90edd,
+        0x000000000e8d4a51, 0x0000000048c27395, 0x000000016bcc41e9,
+        0x000000071afd498d, 0x0000002386f26fc1, 0x000000b1a2bc2ec5,
+        0x000003782dace9d9, 0x00001158e460913d, 0x000056bc75e2d631,
+        0x0001b1ae4d6e2ef5, 0x000878678326eac9, 0x002a5a058fc295ed,
+        0x00d3c21bcecceda1, 0x0422ca8b0a00a425, 0x14adf4b7320334b9};
+
+    static const int compression_ratio = 27;
+
+    // Compute base index.
+    int cache_index = (k - float_info<double>::min_k) / compression_ratio;
+    int kb = cache_index * compression_ratio + float_info<double>::min_k;
+    int offset = k - kb;
+
+    // Get base cache.
+    uint128_fallback base_cache = pow10_significands[cache_index];
+    if (offset == 0) return base_cache;
+
+    // Compute the required amount of bit-shift.
+    int alpha = floor_log2_pow10(kb + offset) - floor_log2_pow10(kb) - offset;
+    FMT_ASSERT(alpha > 0 && alpha < 64, "shifting error detected");
+
+    // Try to recover the real cache.
+    uint64_t pow5 = powers_of_5_64[offset];
+    uint128_fallback recovered_cache = umul128(base_cache.high(), pow5);
+    uint128_fallback middle_low = umul128(base_cache.low(), pow5);
+
+    recovered_cache += middle_low.high();
+
+    uint64_t high_to_middle = recovered_cache.high() << (64 - alpha);
+    uint64_t middle_to_low = recovered_cache.low() << (64 - alpha);
+
+    recovered_cache =
+        uint128_fallback{(recovered_cache.low() >> alpha) | high_to_middle,
+                         ((middle_low.low() >> alpha) | middle_to_low)};
+    FMT_ASSERT(recovered_cache.low() + 1 != 0, "");
+    return {recovered_cache.high(), recovered_cache.low() + 1};
+#endif
+  }
+
+  struct compute_mul_result {
+    carrier_uint result;
+    bool is_integer;
+  };
+  struct compute_mul_parity_result {
+    bool parity;
+    bool is_integer;
+  };
+
+  static compute_mul_result compute_mul(
+      carrier_uint u, const cache_entry_type& cache) noexcept {
+    auto r = umul192_upper128(u, cache);
+    return {r.high(), r.low() == 0};
+  }
+
+  static uint32_t compute_delta(cache_entry_type const& cache,
+                                int beta) noexcept {
+    return static_cast<uint32_t>(cache.high() >> (64 - 1 - beta));
+  }
+
+  static compute_mul_parity_result compute_mul_parity(
+      carrier_uint two_f, const cache_entry_type& cache, int beta) noexcept {
+    FMT_ASSERT(beta >= 1, "");
+    FMT_ASSERT(beta < 64, "");
+
+    auto r = umul192_lower128(two_f, cache);
+    return {((r.high() >> (64 - beta)) & 1) != 0,
+            ((r.high() << beta) | (r.low() >> (64 - beta))) == 0};
+  }
+
+  static carrier_uint compute_left_endpoint_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept {
+    return (cache.high() -
+            (cache.high() >> (num_significand_bits<double>() + 2))) >>
+           (64 - num_significand_bits<double>() - 1 - beta);
+  }
+
+  static carrier_uint compute_right_endpoint_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept {
+    return (cache.high() +
+            (cache.high() >> (num_significand_bits<double>() + 1))) >>
+           (64 - num_significand_bits<double>() - 1 - beta);
+  }
+
+  static carrier_uint compute_round_up_for_shorter_interval_case(
+      const cache_entry_type& cache, int beta) noexcept {
+    return ((cache.high() >> (64 - num_significand_bits<double>() - 2 - beta)) +
+            1) /
+           2;
+  }
+};
+
+// Various integer checks
+template <class T>
+bool is_left_endpoint_integer_shorter_interval(int exponent) noexcept {
+  const int case_shorter_interval_left_endpoint_lower_threshold = 2;
+  const int case_shorter_interval_left_endpoint_upper_threshold = 3;
+  return exponent >= case_shorter_interval_left_endpoint_lower_threshold &&
+         exponent <= case_shorter_interval_left_endpoint_upper_threshold;
+}
+
+// Remove trailing zeros from n and return the number of zeros removed (float)
+FMT_INLINE int remove_trailing_zeros(uint32_t& n) noexcept {
+  FMT_ASSERT(n != 0, "");
+  const uint32_t mod_inv_5 = 0xcccccccd;
+  const uint32_t mod_inv_25 = mod_inv_5 * mod_inv_5;
+
+  int s = 0;
+  while (true) {
+    auto q = rotr(n * mod_inv_25, 2);
+    if (q > max_value<uint32_t>() / 100) break;
+    n = q;
+    s += 2;
+  }
+  auto q = rotr(n * mod_inv_5, 1);
+  if (q <= max_value<uint32_t>() / 10) {
+    n = q;
+    s |= 1;
+  }
+
+  return s;
+}
+
+// Removes trailing zeros and returns the number of zeros removed (double)
+FMT_INLINE int remove_trailing_zeros(uint64_t& n) noexcept {
+  FMT_ASSERT(n != 0, "");
+
+  // This magic number is ceil(2^90 / 10^8).
+  constexpr uint64_t magic_number = 12379400392853802749ull;
+  auto nm = umul128(n, magic_number);
+
+  // Is n is divisible by 10^8?
+  if ((nm.high() & ((1ull << (90 - 64)) - 1)) == 0 && nm.low() < magic_number) {
+    // If yes, work with the quotient.
+    auto n32 = static_cast<uint32_t>(nm.high() >> (90 - 64));
+
+    const uint32_t mod_inv_5 = 0xcccccccd;
+    const uint32_t mod_inv_25 = mod_inv_5 * mod_inv_5;
+
+    int s = 8;
+    while (true) {
+      auto q = rotr(n32 * mod_inv_25, 2);
+      if (q > max_value<uint32_t>() / 100) break;
+      n32 = q;
+      s += 2;
+    }
+    auto q = rotr(n32 * mod_inv_5, 1);
+    if (q <= max_value<uint32_t>() / 10) {
+      n32 = q;
+      s |= 1;
+    }
+
+    n = n32;
+    return s;
+  }
+
+  // If n is not divisible by 10^8, work with n itself.
+  const uint64_t mod_inv_5 = 0xcccccccccccccccd;
+  const uint64_t mod_inv_25 = mod_inv_5 * mod_inv_5;
+
+  int s = 0;
+  while (true) {
+    auto q = rotr(n * mod_inv_25, 2);
+    if (q > max_value<uint64_t>() / 100) break;
+    n = q;
+    s += 2;
+  }
+  auto q = rotr(n * mod_inv_5, 1);
+  if (q <= max_value<uint64_t>() / 10) {
+    n = q;
+    s |= 1;
+  }
+
+  return s;
+}
+
+// The main algorithm for shorter interval case
+template <class T>
+FMT_INLINE decimal_fp<T> shorter_interval_case(int exponent) noexcept {
+  decimal_fp<T> ret_value;
+  // Compute k and beta
+  const int minus_k = floor_log10_pow2_minus_log10_4_over_3(exponent);
+  const int beta = exponent + floor_log2_pow10(-minus_k);
+
+  // Compute xi and zi
+  using cache_entry_type = typename cache_accessor<T>::cache_entry_type;
+  const cache_entry_type cache = cache_accessor<T>::get_cached_power(-minus_k);
+
+  auto xi = cache_accessor<T>::compute_left_endpoint_for_shorter_interval_case(
+      cache, beta);
+  auto zi = cache_accessor<T>::compute_right_endpoint_for_shorter_interval_case(
+      cache, beta);
+
+  // If the left endpoint is not an integer, increase it
+  if (!is_left_endpoint_integer_shorter_interval<T>(exponent)) ++xi;
+
+  // Try bigger divisor
+  ret_value.significand = zi / 10;
+
+  // If succeed, remove trailing zeros if necessary and return
+  if (ret_value.significand * 10 >= xi) {
+    ret_value.exponent = minus_k + 1;
+    ret_value.exponent += remove_trailing_zeros(ret_value.significand);
+    return ret_value;
+  }
+
+  // Otherwise, compute the round-up of y
+  ret_value.significand =
+      cache_accessor<T>::compute_round_up_for_shorter_interval_case(cache,
+                                                                    beta);
+  ret_value.exponent = minus_k;
+
+  // When tie occurs, choose one of them according to the rule
+  if (exponent >= float_info<T>::shorter_interval_tie_lower_threshold &&
+      exponent <= float_info<T>::shorter_interval_tie_upper_threshold) {
+    ret_value.significand = ret_value.significand % 2 == 0
+                                ? ret_value.significand
+                                : ret_value.significand - 1;
+  } else if (ret_value.significand < xi) {
+    ++ret_value.significand;
+  }
+  return ret_value;
+}
+
+template <typename T> decimal_fp<T> to_decimal(T x) noexcept {
+  // Step 1: integer promotion & Schubfach multiplier calculation.
+
+  using carrier_uint = typename float_info<T>::carrier_uint;
+  using cache_entry_type = typename cache_accessor<T>::cache_entry_type;
+  auto br = bit_cast<carrier_uint>(x);
+
+  // Extract significand bits and exponent bits.
+  const carrier_uint significand_mask =
+      (static_cast<carrier_uint>(1) << num_significand_bits<T>()) - 1;
+  carrier_uint significand = (br & significand_mask);
+  int exponent =
+      static_cast<int>((br & exponent_mask<T>()) >> num_significand_bits<T>());
+
+  if (exponent != 0) {  // Check if normal.
+    exponent -= exponent_bias<T>() + num_significand_bits<T>();
+
+    // Shorter interval case; proceed like Schubfach.
+    // In fact, when exponent == 1 and significand == 0, the interval is
+    // regular. However, it can be shown that the end-results are anyway same.
+    if (significand == 0) return shorter_interval_case<T>(exponent);
+
+    significand |= (static_cast<carrier_uint>(1) << num_significand_bits<T>());
+  } else {
+    // Subnormal case; the interval is always regular.
+    if (significand == 0) return {0, 0};
+    exponent =
+        std::numeric_limits<T>::min_exponent - num_significand_bits<T>() - 1;
+  }
+
+  const bool include_left_endpoint = (significand % 2 == 0);
+  const bool include_right_endpoint = include_left_endpoint;
+
+  // Compute k and beta.
+  const int minus_k = floor_log10_pow2(exponent) - float_info<T>::kappa;
+  const cache_entry_type cache = cache_accessor<T>::get_cached_power(-minus_k);
+  const int beta = exponent + floor_log2_pow10(-minus_k);
+
+  // Compute zi and deltai.
+  // 10^kappa <= deltai < 10^(kappa + 1)
+  const uint32_t deltai = cache_accessor<T>::compute_delta(cache, beta);
+  const carrier_uint two_fc = significand << 1;
+
+  // For the case of binary32, the result of integer check is not correct for
+  // 29711844 * 2^-82
+  // = 6.1442653300000000008655037797566933477355632930994033813476... * 10^-18
+  // and 29711844 * 2^-81
+  // = 1.2288530660000000001731007559513386695471126586198806762695... * 10^-17,
+  // and they are the unique counterexamples. However, since 29711844 is even,
+  // this does not cause any problem for the endpoints calculations; it can only
+  // cause a problem when we need to perform integer check for the center.
+  // Fortunately, with these inputs, that branch is never executed, so we are
+  // fine.
+  const typename cache_accessor<T>::compute_mul_result z_mul =
+      cache_accessor<T>::compute_mul((two_fc | 1) << beta, cache);
+
+  // Step 2: Try larger divisor; remove trailing zeros if necessary.
+
+  // Using an upper bound on zi, we might be able to optimize the division
+  // better than the compiler; we are computing zi / big_divisor here.
+  decimal_fp<T> ret_value;
+  ret_value.significand = divide_by_10_to_kappa_plus_1(z_mul.result);
+  uint32_t r = static_cast<uint32_t>(z_mul.result - float_info<T>::big_divisor *
+                                                        ret_value.significand);
+
+  if (r < deltai) {
+    // Exclude the right endpoint if necessary.
+    if (r == 0 && (z_mul.is_integer & !include_right_endpoint)) {
+      --ret_value.significand;
+      r = float_info<T>::big_divisor;
+      goto small_divisor_case_label;
+    }
+  } else if (r > deltai) {
+    goto small_divisor_case_label;
+  } else {
+    // r == deltai; compare fractional parts.
+    const typename cache_accessor<T>::compute_mul_parity_result x_mul =
+        cache_accessor<T>::compute_mul_parity(two_fc - 1, cache, beta);
+
+    if (!(x_mul.parity | (x_mul.is_integer & include_left_endpoint)))
+      goto small_divisor_case_label;
+  }
+  ret_value.exponent = minus_k + float_info<T>::kappa + 1;
+
+  // We may need to remove trailing zeros.
+  ret_value.exponent += remove_trailing_zeros(ret_value.significand);
+  return ret_value;
+
+  // Step 3: Find the significand with the smaller divisor.
+
+small_divisor_case_label:
+  ret_value.significand *= 10;
+  ret_value.exponent = minus_k + float_info<T>::kappa;
+
+  uint32_t dist = r - (deltai / 2) + (float_info<T>::small_divisor / 2);
+  const bool approx_y_parity =
+      ((dist ^ (float_info<T>::small_divisor / 2)) & 1) != 0;
+
+  // Is dist divisible by 10^kappa?
+  const bool divisible_by_small_divisor =
+      check_divisibility_and_divide_by_pow10<float_info<T>::kappa>(dist);
+
+  // Add dist / 10^kappa to the significand.
+  ret_value.significand += dist;
+
+  if (!divisible_by_small_divisor) return ret_value;
+
+  // Check z^(f) >= epsilon^(f).
+  // We have either yi == zi - epsiloni or yi == (zi - epsiloni) - 1,
+  // where yi == zi - epsiloni if and only if z^(f) >= epsilon^(f).
+  // Since there are only 2 possibilities, we only need to care about the
+  // parity. Also, zi and r should have the same parity since the divisor
+  // is an even number.
+  const auto y_mul = cache_accessor<T>::compute_mul_parity(two_fc, cache, beta);
+
+  // If z^(f) >= epsilon^(f), we might have a tie when z^(f) == epsilon^(f),
+  // or equivalently, when y is an integer.
+  if (y_mul.parity != approx_y_parity)
+    --ret_value.significand;
+  else if (y_mul.is_integer & (ret_value.significand % 2 != 0))
+    --ret_value.significand;
+  return ret_value;
+}
+}  // namespace dragonbox
+
+#ifdef _MSC_VER
+FMT_FUNC auto fmt_snprintf(char* buf, size_t size, const char* fmt, ...)
+    -> int {
+  auto args = va_list();
+  va_start(args, fmt);
+  int result = vsnprintf_s(buf, size, _TRUNCATE, fmt, args);
+  va_end(args);
+  return result;
+}
+#endif
+}  // namespace detail
+
+template <> struct formatter<detail::bigint> {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx)
+      -> format_parse_context::iterator {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const detail::bigint& n, FormatContext& ctx) const ->
+      typename FormatContext::iterator {
+    auto out = ctx.out();
+    bool first = true;
+    for (auto i = n.bigits_.size(); i > 0; --i) {
+      auto value = n.bigits_[i - 1u];
+      if (first) {
+        out = format_to(out, FMT_STRING("{:x}"), value);
+        first = false;
+        continue;
+      }
+      out = format_to(out, FMT_STRING("{:08x}"), value);
+    }
+    if (n.exp_ > 0)
+      out = format_to(out, FMT_STRING("p{}"),
+                      n.exp_ * detail::bigint::bigit_bits);
+    return out;
+  }
+};
+
+FMT_FUNC detail::utf8_to_utf16::utf8_to_utf16(string_view s) {
+  for_each_codepoint(s, [this](uint32_t cp, string_view) {
+    if (cp == invalid_code_point) FMT_THROW(std::runtime_error("invalid utf8"));
+    if (cp <= 0xFFFF) {
+      buffer_.push_back(static_cast<wchar_t>(cp));
+    } else {
+      cp -= 0x10000;
+      buffer_.push_back(static_cast<wchar_t>(0xD800 + (cp >> 10)));
+      buffer_.push_back(static_cast<wchar_t>(0xDC00 + (cp & 0x3FF)));
+    }
+    return true;
+  });
+  buffer_.push_back(0);
+}
+
+FMT_FUNC void format_system_error(detail::buffer<char>& out, int error_code,
+                                  const char* message) noexcept {
+  FMT_TRY {
+    auto ec = std::error_code(error_code, std::generic_category());
+    write(std::back_inserter(out), std::system_error(ec, message).what());
+    return;
+  }
+  FMT_CATCH(...) {}
+  format_error_code(out, error_code, message);
+}
+
+FMT_FUNC void report_system_error(int error_code,
+                                  const char* message) noexcept {
+  report_error(format_system_error, error_code, message);
+}
+
+FMT_FUNC std::string vformat(string_view fmt, format_args args) {
+  // Don't optimize the "{}" case to keep the binary size small and because it
+  // can be better optimized in fmt::format anyway.
+  auto buffer = memory_buffer();
+  detail::vformat_to(buffer, fmt, args);
+  return to_string(buffer);
+}
+
+namespace detail {
+#ifdef _WIN32
+using dword = conditional_t<sizeof(long) == 4, unsigned long, unsigned>;
+extern "C" __declspec(dllimport) int __stdcall WriteConsoleW(  //
+    void*, const void*, dword, dword*, void*);
+
+FMT_FUNC bool write_console(std::FILE* f, string_view text) {
+  auto fd = _fileno(f);
+  if (_isatty(fd)) {
+    detail::utf8_to_utf16 u16(string_view(text.data(), text.size()));
+    auto written = detail::dword();
+    if (detail::WriteConsoleW(reinterpret_cast<void*>(_get_osfhandle(fd)),
+                              u16.c_str(), static_cast<uint32_t>(u16.size()),
+                              &written, nullptr)) {
+      return true;
+    }
+  }
+  // We return false if the file descriptor was not TTY, or it was but
+  // SetConsoleW failed which can happen if the output has been redirected to
+  // NUL. In both cases when we return false, we should attempt to do regular
+  // write via fwrite or std::ostream::write.
+  return false;
+}
+#endif
+
+FMT_FUNC void print(std::FILE* f, string_view text) {
+#ifdef _WIN32
+  if (write_console(f, text)) return;
+#endif
+  detail::fwrite_fully(text.data(), 1, text.size(), f);
+}
+}  // namespace detail
+
+FMT_FUNC void vprint(std::FILE* f, string_view format_str, format_args args) {
+  memory_buffer buffer;
+  detail::vformat_to(buffer, format_str, args);
+  detail::print(f, {buffer.data(), buffer.size()});
+}
+
+#ifdef _WIN32
+// Print assuming legacy (non-Unicode) encoding.
+FMT_FUNC void detail::vprint_mojibake(std::FILE* f, string_view format_str,
+                                      format_args args) {
+  memory_buffer buffer;
+  detail::vformat_to(buffer, format_str,
+                     basic_format_args<buffer_context<char>>(args));
+  fwrite_fully(buffer.data(), 1, buffer.size(), f);
+}
+#endif
+
+FMT_FUNC void vprint(string_view format_str, format_args args) {
+  vprint(stdout, format_str, args);
+}
+
+namespace detail {
+
+struct singleton {
+  unsigned char upper;
+  unsigned char lower_count;
+};
+
+inline auto is_printable(uint16_t x, const singleton* singletons,
+                         size_t singletons_size,
+                         const unsigned char* singleton_lowers,
+                         const unsigned char* normal, size_t normal_size)
+    -> bool {
+  auto upper = x >> 8;
+  auto lower_start = 0;
+  for (size_t i = 0; i < singletons_size; ++i) {
+    auto s = singletons[i];
+    auto lower_end = lower_start + s.lower_count;
+    if (upper < s.upper) break;
+    if (upper == s.upper) {
+      for (auto j = lower_start; j < lower_end; ++j) {
+        if (singleton_lowers[j] == (x & 0xff)) return false;
+      }
+    }
+    lower_start = lower_end;
+  }
+
+  auto xsigned = static_cast<int>(x);
+  auto current = true;
+  for (size_t i = 0; i < normal_size; ++i) {
+    auto v = static_cast<int>(normal[i]);
+    auto len = (v & 0x80) != 0 ? (v & 0x7f) << 8 | normal[++i] : v;
+    xsigned -= len;
+    if (xsigned < 0) break;
+    current = !current;
+  }
+  return current;
+}
+
+// This code is generated by support/printable.py.
+FMT_FUNC auto is_printable(uint32_t cp) -> bool {
+  static constexpr singleton singletons0[] = {
+      {0x00, 1},  {0x03, 5},  {0x05, 6},  {0x06, 3},  {0x07, 6},  {0x08, 8},
+      {0x09, 17}, {0x0a, 28}, {0x0b, 25}, {0x0c, 20}, {0x0d, 16}, {0x0e, 13},
+      {0x0f, 4},  {0x10, 3},  {0x12, 18}, {0x13, 9},  {0x16, 1},  {0x17, 5},
+      {0x18, 2},  {0x19, 3},  {0x1a, 7},  {0x1c, 2},  {0x1d, 1},  {0x1f, 22},
+      {0x20, 3},  {0x2b, 3},  {0x2c, 2},  {0x2d, 11}, {0x2e, 1},  {0x30, 3},
+      {0x31, 2},  {0x32, 1},  {0xa7, 2},  {0xa9, 2},  {0xaa, 4},  {0xab, 8},
+      {0xfa, 2},  {0xfb, 5},  {0xfd, 4},  {0xfe, 3},  {0xff, 9},
+  };
+  static constexpr unsigned char singletons0_lower[] = {
+      0xad, 0x78, 0x79, 0x8b, 0x8d, 0xa2, 0x30, 0x57, 0x58, 0x8b, 0x8c, 0x90,
+      0x1c, 0x1d, 0xdd, 0x0e, 0x0f, 0x4b, 0x4c, 0xfb, 0xfc, 0x2e, 0x2f, 0x3f,
+      0x5c, 0x5d, 0x5f, 0xb5, 0xe2, 0x84, 0x8d, 0x8e, 0x91, 0x92, 0xa9, 0xb1,
+      0xba, 0xbb, 0xc5, 0xc6, 0xc9, 0xca, 0xde, 0xe4, 0xe5, 0xff, 0x00, 0x04,
+      0x11, 0x12, 0x29, 0x31, 0x34, 0x37, 0x3a, 0x3b, 0x3d, 0x49, 0x4a, 0x5d,
+      0x84, 0x8e, 0x92, 0xa9, 0xb1, 0xb4, 0xba, 0xbb, 0xc6, 0xca, 0xce, 0xcf,
+      0xe4, 0xe5, 0x00, 0x04, 0x0d, 0x0e, 0x11, 0x12, 0x29, 0x31, 0x34, 0x3a,
+      0x3b, 0x45, 0x46, 0x49, 0x4a, 0x5e, 0x64, 0x65, 0x84, 0x91, 0x9b, 0x9d,
+      0xc9, 0xce, 0xcf, 0x0d, 0x11, 0x29, 0x45, 0x49, 0x57, 0x64, 0x65, 0x8d,
+      0x91, 0xa9, 0xb4, 0xba, 0xbb, 0xc5, 0xc9, 0xdf, 0xe4, 0xe5, 0xf0, 0x0d,
+      0x11, 0x45, 0x49, 0x64, 0x65, 0x80, 0x84, 0xb2, 0xbc, 0xbe, 0xbf, 0xd5,
+      0xd7, 0xf0, 0xf1, 0x83, 0x85, 0x8b, 0xa4, 0xa6, 0xbe, 0xbf, 0xc5, 0xc7,
+      0xce, 0xcf, 0xda, 0xdb, 0x48, 0x98, 0xbd, 0xcd, 0xc6, 0xce, 0xcf, 0x49,
+      0x4e, 0x4f, 0x57, 0x59, 0x5e, 0x5f, 0x89, 0x8e, 0x8f, 0xb1, 0xb6, 0xb7,
+      0xbf, 0xc1, 0xc6, 0xc7, 0xd7, 0x11, 0x16, 0x17, 0x5b, 0x5c, 0xf6, 0xf7,
+      0xfe, 0xff, 0x80, 0x0d, 0x6d, 0x71, 0xde, 0xdf, 0x0e, 0x0f, 0x1f, 0x6e,
+      0x6f, 0x1c, 0x1d, 0x5f, 0x7d, 0x7e, 0xae, 0xaf, 0xbb, 0xbc, 0xfa, 0x16,
+      0x17, 0x1e, 0x1f, 0x46, 0x47, 0x4e, 0x4f, 0x58, 0x5a, 0x5c, 0x5e, 0x7e,
+      0x7f, 0xb5, 0xc5, 0xd4, 0xd5, 0xdc, 0xf0, 0xf1, 0xf5, 0x72, 0x73, 0x8f,
+      0x74, 0x75, 0x96, 0x2f, 0x5f, 0x26, 0x2e, 0x2f, 0xa7, 0xaf, 0xb7, 0xbf,
+      0xc7, 0xcf, 0xd7, 0xdf, 0x9a, 0x40, 0x97, 0x98, 0x30, 0x8f, 0x1f, 0xc0,
+      0xc1, 0xce, 0xff, 0x4e, 0x4f, 0x5a, 0x5b, 0x07, 0x08, 0x0f, 0x10, 0x27,
+      0x2f, 0xee, 0xef, 0x6e, 0x6f, 0x37, 0x3d, 0x3f, 0x42, 0x45, 0x90, 0x91,
+      0xfe, 0xff, 0x53, 0x67, 0x75, 0xc8, 0xc9, 0xd0, 0xd1, 0xd8, 0xd9, 0xe7,
+      0xfe, 0xff,
+  };
+  static constexpr singleton singletons1[] = {
+      {0x00, 6},  {0x01, 1}, {0x03, 1},  {0x04, 2}, {0x08, 8},  {0x09, 2},
+      {0x0a, 5},  {0x0b, 2}, {0x0e, 4},  {0x10, 1}, {0x11, 2},  {0x12, 5},
+      {0x13, 17}, {0x14, 1}, {0x15, 2},  {0x17, 2}, {0x19, 13}, {0x1c, 5},
+      {0x1d, 8},  {0x24, 1}, {0x6a, 3},  {0x6b, 2}, {0xbc, 2},  {0xd1, 2},
+      {0xd4, 12}, {0xd5, 9}, {0xd6, 2},  {0xd7, 2}, {0xda, 1},  {0xe0, 5},
+      {0xe1, 2},  {0xe8, 2}, {0xee, 32}, {0xf0, 4}, {0xf8, 2},  {0xf9, 2},
+      {0xfa, 2},  {0xfb, 1},
+  };
+  static constexpr unsigned char singletons1_lower[] = {
+      0x0c, 0x27, 0x3b, 0x3e, 0x4e, 0x4f, 0x8f, 0x9e, 0x9e, 0x9f, 0x06, 0x07,
+      0x09, 0x36, 0x3d, 0x3e, 0x56, 0xf3, 0xd0, 0xd1, 0x04, 0x14, 0x18, 0x36,
+      0x37, 0x56, 0x57, 0x7f, 0xaa, 0xae, 0xaf, 0xbd, 0x35, 0xe0, 0x12, 0x87,
+      0x89, 0x8e, 0x9e, 0x04, 0x0d, 0x0e, 0x11, 0x12, 0x29, 0x31, 0x34, 0x3a,
+      0x45, 0x46, 0x49, 0x4a, 0x4e, 0x4f, 0x64, 0x65, 0x5c, 0xb6, 0xb7, 0x1b,
+      0x1c, 0x07, 0x08, 0x0a, 0x0b, 0x14, 0x17, 0x36, 0x39, 0x3a, 0xa8, 0xa9,
+      0xd8, 0xd9, 0x09, 0x37, 0x90, 0x91, 0xa8, 0x07, 0x0a, 0x3b, 0x3e, 0x66,
+      0x69, 0x8f, 0x92, 0x6f, 0x5f, 0xee, 0xef, 0x5a, 0x62, 0x9a, 0x9b, 0x27,
+      0x28, 0x55, 0x9d, 0xa0, 0xa1, 0xa3, 0xa4, 0xa7, 0xa8, 0xad, 0xba, 0xbc,
+      0xc4, 0x06, 0x0b, 0x0c, 0x15, 0x1d, 0x3a, 0x3f, 0x45, 0x51, 0xa6, 0xa7,
+      0xcc, 0xcd, 0xa0, 0x07, 0x19, 0x1a, 0x22, 0x25, 0x3e, 0x3f, 0xc5, 0xc6,
+      0x04, 0x20, 0x23, 0x25, 0x26, 0x28, 0x33, 0x38, 0x3a, 0x48, 0x4a, 0x4c,
+      0x50, 0x53, 0x55, 0x56, 0x58, 0x5a, 0x5c, 0x5e, 0x60, 0x63, 0x65, 0x66,
+      0x6b, 0x73, 0x78, 0x7d, 0x7f, 0x8a, 0xa4, 0xaa, 0xaf, 0xb0, 0xc0, 0xd0,
+      0xae, 0xaf, 0x79, 0xcc, 0x6e, 0x6f, 0x93,
+  };
+  static constexpr unsigned char normal0[] = {
+      0x00, 0x20, 0x5f, 0x22, 0x82, 0xdf, 0x04, 0x82, 0x44, 0x08, 0x1b, 0x04,
+      0x06, 0x11, 0x81, 0xac, 0x0e, 0x80, 0xab, 0x35, 0x28, 0x0b, 0x80, 0xe0,
+      0x03, 0x19, 0x08, 0x01, 0x04, 0x2f, 0x04, 0x34, 0x04, 0x07, 0x03, 0x01,
+      0x07, 0x06, 0x07, 0x11, 0x0a, 0x50, 0x0f, 0x12, 0x07, 0x55, 0x07, 0x03,
+      0x04, 0x1c, 0x0a, 0x09, 0x03, 0x08, 0x03, 0x07, 0x03, 0x02, 0x03, 0x03,
+      0x03, 0x0c, 0x04, 0x05, 0x03, 0x0b, 0x06, 0x01, 0x0e, 0x15, 0x05, 0x3a,
+      0x03, 0x11, 0x07, 0x06, 0x05, 0x10, 0x07, 0x57, 0x07, 0x02, 0x07, 0x15,
+      0x0d, 0x50, 0x04, 0x43, 0x03, 0x2d, 0x03, 0x01, 0x04, 0x11, 0x06, 0x0f,
+      0x0c, 0x3a, 0x04, 0x1d, 0x25, 0x5f, 0x20, 0x6d, 0x04, 0x6a, 0x25, 0x80,
+      0xc8, 0x05, 0x82, 0xb0, 0x03, 0x1a, 0x06, 0x82, 0xfd, 0x03, 0x59, 0x07,
+      0x15, 0x0b, 0x17, 0x09, 0x14, 0x0c, 0x14, 0x0c, 0x6a, 0x06, 0x0a, 0x06,
+      0x1a, 0x06, 0x59, 0x07, 0x2b, 0x05, 0x46, 0x0a, 0x2c, 0x04, 0x0c, 0x04,
+      0x01, 0x03, 0x31, 0x0b, 0x2c, 0x04, 0x1a, 0x06, 0x0b, 0x03, 0x80, 0xac,
+      0x06, 0x0a, 0x06, 0x21, 0x3f, 0x4c, 0x04, 0x2d, 0x03, 0x74, 0x08, 0x3c,
+      0x03, 0x0f, 0x03, 0x3c, 0x07, 0x38, 0x08, 0x2b, 0x05, 0x82, 0xff, 0x11,
+      0x18, 0x08, 0x2f, 0x11, 0x2d, 0x03, 0x20, 0x10, 0x21, 0x0f, 0x80, 0x8c,
+      0x04, 0x82, 0x97, 0x19, 0x0b, 0x15, 0x88, 0x94, 0x05, 0x2f, 0x05, 0x3b,
+      0x07, 0x02, 0x0e, 0x18, 0x09, 0x80, 0xb3, 0x2d, 0x74, 0x0c, 0x80, 0xd6,
+      0x1a, 0x0c, 0x05, 0x80, 0xff, 0x05, 0x80, 0xdf, 0x0c, 0xee, 0x0d, 0x03,
+      0x84, 0x8d, 0x03, 0x37, 0x09, 0x81, 0x5c, 0x14, 0x80, 0xb8, 0x08, 0x80,
+      0xcb, 0x2a, 0x38, 0x03, 0x0a, 0x06, 0x38, 0x08, 0x46, 0x08, 0x0c, 0x06,
+      0x74, 0x0b, 0x1e, 0x03, 0x5a, 0x04, 0x59, 0x09, 0x80, 0x83, 0x18, 0x1c,
+      0x0a, 0x16, 0x09, 0x4c, 0x04, 0x80, 0x8a, 0x06, 0xab, 0xa4, 0x0c, 0x17,
+      0x04, 0x31, 0xa1, 0x04, 0x81, 0xda, 0x26, 0x07, 0x0c, 0x05, 0x05, 0x80,
+      0xa5, 0x11, 0x81, 0x6d, 0x10, 0x78, 0x28, 0x2a, 0x06, 0x4c, 0x04, 0x80,
+      0x8d, 0x04, 0x80, 0xbe, 0x03, 0x1b, 0x03, 0x0f, 0x0d,
+  };
+  static constexpr unsigned char normal1[] = {
+      0x5e, 0x22, 0x7b, 0x05, 0x03, 0x04, 0x2d, 0x03, 0x66, 0x03, 0x01, 0x2f,
+      0x2e, 0x80, 0x82, 0x1d, 0x03, 0x31, 0x0f, 0x1c, 0x04, 0x24, 0x09, 0x1e,
+      0x05, 0x2b, 0x05, 0x44, 0x04, 0x0e, 0x2a, 0x80, 0xaa, 0x06, 0x24, 0x04,
+      0x24, 0x04, 0x28, 0x08, 0x34, 0x0b, 0x01, 0x80, 0x90, 0x81, 0x37, 0x09,
+      0x16, 0x0a, 0x08, 0x80, 0x98, 0x39, 0x03, 0x63, 0x08, 0x09, 0x30, 0x16,
+      0x05, 0x21, 0x03, 0x1b, 0x05, 0x01, 0x40, 0x38, 0x04, 0x4b, 0x05, 0x2f,
+      0x04, 0x0a, 0x07, 0x09, 0x07, 0x40, 0x20, 0x27, 0x04, 0x0c, 0x09, 0x36,
+      0x03, 0x3a, 0x05, 0x1a, 0x07, 0x04, 0x0c, 0x07, 0x50, 0x49, 0x37, 0x33,
+      0x0d, 0x33, 0x07, 0x2e, 0x08, 0x0a, 0x81, 0x26, 0x52, 0x4e, 0x28, 0x08,
+      0x2a, 0x56, 0x1c, 0x14, 0x17, 0x09, 0x4e, 0x04, 0x1e, 0x0f, 0x43, 0x0e,
+      0x19, 0x07, 0x0a, 0x06, 0x48, 0x08, 0x27, 0x09, 0x75, 0x0b, 0x3f, 0x41,
+      0x2a, 0x06, 0x3b, 0x05, 0x0a, 0x06, 0x51, 0x06, 0x01, 0x05, 0x10, 0x03,
+      0x05, 0x80, 0x8b, 0x62, 0x1e, 0x48, 0x08, 0x0a, 0x80, 0xa6, 0x5e, 0x22,
+      0x45, 0x0b, 0x0a, 0x06, 0x0d, 0x13, 0x39, 0x07, 0x0a, 0x36, 0x2c, 0x04,
+      0x10, 0x80, 0xc0, 0x3c, 0x64, 0x53, 0x0c, 0x48, 0x09, 0x0a, 0x46, 0x45,
+      0x1b, 0x48, 0x08, 0x53, 0x1d, 0x39, 0x81, 0x07, 0x46, 0x0a, 0x1d, 0x03,
+      0x47, 0x49, 0x37, 0x03, 0x0e, 0x08, 0x0a, 0x06, 0x39, 0x07, 0x0a, 0x81,
+      0x36, 0x19, 0x80, 0xb7, 0x01, 0x0f, 0x32, 0x0d, 0x83, 0x9b, 0x66, 0x75,
+      0x0b, 0x80, 0xc4, 0x8a, 0xbc, 0x84, 0x2f, 0x8f, 0xd1, 0x82, 0x47, 0xa1,
+      0xb9, 0x82, 0x39, 0x07, 0x2a, 0x04, 0x02, 0x60, 0x26, 0x0a, 0x46, 0x0a,
+      0x28, 0x05, 0x13, 0x82, 0xb0, 0x5b, 0x65, 0x4b, 0x04, 0x39, 0x07, 0x11,
+      0x40, 0x05, 0x0b, 0x02, 0x0e, 0x97, 0xf8, 0x08, 0x84, 0xd6, 0x2a, 0x09,
+      0xa2, 0xf7, 0x81, 0x1f, 0x31, 0x03, 0x11, 0x04, 0x08, 0x81, 0x8c, 0x89,
+      0x04, 0x6b, 0x05, 0x0d, 0x03, 0x09, 0x07, 0x10, 0x93, 0x60, 0x80, 0xf6,
+      0x0a, 0x73, 0x08, 0x6e, 0x17, 0x46, 0x80, 0x9a, 0x14, 0x0c, 0x57, 0x09,
+      0x19, 0x80, 0x87, 0x81, 0x47, 0x03, 0x85, 0x42, 0x0f, 0x15, 0x85, 0x50,
+      0x2b, 0x80, 0xd5, 0x2d, 0x03, 0x1a, 0x04, 0x02, 0x81, 0x70, 0x3a, 0x05,
+      0x01, 0x85, 0x00, 0x80, 0xd7, 0x29, 0x4c, 0x04, 0x0a, 0x04, 0x02, 0x83,
+      0x11, 0x44, 0x4c, 0x3d, 0x80, 0xc2, 0x3c, 0x06, 0x01, 0x04, 0x55, 0x05,
+      0x1b, 0x34, 0x02, 0x81, 0x0e, 0x2c, 0x04, 0x64, 0x0c, 0x56, 0x0a, 0x80,
+      0xae, 0x38, 0x1d, 0x0d, 0x2c, 0x04, 0x09, 0x07, 0x02, 0x0e, 0x06, 0x80,
+      0x9a, 0x83, 0xd8, 0x08, 0x0d, 0x03, 0x0d, 0x03, 0x74, 0x0c, 0x59, 0x07,
+      0x0c, 0x14, 0x0c, 0x04, 0x38, 0x08, 0x0a, 0x06, 0x28, 0x08, 0x22, 0x4e,
+      0x81, 0x54, 0x0c, 0x15, 0x03, 0x03, 0x05, 0x07, 0x09, 0x19, 0x07, 0x07,
+      0x09, 0x03, 0x0d, 0x07, 0x29, 0x80, 0xcb, 0x25, 0x0a, 0x84, 0x06,
+  };
+  auto lower = static_cast<uint16_t>(cp);
+  if (cp < 0x10000) {
+    return is_printable(lower, singletons0,
+                        sizeof(singletons0) / sizeof(*singletons0),
+                        singletons0_lower, normal0, sizeof(normal0));
+  }
+  if (cp < 0x20000) {
+    return is_printable(lower, singletons1,
+                        sizeof(singletons1) / sizeof(*singletons1),
+                        singletons1_lower, normal1, sizeof(normal1));
+  }
+  if (0x2a6de <= cp && cp < 0x2a700) return false;
+  if (0x2b735 <= cp && cp < 0x2b740) return false;
+  if (0x2b81e <= cp && cp < 0x2b820) return false;
+  if (0x2cea2 <= cp && cp < 0x2ceb0) return false;
+  if (0x2ebe1 <= cp && cp < 0x2f800) return false;
+  if (0x2fa1e <= cp && cp < 0x30000) return false;
+  if (0x3134b <= cp && cp < 0xe0100) return false;
+  if (0xe01f0 <= cp && cp < 0x110000) return false;
+  return cp < 0x110000;
+}
+
+}  // namespace detail
+
+FMT_END_NAMESPACE
+
+#endif  // FMT_FORMAT_INL_H_
diff --git a/libfuse/lib/fmt/format.h b/libfuse/lib/fmt/format.h
new file mode 100644
index 00000000..7c607dbd
--- /dev/null
+++ b/libfuse/lib/fmt/format.h
@@ -0,0 +1,4217 @@
+/*
+  Formatting library for C++
+
+  Copyright (c) 2012 - present, Victor Zverovich
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+  --- Optional exception to the license ---
+
+  As an exception, if, as a result of your compiling your source code, portions
+  of this Software are embedded into a machine-executable object form of such
+  source code, you may redistribute such embedded portions in such object form
+  without including the above copyright and permission notices.
+ */
+
+#ifndef FMT_FORMAT_H_
+#define FMT_FORMAT_H_
+
+#include <cmath>         // std::signbit
+#include <cstdint>       // uint32_t
+#include <cstring>       // std::memcpy
+#include <limits>        // std::numeric_limits
+#include <memory>        // std::uninitialized_copy
+#include <stdexcept>     // std::runtime_error
+#include <system_error>  // std::system_error
+
+#ifdef __cpp_lib_bit_cast
+#  include <bit>  // std::bitcast
+#endif
+
+#include "core.h"
+
+#if FMT_GCC_VERSION
+#  define FMT_GCC_VISIBILITY_HIDDEN __attribute__((visibility("hidden")))
+#else
+#  define FMT_GCC_VISIBILITY_HIDDEN
+#endif
+
+#ifdef __NVCC__
+#  define FMT_CUDA_VERSION (__CUDACC_VER_MAJOR__ * 100 + __CUDACC_VER_MINOR__)
+#else
+#  define FMT_CUDA_VERSION 0
+#endif
+
+#ifdef __has_builtin
+#  define FMT_HAS_BUILTIN(x) __has_builtin(x)
+#else
+#  define FMT_HAS_BUILTIN(x) 0
+#endif
+
+#if FMT_GCC_VERSION || FMT_CLANG_VERSION
+#  define FMT_NOINLINE __attribute__((noinline))
+#else
+#  define FMT_NOINLINE
+#endif
+
+#if FMT_MSC_VERSION
+#  define FMT_MSC_DEFAULT = default
+#else
+#  define FMT_MSC_DEFAULT
+#endif
+
+#ifndef FMT_THROW
+#  if FMT_EXCEPTIONS
+#    if FMT_MSC_VERSION || defined(__NVCC__)
+FMT_BEGIN_NAMESPACE
+namespace detail {
+template <typename Exception> inline void do_throw(const Exception& x) {
+  // Silence unreachable code warnings in MSVC and NVCC because these
+  // are nearly impossible to fix in a generic code.
+  volatile bool b = true;
+  if (b) throw x;
+}
+}  // namespace detail
+FMT_END_NAMESPACE
+#      define FMT_THROW(x) detail::do_throw(x)
+#    else
+#      define FMT_THROW(x) throw x
+#    endif
+#  else
+#    define FMT_THROW(x)               \
+      do {                             \
+        FMT_ASSERT(false, (x).what()); \
+      } while (false)
+#  endif
+#endif
+
+#if FMT_EXCEPTIONS
+#  define FMT_TRY try
+#  define FMT_CATCH(x) catch (x)
+#else
+#  define FMT_TRY if (true)
+#  define FMT_CATCH(x) if (false)
+#endif
+
+#ifndef FMT_MAYBE_UNUSED
+#  if FMT_HAS_CPP17_ATTRIBUTE(maybe_unused)
+#    define FMT_MAYBE_UNUSED [[maybe_unused]]
+#  else
+#    define FMT_MAYBE_UNUSED
+#  endif
+#endif
+
+#ifndef FMT_USE_USER_DEFINED_LITERALS
+// EDG based compilers (Intel, NVIDIA, Elbrus, etc), GCC and MSVC support UDLs.
+#  if (FMT_HAS_FEATURE(cxx_user_literals) || FMT_GCC_VERSION >= 407 || \
+       FMT_MSC_VERSION >= 1900) &&                                     \
+      (!defined(__EDG_VERSION__) || __EDG_VERSION__ >= /* UDL feature */ 480)
+#    define FMT_USE_USER_DEFINED_LITERALS 1
+#  else
+#    define FMT_USE_USER_DEFINED_LITERALS 0
+#  endif
+#endif
+
+// Defining FMT_REDUCE_INT_INSTANTIATIONS to 1, will reduce the number of
+// integer formatter template instantiations to just one by only using the
+// largest integer type. This results in a reduction in binary size but will
+// cause a decrease in integer formatting performance.
+#if !defined(FMT_REDUCE_INT_INSTANTIATIONS)
+#  define FMT_REDUCE_INT_INSTANTIATIONS 0
+#endif
+
+// __builtin_clz is broken in clang with Microsoft CodeGen:
+// https://github.com/fmtlib/fmt/issues/519.
+#if !FMT_MSC_VERSION
+#  if FMT_HAS_BUILTIN(__builtin_clz) || FMT_GCC_VERSION || FMT_ICC_VERSION
+#    define FMT_BUILTIN_CLZ(n) __builtin_clz(n)
+#  endif
+#  if FMT_HAS_BUILTIN(__builtin_clzll) || FMT_GCC_VERSION || FMT_ICC_VERSION
+#    define FMT_BUILTIN_CLZLL(n) __builtin_clzll(n)
+#  endif
+#endif
+
+// __builtin_ctz is broken in Intel Compiler Classic on Windows:
+// https://github.com/fmtlib/fmt/issues/2510.
+#ifndef __ICL
+#  if FMT_HAS_BUILTIN(__builtin_ctz) || FMT_GCC_VERSION || FMT_ICC_VERSION || \
+      defined(__NVCOMPILER)
+#    define FMT_BUILTIN_CTZ(n) __builtin_ctz(n)
+#  endif
+#  if FMT_HAS_BUILTIN(__builtin_ctzll) || FMT_GCC_VERSION || \
+      FMT_ICC_VERSION || defined(__NVCOMPILER)
+#    define FMT_BUILTIN_CTZLL(n) __builtin_ctzll(n)
+#  endif
+#endif
+
+#if FMT_MSC_VERSION
+#  include <intrin.h>  // _BitScanReverse[64], _BitScanForward[64], _umul128
+#endif
+
+// Some compilers masquerade as both MSVC and GCC-likes or otherwise support
+// __builtin_clz and __builtin_clzll, so only define FMT_BUILTIN_CLZ using the
+// MSVC intrinsics if the clz and clzll builtins are not available.
+#if FMT_MSC_VERSION && !defined(FMT_BUILTIN_CLZLL) && \
+    !defined(FMT_BUILTIN_CTZLL)
+FMT_BEGIN_NAMESPACE
+namespace detail {
+// Avoid Clang with Microsoft CodeGen's -Wunknown-pragmas warning.
+#  if !defined(__clang__)
+#    pragma intrinsic(_BitScanForward)
+#    pragma intrinsic(_BitScanReverse)
+#    if defined(_WIN64)
+#      pragma intrinsic(_BitScanForward64)
+#      pragma intrinsic(_BitScanReverse64)
+#    endif
+#  endif
+
+inline auto clz(uint32_t x) -> int {
+  unsigned long r = 0;
+  _BitScanReverse(&r, x);
+  FMT_ASSERT(x != 0, "");
+  // Static analysis complains about using uninitialized data
+  // "r", but the only way that can happen is if "x" is 0,
+  // which the callers guarantee to not happen.
+  FMT_MSC_WARNING(suppress : 6102)
+  return 31 ^ static_cast<int>(r);
+}
+#  define FMT_BUILTIN_CLZ(n) detail::clz(n)
+
+inline auto clzll(uint64_t x) -> int {
+  unsigned long r = 0;
+#  ifdef _WIN64
+  _BitScanReverse64(&r, x);
+#  else
+  // Scan the high 32 bits.
+  if (_BitScanReverse(&r, static_cast<uint32_t>(x >> 32))) return 63 ^ (r + 32);
+  // Scan the low 32 bits.
+  _BitScanReverse(&r, static_cast<uint32_t>(x));
+#  endif
+  FMT_ASSERT(x != 0, "");
+  FMT_MSC_WARNING(suppress : 6102)  // Suppress a bogus static analysis warning.
+  return 63 ^ static_cast<int>(r);
+}
+#  define FMT_BUILTIN_CLZLL(n) detail::clzll(n)
+
+inline auto ctz(uint32_t x) -> int {
+  unsigned long r = 0;
+  _BitScanForward(&r, x);
+  FMT_ASSERT(x != 0, "");
+  FMT_MSC_WARNING(suppress : 6102)  // Suppress a bogus static analysis warning.
+  return static_cast<int>(r);
+}
+#  define FMT_BUILTIN_CTZ(n) detail::ctz(n)
+
+inline auto ctzll(uint64_t x) -> int {
+  unsigned long r = 0;
+  FMT_ASSERT(x != 0, "");
+  FMT_MSC_WARNING(suppress : 6102)  // Suppress a bogus static analysis warning.
+#  ifdef _WIN64
+  _BitScanForward64(&r, x);
+#  else
+  // Scan the low 32 bits.
+  if (_BitScanForward(&r, static_cast<uint32_t>(x))) return static_cast<int>(r);
+  // Scan the high 32 bits.
+  _BitScanForward(&r, static_cast<uint32_t>(x >> 32));
+  r += 32;
+#  endif
+  return static_cast<int>(r);
+}
+#  define FMT_BUILTIN_CTZLL(n) detail::ctzll(n)
+}  // namespace detail
+FMT_END_NAMESPACE
+#endif
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+
+FMT_CONSTEXPR inline void abort_fuzzing_if(bool condition) {
+  ignore_unused(condition);
+#ifdef FMT_FUZZ
+  if (condition) throw std::runtime_error("fuzzing limit reached");
+#endif
+}
+
+template <typename CharT, CharT... C> struct string_literal {
+  static constexpr CharT value[sizeof...(C)] = {C...};
+  constexpr operator basic_string_view<CharT>() const {
+    return {value, sizeof...(C)};
+  }
+};
+
+#if FMT_CPLUSPLUS < 201703L
+template <typename CharT, CharT... C>
+constexpr CharT string_literal<CharT, C...>::value[sizeof...(C)];
+#endif
+
+template <typename Streambuf> class formatbuf : public Streambuf {
+ private:
+  using char_type = typename Streambuf::char_type;
+  using streamsize = decltype(std::declval<Streambuf>().sputn(nullptr, 0));
+  using int_type = typename Streambuf::int_type;
+  using traits_type = typename Streambuf::traits_type;
+
+  buffer<char_type>& buffer_;
+
+ public:
+  explicit formatbuf(buffer<char_type>& buf) : buffer_(buf) {}
+
+ protected:
+  // The put area is always empty. This makes the implementation simpler and has
+  // the advantage that the streambuf and the buffer are always in sync and
+  // sputc never writes into uninitialized memory. A disadvantage is that each
+  // call to sputc always results in a (virtual) call to overflow. There is no
+  // disadvantage here for sputn since this always results in a call to xsputn.
+
+  auto overflow(int_type ch) -> int_type override {
+    if (!traits_type::eq_int_type(ch, traits_type::eof()))
+      buffer_.push_back(static_cast<char_type>(ch));
+    return ch;
+  }
+
+  auto xsputn(const char_type* s, streamsize count) -> streamsize override {
+    buffer_.append(s, s + count);
+    return count;
+  }
+};
+
+// Implementation of std::bit_cast for pre-C++20.
+template <typename To, typename From, FMT_ENABLE_IF(sizeof(To) == sizeof(From))>
+FMT_CONSTEXPR20 auto bit_cast(const From& from) -> To {
+#ifdef __cpp_lib_bit_cast
+  if (is_constant_evaluated()) return std::bit_cast<To>(from);
+#endif
+  auto to = To();
+  // The cast suppresses a bogus -Wclass-memaccess on GCC.
+  std::memcpy(static_cast<void*>(&to), &from, sizeof(to));
+  return to;
+}
+
+inline auto is_big_endian() -> bool {
+#ifdef _WIN32
+  return false;
+#elif defined(__BIG_ENDIAN__)
+  return true;
+#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__)
+  return __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__;
+#else
+  struct bytes {
+    char data[sizeof(int)];
+  };
+  return bit_cast<bytes>(1).data[0] == 0;
+#endif
+}
+
+class uint128_fallback {
+ private:
+  uint64_t lo_, hi_;
+
+  friend uint128_fallback umul128(uint64_t x, uint64_t y) noexcept;
+
+ public:
+  constexpr uint128_fallback(uint64_t hi, uint64_t lo) : lo_(lo), hi_(hi) {}
+  constexpr uint128_fallback(uint64_t value = 0) : lo_(value), hi_(0) {}
+
+  constexpr uint64_t high() const noexcept { return hi_; }
+  constexpr uint64_t low() const noexcept { return lo_; }
+
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  constexpr explicit operator T() const {
+    return static_cast<T>(lo_);
+  }
+
+  friend constexpr auto operator==(const uint128_fallback& lhs,
+                                   const uint128_fallback& rhs) -> bool {
+    return lhs.hi_ == rhs.hi_ && lhs.lo_ == rhs.lo_;
+  }
+  friend constexpr auto operator!=(const uint128_fallback& lhs,
+                                   const uint128_fallback& rhs) -> bool {
+    return !(lhs == rhs);
+  }
+  friend constexpr auto operator>(const uint128_fallback& lhs,
+                                  const uint128_fallback& rhs) -> bool {
+    return lhs.hi_ != rhs.hi_ ? lhs.hi_ > rhs.hi_ : lhs.lo_ > rhs.lo_;
+  }
+  friend constexpr auto operator|(const uint128_fallback& lhs,
+                                  const uint128_fallback& rhs)
+      -> uint128_fallback {
+    return {lhs.hi_ | rhs.hi_, lhs.lo_ | rhs.lo_};
+  }
+  friend constexpr auto operator&(const uint128_fallback& lhs,
+                                  const uint128_fallback& rhs)
+      -> uint128_fallback {
+    return {lhs.hi_ & rhs.hi_, lhs.lo_ & rhs.lo_};
+  }
+  friend auto operator+(const uint128_fallback& lhs,
+                        const uint128_fallback& rhs) -> uint128_fallback {
+    auto result = uint128_fallback(lhs);
+    result += rhs;
+    return result;
+  }
+  friend auto operator*(const uint128_fallback& lhs, uint32_t rhs)
+      -> uint128_fallback {
+    FMT_ASSERT(lhs.hi_ == 0, "");
+    uint64_t hi = (lhs.lo_ >> 32) * rhs;
+    uint64_t lo = (lhs.lo_ & ~uint32_t()) * rhs;
+    uint64_t new_lo = (hi << 32) + lo;
+    return {(hi >> 32) + (new_lo < lo ? 1 : 0), new_lo};
+  }
+  friend auto operator-(const uint128_fallback& lhs, uint64_t rhs)
+      -> uint128_fallback {
+    return {lhs.hi_ - (lhs.lo_ < rhs ? 1 : 0), lhs.lo_ - rhs};
+  }
+  FMT_CONSTEXPR auto operator>>(int shift) const -> uint128_fallback {
+    if (shift == 64) return {0, hi_};
+    if (shift > 64) return uint128_fallback(0, hi_) >> (shift - 64);
+    return {hi_ >> shift, (hi_ << (64 - shift)) | (lo_ >> shift)};
+  }
+  FMT_CONSTEXPR auto operator<<(int shift) const -> uint128_fallback {
+    if (shift == 64) return {lo_, 0};
+    if (shift > 64) return uint128_fallback(lo_, 0) << (shift - 64);
+    return {hi_ << shift | (lo_ >> (64 - shift)), (lo_ << shift)};
+  }
+  FMT_CONSTEXPR auto operator>>=(int shift) -> uint128_fallback& {
+    return *this = *this >> shift;
+  }
+  FMT_CONSTEXPR void operator+=(uint128_fallback n) {
+    uint64_t new_lo = lo_ + n.lo_;
+    uint64_t new_hi = hi_ + n.hi_ + (new_lo < lo_ ? 1 : 0);
+    FMT_ASSERT(new_hi >= hi_, "");
+    lo_ = new_lo;
+    hi_ = new_hi;
+  }
+
+  FMT_CONSTEXPR20 uint128_fallback& operator+=(uint64_t n) noexcept {
+    if (is_constant_evaluated()) {
+      lo_ += n;
+      hi_ += (lo_ < n ? 1 : 0);
+      return *this;
+    }
+#if FMT_HAS_BUILTIN(__builtin_addcll) && !defined(__ibmxl__)
+    unsigned long long carry;
+    lo_ = __builtin_addcll(lo_, n, 0, &carry);
+    hi_ += carry;
+#elif FMT_HAS_BUILTIN(__builtin_ia32_addcarryx_u64) && !defined(__ibmxl__)
+    unsigned long long result;
+    auto carry = __builtin_ia32_addcarryx_u64(0, lo_, n, &result);
+    lo_ = result;
+    hi_ += carry;
+#elif defined(_MSC_VER) && defined(_M_X64)
+    auto carry = _addcarry_u64(0, lo_, n, &lo_);
+    _addcarry_u64(carry, hi_, 0, &hi_);
+#else
+    lo_ += n;
+    hi_ += (lo_ < n ? 1 : 0);
+#endif
+    return *this;
+  }
+};
+
+using uint128_t = conditional_t<FMT_USE_INT128, uint128_opt, uint128_fallback>;
+
+#ifdef UINTPTR_MAX
+using uintptr_t = ::uintptr_t;
+#else
+using uintptr_t = uint128_t;
+#endif
+
+// Returns the largest possible value for type T. Same as
+// std::numeric_limits<T>::max() but shorter and not affected by the max macro.
+template <typename T> constexpr auto max_value() -> T {
+  return (std::numeric_limits<T>::max)();
+}
+template <typename T> constexpr auto num_bits() -> int {
+  return std::numeric_limits<T>::digits;
+}
+// std::numeric_limits<T>::digits may return 0 for 128-bit ints.
+template <> constexpr auto num_bits<int128_opt>() -> int { return 128; }
+template <> constexpr auto num_bits<uint128_t>() -> int { return 128; }
+
+// A heterogeneous bit_cast used for converting 96-bit long double to uint128_t
+// and 128-bit pointers to uint128_fallback.
+template <typename To, typename From, FMT_ENABLE_IF(sizeof(To) > sizeof(From))>
+inline auto bit_cast(const From& from) -> To {
+  constexpr auto size = static_cast<int>(sizeof(From) / sizeof(unsigned));
+  struct data_t {
+    unsigned value[static_cast<unsigned>(size)];
+  } data = bit_cast<data_t>(from);
+  auto result = To();
+  if (const_check(is_big_endian())) {
+    for (int i = 0; i < size; ++i)
+      result = (result << num_bits<unsigned>()) | data.value[i];
+  } else {
+    for (int i = size - 1; i >= 0; --i)
+      result = (result << num_bits<unsigned>()) | data.value[i];
+  }
+  return result;
+}
+
+FMT_INLINE void assume(bool condition) {
+  (void)condition;
+#if FMT_HAS_BUILTIN(__builtin_assume) && !FMT_ICC_VERSION
+  __builtin_assume(condition);
+#endif
+}
+
+// An approximation of iterator_t for pre-C++20 systems.
+template <typename T>
+using iterator_t = decltype(std::begin(std::declval<T&>()));
+template <typename T> using sentinel_t = decltype(std::end(std::declval<T&>()));
+
+// A workaround for std::string not having mutable data() until C++17.
+template <typename Char>
+inline auto get_data(std::basic_string<Char>& s) -> Char* {
+  return &s[0];
+}
+template <typename Container>
+inline auto get_data(Container& c) -> typename Container::value_type* {
+  return c.data();
+}
+
+#if defined(_SECURE_SCL) && _SECURE_SCL
+// Make a checked iterator to avoid MSVC warnings.
+template <typename T> using checked_ptr = stdext::checked_array_iterator<T*>;
+template <typename T>
+constexpr auto make_checked(T* p, size_t size) -> checked_ptr<T> {
+  return {p, size};
+}
+#else
+template <typename T> using checked_ptr = T*;
+template <typename T> constexpr auto make_checked(T* p, size_t) -> T* {
+  return p;
+}
+#endif
+
+// Attempts to reserve space for n extra characters in the output range.
+// Returns a pointer to the reserved range or a reference to it.
+template <typename Container, FMT_ENABLE_IF(is_contiguous<Container>::value)>
+#if FMT_CLANG_VERSION >= 307 && !FMT_ICC_VERSION
+__attribute__((no_sanitize("undefined")))
+#endif
+inline auto
+reserve(std::back_insert_iterator<Container> it, size_t n)
+    -> checked_ptr<typename Container::value_type> {
+  Container& c = get_container(it);
+  size_t size = c.size();
+  c.resize(size + n);
+  return make_checked(get_data(c) + size, n);
+}
+
+template <typename T>
+inline auto reserve(buffer_appender<T> it, size_t n) -> buffer_appender<T> {
+  buffer<T>& buf = get_container(it);
+  buf.try_reserve(buf.size() + n);
+  return it;
+}
+
+template <typename Iterator>
+constexpr auto reserve(Iterator& it, size_t) -> Iterator& {
+  return it;
+}
+
+template <typename OutputIt>
+using reserve_iterator =
+    remove_reference_t<decltype(reserve(std::declval<OutputIt&>(), 0))>;
+
+template <typename T, typename OutputIt>
+constexpr auto to_pointer(OutputIt, size_t) -> T* {
+  return nullptr;
+}
+template <typename T> auto to_pointer(buffer_appender<T> it, size_t n) -> T* {
+  buffer<T>& buf = get_container(it);
+  auto size = buf.size();
+  if (buf.capacity() < size + n) return nullptr;
+  buf.try_resize(size + n);
+  return buf.data() + size;
+}
+
+template <typename Container, FMT_ENABLE_IF(is_contiguous<Container>::value)>
+inline auto base_iterator(std::back_insert_iterator<Container>& it,
+                          checked_ptr<typename Container::value_type>)
+    -> std::back_insert_iterator<Container> {
+  return it;
+}
+
+template <typename Iterator>
+constexpr auto base_iterator(Iterator, Iterator it) -> Iterator {
+  return it;
+}
+
+// <algorithm> is spectacularly slow to compile in C++20 so use a simple fill_n
+// instead (#1998).
+template <typename OutputIt, typename Size, typename T>
+FMT_CONSTEXPR auto fill_n(OutputIt out, Size count, const T& value)
+    -> OutputIt {
+  for (Size i = 0; i < count; ++i) *out++ = value;
+  return out;
+}
+template <typename T, typename Size>
+FMT_CONSTEXPR20 auto fill_n(T* out, Size count, char value) -> T* {
+  if (is_constant_evaluated()) {
+    return fill_n<T*, Size, T>(out, count, value);
+  }
+  std::memset(out, value, to_unsigned(count));
+  return out + count;
+}
+
+#ifdef __cpp_char8_t
+using char8_type = char8_t;
+#else
+enum char8_type : unsigned char {};
+#endif
+
+template <typename OutChar, typename InputIt, typename OutputIt>
+FMT_CONSTEXPR FMT_NOINLINE auto copy_str_noinline(InputIt begin, InputIt end,
+                                                  OutputIt out) -> OutputIt {
+  return copy_str<OutChar>(begin, end, out);
+}
+
+// A public domain branchless UTF-8 decoder by Christopher Wellons:
+// https://github.com/skeeto/branchless-utf8
+/* Decode the next character, c, from s, reporting errors in e.
+ *
+ * Since this is a branchless decoder, four bytes will be read from the
+ * buffer regardless of the actual length of the next character. This
+ * means the buffer _must_ have at least three bytes of zero padding
+ * following the end of the data stream.
+ *
+ * Errors are reported in e, which will be non-zero if the parsed
+ * character was somehow invalid: invalid byte sequence, non-canonical
+ * encoding, or a surrogate half.
+ *
+ * The function returns a pointer to the next character. When an error
+ * occurs, this pointer will be a guess that depends on the particular
+ * error, but it will always advance at least one byte.
+ */
+FMT_CONSTEXPR inline auto utf8_decode(const char* s, uint32_t* c, int* e)
+    -> const char* {
+  constexpr const int masks[] = {0x00, 0x7f, 0x1f, 0x0f, 0x07};
+  constexpr const uint32_t mins[] = {4194304, 0, 128, 2048, 65536};
+  constexpr const int shiftc[] = {0, 18, 12, 6, 0};
+  constexpr const int shifte[] = {0, 6, 4, 2, 0};
+
+  int len = code_point_length_impl(*s);
+  // Compute the pointer to the next character early so that the next
+  // iteration can start working on the next character. Neither Clang
+  // nor GCC figure out this reordering on their own.
+  const char* next = s + len + !len;
+
+  using uchar = unsigned char;
+
+  // Assume a four-byte character and load four bytes. Unused bits are
+  // shifted out.
+  *c = uint32_t(uchar(s[0]) & masks[len]) << 18;
+  *c |= uint32_t(uchar(s[1]) & 0x3f) << 12;
+  *c |= uint32_t(uchar(s[2]) & 0x3f) << 6;
+  *c |= uint32_t(uchar(s[3]) & 0x3f) << 0;
+  *c >>= shiftc[len];
+
+  // Accumulate the various error conditions.
+  *e = (*c < mins[len]) << 6;       // non-canonical encoding
+  *e |= ((*c >> 11) == 0x1b) << 7;  // surrogate half?
+  *e |= (*c > 0x10FFFF) << 8;       // out of range?
+  *e |= (uchar(s[1]) & 0xc0) >> 2;
+  *e |= (uchar(s[2]) & 0xc0) >> 4;
+  *e |= uchar(s[3]) >> 6;
+  *e ^= 0x2a;  // top two bits of each tail byte correct?
+  *e >>= shifte[len];
+
+  return next;
+}
+
+constexpr uint32_t invalid_code_point = ~uint32_t();
+
+// Invokes f(cp, sv) for every code point cp in s with sv being the string view
+// corresponding to the code point. cp is invalid_code_point on error.
+template <typename F>
+FMT_CONSTEXPR void for_each_codepoint(string_view s, F f) {
+  auto decode = [f](const char* buf_ptr, const char* ptr) {
+    auto cp = uint32_t();
+    auto error = 0;
+    auto end = utf8_decode(buf_ptr, &cp, &error);
+    bool result = f(error ? invalid_code_point : cp,
+                    string_view(ptr, error ? 1 : to_unsigned(end - buf_ptr)));
+    return result ? (error ? buf_ptr + 1 : end) : nullptr;
+  };
+  auto p = s.data();
+  const size_t block_size = 4;  // utf8_decode always reads blocks of 4 chars.
+  if (s.size() >= block_size) {
+    for (auto end = p + s.size() - block_size + 1; p < end;) {
+      p = decode(p, p);
+      if (!p) return;
+    }
+  }
+  if (auto num_chars_left = s.data() + s.size() - p) {
+    char buf[2 * block_size - 1] = {};
+    copy_str<char>(p, p + num_chars_left, buf);
+    const char* buf_ptr = buf;
+    do {
+      auto end = decode(buf_ptr, p);
+      if (!end) return;
+      p += end - buf_ptr;
+      buf_ptr = end;
+    } while (buf_ptr - buf < num_chars_left);
+  }
+}
+
+template <typename Char>
+inline auto compute_width(basic_string_view<Char> s) -> size_t {
+  return s.size();
+}
+
+// Computes approximate display width of a UTF-8 string.
+FMT_CONSTEXPR inline size_t compute_width(string_view s) {
+  size_t num_code_points = 0;
+  // It is not a lambda for compatibility with C++14.
+  struct count_code_points {
+    size_t* count;
+    FMT_CONSTEXPR auto operator()(uint32_t cp, string_view) const -> bool {
+      *count += detail::to_unsigned(
+          1 +
+          (cp >= 0x1100 &&
+           (cp <= 0x115f ||  // Hangul Jamo init. consonants
+            cp == 0x2329 ||  // LEFT-POINTING ANGLE BRACKET
+            cp == 0x232a ||  // RIGHT-POINTING ANGLE BRACKET
+            // CJK ... Yi except IDEOGRAPHIC HALF FILL SPACE:
+            (cp >= 0x2e80 && cp <= 0xa4cf && cp != 0x303f) ||
+            (cp >= 0xac00 && cp <= 0xd7a3) ||    // Hangul Syllables
+            (cp >= 0xf900 && cp <= 0xfaff) ||    // CJK Compatibility Ideographs
+            (cp >= 0xfe10 && cp <= 0xfe19) ||    // Vertical Forms
+            (cp >= 0xfe30 && cp <= 0xfe6f) ||    // CJK Compatibility Forms
+            (cp >= 0xff00 && cp <= 0xff60) ||    // Fullwidth Forms
+            (cp >= 0xffe0 && cp <= 0xffe6) ||    // Fullwidth Forms
+            (cp >= 0x20000 && cp <= 0x2fffd) ||  // CJK
+            (cp >= 0x30000 && cp <= 0x3fffd) ||
+            // Miscellaneous Symbols and Pictographs + Emoticons:
+            (cp >= 0x1f300 && cp <= 0x1f64f) ||
+            // Supplemental Symbols and Pictographs:
+            (cp >= 0x1f900 && cp <= 0x1f9ff))));
+      return true;
+    }
+  };
+  for_each_codepoint(s, count_code_points{&num_code_points});
+  return num_code_points;
+}
+
+inline auto compute_width(basic_string_view<char8_type> s) -> size_t {
+  return compute_width(
+      string_view(reinterpret_cast<const char*>(s.data()), s.size()));
+}
+
+template <typename Char>
+inline auto code_point_index(basic_string_view<Char> s, size_t n) -> size_t {
+  size_t size = s.size();
+  return n < size ? n : size;
+}
+
+// Calculates the index of the nth code point in a UTF-8 string.
+inline auto code_point_index(string_view s, size_t n) -> size_t {
+  const char* data = s.data();
+  size_t num_code_points = 0;
+  for (size_t i = 0, size = s.size(); i != size; ++i) {
+    if ((data[i] & 0xc0) != 0x80 && ++num_code_points > n) return i;
+  }
+  return s.size();
+}
+
+inline auto code_point_index(basic_string_view<char8_type> s, size_t n)
+    -> size_t {
+  return code_point_index(
+      string_view(reinterpret_cast<const char*>(s.data()), s.size()), n);
+}
+
+#ifndef FMT_USE_FLOAT128
+#  ifdef __SIZEOF_FLOAT128__
+#    define FMT_USE_FLOAT128 1
+#  else
+#    define FMT_USE_FLOAT128 0
+#  endif
+#endif
+#if FMT_USE_FLOAT128
+using float128 = __float128;
+#else
+using float128 = void;
+#endif
+template <typename T> using is_float128 = std::is_same<T, float128>;
+
+template <typename T>
+using is_floating_point =
+    bool_constant<std::is_floating_point<T>::value || is_float128<T>::value>;
+
+template <typename T, bool = std::is_floating_point<T>::value>
+struct is_fast_float : bool_constant<std::numeric_limits<T>::is_iec559 &&
+                                     sizeof(T) <= sizeof(double)> {};
+template <typename T> struct is_fast_float<T, false> : std::false_type {};
+
+template <typename T>
+using is_double_double = bool_constant<std::numeric_limits<T>::digits == 106>;
+
+#ifndef FMT_USE_FULL_CACHE_DRAGONBOX
+#  define FMT_USE_FULL_CACHE_DRAGONBOX 0
+#endif
+
+template <typename T>
+template <typename U>
+void buffer<T>::append(const U* begin, const U* end) {
+  while (begin != end) {
+    auto count = to_unsigned(end - begin);
+    try_reserve(size_ + count);
+    auto free_cap = capacity_ - size_;
+    if (free_cap < count) count = free_cap;
+    std::uninitialized_copy_n(begin, count, make_checked(ptr_ + size_, count));
+    size_ += count;
+    begin += count;
+  }
+}
+
+template <typename T, typename Enable = void>
+struct is_locale : std::false_type {};
+template <typename T>
+struct is_locale<T, void_t<decltype(T::classic())>> : std::true_type {};
+}  // namespace detail
+
+FMT_MODULE_EXPORT_BEGIN
+
+// The number of characters to store in the basic_memory_buffer object itself
+// to avoid dynamic memory allocation.
+enum { inline_buffer_size = 500 };
+
+/**
+  \rst
+  A dynamically growing memory buffer for trivially copyable/constructible types
+  with the first ``SIZE`` elements stored in the object itself.
+
+  You can use the ``memory_buffer`` type alias for ``char`` instead.
+
+  **Example**::
+
+     auto out = fmt::memory_buffer();
+     format_to(std::back_inserter(out), "The answer is {}.", 42);
+
+  This will append the following output to the ``out`` object:
+
+  .. code-block:: none
+
+     The answer is 42.
+
+  The output can be converted to an ``std::string`` with ``to_string(out)``.
+  \endrst
+ */
+template <typename T, size_t SIZE = inline_buffer_size,
+          typename Allocator = std::allocator<T>>
+class basic_memory_buffer final : public detail::buffer<T> {
+ private:
+  T store_[SIZE];
+
+  // Don't inherit from Allocator avoid generating type_info for it.
+  Allocator alloc_;
+
+  // Deallocate memory allocated by the buffer.
+  FMT_CONSTEXPR20 void deallocate() {
+    T* data = this->data();
+    if (data != store_) alloc_.deallocate(data, this->capacity());
+  }
+
+ protected:
+  FMT_CONSTEXPR20 void grow(size_t size) override;
+
+ public:
+  using value_type = T;
+  using const_reference = const T&;
+
+  FMT_CONSTEXPR20 explicit basic_memory_buffer(
+      const Allocator& alloc = Allocator())
+      : alloc_(alloc) {
+    this->set(store_, SIZE);
+    if (detail::is_constant_evaluated()) detail::fill_n(store_, SIZE, T());
+  }
+  FMT_CONSTEXPR20 ~basic_memory_buffer() { deallocate(); }
+
+ private:
+  // Move data from other to this buffer.
+  FMT_CONSTEXPR20 void move(basic_memory_buffer& other) {
+    alloc_ = std::move(other.alloc_);
+    T* data = other.data();
+    size_t size = other.size(), capacity = other.capacity();
+    if (data == other.store_) {
+      this->set(store_, capacity);
+      detail::copy_str<T>(other.store_, other.store_ + size,
+                          detail::make_checked(store_, capacity));
+    } else {
+      this->set(data, capacity);
+      // Set pointer to the inline array so that delete is not called
+      // when deallocating.
+      other.set(other.store_, 0);
+      other.clear();
+    }
+    this->resize(size);
+  }
+
+ public:
+  /**
+    \rst
+    Constructs a :class:`fmt::basic_memory_buffer` object moving the content
+    of the other object to it.
+    \endrst
+   */
+  FMT_CONSTEXPR20 basic_memory_buffer(basic_memory_buffer&& other) noexcept {
+    move(other);
+  }
+
+  /**
+    \rst
+    Moves the content of the other ``basic_memory_buffer`` object to this one.
+    \endrst
+   */
+  auto operator=(basic_memory_buffer&& other) noexcept -> basic_memory_buffer& {
+    FMT_ASSERT(this != &other, "");
+    deallocate();
+    move(other);
+    return *this;
+  }
+
+  // Returns a copy of the allocator associated with this buffer.
+  auto get_allocator() const -> Allocator { return alloc_; }
+
+  /**
+    Resizes the buffer to contain *count* elements. If T is a POD type new
+    elements may not be initialized.
+   */
+  FMT_CONSTEXPR20 void resize(size_t count) { this->try_resize(count); }
+
+  /** Increases the buffer capacity to *new_capacity*. */
+  void reserve(size_t new_capacity) { this->try_reserve(new_capacity); }
+
+  // Directly append data into the buffer
+  using detail::buffer<T>::append;
+  template <typename ContiguousRange>
+  void append(const ContiguousRange& range) {
+    append(range.data(), range.data() + range.size());
+  }
+};
+
+template <typename T, size_t SIZE, typename Allocator>
+FMT_CONSTEXPR20 void basic_memory_buffer<T, SIZE, Allocator>::grow(
+    size_t size) {
+  detail::abort_fuzzing_if(size > 5000);
+  const size_t max_size = std::allocator_traits<Allocator>::max_size(alloc_);
+  size_t old_capacity = this->capacity();
+  size_t new_capacity = old_capacity + old_capacity / 2;
+  if (size > new_capacity)
+    new_capacity = size;
+  else if (new_capacity > max_size)
+    new_capacity = size > max_size ? size : max_size;
+  T* old_data = this->data();
+  T* new_data =
+      std::allocator_traits<Allocator>::allocate(alloc_, new_capacity);
+  // The following code doesn't throw, so the raw pointer above doesn't leak.
+  std::uninitialized_copy(old_data, old_data + this->size(),
+                          detail::make_checked(new_data, new_capacity));
+  this->set(new_data, new_capacity);
+  // deallocate must not throw according to the standard, but even if it does,
+  // the buffer already uses the new storage and will deallocate it in
+  // destructor.
+  if (old_data != store_) alloc_.deallocate(old_data, old_capacity);
+}
+
+using memory_buffer = basic_memory_buffer<char>;
+
+template <typename T, size_t SIZE, typename Allocator>
+struct is_contiguous<basic_memory_buffer<T, SIZE, Allocator>> : std::true_type {
+};
+
+namespace detail {
+#ifdef _WIN32
+FMT_API bool write_console(std::FILE* f, string_view text);
+#endif
+FMT_API void print(std::FILE*, string_view);
+}  // namespace detail
+
+/** A formatting error such as invalid format string. */
+FMT_CLASS_API
+class FMT_API format_error : public std::runtime_error {
+ public:
+  explicit format_error(const char* message) : std::runtime_error(message) {}
+  explicit format_error(const std::string& message)
+      : std::runtime_error(message) {}
+  format_error(const format_error&) = default;
+  format_error& operator=(const format_error&) = default;
+  format_error(format_error&&) = default;
+  format_error& operator=(format_error&&) = default;
+  ~format_error() noexcept override FMT_MSC_DEFAULT;
+};
+
+namespace detail_exported {
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+template <typename Char, size_t N> struct fixed_string {
+  constexpr fixed_string(const Char (&str)[N]) {
+    detail::copy_str<Char, const Char*, Char*>(static_cast<const Char*>(str),
+                                               str + N, data);
+  }
+  Char data[N] = {};
+};
+#endif
+
+// Converts a compile-time string to basic_string_view.
+template <typename Char, size_t N>
+constexpr auto compile_string_to_view(const Char (&s)[N])
+    -> basic_string_view<Char> {
+  // Remove trailing NUL character if needed. Won't be present if this is used
+  // with a raw character array (i.e. not defined as a string).
+  return {s, N - (std::char_traits<Char>::to_int_type(s[N - 1]) == 0 ? 1 : 0)};
+}
+template <typename Char>
+constexpr auto compile_string_to_view(detail::std_string_view<Char> s)
+    -> basic_string_view<Char> {
+  return {s.data(), s.size()};
+}
+}  // namespace detail_exported
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+template <typename T> struct is_integral : std::is_integral<T> {};
+template <> struct is_integral<int128_opt> : std::true_type {};
+template <> struct is_integral<uint128_t> : std::true_type {};
+
+template <typename T>
+using is_signed =
+    std::integral_constant<bool, std::numeric_limits<T>::is_signed ||
+                                     std::is_same<T, int128_opt>::value>;
+
+// Returns true if value is negative, false otherwise.
+// Same as `value < 0` but doesn't produce warnings if T is an unsigned type.
+template <typename T, FMT_ENABLE_IF(is_signed<T>::value)>
+constexpr auto is_negative(T value) -> bool {
+  return value < 0;
+}
+template <typename T, FMT_ENABLE_IF(!is_signed<T>::value)>
+constexpr auto is_negative(T) -> bool {
+  return false;
+}
+
+template <typename T>
+FMT_CONSTEXPR auto is_supported_floating_point(T) -> bool {
+  if (std::is_same<T, float>()) return FMT_USE_FLOAT;
+  if (std::is_same<T, double>()) return FMT_USE_DOUBLE;
+  if (std::is_same<T, long double>()) return FMT_USE_LONG_DOUBLE;
+  return true;
+}
+
+// Smallest of uint32_t, uint64_t, uint128_t that is large enough to
+// represent all values of an integral type T.
+template <typename T>
+using uint32_or_64_or_128_t =
+    conditional_t<num_bits<T>() <= 32 && !FMT_REDUCE_INT_INSTANTIATIONS,
+                  uint32_t,
+                  conditional_t<num_bits<T>() <= 64, uint64_t, uint128_t>>;
+template <typename T>
+using uint64_or_128_t = conditional_t<num_bits<T>() <= 64, uint64_t, uint128_t>;
+
+#define FMT_POWERS_OF_10(factor)                                             \
+  factor * 10, (factor)*100, (factor)*1000, (factor)*10000, (factor)*100000, \
+      (factor)*1000000, (factor)*10000000, (factor)*100000000,               \
+      (factor)*1000000000
+
+// Converts value in the range [0, 100) to a string.
+constexpr const char* digits2(size_t value) {
+  // GCC generates slightly better code when value is pointer-size.
+  return &"0001020304050607080910111213141516171819"
+         "2021222324252627282930313233343536373839"
+         "4041424344454647484950515253545556575859"
+         "6061626364656667686970717273747576777879"
+         "8081828384858687888990919293949596979899"[value * 2];
+}
+
+// Sign is a template parameter to workaround a bug in gcc 4.8.
+template <typename Char, typename Sign> constexpr Char sign(Sign s) {
+#if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 604
+  static_assert(std::is_same<Sign, sign_t>::value, "");
+#endif
+  return static_cast<Char>("\0-+ "[s]);
+}
+
+template <typename T> FMT_CONSTEXPR auto count_digits_fallback(T n) -> int {
+  int count = 1;
+  for (;;) {
+    // Integer division is slow so do it for a group of four digits instead
+    // of for every digit. The idea comes from the talk by Alexandrescu
+    // "Three Optimization Tips for C++". See speed-test for a comparison.
+    if (n < 10) return count;
+    if (n < 100) return count + 1;
+    if (n < 1000) return count + 2;
+    if (n < 10000) return count + 3;
+    n /= 10000u;
+    count += 4;
+  }
+}
+#if FMT_USE_INT128
+FMT_CONSTEXPR inline auto count_digits(uint128_opt n) -> int {
+  return count_digits_fallback(n);
+}
+#endif
+
+#ifdef FMT_BUILTIN_CLZLL
+// It is a separate function rather than a part of count_digits to workaround
+// the lack of static constexpr in constexpr functions.
+inline auto do_count_digits(uint64_t n) -> int {
+  // This has comparable performance to the version by Kendall Willets
+  // (https://github.com/fmtlib/format-benchmark/blob/master/digits10)
+  // but uses smaller tables.
+  // Maps bsr(n) to ceil(log10(pow(2, bsr(n) + 1) - 1)).
+  static constexpr uint8_t bsr2log10[] = {
+      1,  1,  1,  2,  2,  2,  3,  3,  3,  4,  4,  4,  4,  5,  5,  5,
+      6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  9,  9,  9,  10, 10, 10,
+      10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 15, 15,
+      15, 16, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 19, 19, 20};
+  auto t = bsr2log10[FMT_BUILTIN_CLZLL(n | 1) ^ 63];
+  static constexpr const uint64_t zero_or_powers_of_10[] = {
+      0, 0, FMT_POWERS_OF_10(1U), FMT_POWERS_OF_10(1000000000ULL),
+      10000000000000000000ULL};
+  return t - (n < zero_or_powers_of_10[t]);
+}
+#endif
+
+// Returns the number of decimal digits in n. Leading zeros are not counted
+// except for n == 0 in which case count_digits returns 1.
+FMT_CONSTEXPR20 inline auto count_digits(uint64_t n) -> int {
+#ifdef FMT_BUILTIN_CLZLL
+  if (!is_constant_evaluated()) {
+    return do_count_digits(n);
+  }
+#endif
+  return count_digits_fallback(n);
+}
+
+// Counts the number of digits in n. BITS = log2(radix).
+template <int BITS, typename UInt>
+FMT_CONSTEXPR auto count_digits(UInt n) -> int {
+#ifdef FMT_BUILTIN_CLZ
+  if (!is_constant_evaluated() && num_bits<UInt>() == 32)
+    return (FMT_BUILTIN_CLZ(static_cast<uint32_t>(n) | 1) ^ 31) / BITS + 1;
+#endif
+  // Lambda avoids unreachable code warnings from NVHPC.
+  return [](UInt m) {
+    int num_digits = 0;
+    do {
+      ++num_digits;
+    } while ((m >>= BITS) != 0);
+    return num_digits;
+  }(n);
+}
+
+#ifdef FMT_BUILTIN_CLZ
+// It is a separate function rather than a part of count_digits to workaround
+// the lack of static constexpr in constexpr functions.
+FMT_INLINE auto do_count_digits(uint32_t n) -> int {
+// An optimization by Kendall Willets from https://bit.ly/3uOIQrB.
+// This increments the upper 32 bits (log10(T) - 1) when >= T is added.
+#  define FMT_INC(T) (((sizeof(#  T) - 1ull) << 32) - T)
+  static constexpr uint64_t table[] = {
+      FMT_INC(0),          FMT_INC(0),          FMT_INC(0),           // 8
+      FMT_INC(10),         FMT_INC(10),         FMT_INC(10),          // 64
+      FMT_INC(100),        FMT_INC(100),        FMT_INC(100),         // 512
+      FMT_INC(1000),       FMT_INC(1000),       FMT_INC(1000),        // 4096
+      FMT_INC(10000),      FMT_INC(10000),      FMT_INC(10000),       // 32k
+      FMT_INC(100000),     FMT_INC(100000),     FMT_INC(100000),      // 256k
+      FMT_INC(1000000),    FMT_INC(1000000),    FMT_INC(1000000),     // 2048k
+      FMT_INC(10000000),   FMT_INC(10000000),   FMT_INC(10000000),    // 16M
+      FMT_INC(100000000),  FMT_INC(100000000),  FMT_INC(100000000),   // 128M
+      FMT_INC(1000000000), FMT_INC(1000000000), FMT_INC(1000000000),  // 1024M
+      FMT_INC(1000000000), FMT_INC(1000000000)                        // 4B
+  };
+  auto inc = table[FMT_BUILTIN_CLZ(n | 1) ^ 31];
+  return static_cast<int>((n + inc) >> 32);
+}
+#endif
+
+// Optional version of count_digits for better performance on 32-bit platforms.
+FMT_CONSTEXPR20 inline auto count_digits(uint32_t n) -> int {
+#ifdef FMT_BUILTIN_CLZ
+  if (!is_constant_evaluated()) {
+    return do_count_digits(n);
+  }
+#endif
+  return count_digits_fallback(n);
+}
+
+template <typename Int> constexpr auto digits10() noexcept -> int {
+  return std::numeric_limits<Int>::digits10;
+}
+template <> constexpr auto digits10<int128_opt>() noexcept -> int { return 38; }
+template <> constexpr auto digits10<uint128_t>() noexcept -> int { return 38; }
+
+template <typename Char> struct thousands_sep_result {
+  std::string grouping;
+  Char thousands_sep;
+};
+
+template <typename Char>
+FMT_API auto thousands_sep_impl(locale_ref loc) -> thousands_sep_result<Char>;
+template <typename Char>
+inline auto thousands_sep(locale_ref loc) -> thousands_sep_result<Char> {
+  auto result = thousands_sep_impl<char>(loc);
+  return {result.grouping, Char(result.thousands_sep)};
+}
+template <>
+inline auto thousands_sep(locale_ref loc) -> thousands_sep_result<wchar_t> {
+  return thousands_sep_impl<wchar_t>(loc);
+}
+
+template <typename Char>
+FMT_API auto decimal_point_impl(locale_ref loc) -> Char;
+template <typename Char> inline auto decimal_point(locale_ref loc) -> Char {
+  return Char(decimal_point_impl<char>(loc));
+}
+template <> inline auto decimal_point(locale_ref loc) -> wchar_t {
+  return decimal_point_impl<wchar_t>(loc);
+}
+
+// Compares two characters for equality.
+template <typename Char> auto equal2(const Char* lhs, const char* rhs) -> bool {
+  return lhs[0] == Char(rhs[0]) && lhs[1] == Char(rhs[1]);
+}
+inline auto equal2(const char* lhs, const char* rhs) -> bool {
+  return memcmp(lhs, rhs, 2) == 0;
+}
+
+// Copies two characters from src to dst.
+template <typename Char>
+FMT_CONSTEXPR20 FMT_INLINE void copy2(Char* dst, const char* src) {
+  if (!is_constant_evaluated() && sizeof(Char) == sizeof(char)) {
+    memcpy(dst, src, 2);
+    return;
+  }
+  *dst++ = static_cast<Char>(*src++);
+  *dst = static_cast<Char>(*src);
+}
+
+template <typename Iterator> struct format_decimal_result {
+  Iterator begin;
+  Iterator end;
+};
+
+// Formats a decimal unsigned integer value writing into out pointing to a
+// buffer of specified size. The caller must ensure that the buffer is large
+// enough.
+template <typename Char, typename UInt>
+FMT_CONSTEXPR20 auto format_decimal(Char* out, UInt value, int size)
+    -> format_decimal_result<Char*> {
+  FMT_ASSERT(size >= count_digits(value), "invalid digit count");
+  out += size;
+  Char* end = out;
+  while (value >= 100) {
+    // Integer division is slow so do it for a group of two digits instead
+    // of for every digit. The idea comes from the talk by Alexandrescu
+    // "Three Optimization Tips for C++". See speed-test for a comparison.
+    out -= 2;
+    copy2(out, digits2(static_cast<size_t>(value % 100)));
+    value /= 100;
+  }
+  if (value < 10) {
+    *--out = static_cast<Char>('0' + value);
+    return {out, end};
+  }
+  out -= 2;
+  copy2(out, digits2(static_cast<size_t>(value)));
+  return {out, end};
+}
+
+template <typename Char, typename UInt, typename Iterator,
+          FMT_ENABLE_IF(!std::is_pointer<remove_cvref_t<Iterator>>::value)>
+FMT_CONSTEXPR inline auto format_decimal(Iterator out, UInt value, int size)
+    -> format_decimal_result<Iterator> {
+  // Buffer is large enough to hold all digits (digits10 + 1).
+  Char buffer[digits10<UInt>() + 1];
+  auto end = format_decimal(buffer, value, size).end;
+  return {out, detail::copy_str_noinline<Char>(buffer, end, out)};
+}
+
+template <unsigned BASE_BITS, typename Char, typename UInt>
+FMT_CONSTEXPR auto format_uint(Char* buffer, UInt value, int num_digits,
+                               bool upper = false) -> Char* {
+  buffer += num_digits;
+  Char* end = buffer;
+  do {
+    const char* digits = upper ? "0123456789ABCDEF" : "0123456789abcdef";
+    unsigned digit = static_cast<unsigned>(value & ((1 << BASE_BITS) - 1));
+    *--buffer = static_cast<Char>(BASE_BITS < 4 ? static_cast<char>('0' + digit)
+                                                : digits[digit]);
+  } while ((value >>= BASE_BITS) != 0);
+  return end;
+}
+
+template <unsigned BASE_BITS, typename Char, typename It, typename UInt>
+inline auto format_uint(It out, UInt value, int num_digits, bool upper = false)
+    -> It {
+  if (auto ptr = to_pointer<Char>(out, to_unsigned(num_digits))) {
+    format_uint<BASE_BITS>(ptr, value, num_digits, upper);
+    return out;
+  }
+  // Buffer should be large enough to hold all digits (digits / BASE_BITS + 1).
+  char buffer[num_bits<UInt>() / BASE_BITS + 1];
+  format_uint<BASE_BITS>(buffer, value, num_digits, upper);
+  return detail::copy_str_noinline<Char>(buffer, buffer + num_digits, out);
+}
+
+// A converter from UTF-8 to UTF-16.
+class utf8_to_utf16 {
+ private:
+  basic_memory_buffer<wchar_t> buffer_;
+
+ public:
+  FMT_API explicit utf8_to_utf16(string_view s);
+  operator basic_string_view<wchar_t>() const { return {&buffer_[0], size()}; }
+  auto size() const -> size_t { return buffer_.size() - 1; }
+  auto c_str() const -> const wchar_t* { return &buffer_[0]; }
+  auto str() const -> std::wstring { return {&buffer_[0], size()}; }
+};
+
+namespace dragonbox {
+
+// Type-specific information that Dragonbox uses.
+template <typename T, typename Enable = void> struct float_info;
+
+template <> struct float_info<float> {
+  using carrier_uint = uint32_t;
+  static const int exponent_bits = 8;
+  static const int kappa = 1;
+  static const int big_divisor = 100;
+  static const int small_divisor = 10;
+  static const int min_k = -31;
+  static const int max_k = 46;
+  static const int shorter_interval_tie_lower_threshold = -35;
+  static const int shorter_interval_tie_upper_threshold = -35;
+};
+
+template <> struct float_info<double> {
+  using carrier_uint = uint64_t;
+  static const int exponent_bits = 11;
+  static const int kappa = 2;
+  static const int big_divisor = 1000;
+  static const int small_divisor = 100;
+  static const int min_k = -292;
+  static const int max_k = 326;
+  static const int shorter_interval_tie_lower_threshold = -77;
+  static const int shorter_interval_tie_upper_threshold = -77;
+};
+
+// An 80- or 128-bit floating point number.
+template <typename T>
+struct float_info<T, enable_if_t<std::numeric_limits<T>::digits == 64 ||
+                                 std::numeric_limits<T>::digits == 113 ||
+                                 is_float128<T>::value>> {
+  using carrier_uint = detail::uint128_t;
+  static const int exponent_bits = 15;
+};
+
+// A double-double floating point number.
+template <typename T>
+struct float_info<T, enable_if_t<is_double_double<T>::value>> {
+  using carrier_uint = detail::uint128_t;
+};
+
+template <typename T> struct decimal_fp {
+  using significand_type = typename float_info<T>::carrier_uint;
+  significand_type significand;
+  int exponent;
+};
+
+template <typename T> FMT_API auto to_decimal(T x) noexcept -> decimal_fp<T>;
+}  // namespace dragonbox
+
+// Returns true iff Float has the implicit bit which is not stored.
+template <typename Float> constexpr bool has_implicit_bit() {
+  // An 80-bit FP number has a 64-bit significand an no implicit bit.
+  return std::numeric_limits<Float>::digits != 64;
+}
+
+// Returns the number of significand bits stored in Float. The implicit bit is
+// not counted since it is not stored.
+template <typename Float> constexpr int num_significand_bits() {
+  // std::numeric_limits may not support __float128.
+  return is_float128<Float>() ? 112
+                              : (std::numeric_limits<Float>::digits -
+                                 (has_implicit_bit<Float>() ? 1 : 0));
+}
+
+template <typename Float>
+constexpr auto exponent_mask() ->
+    typename dragonbox::float_info<Float>::carrier_uint {
+  using uint = typename dragonbox::float_info<Float>::carrier_uint;
+  return ((uint(1) << dragonbox::float_info<Float>::exponent_bits) - 1)
+         << num_significand_bits<Float>();
+}
+template <typename Float> constexpr auto exponent_bias() -> int {
+  // std::numeric_limits may not support __float128.
+  return is_float128<Float>() ? 16383
+                              : std::numeric_limits<Float>::max_exponent - 1;
+}
+
+// Writes the exponent exp in the form "[+-]d{2,3}" to buffer.
+template <typename Char, typename It>
+FMT_CONSTEXPR auto write_exponent(int exp, It it) -> It {
+  FMT_ASSERT(-10000 < exp && exp < 10000, "exponent out of range");
+  if (exp < 0) {
+    *it++ = static_cast<Char>('-');
+    exp = -exp;
+  } else {
+    *it++ = static_cast<Char>('+');
+  }
+  if (exp >= 100) {
+    const char* top = digits2(to_unsigned(exp / 100));
+    if (exp >= 1000) *it++ = static_cast<Char>(top[0]);
+    *it++ = static_cast<Char>(top[1]);
+    exp %= 100;
+  }
+  const char* d = digits2(to_unsigned(exp));
+  *it++ = static_cast<Char>(d[0]);
+  *it++ = static_cast<Char>(d[1]);
+  return it;
+}
+
+// A floating-point number f * pow(2, e) where F is an unsigned type.
+template <typename F> struct basic_fp {
+  F f;
+  int e;
+
+  static constexpr const int num_significand_bits =
+      static_cast<int>(sizeof(F) * num_bits<unsigned char>());
+
+  constexpr basic_fp() : f(0), e(0) {}
+  constexpr basic_fp(uint64_t f_val, int e_val) : f(f_val), e(e_val) {}
+
+  // Constructs fp from an IEEE754 floating-point number.
+  template <typename Float> FMT_CONSTEXPR basic_fp(Float n) { assign(n); }
+
+  // Assigns n to this and return true iff predecessor is closer than successor.
+  template <typename Float, FMT_ENABLE_IF(!is_double_double<Float>::value)>
+  FMT_CONSTEXPR auto assign(Float n) -> bool {
+    static_assert(std::numeric_limits<Float>::digits <= 113, "unsupported FP");
+    // Assume Float is in the format [sign][exponent][significand].
+    using carrier_uint = typename dragonbox::float_info<Float>::carrier_uint;
+    const auto num_float_significand_bits =
+        detail::num_significand_bits<Float>();
+    const auto implicit_bit = carrier_uint(1) << num_float_significand_bits;
+    const auto significand_mask = implicit_bit - 1;
+    auto u = bit_cast<carrier_uint>(n);
+    f = static_cast<F>(u & significand_mask);
+    auto biased_e = static_cast<int>((u & exponent_mask<Float>()) >>
+                                     num_float_significand_bits);
+    // The predecessor is closer if n is a normalized power of 2 (f == 0)
+    // other than the smallest normalized number (biased_e > 1).
+    auto is_predecessor_closer = f == 0 && biased_e > 1;
+    if (biased_e == 0)
+      biased_e = 1;  // Subnormals use biased exponent 1 (min exponent).
+    else if (has_implicit_bit<Float>())
+      f += static_cast<F>(implicit_bit);
+    e = biased_e - exponent_bias<Float>() - num_float_significand_bits;
+    if (!has_implicit_bit<Float>()) ++e;
+    return is_predecessor_closer;
+  }
+
+  template <typename Float, FMT_ENABLE_IF(is_double_double<Float>::value)>
+  FMT_CONSTEXPR auto assign(Float n) -> bool {
+    static_assert(std::numeric_limits<double>::is_iec559, "unsupported FP");
+    return assign(static_cast<double>(n));
+  }
+};
+
+using fp = basic_fp<unsigned long long>;
+
+// Normalizes the value converted from double and multiplied by (1 << SHIFT).
+template <int SHIFT = 0, typename F>
+FMT_CONSTEXPR basic_fp<F> normalize(basic_fp<F> value) {
+  // Handle subnormals.
+  const auto implicit_bit = F(1) << num_significand_bits<double>();
+  const auto shifted_implicit_bit = implicit_bit << SHIFT;
+  while ((value.f & shifted_implicit_bit) == 0) {
+    value.f <<= 1;
+    --value.e;
+  }
+  // Subtract 1 to account for hidden bit.
+  const auto offset = basic_fp<F>::num_significand_bits -
+                      num_significand_bits<double>() - SHIFT - 1;
+  value.f <<= offset;
+  value.e -= offset;
+  return value;
+}
+
+// Computes lhs * rhs / pow(2, 64) rounded to nearest with half-up tie breaking.
+FMT_CONSTEXPR inline uint64_t multiply(uint64_t lhs, uint64_t rhs) {
+#if FMT_USE_INT128
+  auto product = static_cast<__uint128_t>(lhs) * rhs;
+  auto f = static_cast<uint64_t>(product >> 64);
+  return (static_cast<uint64_t>(product) & (1ULL << 63)) != 0 ? f + 1 : f;
+#else
+  // Multiply 32-bit parts of significands.
+  uint64_t mask = (1ULL << 32) - 1;
+  uint64_t a = lhs >> 32, b = lhs & mask;
+  uint64_t c = rhs >> 32, d = rhs & mask;
+  uint64_t ac = a * c, bc = b * c, ad = a * d, bd = b * d;
+  // Compute mid 64-bit of result and round.
+  uint64_t mid = (bd >> 32) + (ad & mask) + (bc & mask) + (1U << 31);
+  return ac + (ad >> 32) + (bc >> 32) + (mid >> 32);
+#endif
+}
+
+FMT_CONSTEXPR inline fp operator*(fp x, fp y) {
+  return {multiply(x.f, y.f), x.e + y.e + 64};
+}
+
+template <typename T = void> struct basic_data {
+  // Normalized 64-bit significands of pow(10, k), for k = -348, -340, ..., 340.
+  // These are generated by support/compute-powers.py.
+  static constexpr uint64_t pow10_significands[87] = {
+      0xfa8fd5a0081c0288, 0xbaaee17fa23ebf76, 0x8b16fb203055ac76,
+      0xcf42894a5dce35ea, 0x9a6bb0aa55653b2d, 0xe61acf033d1a45df,
+      0xab70fe17c79ac6ca, 0xff77b1fcbebcdc4f, 0xbe5691ef416bd60c,
+      0x8dd01fad907ffc3c, 0xd3515c2831559a83, 0x9d71ac8fada6c9b5,
+      0xea9c227723ee8bcb, 0xaecc49914078536d, 0x823c12795db6ce57,
+      0xc21094364dfb5637, 0x9096ea6f3848984f, 0xd77485cb25823ac7,
+      0xa086cfcd97bf97f4, 0xef340a98172aace5, 0xb23867fb2a35b28e,
+      0x84c8d4dfd2c63f3b, 0xc5dd44271ad3cdba, 0x936b9fcebb25c996,
+      0xdbac6c247d62a584, 0xa3ab66580d5fdaf6, 0xf3e2f893dec3f126,
+      0xb5b5ada8aaff80b8, 0x87625f056c7c4a8b, 0xc9bcff6034c13053,
+      0x964e858c91ba2655, 0xdff9772470297ebd, 0xa6dfbd9fb8e5b88f,
+      0xf8a95fcf88747d94, 0xb94470938fa89bcf, 0x8a08f0f8bf0f156b,
+      0xcdb02555653131b6, 0x993fe2c6d07b7fac, 0xe45c10c42a2b3b06,
+      0xaa242499697392d3, 0xfd87b5f28300ca0e, 0xbce5086492111aeb,
+      0x8cbccc096f5088cc, 0xd1b71758e219652c, 0x9c40000000000000,
+      0xe8d4a51000000000, 0xad78ebc5ac620000, 0x813f3978f8940984,
+      0xc097ce7bc90715b3, 0x8f7e32ce7bea5c70, 0xd5d238a4abe98068,
+      0x9f4f2726179a2245, 0xed63a231d4c4fb27, 0xb0de65388cc8ada8,
+      0x83c7088e1aab65db, 0xc45d1df942711d9a, 0x924d692ca61be758,
+      0xda01ee641a708dea, 0xa26da3999aef774a, 0xf209787bb47d6b85,
+      0xb454e4a179dd1877, 0x865b86925b9bc5c2, 0xc83553c5c8965d3d,
+      0x952ab45cfa97a0b3, 0xde469fbd99a05fe3, 0xa59bc234db398c25,
+      0xf6c69a72a3989f5c, 0xb7dcbf5354e9bece, 0x88fcf317f22241e2,
+      0xcc20ce9bd35c78a5, 0x98165af37b2153df, 0xe2a0b5dc971f303a,
+      0xa8d9d1535ce3b396, 0xfb9b7cd9a4a7443c, 0xbb764c4ca7a44410,
+      0x8bab8eefb6409c1a, 0xd01fef10a657842c, 0x9b10a4e5e9913129,
+      0xe7109bfba19c0c9d, 0xac2820d9623bf429, 0x80444b5e7aa7cf85,
+      0xbf21e44003acdd2d, 0x8e679c2f5e44ff8f, 0xd433179d9c8cb841,
+      0x9e19db92b4e31ba9, 0xeb96bf6ebadf77d9, 0xaf87023b9bf0ee6b,
+  };
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+#  pragma GCC diagnostic push
+#  pragma GCC diagnostic ignored "-Wnarrowing"
+#endif
+  // Binary exponents of pow(10, k), for k = -348, -340, ..., 340, corresponding
+  // to significands above.
+  static constexpr int16_t pow10_exponents[87] = {
+      -1220, -1193, -1166, -1140, -1113, -1087, -1060, -1034, -1007, -980, -954,
+      -927,  -901,  -874,  -847,  -821,  -794,  -768,  -741,  -715,  -688, -661,
+      -635,  -608,  -582,  -555,  -529,  -502,  -475,  -449,  -422,  -396, -369,
+      -343,  -316,  -289,  -263,  -236,  -210,  -183,  -157,  -130,  -103, -77,
+      -50,   -24,   3,     30,    56,    83,    109,   136,   162,   189,  216,
+      242,   269,   295,   322,   348,   375,   402,   428,   455,   481,  508,
+      534,   561,   588,   614,   641,   667,   694,   720,   747,   774,  800,
+      827,   853,   880,   907,   933,   960,   986,   1013,  1039,  1066};
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+#  pragma GCC diagnostic pop
+#endif
+
+  static constexpr uint64_t power_of_10_64[20] = {
+      1, FMT_POWERS_OF_10(1ULL), FMT_POWERS_OF_10(1000000000ULL),
+      10000000000000000000ULL};
+};
+
+#if FMT_CPLUSPLUS < 201703L
+template <typename T> constexpr uint64_t basic_data<T>::pow10_significands[];
+template <typename T> constexpr int16_t basic_data<T>::pow10_exponents[];
+template <typename T> constexpr uint64_t basic_data<T>::power_of_10_64[];
+#endif
+
+// This is a struct rather than an alias to avoid shadowing warnings in gcc.
+struct data : basic_data<> {};
+
+// Returns a cached power of 10 `c_k = c_k.f * pow(2, c_k.e)` such that its
+// (binary) exponent satisfies `min_exponent <= c_k.e <= min_exponent + 28`.
+FMT_CONSTEXPR inline fp get_cached_power(int min_exponent,
+                                         int& pow10_exponent) {
+  const int shift = 32;
+  // log10(2) = 0x0.4d104d427de7fbcc...
+  const int64_t significand = 0x4d104d427de7fbcc;
+  int index = static_cast<int>(
+      ((min_exponent + fp::num_significand_bits - 1) * (significand >> shift) +
+       ((int64_t(1) << shift) - 1))  // ceil
+      >> 32                          // arithmetic shift
+  );
+  // Decimal exponent of the first (smallest) cached power of 10.
+  const int first_dec_exp = -348;
+  // Difference between 2 consecutive decimal exponents in cached powers of 10.
+  const int dec_exp_step = 8;
+  index = (index - first_dec_exp - 1) / dec_exp_step + 1;
+  pow10_exponent = first_dec_exp + index * dec_exp_step;
+  // Using *(x + index) instead of x[index] avoids an issue with some compilers
+  // using the EDG frontend (e.g. nvhpc/22.3 in C++17 mode).
+  return {*(data::pow10_significands + index),
+          *(data::pow10_exponents + index)};
+}
+
+#ifndef _MSC_VER
+#  define FMT_SNPRINTF snprintf
+#else
+FMT_API auto fmt_snprintf(char* buf, size_t size, const char* fmt, ...) -> int;
+#  define FMT_SNPRINTF fmt_snprintf
+#endif  // _MSC_VER
+
+// Formats a floating-point number with snprintf using the hexfloat format.
+template <typename T>
+auto snprintf_float(T value, int precision, float_specs specs,
+                    buffer<char>& buf) -> int {
+  // Buffer capacity must be non-zero, otherwise MSVC's vsnprintf_s will fail.
+  FMT_ASSERT(buf.capacity() > buf.size(), "empty buffer");
+  FMT_ASSERT(specs.format == float_format::hex, "");
+  static_assert(!std::is_same<T, float>::value, "");
+
+  // Build the format string.
+  char format[7];  // The longest format is "%#.*Le".
+  char* format_ptr = format;
+  *format_ptr++ = '%';
+  if (specs.showpoint) *format_ptr++ = '#';
+  if (precision >= 0) {
+    *format_ptr++ = '.';
+    *format_ptr++ = '*';
+  }
+  if (std::is_same<T, long double>()) *format_ptr++ = 'L';
+  *format_ptr++ = specs.upper ? 'A' : 'a';
+  *format_ptr = '\0';
+
+  // Format using snprintf.
+  auto offset = buf.size();
+  for (;;) {
+    auto begin = buf.data() + offset;
+    auto capacity = buf.capacity() - offset;
+    abort_fuzzing_if(precision > 100000);
+    // Suppress the warning about a nonliteral format string.
+    // Cannot use auto because of a bug in MinGW (#1532).
+    int (*snprintf_ptr)(char*, size_t, const char*, ...) = FMT_SNPRINTF;
+    int result = precision >= 0
+                     ? snprintf_ptr(begin, capacity, format, precision, value)
+                     : snprintf_ptr(begin, capacity, format, value);
+    if (result < 0) {
+      // The buffer will grow exponentially.
+      buf.try_reserve(buf.capacity() + 1);
+      continue;
+    }
+    auto size = to_unsigned(result);
+    // Size equal to capacity means that the last character was truncated.
+    if (size < capacity) {
+      buf.try_resize(size + offset);
+      return 0;
+    }
+    buf.try_reserve(size + offset + 1);  // Add 1 for the terminating '\0'.
+  }
+}
+
+template <typename T>
+using convert_float_result =
+    conditional_t<std::is_same<T, float>::value || sizeof(T) == sizeof(double),
+                  double, T>;
+
+template <typename T>
+constexpr auto convert_float(T value) -> convert_float_result<T> {
+  return static_cast<convert_float_result<T>>(value);
+}
+
+template <typename OutputIt, typename Char>
+FMT_NOINLINE FMT_CONSTEXPR auto fill(OutputIt it, size_t n,
+                                     const fill_t<Char>& fill) -> OutputIt {
+  auto fill_size = fill.size();
+  if (fill_size == 1) return detail::fill_n(it, n, fill[0]);
+  auto data = fill.data();
+  for (size_t i = 0; i < n; ++i)
+    it = copy_str<Char>(data, data + fill_size, it);
+  return it;
+}
+
+// Writes the output of f, padded according to format specifications in specs.
+// size: output size in code units.
+// width: output display width in (terminal) column positions.
+template <align::type align = align::left, typename OutputIt, typename Char,
+          typename F>
+FMT_CONSTEXPR auto write_padded(OutputIt out,
+                                const basic_format_specs<Char>& specs,
+                                size_t size, size_t width, F&& f) -> OutputIt {
+  static_assert(align == align::left || align == align::right, "");
+  unsigned spec_width = to_unsigned(specs.width);
+  size_t padding = spec_width > width ? spec_width - width : 0;
+  // Shifts are encoded as string literals because static constexpr is not
+  // supported in constexpr functions.
+  auto* shifts = align == align::left ? "\x1f\x1f\x00\x01" : "\x00\x1f\x00\x01";
+  size_t left_padding = padding >> shifts[specs.align];
+  size_t right_padding = padding - left_padding;
+  auto it = reserve(out, size + padding * specs.fill.size());
+  if (left_padding != 0) it = fill(it, left_padding, specs.fill);
+  it = f(it);
+  if (right_padding != 0) it = fill(it, right_padding, specs.fill);
+  return base_iterator(out, it);
+}
+
+template <align::type align = align::left, typename OutputIt, typename Char,
+          typename F>
+constexpr auto write_padded(OutputIt out, const basic_format_specs<Char>& specs,
+                            size_t size, F&& f) -> OutputIt {
+  return write_padded<align>(out, specs, size, size, f);
+}
+
+template <align::type align = align::left, typename Char, typename OutputIt>
+FMT_CONSTEXPR auto write_bytes(OutputIt out, string_view bytes,
+                               const basic_format_specs<Char>& specs)
+    -> OutputIt {
+  return write_padded<align>(
+      out, specs, bytes.size(), [bytes](reserve_iterator<OutputIt> it) {
+        const char* data = bytes.data();
+        return copy_str<Char>(data, data + bytes.size(), it);
+      });
+}
+
+template <typename Char, typename OutputIt, typename UIntPtr>
+auto write_ptr(OutputIt out, UIntPtr value,
+               const basic_format_specs<Char>* specs) -> OutputIt {
+  int num_digits = count_digits<4>(value);
+  auto size = to_unsigned(num_digits) + size_t(2);
+  auto write = [=](reserve_iterator<OutputIt> it) {
+    *it++ = static_cast<Char>('0');
+    *it++ = static_cast<Char>('x');
+    return format_uint<4, Char>(it, value, num_digits);
+  };
+  return specs ? write_padded<align::right>(out, *specs, size, write)
+               : base_iterator(out, write(reserve(out, size)));
+}
+
+// Returns true iff the code point cp is printable.
+FMT_API auto is_printable(uint32_t cp) -> bool;
+
+inline auto needs_escape(uint32_t cp) -> bool {
+  return cp < 0x20 || cp == 0x7f || cp == '"' || cp == '\\' ||
+         !is_printable(cp);
+}
+
+template <typename Char> struct find_escape_result {
+  const Char* begin;
+  const Char* end;
+  uint32_t cp;
+};
+
+template <typename Char>
+using make_unsigned_char =
+    typename conditional_t<std::is_integral<Char>::value,
+                           std::make_unsigned<Char>,
+                           type_identity<uint32_t>>::type;
+
+template <typename Char>
+auto find_escape(const Char* begin, const Char* end)
+    -> find_escape_result<Char> {
+  for (; begin != end; ++begin) {
+    uint32_t cp = static_cast<make_unsigned_char<Char>>(*begin);
+    if (const_check(sizeof(Char) == 1) && cp >= 0x80) continue;
+    if (needs_escape(cp)) return {begin, begin + 1, cp};
+  }
+  return {begin, nullptr, 0};
+}
+
+inline auto find_escape(const char* begin, const char* end)
+    -> find_escape_result<char> {
+  if (!is_utf8()) return find_escape<char>(begin, end);
+  auto result = find_escape_result<char>{end, nullptr, 0};
+  for_each_codepoint(string_view(begin, to_unsigned(end - begin)),
+                     [&](uint32_t cp, string_view sv) {
+                       if (needs_escape(cp)) {
+                         result = {sv.begin(), sv.end(), cp};
+                         return false;
+                       }
+                       return true;
+                     });
+  return result;
+}
+
+#define FMT_STRING_IMPL(s, base, explicit)                                    \
+  [] {                                                                        \
+    /* Use the hidden visibility as a workaround for a GCC bug (#1973). */    \
+    /* Use a macro-like name to avoid shadowing warnings. */                  \
+    struct FMT_GCC_VISIBILITY_HIDDEN FMT_COMPILE_STRING : base {              \
+      using char_type FMT_MAYBE_UNUSED = fmt::remove_cvref_t<decltype(s[0])>; \
+      FMT_MAYBE_UNUSED FMT_CONSTEXPR explicit                                 \
+      operator fmt::basic_string_view<char_type>() const {                    \
+        return fmt::detail_exported::compile_string_to_view<char_type>(s);    \
+      }                                                                       \
+    };                                                                        \
+    return FMT_COMPILE_STRING();                                              \
+  }()
+
+/**
+  \rst
+  Constructs a compile-time format string from a string literal *s*.
+
+  **Example**::
+
+    // A compile-time error because 'd' is an invalid specifier for strings.
+    std::string s = fmt::format(FMT_STRING("{:d}"), "foo");
+  \endrst
+ */
+#define FMT_STRING(s) FMT_STRING_IMPL(s, fmt::detail::compile_string, )
+
+template <size_t width, typename Char, typename OutputIt>
+auto write_codepoint(OutputIt out, char prefix, uint32_t cp) -> OutputIt {
+  *out++ = static_cast<Char>('\\');
+  *out++ = static_cast<Char>(prefix);
+  Char buf[width];
+  fill_n(buf, width, static_cast<Char>('0'));
+  format_uint<4>(buf, cp, width);
+  return copy_str<Char>(buf, buf + width, out);
+}
+
+template <typename OutputIt, typename Char>
+auto write_escaped_cp(OutputIt out, const find_escape_result<Char>& escape)
+    -> OutputIt {
+  auto c = static_cast<Char>(escape.cp);
+  switch (escape.cp) {
+  case '\n':
+    *out++ = static_cast<Char>('\\');
+    c = static_cast<Char>('n');
+    break;
+  case '\r':
+    *out++ = static_cast<Char>('\\');
+    c = static_cast<Char>('r');
+    break;
+  case '\t':
+    *out++ = static_cast<Char>('\\');
+    c = static_cast<Char>('t');
+    break;
+  case '"':
+    FMT_FALLTHROUGH;
+  case '\'':
+    FMT_FALLTHROUGH;
+  case '\\':
+    *out++ = static_cast<Char>('\\');
+    break;
+  default:
+    if (is_utf8()) {
+      if (escape.cp < 0x100) {
+        return write_codepoint<2, Char>(out, 'x', escape.cp);
+      }
+      if (escape.cp < 0x10000) {
+        return write_codepoint<4, Char>(out, 'u', escape.cp);
+      }
+      if (escape.cp < 0x110000) {
+        return write_codepoint<8, Char>(out, 'U', escape.cp);
+      }
+    }
+    for (Char escape_char : basic_string_view<Char>(
+             escape.begin, to_unsigned(escape.end - escape.begin))) {
+      out = write_codepoint<2, Char>(out, 'x',
+                                     static_cast<uint32_t>(escape_char) & 0xFF);
+    }
+    return out;
+  }
+  *out++ = c;
+  return out;
+}
+
+template <typename Char, typename OutputIt>
+auto write_escaped_string(OutputIt out, basic_string_view<Char> str)
+    -> OutputIt {
+  *out++ = static_cast<Char>('"');
+  auto begin = str.begin(), end = str.end();
+  do {
+    auto escape = find_escape(begin, end);
+    out = copy_str<Char>(begin, escape.begin, out);
+    begin = escape.end;
+    if (!begin) break;
+    out = write_escaped_cp<OutputIt, Char>(out, escape);
+  } while (begin != end);
+  *out++ = static_cast<Char>('"');
+  return out;
+}
+
+template <typename Char, typename OutputIt>
+auto write_escaped_char(OutputIt out, Char v) -> OutputIt {
+  *out++ = static_cast<Char>('\'');
+  if ((needs_escape(static_cast<uint32_t>(v)) && v != static_cast<Char>('"')) ||
+      v == static_cast<Char>('\'')) {
+    out = write_escaped_cp(
+        out, find_escape_result<Char>{&v, &v + 1, static_cast<uint32_t>(v)});
+  } else {
+    *out++ = v;
+  }
+  *out++ = static_cast<Char>('\'');
+  return out;
+}
+
+template <typename Char, typename OutputIt>
+FMT_CONSTEXPR auto write_char(OutputIt out, Char value,
+                              const basic_format_specs<Char>& specs)
+    -> OutputIt {
+  bool is_debug = specs.type == presentation_type::debug;
+  return write_padded(out, specs, 1, [=](reserve_iterator<OutputIt> it) {
+    if (is_debug) return write_escaped_char(it, value);
+    *it++ = value;
+    return it;
+  });
+}
+template <typename Char, typename OutputIt>
+FMT_CONSTEXPR auto write(OutputIt out, Char value,
+                         const basic_format_specs<Char>& specs,
+                         locale_ref loc = {}) -> OutputIt {
+  return check_char_specs(specs)
+             ? write_char(out, value, specs)
+             : write(out, static_cast<int>(value), specs, loc);
+}
+
+// Data for write_int that doesn't depend on output iterator type. It is used to
+// avoid template code bloat.
+template <typename Char> struct write_int_data {
+  size_t size;
+  size_t padding;
+
+  FMT_CONSTEXPR write_int_data(int num_digits, unsigned prefix,
+                               const basic_format_specs<Char>& specs)
+      : size((prefix >> 24) + to_unsigned(num_digits)), padding(0) {
+    if (specs.align == align::numeric) {
+      auto width = to_unsigned(specs.width);
+      if (width > size) {
+        padding = width - size;
+        size = width;
+      }
+    } else if (specs.precision > num_digits) {
+      size = (prefix >> 24) + to_unsigned(specs.precision);
+      padding = to_unsigned(specs.precision - num_digits);
+    }
+  }
+};
+
+// Writes an integer in the format
+//   <left-padding><prefix><numeric-padding><digits><right-padding>
+// where <digits> are written by write_digits(it).
+// prefix contains chars in three lower bytes and the size in the fourth byte.
+template <typename OutputIt, typename Char, typename W>
+FMT_CONSTEXPR FMT_INLINE auto write_int(OutputIt out, int num_digits,
+                                        unsigned prefix,
+                                        const basic_format_specs<Char>& specs,
+                                        W write_digits) -> OutputIt {
+  // Slightly faster check for specs.width == 0 && specs.precision == -1.
+  if ((specs.width | (specs.precision + 1)) == 0) {
+    auto it = reserve(out, to_unsigned(num_digits) + (prefix >> 24));
+    if (prefix != 0) {
+      for (unsigned p = prefix & 0xffffff; p != 0; p >>= 8)
+        *it++ = static_cast<Char>(p & 0xff);
+    }
+    return base_iterator(out, write_digits(it));
+  }
+  auto data = write_int_data<Char>(num_digits, prefix, specs);
+  return write_padded<align::right>(
+      out, specs, data.size, [=](reserve_iterator<OutputIt> it) {
+        for (unsigned p = prefix & 0xffffff; p != 0; p >>= 8)
+          *it++ = static_cast<Char>(p & 0xff);
+        it = detail::fill_n(it, data.padding, static_cast<Char>('0'));
+        return write_digits(it);
+      });
+}
+
+template <typename Char> class digit_grouping {
+ private:
+  thousands_sep_result<Char> sep_;
+
+  struct next_state {
+    std::string::const_iterator group;
+    int pos;
+  };
+  next_state initial_state() const { return {sep_.grouping.begin(), 0}; }
+
+  // Returns the next digit group separator position.
+  int next(next_state& state) const {
+    if (!sep_.thousands_sep) return max_value<int>();
+    if (state.group == sep_.grouping.end())
+      return state.pos += sep_.grouping.back();
+    if (*state.group <= 0 || *state.group == max_value<char>())
+      return max_value<int>();
+    state.pos += *state.group++;
+    return state.pos;
+  }
+
+ public:
+  explicit digit_grouping(locale_ref loc, bool localized = true) {
+    if (localized)
+      sep_ = thousands_sep<Char>(loc);
+    else
+      sep_.thousands_sep = Char();
+  }
+  explicit digit_grouping(thousands_sep_result<Char> sep) : sep_(sep) {}
+
+  Char separator() const { return sep_.thousands_sep; }
+
+  int count_separators(int num_digits) const {
+    int count = 0;
+    auto state = initial_state();
+    while (num_digits > next(state)) ++count;
+    return count;
+  }
+
+  // Applies grouping to digits and write the output to out.
+  template <typename Out, typename C>
+  Out apply(Out out, basic_string_view<C> digits) const {
+    auto num_digits = static_cast<int>(digits.size());
+    auto separators = basic_memory_buffer<int>();
+    separators.push_back(0);
+    auto state = initial_state();
+    while (int i = next(state)) {
+      if (i >= num_digits) break;
+      separators.push_back(i);
+    }
+    for (int i = 0, sep_index = static_cast<int>(separators.size() - 1);
+         i < num_digits; ++i) {
+      if (num_digits - i == separators[sep_index]) {
+        *out++ = separator();
+        --sep_index;
+      }
+      *out++ = static_cast<Char>(digits[to_unsigned(i)]);
+    }
+    return out;
+  }
+};
+
+template <typename OutputIt, typename UInt, typename Char>
+auto write_int_localized(OutputIt out, UInt value, unsigned prefix,
+                         const basic_format_specs<Char>& specs,
+                         const digit_grouping<Char>& grouping) -> OutputIt {
+  static_assert(std::is_same<uint64_or_128_t<UInt>, UInt>::value, "");
+  int num_digits = count_digits(value);
+  char digits[40];
+  format_decimal(digits, value, num_digits);
+  unsigned size = to_unsigned((prefix != 0 ? 1 : 0) + num_digits +
+                              grouping.count_separators(num_digits));
+  return write_padded<align::right>(
+      out, specs, size, size, [&](reserve_iterator<OutputIt> it) {
+        if (prefix != 0) {
+          char sign = static_cast<char>(prefix);
+          *it++ = static_cast<Char>(sign);
+        }
+        return grouping.apply(it, string_view(digits, to_unsigned(num_digits)));
+      });
+}
+
+template <typename OutputIt, typename UInt, typename Char>
+auto write_int_localized(OutputIt& out, UInt value, unsigned prefix,
+                         const basic_format_specs<Char>& specs, locale_ref loc)
+    -> bool {
+  auto grouping = digit_grouping<Char>(loc);
+  out = write_int_localized(out, value, prefix, specs, grouping);
+  return true;
+}
+
+FMT_CONSTEXPR inline void prefix_append(unsigned& prefix, unsigned value) {
+  prefix |= prefix != 0 ? value << 8 : value;
+  prefix += (1u + (value > 0xff ? 1 : 0)) << 24;
+}
+
+template <typename UInt> struct write_int_arg {
+  UInt abs_value;
+  unsigned prefix;
+};
+
+template <typename T>
+FMT_CONSTEXPR auto make_write_int_arg(T value, sign_t sign)
+    -> write_int_arg<uint32_or_64_or_128_t<T>> {
+  auto prefix = 0u;
+  auto abs_value = static_cast<uint32_or_64_or_128_t<T>>(value);
+  if (is_negative(value)) {
+    prefix = 0x01000000 | '-';
+    abs_value = 0 - abs_value;
+  } else {
+    constexpr const unsigned prefixes[4] = {0, 0, 0x1000000u | '+',
+                                            0x1000000u | ' '};
+    prefix = prefixes[sign];
+  }
+  return {abs_value, prefix};
+}
+
+template <typename Char, typename OutputIt, typename T>
+FMT_CONSTEXPR FMT_INLINE auto write_int(OutputIt out, write_int_arg<T> arg,
+                                        const basic_format_specs<Char>& specs,
+                                        locale_ref loc) -> OutputIt {
+  static_assert(std::is_same<T, uint32_or_64_or_128_t<T>>::value, "");
+  auto abs_value = arg.abs_value;
+  auto prefix = arg.prefix;
+  switch (specs.type) {
+  case presentation_type::none:
+  case presentation_type::dec: {
+    if (specs.localized &&
+        write_int_localized(out, static_cast<uint64_or_128_t<T>>(abs_value),
+                            prefix, specs, loc)) {
+      return out;
+    }
+    auto num_digits = count_digits(abs_value);
+    return write_int(
+        out, num_digits, prefix, specs, [=](reserve_iterator<OutputIt> it) {
+          return format_decimal<Char>(it, abs_value, num_digits).end;
+        });
+  }
+  case presentation_type::hex_lower:
+  case presentation_type::hex_upper: {
+    bool upper = specs.type == presentation_type::hex_upper;
+    if (specs.alt)
+      prefix_append(prefix, unsigned(upper ? 'X' : 'x') << 8 | '0');
+    int num_digits = count_digits<4>(abs_value);
+    return write_int(
+        out, num_digits, prefix, specs, [=](reserve_iterator<OutputIt> it) {
+          return format_uint<4, Char>(it, abs_value, num_digits, upper);
+        });
+  }
+  case presentation_type::bin_lower:
+  case presentation_type::bin_upper: {
+    bool upper = specs.type == presentation_type::bin_upper;
+    if (specs.alt)
+      prefix_append(prefix, unsigned(upper ? 'B' : 'b') << 8 | '0');
+    int num_digits = count_digits<1>(abs_value);
+    return write_int(out, num_digits, prefix, specs,
+                     [=](reserve_iterator<OutputIt> it) {
+                       return format_uint<1, Char>(it, abs_value, num_digits);
+                     });
+  }
+  case presentation_type::oct: {
+    int num_digits = count_digits<3>(abs_value);
+    // Octal prefix '0' is counted as a digit, so only add it if precision
+    // is not greater than the number of digits.
+    if (specs.alt && specs.precision <= num_digits && abs_value != 0)
+      prefix_append(prefix, '0');
+    return write_int(out, num_digits, prefix, specs,
+                     [=](reserve_iterator<OutputIt> it) {
+                       return format_uint<3, Char>(it, abs_value, num_digits);
+                     });
+  }
+  case presentation_type::chr:
+    return write_char(out, static_cast<Char>(abs_value), specs);
+  default:
+    throw_format_error("invalid type specifier");
+  }
+  return out;
+}
+template <typename Char, typename OutputIt, typename T>
+FMT_CONSTEXPR FMT_NOINLINE auto write_int_noinline(
+    OutputIt out, write_int_arg<T> arg, const basic_format_specs<Char>& specs,
+    locale_ref loc) -> OutputIt {
+  return write_int(out, arg, specs, loc);
+}
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(is_integral<T>::value &&
+                        !std::is_same<T, bool>::value &&
+                        std::is_same<OutputIt, buffer_appender<Char>>::value)>
+FMT_CONSTEXPR FMT_INLINE auto write(OutputIt out, T value,
+                                    const basic_format_specs<Char>& specs,
+                                    locale_ref loc) -> OutputIt {
+  return write_int_noinline(out, make_write_int_arg(value, specs.sign), specs,
+                            loc);
+}
+// An inlined version of write used in format string compilation.
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(is_integral<T>::value &&
+                        !std::is_same<T, bool>::value &&
+                        !std::is_same<OutputIt, buffer_appender<Char>>::value)>
+FMT_CONSTEXPR FMT_INLINE auto write(OutputIt out, T value,
+                                    const basic_format_specs<Char>& specs,
+                                    locale_ref loc) -> OutputIt {
+  return write_int(out, make_write_int_arg(value, specs.sign), specs, loc);
+}
+
+// An output iterator that counts the number of objects written to it and
+// discards them.
+class counting_iterator {
+ private:
+  size_t count_;
+
+ public:
+  using iterator_category = std::output_iterator_tag;
+  using difference_type = std::ptrdiff_t;
+  using pointer = void;
+  using reference = void;
+  FMT_UNCHECKED_ITERATOR(counting_iterator);
+
+  struct value_type {
+    template <typename T> FMT_CONSTEXPR void operator=(const T&) {}
+  };
+
+  FMT_CONSTEXPR counting_iterator() : count_(0) {}
+
+  FMT_CONSTEXPR size_t count() const { return count_; }
+
+  FMT_CONSTEXPR counting_iterator& operator++() {
+    ++count_;
+    return *this;
+  }
+  FMT_CONSTEXPR counting_iterator operator++(int) {
+    auto it = *this;
+    ++*this;
+    return it;
+  }
+
+  FMT_CONSTEXPR friend counting_iterator operator+(counting_iterator it,
+                                                   difference_type n) {
+    it.count_ += static_cast<size_t>(n);
+    return it;
+  }
+
+  FMT_CONSTEXPR value_type operator*() const { return {}; }
+};
+
+template <typename Char, typename OutputIt>
+FMT_CONSTEXPR auto write(OutputIt out, basic_string_view<Char> s,
+                         const basic_format_specs<Char>& specs) -> OutputIt {
+  auto data = s.data();
+  auto size = s.size();
+  if (specs.precision >= 0 && to_unsigned(specs.precision) < size)
+    size = code_point_index(s, to_unsigned(specs.precision));
+  bool is_debug = specs.type == presentation_type::debug;
+  size_t width = 0;
+  if (specs.width != 0) {
+    if (is_debug)
+      width = write_escaped_string(counting_iterator{}, s).count();
+    else
+      width = compute_width(basic_string_view<Char>(data, size));
+  }
+  return write_padded(out, specs, size, width,
+                      [=](reserve_iterator<OutputIt> it) {
+                        if (is_debug) return write_escaped_string(it, s);
+                        return copy_str<Char>(data, data + size, it);
+                      });
+}
+template <typename Char, typename OutputIt>
+FMT_CONSTEXPR auto write(OutputIt out,
+                         basic_string_view<type_identity_t<Char>> s,
+                         const basic_format_specs<Char>& specs, locale_ref)
+    -> OutputIt {
+  check_string_type_spec(specs.type);
+  return write(out, s, specs);
+}
+template <typename Char, typename OutputIt>
+FMT_CONSTEXPR auto write(OutputIt out, const Char* s,
+                         const basic_format_specs<Char>& specs, locale_ref)
+    -> OutputIt {
+  return check_cstring_type_spec(specs.type)
+             ? write(out, basic_string_view<Char>(s), specs, {})
+             : write_ptr<Char>(out, bit_cast<uintptr_t>(s), &specs);
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(is_integral<T>::value &&
+                        !std::is_same<T, bool>::value &&
+                        !std::is_same<T, Char>::value)>
+FMT_CONSTEXPR auto write(OutputIt out, T value) -> OutputIt {
+  auto abs_value = static_cast<uint32_or_64_or_128_t<T>>(value);
+  bool negative = is_negative(value);
+  // Don't do -abs_value since it trips unsigned-integer-overflow sanitizer.
+  if (negative) abs_value = ~abs_value + 1;
+  int num_digits = count_digits(abs_value);
+  auto size = (negative ? 1 : 0) + static_cast<size_t>(num_digits);
+  auto it = reserve(out, size);
+  if (auto ptr = to_pointer<Char>(it, size)) {
+    if (negative) *ptr++ = static_cast<Char>('-');
+    format_decimal<Char>(ptr, abs_value, num_digits);
+    return out;
+  }
+  if (negative) *it++ = static_cast<Char>('-');
+  it = format_decimal<Char>(it, abs_value, num_digits).end;
+  return base_iterator(out, it);
+}
+
+template <typename Char, typename OutputIt>
+FMT_CONSTEXPR20 auto write_nonfinite(OutputIt out, bool isnan,
+                                     basic_format_specs<Char> specs,
+                                     const float_specs& fspecs) -> OutputIt {
+  auto str =
+      isnan ? (fspecs.upper ? "NAN" : "nan") : (fspecs.upper ? "INF" : "inf");
+  constexpr size_t str_size = 3;
+  auto sign = fspecs.sign;
+  auto size = str_size + (sign ? 1 : 0);
+  // Replace '0'-padding with space for non-finite values.
+  const bool is_zero_fill =
+      specs.fill.size() == 1 && *specs.fill.data() == static_cast<Char>('0');
+  if (is_zero_fill) specs.fill[0] = static_cast<Char>(' ');
+  return write_padded(out, specs, size, [=](reserve_iterator<OutputIt> it) {
+    if (sign) *it++ = detail::sign<Char>(sign);
+    return copy_str<Char>(str, str + str_size, it);
+  });
+}
+
+// A decimal floating-point number significand * pow(10, exp).
+struct big_decimal_fp {
+  const char* significand;
+  int significand_size;
+  int exponent;
+};
+
+constexpr auto get_significand_size(const big_decimal_fp& f) -> int {
+  return f.significand_size;
+}
+template <typename T>
+inline auto get_significand_size(const dragonbox::decimal_fp<T>& f) -> int {
+  return count_digits(f.significand);
+}
+
+template <typename Char, typename OutputIt>
+constexpr auto write_significand(OutputIt out, const char* significand,
+                                 int significand_size) -> OutputIt {
+  return copy_str<Char>(significand, significand + significand_size, out);
+}
+template <typename Char, typename OutputIt, typename UInt>
+inline auto write_significand(OutputIt out, UInt significand,
+                              int significand_size) -> OutputIt {
+  return format_decimal<Char>(out, significand, significand_size).end;
+}
+template <typename Char, typename OutputIt, typename T, typename Grouping>
+FMT_CONSTEXPR20 auto write_significand(OutputIt out, T significand,
+                                       int significand_size, int exponent,
+                                       const Grouping& grouping) -> OutputIt {
+  if (!grouping.separator()) {
+    out = write_significand<Char>(out, significand, significand_size);
+    return detail::fill_n(out, exponent, static_cast<Char>('0'));
+  }
+  auto buffer = memory_buffer();
+  write_significand<char>(appender(buffer), significand, significand_size);
+  detail::fill_n(appender(buffer), exponent, '0');
+  return grouping.apply(out, string_view(buffer.data(), buffer.size()));
+}
+
+template <typename Char, typename UInt,
+          FMT_ENABLE_IF(std::is_integral<UInt>::value)>
+inline auto write_significand(Char* out, UInt significand, int significand_size,
+                              int integral_size, Char decimal_point) -> Char* {
+  if (!decimal_point)
+    return format_decimal(out, significand, significand_size).end;
+  out += significand_size + 1;
+  Char* end = out;
+  int floating_size = significand_size - integral_size;
+  for (int i = floating_size / 2; i > 0; --i) {
+    out -= 2;
+    copy2(out, digits2(static_cast<std::size_t>(significand % 100)));
+    significand /= 100;
+  }
+  if (floating_size % 2 != 0) {
+    *--out = static_cast<Char>('0' + significand % 10);
+    significand /= 10;
+  }
+  *--out = decimal_point;
+  format_decimal(out - integral_size, significand, integral_size);
+  return end;
+}
+
+template <typename OutputIt, typename UInt, typename Char,
+          FMT_ENABLE_IF(!std::is_pointer<remove_cvref_t<OutputIt>>::value)>
+inline auto write_significand(OutputIt out, UInt significand,
+                              int significand_size, int integral_size,
+                              Char decimal_point) -> OutputIt {
+  // Buffer is large enough to hold digits (digits10 + 1) and a decimal point.
+  Char buffer[digits10<UInt>() + 2];
+  auto end = write_significand(buffer, significand, significand_size,
+                               integral_size, decimal_point);
+  return detail::copy_str_noinline<Char>(buffer, end, out);
+}
+
+template <typename OutputIt, typename Char>
+FMT_CONSTEXPR auto write_significand(OutputIt out, const char* significand,
+                                     int significand_size, int integral_size,
+                                     Char decimal_point) -> OutputIt {
+  out = detail::copy_str_noinline<Char>(significand,
+                                        significand + integral_size, out);
+  if (!decimal_point) return out;
+  *out++ = decimal_point;
+  return detail::copy_str_noinline<Char>(significand + integral_size,
+                                         significand + significand_size, out);
+}
+
+template <typename OutputIt, typename Char, typename T, typename Grouping>
+FMT_CONSTEXPR20 auto write_significand(OutputIt out, T significand,
+                                       int significand_size, int integral_size,
+                                       Char decimal_point,
+                                       const Grouping& grouping) -> OutputIt {
+  if (!grouping.separator()) {
+    return write_significand(out, significand, significand_size, integral_size,
+                             decimal_point);
+  }
+  auto buffer = basic_memory_buffer<Char>();
+  write_significand(buffer_appender<Char>(buffer), significand,
+                    significand_size, integral_size, decimal_point);
+  grouping.apply(
+      out, basic_string_view<Char>(buffer.data(), to_unsigned(integral_size)));
+  return detail::copy_str_noinline<Char>(buffer.data() + integral_size,
+                                         buffer.end(), out);
+}
+
+template <typename OutputIt, typename DecimalFP, typename Char,
+          typename Grouping = digit_grouping<Char>>
+FMT_CONSTEXPR20 auto do_write_float(OutputIt out, const DecimalFP& f,
+                                    const basic_format_specs<Char>& specs,
+                                    float_specs fspecs, locale_ref loc)
+    -> OutputIt {
+  auto significand = f.significand;
+  int significand_size = get_significand_size(f);
+  const Char zero = static_cast<Char>('0');
+  auto sign = fspecs.sign;
+  size_t size = to_unsigned(significand_size) + (sign ? 1 : 0);
+  using iterator = reserve_iterator<OutputIt>;
+
+  Char decimal_point =
+      fspecs.locale ? detail::decimal_point<Char>(loc) : static_cast<Char>('.');
+
+  int output_exp = f.exponent + significand_size - 1;
+  auto use_exp_format = [=]() {
+    if (fspecs.format == float_format::exp) return true;
+    if (fspecs.format != float_format::general) return false;
+    // Use the fixed notation if the exponent is in [exp_lower, exp_upper),
+    // e.g. 0.0001 instead of 1e-04. Otherwise use the exponent notation.
+    const int exp_lower = -4, exp_upper = 16;
+    return output_exp < exp_lower ||
+           output_exp >= (fspecs.precision > 0 ? fspecs.precision : exp_upper);
+  };
+  if (use_exp_format()) {
+    int num_zeros = 0;
+    if (fspecs.showpoint) {
+      num_zeros = fspecs.precision - significand_size;
+      if (num_zeros < 0) num_zeros = 0;
+      size += to_unsigned(num_zeros);
+    } else if (significand_size == 1) {
+      decimal_point = Char();
+    }
+    auto abs_output_exp = output_exp >= 0 ? output_exp : -output_exp;
+    int exp_digits = 2;
+    if (abs_output_exp >= 100) exp_digits = abs_output_exp >= 1000 ? 4 : 3;
+
+    size += to_unsigned((decimal_point ? 1 : 0) + 2 + exp_digits);
+    char exp_char = fspecs.upper ? 'E' : 'e';
+    auto write = [=](iterator it) {
+      if (sign) *it++ = detail::sign<Char>(sign);
+      // Insert a decimal point after the first digit and add an exponent.
+      it = write_significand(it, significand, significand_size, 1,
+                             decimal_point);
+      if (num_zeros > 0) it = detail::fill_n(it, num_zeros, zero);
+      *it++ = static_cast<Char>(exp_char);
+      return write_exponent<Char>(output_exp, it);
+    };
+    return specs.width > 0 ? write_padded<align::right>(out, specs, size, write)
+                           : base_iterator(out, write(reserve(out, size)));
+  }
+
+  int exp = f.exponent + significand_size;
+  if (f.exponent >= 0) {
+    // 1234e5 -> 123400000[.0+]
+    size += to_unsigned(f.exponent);
+    int num_zeros = fspecs.precision - exp;
+    abort_fuzzing_if(num_zeros > 5000);
+    if (fspecs.showpoint) {
+      ++size;
+      if (num_zeros <= 0 && fspecs.format != float_format::fixed) num_zeros = 1;
+      if (num_zeros > 0) size += to_unsigned(num_zeros);
+    }
+    auto grouping = Grouping(loc, fspecs.locale);
+    size += to_unsigned(grouping.count_separators(exp));
+    return write_padded<align::right>(out, specs, size, [&](iterator it) {
+      if (sign) *it++ = detail::sign<Char>(sign);
+      it = write_significand<Char>(it, significand, significand_size,
+                                   f.exponent, grouping);
+      if (!fspecs.showpoint) return it;
+      *it++ = decimal_point;
+      return num_zeros > 0 ? detail::fill_n(it, num_zeros, zero) : it;
+    });
+  } else if (exp > 0) {
+    // 1234e-2 -> 12.34[0+]
+    int num_zeros = fspecs.showpoint ? fspecs.precision - significand_size : 0;
+    size += 1 + to_unsigned(num_zeros > 0 ? num_zeros : 0);
+    auto grouping = Grouping(loc, fspecs.locale);
+    size += to_unsigned(grouping.count_separators(significand_size));
+    return write_padded<align::right>(out, specs, size, [&](iterator it) {
+      if (sign) *it++ = detail::sign<Char>(sign);
+      it = write_significand(it, significand, significand_size, exp,
+                             decimal_point, grouping);
+      return num_zeros > 0 ? detail::fill_n(it, num_zeros, zero) : it;
+    });
+  }
+  // 1234e-6 -> 0.001234
+  int num_zeros = -exp;
+  if (significand_size == 0 && fspecs.precision >= 0 &&
+      fspecs.precision < num_zeros) {
+    num_zeros = fspecs.precision;
+  }
+  bool pointy = num_zeros != 0 || significand_size != 0 || fspecs.showpoint;
+  size += 1 + (pointy ? 1 : 0) + to_unsigned(num_zeros);
+  return write_padded<align::right>(out, specs, size, [&](iterator it) {
+    if (sign) *it++ = detail::sign<Char>(sign);
+    *it++ = zero;
+    if (!pointy) return it;
+    *it++ = decimal_point;
+    it = detail::fill_n(it, num_zeros, zero);
+    return write_significand<Char>(it, significand, significand_size);
+  });
+}
+
+template <typename Char> class fallback_digit_grouping {
+ public:
+  constexpr fallback_digit_grouping(locale_ref, bool) {}
+
+  constexpr Char separator() const { return Char(); }
+
+  constexpr int count_separators(int) const { return 0; }
+
+  template <typename Out, typename C>
+  constexpr Out apply(Out out, basic_string_view<C>) const {
+    return out;
+  }
+};
+
+template <typename OutputIt, typename DecimalFP, typename Char>
+FMT_CONSTEXPR20 auto write_float(OutputIt out, const DecimalFP& f,
+                                 const basic_format_specs<Char>& specs,
+                                 float_specs fspecs, locale_ref loc)
+    -> OutputIt {
+  if (is_constant_evaluated()) {
+    return do_write_float<OutputIt, DecimalFP, Char,
+                          fallback_digit_grouping<Char>>(out, f, specs, fspecs,
+                                                         loc);
+  } else {
+    return do_write_float(out, f, specs, fspecs, loc);
+  }
+}
+
+template <typename T> constexpr bool isnan(T value) {
+  return !(value >= value);  // std::isnan doesn't support __float128.
+}
+
+template <typename T, typename Enable = void>
+struct has_isfinite : std::false_type {};
+
+template <typename T>
+struct has_isfinite<T, enable_if_t<sizeof(std::isfinite(T())) != 0>>
+    : std::true_type {};
+
+template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value&&
+                                        has_isfinite<T>::value)>
+FMT_CONSTEXPR20 bool isfinite(T value) {
+  constexpr T inf = T(std::numeric_limits<double>::infinity());
+  if (is_constant_evaluated())
+    return !detail::isnan(value) && value != inf && value != -inf;
+  return std::isfinite(value);
+}
+template <typename T, FMT_ENABLE_IF(!has_isfinite<T>::value)>
+FMT_CONSTEXPR bool isfinite(T value) {
+  T inf = T(std::numeric_limits<double>::infinity());
+  // std::isfinite doesn't support __float128.
+  return !detail::isnan(value) && value != inf && value != -inf;
+}
+
+template <typename T, FMT_ENABLE_IF(is_floating_point<T>::value)>
+FMT_INLINE FMT_CONSTEXPR bool signbit(T value) {
+  if (is_constant_evaluated()) {
+#ifdef __cpp_if_constexpr
+    if constexpr (std::numeric_limits<double>::is_iec559) {
+      auto bits = detail::bit_cast<uint64_t>(static_cast<double>(value));
+      return (bits >> (num_bits<uint64_t>() - 1)) != 0;
+    }
+#endif
+  }
+  return std::signbit(static_cast<double>(value));
+}
+
+enum class round_direction { unknown, up, down };
+
+// Given the divisor (normally a power of 10), the remainder = v % divisor for
+// some number v and the error, returns whether v should be rounded up, down, or
+// whether the rounding direction can't be determined due to error.
+// error should be less than divisor / 2.
+FMT_CONSTEXPR inline round_direction get_round_direction(uint64_t divisor,
+                                                         uint64_t remainder,
+                                                         uint64_t error) {
+  FMT_ASSERT(remainder < divisor, "");  // divisor - remainder won't overflow.
+  FMT_ASSERT(error < divisor, "");      // divisor - error won't overflow.
+  FMT_ASSERT(error < divisor - error, "");  // error * 2 won't overflow.
+  // Round down if (remainder + error) * 2 <= divisor.
+  if (remainder <= divisor - remainder && error * 2 <= divisor - remainder * 2)
+    return round_direction::down;
+  // Round up if (remainder - error) * 2 >= divisor.
+  if (remainder >= error &&
+      remainder - error >= divisor - (remainder - error)) {
+    return round_direction::up;
+  }
+  return round_direction::unknown;
+}
+
+namespace digits {
+enum result {
+  more,  // Generate more digits.
+  done,  // Done generating digits.
+  error  // Digit generation cancelled due to an error.
+};
+}
+
+struct gen_digits_handler {
+  char* buf;
+  int size;
+  int precision;
+  int exp10;
+  bool fixed;
+
+  FMT_CONSTEXPR digits::result on_digit(char digit, uint64_t divisor,
+                                        uint64_t remainder, uint64_t error,
+                                        bool integral) {
+    FMT_ASSERT(remainder < divisor, "");
+    buf[size++] = digit;
+    if (!integral && error >= remainder) return digits::error;
+    if (size < precision) return digits::more;
+    if (!integral) {
+      // Check if error * 2 < divisor with overflow prevention.
+      // The check is not needed for the integral part because error = 1
+      // and divisor > (1 << 32) there.
+      if (error >= divisor || error >= divisor - error) return digits::error;
+    } else {
+      FMT_ASSERT(error == 1 && divisor > 2, "");
+    }
+    auto dir = get_round_direction(divisor, remainder, error);
+    if (dir != round_direction::up)
+      return dir == round_direction::down ? digits::done : digits::error;
+    ++buf[size - 1];
+    for (int i = size - 1; i > 0 && buf[i] > '9'; --i) {
+      buf[i] = '0';
+      ++buf[i - 1];
+    }
+    if (buf[0] > '9') {
+      buf[0] = '1';
+      if (fixed)
+        buf[size++] = '0';
+      else
+        ++exp10;
+    }
+    return digits::done;
+  }
+};
+
+inline FMT_CONSTEXPR20 void adjust_precision(int& precision, int exp10) {
+  // Adjust fixed precision by exponent because it is relative to decimal
+  // point.
+  if (exp10 > 0 && precision > max_value<int>() - exp10)
+    FMT_THROW(format_error("number is too big"));
+  precision += exp10;
+}
+
+// Generates output using the Grisu digit-gen algorithm.
+// error: the size of the region (lower, upper) outside of which numbers
+// definitely do not round to value (Delta in Grisu3).
+FMT_INLINE FMT_CONSTEXPR20 auto grisu_gen_digits(fp value, uint64_t error,
+                                                 int& exp,
+                                                 gen_digits_handler& handler)
+    -> digits::result {
+  const fp one(1ULL << -value.e, value.e);
+  // The integral part of scaled value (p1 in Grisu) = value / one. It cannot be
+  // zero because it contains a product of two 64-bit numbers with MSB set (due
+  // to normalization) - 1, shifted right by at most 60 bits.
+  auto integral = static_cast<uint32_t>(value.f >> -one.e);
+  FMT_ASSERT(integral != 0, "");
+  FMT_ASSERT(integral == value.f >> -one.e, "");
+  // The fractional part of scaled value (p2 in Grisu) c = value % one.
+  uint64_t fractional = value.f & (one.f - 1);
+  exp = count_digits(integral);  // kappa in Grisu.
+  // Non-fixed formats require at least one digit and no precision adjustment.
+  if (handler.fixed) {
+    adjust_precision(handler.precision, exp + handler.exp10);
+    // Check if precision is satisfied just by leading zeros, e.g.
+    // format("{:.2f}", 0.001) gives "0.00" without generating any digits.
+    if (handler.precision <= 0) {
+      if (handler.precision < 0) return digits::done;
+      // Divide by 10 to prevent overflow.
+      uint64_t divisor = data::power_of_10_64[exp - 1] << -one.e;
+      auto dir = get_round_direction(divisor, value.f / 10, error * 10);
+      if (dir == round_direction::unknown) return digits::error;
+      handler.buf[handler.size++] = dir == round_direction::up ? '1' : '0';
+      return digits::done;
+    }
+  }
+  // Generate digits for the integral part. This can produce up to 10 digits.
+  do {
+    uint32_t digit = 0;
+    auto divmod_integral = [&](uint32_t divisor) {
+      digit = integral / divisor;
+      integral %= divisor;
+    };
+    // This optimization by Milo Yip reduces the number of integer divisions by
+    // one per iteration.
+    switch (exp) {
+    case 10:
+      divmod_integral(1000000000);
+      break;
+    case 9:
+      divmod_integral(100000000);
+      break;
+    case 8:
+      divmod_integral(10000000);
+      break;
+    case 7:
+      divmod_integral(1000000);
+      break;
+    case 6:
+      divmod_integral(100000);
+      break;
+    case 5:
+      divmod_integral(10000);
+      break;
+    case 4:
+      divmod_integral(1000);
+      break;
+    case 3:
+      divmod_integral(100);
+      break;
+    case 2:
+      divmod_integral(10);
+      break;
+    case 1:
+      digit = integral;
+      integral = 0;
+      break;
+    default:
+      FMT_ASSERT(false, "invalid number of digits");
+    }
+    --exp;
+    auto remainder = (static_cast<uint64_t>(integral) << -one.e) + fractional;
+    auto result = handler.on_digit(static_cast<char>('0' + digit),
+                                   data::power_of_10_64[exp] << -one.e,
+                                   remainder, error, true);
+    if (result != digits::more) return result;
+  } while (exp > 0);
+  // Generate digits for the fractional part.
+  for (;;) {
+    fractional *= 10;
+    error *= 10;
+    char digit = static_cast<char>('0' + (fractional >> -one.e));
+    fractional &= one.f - 1;
+    --exp;
+    auto result = handler.on_digit(digit, one.f, fractional, error, false);
+    if (result != digits::more) return result;
+  }
+}
+
+class bigint {
+ private:
+  // A bigint is stored as an array of bigits (big digits), with bigit at index
+  // 0 being the least significant one.
+  using bigit = uint32_t;
+  using double_bigit = uint64_t;
+  enum { bigits_capacity = 32 };
+  basic_memory_buffer<bigit, bigits_capacity> bigits_;
+  int exp_;
+
+  FMT_CONSTEXPR20 bigit operator[](int index) const {
+    return bigits_[to_unsigned(index)];
+  }
+  FMT_CONSTEXPR20 bigit& operator[](int index) {
+    return bigits_[to_unsigned(index)];
+  }
+
+  static constexpr const int bigit_bits = num_bits<bigit>();
+
+  friend struct formatter<bigint>;
+
+  FMT_CONSTEXPR20 void subtract_bigits(int index, bigit other, bigit& borrow) {
+    auto result = static_cast<double_bigit>((*this)[index]) - other - borrow;
+    (*this)[index] = static_cast<bigit>(result);
+    borrow = static_cast<bigit>(result >> (bigit_bits * 2 - 1));
+  }
+
+  FMT_CONSTEXPR20 void remove_leading_zeros() {
+    int num_bigits = static_cast<int>(bigits_.size()) - 1;
+    while (num_bigits > 0 && (*this)[num_bigits] == 0) --num_bigits;
+    bigits_.resize(to_unsigned(num_bigits + 1));
+  }
+
+  // Computes *this -= other assuming aligned bigints and *this >= other.
+  FMT_CONSTEXPR20 void subtract_aligned(const bigint& other) {
+    FMT_ASSERT(other.exp_ >= exp_, "unaligned bigints");
+    FMT_ASSERT(compare(*this, other) >= 0, "");
+    bigit borrow = 0;
+    int i = other.exp_ - exp_;
+    for (size_t j = 0, n = other.bigits_.size(); j != n; ++i, ++j)
+      subtract_bigits(i, other.bigits_[j], borrow);
+    while (borrow > 0) subtract_bigits(i, 0, borrow);
+    remove_leading_zeros();
+  }
+
+  FMT_CONSTEXPR20 void multiply(uint32_t value) {
+    const double_bigit wide_value = value;
+    bigit carry = 0;
+    for (size_t i = 0, n = bigits_.size(); i < n; ++i) {
+      double_bigit result = bigits_[i] * wide_value + carry;
+      bigits_[i] = static_cast<bigit>(result);
+      carry = static_cast<bigit>(result >> bigit_bits);
+    }
+    if (carry != 0) bigits_.push_back(carry);
+  }
+
+  template <typename UInt, FMT_ENABLE_IF(std::is_same<UInt, uint64_t>::value ||
+                                         std::is_same<UInt, uint128_t>::value)>
+  FMT_CONSTEXPR20 void multiply(UInt value) {
+    using half_uint =
+        conditional_t<std::is_same<UInt, uint128_t>::value, uint64_t, uint32_t>;
+    const int shift = num_bits<half_uint>() - bigit_bits;
+    const UInt lower = static_cast<half_uint>(value);
+    const UInt upper = value >> num_bits<half_uint>();
+    UInt carry = 0;
+    for (size_t i = 0, n = bigits_.size(); i < n; ++i) {
+      UInt result = lower * bigits_[i] + static_cast<bigit>(carry);
+      carry = (upper * bigits_[i] << shift) + (result >> bigit_bits) +
+              (carry >> bigit_bits);
+      bigits_[i] = static_cast<bigit>(result);
+    }
+    while (carry != 0) {
+      bigits_.push_back(static_cast<bigit>(carry));
+      carry >>= bigit_bits;
+    }
+  }
+
+  template <typename UInt, FMT_ENABLE_IF(std::is_same<UInt, uint64_t>::value ||
+                                         std::is_same<UInt, uint128_t>::value)>
+  FMT_CONSTEXPR20 void assign(UInt n) {
+    size_t num_bigits = 0;
+    do {
+      bigits_[num_bigits++] = static_cast<bigit>(n);
+      n >>= bigit_bits;
+    } while (n != 0);
+    bigits_.resize(num_bigits);
+    exp_ = 0;
+  }
+
+ public:
+  FMT_CONSTEXPR20 bigint() : exp_(0) {}
+  explicit bigint(uint64_t n) { assign(n); }
+
+  bigint(const bigint&) = delete;
+  void operator=(const bigint&) = delete;
+
+  FMT_CONSTEXPR20 void assign(const bigint& other) {
+    auto size = other.bigits_.size();
+    bigits_.resize(size);
+    auto data = other.bigits_.data();
+    std::copy(data, data + size, make_checked(bigits_.data(), size));
+    exp_ = other.exp_;
+  }
+
+  template <typename Int> FMT_CONSTEXPR20 void operator=(Int n) {
+    FMT_ASSERT(n > 0, "");
+    assign(uint64_or_128_t<Int>(n));
+  }
+
+  FMT_CONSTEXPR20 int num_bigits() const {
+    return static_cast<int>(bigits_.size()) + exp_;
+  }
+
+  FMT_NOINLINE FMT_CONSTEXPR20 bigint& operator<<=(int shift) {
+    FMT_ASSERT(shift >= 0, "");
+    exp_ += shift / bigit_bits;
+    shift %= bigit_bits;
+    if (shift == 0) return *this;
+    bigit carry = 0;
+    for (size_t i = 0, n = bigits_.size(); i < n; ++i) {
+      bigit c = bigits_[i] >> (bigit_bits - shift);
+      bigits_[i] = (bigits_[i] << shift) + carry;
+      carry = c;
+    }
+    if (carry != 0) bigits_.push_back(carry);
+    return *this;
+  }
+
+  template <typename Int> FMT_CONSTEXPR20 bigint& operator*=(Int value) {
+    FMT_ASSERT(value > 0, "");
+    multiply(uint32_or_64_or_128_t<Int>(value));
+    return *this;
+  }
+
+  friend FMT_CONSTEXPR20 int compare(const bigint& lhs, const bigint& rhs) {
+    int num_lhs_bigits = lhs.num_bigits(), num_rhs_bigits = rhs.num_bigits();
+    if (num_lhs_bigits != num_rhs_bigits)
+      return num_lhs_bigits > num_rhs_bigits ? 1 : -1;
+    int i = static_cast<int>(lhs.bigits_.size()) - 1;
+    int j = static_cast<int>(rhs.bigits_.size()) - 1;
+    int end = i - j;
+    if (end < 0) end = 0;
+    for (; i >= end; --i, --j) {
+      bigit lhs_bigit = lhs[i], rhs_bigit = rhs[j];
+      if (lhs_bigit != rhs_bigit) return lhs_bigit > rhs_bigit ? 1 : -1;
+    }
+    if (i != j) return i > j ? 1 : -1;
+    return 0;
+  }
+
+  // Returns compare(lhs1 + lhs2, rhs).
+  friend FMT_CONSTEXPR20 int add_compare(const bigint& lhs1, const bigint& lhs2,
+                                         const bigint& rhs) {
+    auto minimum = [](int a, int b) { return a < b ? a : b; };
+    auto maximum = [](int a, int b) { return a > b ? a : b; };
+    int max_lhs_bigits = maximum(lhs1.num_bigits(), lhs2.num_bigits());
+    int num_rhs_bigits = rhs.num_bigits();
+    if (max_lhs_bigits + 1 < num_rhs_bigits) return -1;
+    if (max_lhs_bigits > num_rhs_bigits) return 1;
+    auto get_bigit = [](const bigint& n, int i) -> bigit {
+      return i >= n.exp_ && i < n.num_bigits() ? n[i - n.exp_] : 0;
+    };
+    double_bigit borrow = 0;
+    int min_exp = minimum(minimum(lhs1.exp_, lhs2.exp_), rhs.exp_);
+    for (int i = num_rhs_bigits - 1; i >= min_exp; --i) {
+      double_bigit sum =
+          static_cast<double_bigit>(get_bigit(lhs1, i)) + get_bigit(lhs2, i);
+      bigit rhs_bigit = get_bigit(rhs, i);
+      if (sum > rhs_bigit + borrow) return 1;
+      borrow = rhs_bigit + borrow - sum;
+      if (borrow > 1) return -1;
+      borrow <<= bigit_bits;
+    }
+    return borrow != 0 ? -1 : 0;
+  }
+
+  // Assigns pow(10, exp) to this bigint.
+  FMT_CONSTEXPR20 void assign_pow10(int exp) {
+    FMT_ASSERT(exp >= 0, "");
+    if (exp == 0) return *this = 1;
+    // Find the top bit.
+    int bitmask = 1;
+    while (exp >= bitmask) bitmask <<= 1;
+    bitmask >>= 1;
+    // pow(10, exp) = pow(5, exp) * pow(2, exp). First compute pow(5, exp) by
+    // repeated squaring and multiplication.
+    *this = 5;
+    bitmask >>= 1;
+    while (bitmask != 0) {
+      square();
+      if ((exp & bitmask) != 0) *this *= 5;
+      bitmask >>= 1;
+    }
+    *this <<= exp;  // Multiply by pow(2, exp) by shifting.
+  }
+
+  FMT_CONSTEXPR20 void square() {
+    int num_bigits = static_cast<int>(bigits_.size());
+    int num_result_bigits = 2 * num_bigits;
+    basic_memory_buffer<bigit, bigits_capacity> n(std::move(bigits_));
+    bigits_.resize(to_unsigned(num_result_bigits));
+    auto sum = uint128_t();
+    for (int bigit_index = 0; bigit_index < num_bigits; ++bigit_index) {
+      // Compute bigit at position bigit_index of the result by adding
+      // cross-product terms n[i] * n[j] such that i + j == bigit_index.
+      for (int i = 0, j = bigit_index; j >= 0; ++i, --j) {
+        // Most terms are multiplied twice which can be optimized in the future.
+        sum += static_cast<double_bigit>(n[i]) * n[j];
+      }
+      (*this)[bigit_index] = static_cast<bigit>(sum);
+      sum >>= num_bits<bigit>();  // Compute the carry.
+    }
+    // Do the same for the top half.
+    for (int bigit_index = num_bigits; bigit_index < num_result_bigits;
+         ++bigit_index) {
+      for (int j = num_bigits - 1, i = bigit_index - j; i < num_bigits;)
+        sum += static_cast<double_bigit>(n[i++]) * n[j--];
+      (*this)[bigit_index] = static_cast<bigit>(sum);
+      sum >>= num_bits<bigit>();
+    }
+    remove_leading_zeros();
+    exp_ *= 2;
+  }
+
+  // If this bigint has a bigger exponent than other, adds trailing zero to make
+  // exponents equal. This simplifies some operations such as subtraction.
+  FMT_CONSTEXPR20 void align(const bigint& other) {
+    int exp_difference = exp_ - other.exp_;
+    if (exp_difference <= 0) return;
+    int num_bigits = static_cast<int>(bigits_.size());
+    bigits_.resize(to_unsigned(num_bigits + exp_difference));
+    for (int i = num_bigits - 1, j = i + exp_difference; i >= 0; --i, --j)
+      bigits_[j] = bigits_[i];
+    std::uninitialized_fill_n(bigits_.data(), exp_difference, 0);
+    exp_ -= exp_difference;
+  }
+
+  // Divides this bignum by divisor, assigning the remainder to this and
+  // returning the quotient.
+  FMT_CONSTEXPR20 int divmod_assign(const bigint& divisor) {
+    FMT_ASSERT(this != &divisor, "");
+    if (compare(*this, divisor) < 0) return 0;
+    FMT_ASSERT(divisor.bigits_[divisor.bigits_.size() - 1u] != 0, "");
+    align(divisor);
+    int quotient = 0;
+    do {
+      subtract_aligned(divisor);
+      ++quotient;
+    } while (compare(*this, divisor) >= 0);
+    return quotient;
+  }
+};
+
+// format_dragon flags.
+enum dragon {
+  predecessor_closer = 1,
+  fixup = 2,  // Run fixup to correct exp10 which can be off by one.
+  fixed = 4,
+};
+
+// Formats a floating-point number using a variation of the Fixed-Precision
+// Positive Floating-Point Printout ((FPP)^2) algorithm by Steele & White:
+// https://fmt.dev/papers/p372-steele.pdf.
+FMT_CONSTEXPR20 inline void format_dragon(basic_fp<uint128_t> value,
+                                          unsigned flags, int num_digits,
+                                          buffer<char>& buf, int& exp10) {
+  bigint numerator;    // 2 * R in (FPP)^2.
+  bigint denominator;  // 2 * S in (FPP)^2.
+  // lower and upper are differences between value and corresponding boundaries.
+  bigint lower;             // (M^- in (FPP)^2).
+  bigint upper_store;       // upper's value if different from lower.
+  bigint* upper = nullptr;  // (M^+ in (FPP)^2).
+  // Shift numerator and denominator by an extra bit or two (if lower boundary
+  // is closer) to make lower and upper integers. This eliminates multiplication
+  // by 2 during later computations.
+  bool is_predecessor_closer = (flags & dragon::predecessor_closer) != 0;
+  int shift = is_predecessor_closer ? 2 : 1;
+  if (value.e >= 0) {
+    numerator = value.f;
+    numerator <<= value.e + shift;
+    lower = 1;
+    lower <<= value.e;
+    if (is_predecessor_closer) {
+      upper_store = 1;
+      upper_store <<= value.e + 1;
+      upper = &upper_store;
+    }
+    denominator.assign_pow10(exp10);
+    denominator <<= shift;
+  } else if (exp10 < 0) {
+    numerator.assign_pow10(-exp10);
+    lower.assign(numerator);
+    if (is_predecessor_closer) {
+      upper_store.assign(numerator);
+      upper_store <<= 1;
+      upper = &upper_store;
+    }
+    numerator *= value.f;
+    numerator <<= shift;
+    denominator = 1;
+    denominator <<= shift - value.e;
+  } else {
+    numerator = value.f;
+    numerator <<= shift;
+    denominator.assign_pow10(exp10);
+    denominator <<= shift - value.e;
+    lower = 1;
+    if (is_predecessor_closer) {
+      upper_store = 1ULL << 1;
+      upper = &upper_store;
+    }
+  }
+  int even = static_cast<int>((value.f & 1) == 0);
+  if (!upper) upper = &lower;
+  if ((flags & dragon::fixup) != 0) {
+    if (add_compare(numerator, *upper, denominator) + even <= 0) {
+      --exp10;
+      numerator *= 10;
+      if (num_digits < 0) {
+        lower *= 10;
+        if (upper != &lower) *upper *= 10;
+      }
+    }
+    if ((flags & dragon::fixed) != 0) adjust_precision(num_digits, exp10 + 1);
+  }
+  // Invariant: value == (numerator / denominator) * pow(10, exp10).
+  if (num_digits < 0) {
+    // Generate the shortest representation.
+    num_digits = 0;
+    char* data = buf.data();
+    for (;;) {
+      int digit = numerator.divmod_assign(denominator);
+      bool low = compare(numerator, lower) - even < 0;  // numerator <[=] lower.
+      // numerator + upper >[=] pow10:
+      bool high = add_compare(numerator, *upper, denominator) + even > 0;
+      data[num_digits++] = static_cast<char>('0' + digit);
+      if (low || high) {
+        if (!low) {
+          ++data[num_digits - 1];
+        } else if (high) {
+          int result = add_compare(numerator, numerator, denominator);
+          // Round half to even.
+          if (result > 0 || (result == 0 && (digit % 2) != 0))
+            ++data[num_digits - 1];
+        }
+        buf.try_resize(to_unsigned(num_digits));
+        exp10 -= num_digits - 1;
+        return;
+      }
+      numerator *= 10;
+      lower *= 10;
+      if (upper != &lower) *upper *= 10;
+    }
+  }
+  // Generate the given number of digits.
+  exp10 -= num_digits - 1;
+  if (num_digits == 0) {
+    denominator *= 10;
+    auto digit = add_compare(numerator, numerator, denominator) > 0 ? '1' : '0';
+    buf.push_back(digit);
+    return;
+  }
+  buf.try_resize(to_unsigned(num_digits));
+  for (int i = 0; i < num_digits - 1; ++i) {
+    int digit = numerator.divmod_assign(denominator);
+    buf[i] = static_cast<char>('0' + digit);
+    numerator *= 10;
+  }
+  int digit = numerator.divmod_assign(denominator);
+  auto result = add_compare(numerator, numerator, denominator);
+  if (result > 0 || (result == 0 && (digit % 2) != 0)) {
+    if (digit == 9) {
+      const auto overflow = '0' + 10;
+      buf[num_digits - 1] = overflow;
+      // Propagate the carry.
+      for (int i = num_digits - 1; i > 0 && buf[i] == overflow; --i) {
+        buf[i] = '0';
+        ++buf[i - 1];
+      }
+      if (buf[0] == overflow) {
+        buf[0] = '1';
+        ++exp10;
+      }
+      return;
+    }
+    ++digit;
+  }
+  buf[num_digits - 1] = static_cast<char>('0' + digit);
+}
+
+template <typename Float>
+FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
+                                  buffer<char>& buf) -> int {
+  // float is passed as double to reduce the number of instantiations.
+  static_assert(!std::is_same<Float, float>::value, "");
+  FMT_ASSERT(value >= 0, "value is negative");
+  auto converted_value = convert_float(value);
+
+  const bool fixed = specs.format == float_format::fixed;
+  if (value <= 0) {  // <= instead of == to silence a warning.
+    if (precision <= 0 || !fixed) {
+      buf.push_back('0');
+      return 0;
+    }
+    buf.try_resize(to_unsigned(precision));
+    fill_n(buf.data(), precision, '0');
+    return -precision;
+  }
+
+  int exp = 0;
+  bool use_dragon = true;
+  unsigned dragon_flags = 0;
+  if (!is_fast_float<Float>()) {
+    const auto inv_log2_10 = 0.3010299956639812;  // 1 / log2(10)
+    using info = dragonbox::float_info<decltype(converted_value)>;
+    const auto f = basic_fp<typename info::carrier_uint>(converted_value);
+    // Compute exp, an approximate power of 10, such that
+    //   10^(exp - 1) <= value < 10^exp or 10^exp <= value < 10^(exp + 1).
+    // This is based on log10(value) == log2(value) / log2(10) and approximation
+    // of log2(value) by e + num_fraction_bits idea from double-conversion.
+    exp = static_cast<int>(
+        std::ceil((f.e + count_digits<1>(f.f) - 1) * inv_log2_10 - 1e-10));
+    dragon_flags = dragon::fixup;
+  } else if (!is_constant_evaluated() && precision < 0) {
+    // Use Dragonbox for the shortest format.
+    if (specs.binary32) {
+      auto dec = dragonbox::to_decimal(static_cast<float>(value));
+      write<char>(buffer_appender<char>(buf), dec.significand);
+      return dec.exponent;
+    }
+    auto dec = dragonbox::to_decimal(static_cast<double>(value));
+    write<char>(buffer_appender<char>(buf), dec.significand);
+    return dec.exponent;
+  } else {
+    // Use Grisu + Dragon4 for the given precision:
+    // https://www.cs.tufts.edu/~nr/cs257/archive/florian-loitsch/printf.pdf.
+    const int min_exp = -60;  // alpha in Grisu.
+    int cached_exp10 = 0;     // K in Grisu.
+    fp normalized = normalize(fp(converted_value));
+    const auto cached_pow = get_cached_power(
+        min_exp - (normalized.e + fp::num_significand_bits), cached_exp10);
+    normalized = normalized * cached_pow;
+    gen_digits_handler handler{buf.data(), 0, precision, -cached_exp10, fixed};
+    if (grisu_gen_digits(normalized, 1, exp, handler) != digits::error &&
+        !is_constant_evaluated()) {
+      exp += handler.exp10;
+      buf.try_resize(to_unsigned(handler.size));
+      use_dragon = false;
+    } else {
+      exp += handler.size - cached_exp10 - 1;
+      precision = handler.precision;
+    }
+  }
+  if (use_dragon) {
+    auto f = basic_fp<uint128_t>();
+    bool is_predecessor_closer = specs.binary32
+                                     ? f.assign(static_cast<float>(value))
+                                     : f.assign(converted_value);
+    if (is_predecessor_closer) dragon_flags |= dragon::predecessor_closer;
+    if (fixed) dragon_flags |= dragon::fixed;
+    // Limit precision to the maximum possible number of significant digits in
+    // an IEEE754 double because we don't need to generate zeros.
+    const int max_double_digits = 767;
+    if (precision > max_double_digits) precision = max_double_digits;
+    format_dragon(f, dragon_flags, precision, buf, exp);
+  }
+  if (!fixed && !specs.showpoint) {
+    // Remove trailing zeros.
+    auto num_digits = buf.size();
+    while (num_digits > 0 && buf[num_digits - 1] == '0') {
+      --num_digits;
+      ++exp;
+    }
+    buf.try_resize(num_digits);
+  }
+  return exp;
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(is_floating_point<T>::value)>
+FMT_CONSTEXPR20 auto write(OutputIt out, T value,
+                           basic_format_specs<Char> specs, locale_ref loc = {})
+    -> OutputIt {
+  if (const_check(!is_supported_floating_point(value))) return out;
+  float_specs fspecs = parse_float_type_spec(specs);
+  fspecs.sign = specs.sign;
+  if (detail::signbit(value)) {  // value < 0 is false for NaN so use signbit.
+    fspecs.sign = sign::minus;
+    value = -value;
+  } else if (fspecs.sign == sign::minus) {
+    fspecs.sign = sign::none;
+  }
+
+  if (!detail::isfinite(value))
+    return write_nonfinite(out, detail::isnan(value), specs, fspecs);
+
+  if (specs.align == align::numeric && fspecs.sign) {
+    auto it = reserve(out, 1);
+    *it++ = detail::sign<Char>(fspecs.sign);
+    out = base_iterator(out, it);
+    fspecs.sign = sign::none;
+    if (specs.width != 0) --specs.width;
+  }
+
+  memory_buffer buffer;
+  if (fspecs.format == float_format::hex) {
+    if (fspecs.sign) buffer.push_back(detail::sign<char>(fspecs.sign));
+    snprintf_float(convert_float(value), specs.precision, fspecs, buffer);
+    return write_bytes<align::right>(out, {buffer.data(), buffer.size()},
+                                     specs);
+  }
+  int precision = specs.precision >= 0 || specs.type == presentation_type::none
+                      ? specs.precision
+                      : 6;
+  if (fspecs.format == float_format::exp) {
+    if (precision == max_value<int>())
+      throw_format_error("number is too big");
+    else
+      ++precision;
+  } else if (fspecs.format != float_format::fixed && precision == 0) {
+    precision = 1;
+  }
+  if (const_check(std::is_same<T, float>())) fspecs.binary32 = true;
+  int exp = format_float(convert_float(value), precision, fspecs, buffer);
+  fspecs.precision = precision;
+  auto f = big_decimal_fp{buffer.data(), static_cast<int>(buffer.size()), exp};
+  return write_float(out, f, specs, fspecs, loc);
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(is_fast_float<T>::value)>
+FMT_CONSTEXPR20 auto write(OutputIt out, T value) -> OutputIt {
+  if (is_constant_evaluated())
+    return write(out, value, basic_format_specs<Char>());
+  if (const_check(!is_supported_floating_point(value))) return out;
+
+  auto fspecs = float_specs();
+  if (detail::signbit(value)) {
+    fspecs.sign = sign::minus;
+    value = -value;
+  }
+
+  constexpr auto specs = basic_format_specs<Char>();
+  using floaty = conditional_t<std::is_same<T, long double>::value, double, T>;
+  using uint = typename dragonbox::float_info<floaty>::carrier_uint;
+  uint mask = exponent_mask<floaty>();
+  if ((bit_cast<uint>(value) & mask) == mask)
+    return write_nonfinite(out, std::isnan(value), specs, fspecs);
+
+  auto dec = dragonbox::to_decimal(static_cast<floaty>(value));
+  return write_float(out, dec, specs, fspecs, {});
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(is_floating_point<T>::value &&
+                        !is_fast_float<T>::value)>
+inline auto write(OutputIt out, T value) -> OutputIt {
+  return write(out, value, basic_format_specs<Char>());
+}
+
+template <typename Char, typename OutputIt>
+auto write(OutputIt out, monostate, basic_format_specs<Char> = {},
+           locale_ref = {}) -> OutputIt {
+  FMT_ASSERT(false, "");
+  return out;
+}
+
+template <typename Char, typename OutputIt>
+FMT_CONSTEXPR auto write(OutputIt out, basic_string_view<Char> value)
+    -> OutputIt {
+  auto it = reserve(out, value.size());
+  it = copy_str_noinline<Char>(value.begin(), value.end(), it);
+  return base_iterator(out, it);
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(is_string<T>::value)>
+constexpr auto write(OutputIt out, const T& value) -> OutputIt {
+  return write<Char>(out, to_string_view(value));
+}
+
+// FMT_ENABLE_IF() condition separated to workaround an MSVC bug.
+template <
+    typename Char, typename OutputIt, typename T,
+    bool check =
+        std::is_enum<T>::value && !std::is_same<T, Char>::value &&
+        mapped_type_constant<T, basic_format_context<OutputIt, Char>>::value !=
+            type::custom_type,
+    FMT_ENABLE_IF(check)>
+FMT_CONSTEXPR auto write(OutputIt out, T value) -> OutputIt {
+  return write<Char>(out, static_cast<underlying_t<T>>(value));
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_same<T, bool>::value)>
+FMT_CONSTEXPR auto write(OutputIt out, T value,
+                         const basic_format_specs<Char>& specs = {},
+                         locale_ref = {}) -> OutputIt {
+  return specs.type != presentation_type::none &&
+                 specs.type != presentation_type::string
+             ? write(out, value ? 1 : 0, specs, {})
+             : write_bytes(out, value ? "true" : "false", specs);
+}
+
+template <typename Char, typename OutputIt>
+FMT_CONSTEXPR auto write(OutputIt out, Char value) -> OutputIt {
+  auto it = reserve(out, 1);
+  *it++ = value;
+  return base_iterator(out, it);
+}
+
+template <typename Char, typename OutputIt>
+FMT_CONSTEXPR_CHAR_TRAITS auto write(OutputIt out, const Char* value)
+    -> OutputIt {
+  if (!value) {
+    throw_format_error("string pointer is null");
+  } else {
+    out = write(out, basic_string_view<Char>(value));
+  }
+  return out;
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_same<T, void>::value)>
+auto write(OutputIt out, const T* value,
+           const basic_format_specs<Char>& specs = {}, locale_ref = {})
+    -> OutputIt {
+  check_pointer_type_spec(specs.type, error_handler());
+  return write_ptr<Char>(out, bit_cast<uintptr_t>(value), &specs);
+}
+
+// A write overload that handles implicit conversions.
+template <typename Char, typename OutputIt, typename T,
+          typename Context = basic_format_context<OutputIt, Char>>
+FMT_CONSTEXPR auto write(OutputIt out, const T& value) -> enable_if_t<
+    std::is_class<T>::value && !is_string<T>::value &&
+        !is_floating_point<T>::value && !std::is_same<T, Char>::value &&
+        !std::is_same<const T&,
+                      decltype(arg_mapper<Context>().map(value))>::value,
+    OutputIt> {
+  return write<Char>(out, arg_mapper<Context>().map(value));
+}
+
+template <typename Char, typename OutputIt, typename T,
+          typename Context = basic_format_context<OutputIt, Char>>
+FMT_CONSTEXPR auto write(OutputIt out, const T& value)
+    -> enable_if_t<mapped_type_constant<T, Context>::value == type::custom_type,
+                   OutputIt> {
+  using formatter_type =
+      conditional_t<has_formatter<T, Context>::value,
+                    typename Context::template formatter_type<T>,
+                    fallback_formatter<T, Char>>;
+  auto ctx = Context(out, {}, {});
+  return formatter_type().format(value, ctx);
+}
+
+// An argument visitor that formats the argument and writes it via the output
+// iterator. It's a class and not a generic lambda for compatibility with C++11.
+template <typename Char> struct default_arg_formatter {
+  using iterator = buffer_appender<Char>;
+  using context = buffer_context<Char>;
+
+  iterator out;
+  basic_format_args<context> args;
+  locale_ref loc;
+
+  template <typename T> auto operator()(T value) -> iterator {
+    return write<Char>(out, value);
+  }
+  auto operator()(typename basic_format_arg<context>::handle h) -> iterator {
+    basic_format_parse_context<Char> parse_ctx({});
+    context format_ctx(out, args, loc);
+    h.format(parse_ctx, format_ctx);
+    return format_ctx.out();
+  }
+};
+
+template <typename Char> struct arg_formatter {
+  using iterator = buffer_appender<Char>;
+  using context = buffer_context<Char>;
+
+  iterator out;
+  const basic_format_specs<Char>& specs;
+  locale_ref locale;
+
+  template <typename T>
+  FMT_CONSTEXPR FMT_INLINE auto operator()(T value) -> iterator {
+    return detail::write(out, value, specs, locale);
+  }
+  auto operator()(typename basic_format_arg<context>::handle) -> iterator {
+    // User-defined types are handled separately because they require access
+    // to the parse context.
+    return out;
+  }
+};
+
+template <typename Char> struct custom_formatter {
+  basic_format_parse_context<Char>& parse_ctx;
+  buffer_context<Char>& ctx;
+
+  void operator()(
+      typename basic_format_arg<buffer_context<Char>>::handle h) const {
+    h.format(parse_ctx, ctx);
+  }
+  template <typename T> void operator()(T) const {}
+};
+
+template <typename T>
+using is_integer =
+    bool_constant<is_integral<T>::value && !std::is_same<T, bool>::value &&
+                  !std::is_same<T, char>::value &&
+                  !std::is_same<T, wchar_t>::value>;
+
+template <typename ErrorHandler> class width_checker {
+ public:
+  explicit FMT_CONSTEXPR width_checker(ErrorHandler& eh) : handler_(eh) {}
+
+  template <typename T, FMT_ENABLE_IF(is_integer<T>::value)>
+  FMT_CONSTEXPR auto operator()(T value) -> unsigned long long {
+    if (is_negative(value)) handler_.on_error("negative width");
+    return static_cast<unsigned long long>(value);
+  }
+
+  template <typename T, FMT_ENABLE_IF(!is_integer<T>::value)>
+  FMT_CONSTEXPR auto operator()(T) -> unsigned long long {
+    handler_.on_error("width is not integer");
+    return 0;
+  }
+
+ private:
+  ErrorHandler& handler_;
+};
+
+template <typename ErrorHandler> class precision_checker {
+ public:
+  explicit FMT_CONSTEXPR precision_checker(ErrorHandler& eh) : handler_(eh) {}
+
+  template <typename T, FMT_ENABLE_IF(is_integer<T>::value)>
+  FMT_CONSTEXPR auto operator()(T value) -> unsigned long long {
+    if (is_negative(value)) handler_.on_error("negative precision");
+    return static_cast<unsigned long long>(value);
+  }
+
+  template <typename T, FMT_ENABLE_IF(!is_integer<T>::value)>
+  FMT_CONSTEXPR auto operator()(T) -> unsigned long long {
+    handler_.on_error("precision is not integer");
+    return 0;
+  }
+
+ private:
+  ErrorHandler& handler_;
+};
+
+template <template <typename> class Handler, typename FormatArg,
+          typename ErrorHandler>
+FMT_CONSTEXPR auto get_dynamic_spec(FormatArg arg, ErrorHandler eh) -> int {
+  unsigned long long value = visit_format_arg(Handler<ErrorHandler>(eh), arg);
+  if (value > to_unsigned(max_value<int>())) eh.on_error("number is too big");
+  return static_cast<int>(value);
+}
+
+template <typename Context, typename ID>
+FMT_CONSTEXPR auto get_arg(Context& ctx, ID id) ->
+    typename Context::format_arg {
+  auto arg = ctx.arg(id);
+  if (!arg) ctx.on_error("argument not found");
+  return arg;
+}
+
+// The standard format specifier handler with checking.
+template <typename Char> class specs_handler : public specs_setter<Char> {
+ private:
+  basic_format_parse_context<Char>& parse_context_;
+  buffer_context<Char>& context_;
+
+  // This is only needed for compatibility with gcc 4.4.
+  using format_arg = basic_format_arg<buffer_context<Char>>;
+
+  FMT_CONSTEXPR auto get_arg(auto_id) -> format_arg {
+    return detail::get_arg(context_, parse_context_.next_arg_id());
+  }
+
+  FMT_CONSTEXPR auto get_arg(int arg_id) -> format_arg {
+    parse_context_.check_arg_id(arg_id);
+    return detail::get_arg(context_, arg_id);
+  }
+
+  FMT_CONSTEXPR auto get_arg(basic_string_view<Char> arg_id) -> format_arg {
+    parse_context_.check_arg_id(arg_id);
+    return detail::get_arg(context_, arg_id);
+  }
+
+ public:
+  FMT_CONSTEXPR specs_handler(basic_format_specs<Char>& specs,
+                              basic_format_parse_context<Char>& parse_ctx,
+                              buffer_context<Char>& ctx)
+      : specs_setter<Char>(specs), parse_context_(parse_ctx), context_(ctx) {}
+
+  template <typename Id> FMT_CONSTEXPR void on_dynamic_width(Id arg_id) {
+    this->specs_.width = get_dynamic_spec<width_checker>(
+        get_arg(arg_id), context_.error_handler());
+  }
+
+  template <typename Id> FMT_CONSTEXPR void on_dynamic_precision(Id arg_id) {
+    this->specs_.precision = get_dynamic_spec<precision_checker>(
+        get_arg(arg_id), context_.error_handler());
+  }
+
+  void on_error(const char* message) { context_.on_error(message); }
+};
+
+template <template <typename> class Handler, typename Context>
+FMT_CONSTEXPR void handle_dynamic_spec(int& value,
+                                       arg_ref<typename Context::char_type> ref,
+                                       Context& ctx) {
+  switch (ref.kind) {
+  case arg_id_kind::none:
+    break;
+  case arg_id_kind::index:
+    value = detail::get_dynamic_spec<Handler>(ctx.arg(ref.val.index),
+                                              ctx.error_handler());
+    break;
+  case arg_id_kind::name:
+    value = detail::get_dynamic_spec<Handler>(ctx.arg(ref.val.name),
+                                              ctx.error_handler());
+    break;
+  }
+}
+
+#if FMT_USE_USER_DEFINED_LITERALS
+template <typename Char> struct udl_formatter {
+  basic_string_view<Char> str;
+
+  template <typename... T>
+  auto operator()(T&&... args) const -> std::basic_string<Char> {
+    return vformat(str, fmt::make_format_args<buffer_context<Char>>(args...));
+  }
+};
+
+#  if FMT_USE_NONTYPE_TEMPLATE_ARGS
+template <typename T, typename Char, size_t N,
+          fmt::detail_exported::fixed_string<Char, N> Str>
+struct statically_named_arg : view {
+  static constexpr auto name = Str.data;
+
+  const T& value;
+  statically_named_arg(const T& v) : value(v) {}
+};
+
+template <typename T, typename Char, size_t N,
+          fmt::detail_exported::fixed_string<Char, N> Str>
+struct is_named_arg<statically_named_arg<T, Char, N, Str>> : std::true_type {};
+
+template <typename T, typename Char, size_t N,
+          fmt::detail_exported::fixed_string<Char, N> Str>
+struct is_statically_named_arg<statically_named_arg<T, Char, N, Str>>
+    : std::true_type {};
+
+template <typename Char, size_t N,
+          fmt::detail_exported::fixed_string<Char, N> Str>
+struct udl_arg {
+  template <typename T> auto operator=(T&& value) const {
+    return statically_named_arg<T, Char, N, Str>(std::forward<T>(value));
+  }
+};
+#  else
+template <typename Char> struct udl_arg {
+  const Char* str;
+
+  template <typename T> auto operator=(T&& value) const -> named_arg<Char, T> {
+    return {str, std::forward<T>(value)};
+  }
+};
+#  endif
+#endif  // FMT_USE_USER_DEFINED_LITERALS
+
+template <typename Locale, typename Char>
+auto vformat(const Locale& loc, basic_string_view<Char> format_str,
+             basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  basic_memory_buffer<Char> buffer;
+  detail::vformat_to(buffer, format_str, args, detail::locale_ref(loc));
+  return {buffer.data(), buffer.size()};
+}
+
+using format_func = void (*)(detail::buffer<char>&, int, const char*);
+
+FMT_API void format_error_code(buffer<char>& out, int error_code,
+                               string_view message) noexcept;
+
+FMT_API void report_error(format_func func, int error_code,
+                          const char* message) noexcept;
+FMT_END_DETAIL_NAMESPACE
+
+FMT_API auto vsystem_error(int error_code, string_view format_str,
+                           format_args args) -> std::system_error;
+
+/**
+ \rst
+ Constructs :class:`std::system_error` with a message formatted with
+ ``fmt::format(fmt, args...)``.
+  *error_code* is a system error code as given by ``errno``.
+
+ **Example**::
+
+   // This throws std::system_error with the description
+   //   cannot open file 'madeup': No such file or directory
+   // or similar (system message may vary).
+   const char* filename = "madeup";
+   std::FILE* file = std::fopen(filename, "r");
+   if (!file)
+     throw fmt::system_error(errno, "cannot open file '{}'", filename);
+ \endrst
+*/
+template <typename... T>
+auto system_error(int error_code, format_string<T...> fmt, T&&... args)
+    -> std::system_error {
+  return vsystem_error(error_code, fmt, fmt::make_format_args(args...));
+}
+
+/**
+  \rst
+  Formats an error message for an error returned by an operating system or a
+  language runtime, for example a file opening error, and writes it to *out*.
+  The format is the same as the one used by ``std::system_error(ec, message)``
+  where ``ec`` is ``std::error_code(error_code, std::generic_category()})``.
+  It is implementation-defined but normally looks like:
+
+  .. parsed-literal::
+     *<message>*: *<system-message>*
+
+  where *<message>* is the passed message and *<system-message>* is the system
+  message corresponding to the error code.
+  *error_code* is a system error code as given by ``errno``.
+  \endrst
+ */
+FMT_API void format_system_error(detail::buffer<char>& out, int error_code,
+                                 const char* message) noexcept;
+
+// Reports a system error without throwing an exception.
+// Can be used to report errors from destructors.
+FMT_API void report_system_error(int error_code, const char* message) noexcept;
+
+/** Fast integer formatter. */
+class format_int {
+ private:
+  // Buffer should be large enough to hold all digits (digits10 + 1),
+  // a sign and a null character.
+  enum { buffer_size = std::numeric_limits<unsigned long long>::digits10 + 3 };
+  mutable char buffer_[buffer_size];
+  char* str_;
+
+  template <typename UInt> auto format_unsigned(UInt value) -> char* {
+    auto n = static_cast<detail::uint32_or_64_or_128_t<UInt>>(value);
+    return detail::format_decimal(buffer_, n, buffer_size - 1).begin;
+  }
+
+  template <typename Int> auto format_signed(Int value) -> char* {
+    auto abs_value = static_cast<detail::uint32_or_64_or_128_t<Int>>(value);
+    bool negative = value < 0;
+    if (negative) abs_value = 0 - abs_value;
+    auto begin = format_unsigned(abs_value);
+    if (negative) *--begin = '-';
+    return begin;
+  }
+
+ public:
+  explicit format_int(int value) : str_(format_signed(value)) {}
+  explicit format_int(long value) : str_(format_signed(value)) {}
+  explicit format_int(long long value) : str_(format_signed(value)) {}
+  explicit format_int(unsigned value) : str_(format_unsigned(value)) {}
+  explicit format_int(unsigned long value) : str_(format_unsigned(value)) {}
+  explicit format_int(unsigned long long value)
+      : str_(format_unsigned(value)) {}
+
+  /** Returns the number of characters written to the output buffer. */
+  auto size() const -> size_t {
+    return detail::to_unsigned(buffer_ - str_ + buffer_size - 1);
+  }
+
+  /**
+    Returns a pointer to the output buffer content. No terminating null
+    character is appended.
+   */
+  auto data() const -> const char* { return str_; }
+
+  /**
+    Returns a pointer to the output buffer content with terminating null
+    character appended.
+   */
+  auto c_str() const -> const char* {
+    buffer_[buffer_size - 1] = '\0';
+    return str_;
+  }
+
+  /**
+    \rst
+    Returns the content of the output buffer as an ``std::string``.
+    \endrst
+   */
+  auto str() const -> std::string { return std::string(str_, size()); }
+};
+
+template <typename T, typename Char>
+template <typename FormatContext>
+FMT_CONSTEXPR FMT_INLINE auto
+formatter<T, Char,
+          enable_if_t<detail::type_constant<T, Char>::value !=
+                      detail::type::custom_type>>::format(const T& val,
+                                                          FormatContext& ctx)
+    const -> decltype(ctx.out()) {
+  if (specs_.width_ref.kind != detail::arg_id_kind::none ||
+      specs_.precision_ref.kind != detail::arg_id_kind::none) {
+    auto specs = specs_;
+    detail::handle_dynamic_spec<detail::width_checker>(specs.width,
+                                                       specs.width_ref, ctx);
+    detail::handle_dynamic_spec<detail::precision_checker>(
+        specs.precision, specs.precision_ref, ctx);
+    return detail::write<Char>(ctx.out(), val, specs, ctx.locale());
+  }
+  return detail::write<Char>(ctx.out(), val, specs_, ctx.locale());
+}
+
+template <typename Char>
+struct formatter<void*, Char> : formatter<const void*, Char> {
+  template <typename FormatContext>
+  auto format(void* val, FormatContext& ctx) const -> decltype(ctx.out()) {
+    return formatter<const void*, Char>::format(val, ctx);
+  }
+};
+
+template <typename Char, size_t N>
+struct formatter<Char[N], Char> : formatter<basic_string_view<Char>, Char> {
+  template <typename FormatContext>
+  FMT_CONSTEXPR auto format(const Char* val, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return formatter<basic_string_view<Char>, Char>::format(val, ctx);
+  }
+};
+
+// A formatter for types known only at run time such as variant alternatives.
+//
+// Usage:
+//   using variant = std::variant<int, std::string>;
+//   template <>
+//   struct formatter<variant>: dynamic_formatter<> {
+//     auto format(const variant& v, format_context& ctx) {
+//       return visit([&](const auto& val) {
+//           return dynamic_formatter<>::format(val, ctx);
+//       }, v);
+//     }
+//   };
+template <typename Char = char> class dynamic_formatter {
+ private:
+  detail::dynamic_format_specs<Char> specs_;
+  const Char* format_str_;
+
+  struct null_handler : detail::error_handler {
+    void on_align(align_t) {}
+    void on_sign(sign_t) {}
+    void on_hash() {}
+  };
+
+  template <typename Context> void handle_specs(Context& ctx) {
+    detail::handle_dynamic_spec<detail::width_checker>(specs_.width,
+                                                       specs_.width_ref, ctx);
+    detail::handle_dynamic_spec<detail::precision_checker>(
+        specs_.precision, specs_.precision_ref, ctx);
+  }
+
+ public:
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    format_str_ = ctx.begin();
+    // Checks are deferred to formatting time when the argument type is known.
+    detail::dynamic_specs_handler<ParseContext> handler(specs_, ctx);
+    return detail::parse_format_specs(ctx.begin(), ctx.end(), handler);
+  }
+
+  template <typename T, typename FormatContext>
+  auto format(const T& val, FormatContext& ctx) -> decltype(ctx.out()) {
+    handle_specs(ctx);
+    detail::specs_checker<null_handler> checker(
+        null_handler(), detail::mapped_type_constant<T, FormatContext>::value);
+    checker.on_align(specs_.align);
+    if (specs_.sign != sign::none) checker.on_sign(specs_.sign);
+    if (specs_.alt) checker.on_hash();
+    if (specs_.precision >= 0) checker.end_precision();
+    return detail::write<Char>(ctx.out(), val, specs_, ctx.locale());
+  }
+};
+
+/**
+  \rst
+  Converts ``p`` to ``const void*`` for pointer formatting.
+
+  **Example**::
+
+    auto s = fmt::format("{}", fmt::ptr(p));
+  \endrst
+ */
+template <typename T> auto ptr(T p) -> const void* {
+  static_assert(std::is_pointer<T>::value, "");
+  return detail::bit_cast<const void*>(p);
+}
+template <typename T> auto ptr(const std::unique_ptr<T>& p) -> const void* {
+  return p.get();
+}
+template <typename T> auto ptr(const std::shared_ptr<T>& p) -> const void* {
+  return p.get();
+}
+
+/**
+  \rst
+  Converts ``e`` to the underlying type.
+
+  **Example**::
+
+    enum class color { red, green, blue };
+    auto s = fmt::format("{}", fmt::underlying(color::red));
+  \endrst
+ */
+template <typename Enum>
+constexpr auto underlying(Enum e) noexcept -> underlying_t<Enum> {
+  return static_cast<underlying_t<Enum>>(e);
+}
+
+namespace enums {
+template <typename Enum, FMT_ENABLE_IF(std::is_enum<Enum>::value)>
+constexpr auto format_as(Enum e) noexcept -> underlying_t<Enum> {
+  return static_cast<underlying_t<Enum>>(e);
+}
+}  // namespace enums
+
+class bytes {
+ private:
+  string_view data_;
+  friend struct formatter<bytes>;
+
+ public:
+  explicit bytes(string_view data) : data_(data) {}
+};
+
+template <> struct formatter<bytes> {
+ private:
+  detail::dynamic_format_specs<char> specs_;
+
+ public:
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    using handler_type = detail::dynamic_specs_handler<ParseContext>;
+    detail::specs_checker<handler_type> handler(handler_type(specs_, ctx),
+                                                detail::type::string_type);
+    auto it = parse_format_specs(ctx.begin(), ctx.end(), handler);
+    detail::check_string_type_spec(specs_.type, ctx.error_handler());
+    return it;
+  }
+
+  template <typename FormatContext>
+  auto format(bytes b, FormatContext& ctx) -> decltype(ctx.out()) {
+    detail::handle_dynamic_spec<detail::width_checker>(specs_.width,
+                                                       specs_.width_ref, ctx);
+    detail::handle_dynamic_spec<detail::precision_checker>(
+        specs_.precision, specs_.precision_ref, ctx);
+    return detail::write_bytes(ctx.out(), b.data_, specs_);
+  }
+};
+
+// group_digits_view is not derived from view because it copies the argument.
+template <typename T> struct group_digits_view { T value; };
+
+/**
+  \rst
+  Returns a view that formats an integer value using ',' as a locale-independent
+  thousands separator.
+
+  **Example**::
+
+    fmt::print("{}", fmt::group_digits(12345));
+    // Output: "12,345"
+  \endrst
+ */
+template <typename T> auto group_digits(T value) -> group_digits_view<T> {
+  return {value};
+}
+
+template <typename T> struct formatter<group_digits_view<T>> : formatter<T> {
+ private:
+  detail::dynamic_format_specs<char> specs_;
+
+ public:
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    using handler_type = detail::dynamic_specs_handler<ParseContext>;
+    detail::specs_checker<handler_type> handler(handler_type(specs_, ctx),
+                                                detail::type::int_type);
+    auto it = parse_format_specs(ctx.begin(), ctx.end(), handler);
+    detail::check_string_type_spec(specs_.type, ctx.error_handler());
+    return it;
+  }
+
+  template <typename FormatContext>
+  auto format(group_digits_view<T> t, FormatContext& ctx)
+      -> decltype(ctx.out()) {
+    detail::handle_dynamic_spec<detail::width_checker>(specs_.width,
+                                                       specs_.width_ref, ctx);
+    detail::handle_dynamic_spec<detail::precision_checker>(
+        specs_.precision, specs_.precision_ref, ctx);
+    return detail::write_int_localized(
+        ctx.out(), static_cast<detail::uint64_or_128_t<T>>(t.value), 0, specs_,
+        detail::digit_grouping<char>({"\3", ','}));
+  }
+};
+
+template <typename It, typename Sentinel, typename Char = char>
+struct join_view : detail::view {
+  It begin;
+  Sentinel end;
+  basic_string_view<Char> sep;
+
+  join_view(It b, Sentinel e, basic_string_view<Char> s)
+      : begin(b), end(e), sep(s) {}
+};
+
+template <typename It, typename Sentinel, typename Char>
+struct formatter<join_view<It, Sentinel, Char>, Char> {
+ private:
+  using value_type =
+#ifdef __cpp_lib_ranges
+      std::iter_value_t<It>;
+#else
+      typename std::iterator_traits<It>::value_type;
+#endif
+  using context = buffer_context<Char>;
+  using mapper = detail::arg_mapper<context>;
+
+  template <typename T, FMT_ENABLE_IF(has_formatter<T, context>::value)>
+  static auto map(const T& value) -> const T& {
+    return value;
+  }
+  template <typename T, FMT_ENABLE_IF(!has_formatter<T, context>::value)>
+  static auto map(const T& value) -> decltype(mapper().map(value)) {
+    return mapper().map(value);
+  }
+
+  using formatter_type =
+      conditional_t<is_formattable<value_type, Char>::value,
+                    formatter<remove_cvref_t<decltype(map(
+                                  std::declval<const value_type&>()))>,
+                              Char>,
+                    detail::fallback_formatter<value_type, Char>>;
+
+  formatter_type value_formatter_;
+
+ public:
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return value_formatter_.parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(const join_view<It, Sentinel, Char>& value,
+              FormatContext& ctx) const -> decltype(ctx.out()) {
+    auto it = value.begin;
+    auto out = ctx.out();
+    if (it != value.end) {
+      out = value_formatter_.format(map(*it), ctx);
+      ++it;
+      while (it != value.end) {
+        out = detail::copy_str<Char>(value.sep.begin(), value.sep.end(), out);
+        ctx.advance_to(out);
+        out = value_formatter_.format(map(*it), ctx);
+        ++it;
+      }
+    }
+    return out;
+  }
+};
+
+/**
+  Returns a view that formats the iterator range `[begin, end)` with elements
+  separated by `sep`.
+ */
+template <typename It, typename Sentinel>
+auto join(It begin, Sentinel end, string_view sep) -> join_view<It, Sentinel> {
+  return {begin, end, sep};
+}
+
+/**
+  \rst
+  Returns a view that formats `range` with elements separated by `sep`.
+
+  **Example**::
+
+    std::vector<int> v = {1, 2, 3};
+    fmt::print("{}", fmt::join(v, ", "));
+    // Output: "1, 2, 3"
+
+  ``fmt::join`` applies passed format specifiers to the range elements::
+
+    fmt::print("{:02}", fmt::join(v, ", "));
+    // Output: "01, 02, 03"
+  \endrst
+ */
+template <typename Range>
+auto join(Range&& range, string_view sep)
+    -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>> {
+  return join(std::begin(range), std::end(range), sep);
+}
+
+/**
+  \rst
+  Converts *value* to ``std::string`` using the default format for type *T*.
+
+  **Example**::
+
+    #include <fmt/format.h>
+
+    std::string answer = fmt::to_string(42);
+  \endrst
+ */
+template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+inline auto to_string(const T& value) -> std::string {
+  auto result = std::string();
+  detail::write<char>(std::back_inserter(result), value);
+  return result;
+}
+
+template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+FMT_NODISCARD inline auto to_string(T value) -> std::string {
+  // The buffer should be large enough to store the number including the sign
+  // or "false" for bool.
+  constexpr int max_size = detail::digits10<T>() + 2;
+  char buffer[max_size > 5 ? static_cast<unsigned>(max_size) : 5];
+  char* begin = buffer;
+  return std::string(begin, detail::write<char>(begin, value));
+}
+
+template <typename Char, size_t SIZE>
+FMT_NODISCARD auto to_string(const basic_memory_buffer<Char, SIZE>& buf)
+    -> std::basic_string<Char> {
+  auto size = buf.size();
+  detail::assume(size < std::basic_string<Char>().max_size());
+  return std::basic_string<Char>(buf.data(), size);
+}
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+template <typename Char>
+void vformat_to(
+    buffer<Char>& buf, basic_string_view<Char> fmt,
+    basic_format_args<FMT_BUFFER_CONTEXT(type_identity_t<Char>)> args,
+    locale_ref loc) {
+  // workaround for msvc bug regarding name-lookup in module
+  // link names into function scope
+  using detail::arg_formatter;
+  using detail::buffer_appender;
+  using detail::custom_formatter;
+  using detail::default_arg_formatter;
+  using detail::get_arg;
+  using detail::locale_ref;
+  using detail::parse_format_specs;
+  using detail::specs_checker;
+  using detail::specs_handler;
+  using detail::to_unsigned;
+  using detail::type;
+  using detail::write;
+  auto out = buffer_appender<Char>(buf);
+  if (fmt.size() == 2 && equal2(fmt.data(), "{}")) {
+    auto arg = args.get(0);
+    if (!arg) error_handler().on_error("argument not found");
+    visit_format_arg(default_arg_formatter<Char>{out, args, loc}, arg);
+    return;
+  }
+
+  struct format_handler : error_handler {
+    basic_format_parse_context<Char> parse_context;
+    buffer_context<Char> context;
+
+    format_handler(buffer_appender<Char> p_out, basic_string_view<Char> str,
+                   basic_format_args<buffer_context<Char>> p_args,
+                   locale_ref p_loc)
+        : parse_context(str), context(p_out, p_args, p_loc) {}
+
+    void on_text(const Char* begin, const Char* end) {
+      auto text = basic_string_view<Char>(begin, to_unsigned(end - begin));
+      context.advance_to(write<Char>(context.out(), text));
+    }
+
+    FMT_CONSTEXPR auto on_arg_id() -> int {
+      return parse_context.next_arg_id();
+    }
+    FMT_CONSTEXPR auto on_arg_id(int id) -> int {
+      return parse_context.check_arg_id(id), id;
+    }
+    FMT_CONSTEXPR auto on_arg_id(basic_string_view<Char> id) -> int {
+      int arg_id = context.arg_id(id);
+      if (arg_id < 0) on_error("argument not found");
+      return arg_id;
+    }
+
+    FMT_INLINE void on_replacement_field(int id, const Char*) {
+      auto arg = get_arg(context, id);
+      context.advance_to(visit_format_arg(
+          default_arg_formatter<Char>{context.out(), context.args(),
+                                      context.locale()},
+          arg));
+    }
+
+    auto on_format_specs(int id, const Char* begin, const Char* end)
+        -> const Char* {
+      auto arg = get_arg(context, id);
+      if (arg.type() == type::custom_type) {
+        parse_context.advance_to(parse_context.begin() +
+                                 (begin - &*parse_context.begin()));
+        visit_format_arg(custom_formatter<Char>{parse_context, context}, arg);
+        return parse_context.begin();
+      }
+      auto specs = basic_format_specs<Char>();
+      specs_checker<specs_handler<Char>> handler(
+          specs_handler<Char>(specs, parse_context, context), arg.type());
+      begin = parse_format_specs(begin, end, handler);
+      if (begin == end || *begin != '}')
+        on_error("missing '}' in format string");
+      auto f = arg_formatter<Char>{context.out(), specs, context.locale()};
+      context.advance_to(visit_format_arg(f, arg));
+      return begin;
+    }
+  };
+  detail::parse_format_string<false>(fmt, format_handler(out, fmt, args, loc));
+}
+
+#ifndef FMT_HEADER_ONLY
+extern template FMT_API auto thousands_sep_impl<char>(locale_ref)
+    -> thousands_sep_result<char>;
+extern template FMT_API auto thousands_sep_impl<wchar_t>(locale_ref)
+    -> thousands_sep_result<wchar_t>;
+extern template FMT_API auto decimal_point_impl(locale_ref) -> char;
+extern template FMT_API auto decimal_point_impl(locale_ref) -> wchar_t;
+#endif  // FMT_HEADER_ONLY
+
+FMT_END_DETAIL_NAMESPACE
+
+#if FMT_USE_USER_DEFINED_LITERALS
+inline namespace literals {
+/**
+  \rst
+  User-defined literal equivalent of :func:`fmt::arg`.
+
+  **Example**::
+
+    using namespace fmt::literals;
+    fmt::print("Elapsed time: {s:.2f} seconds", "s"_a=1.23);
+  \endrst
+ */
+#  if FMT_USE_NONTYPE_TEMPLATE_ARGS
+template <detail_exported::fixed_string Str> constexpr auto operator""_a() {
+  using char_t = remove_cvref_t<decltype(Str.data[0])>;
+  return detail::udl_arg<char_t, sizeof(Str.data) / sizeof(char_t), Str>();
+}
+#  else
+constexpr auto operator"" _a(const char* s, size_t) -> detail::udl_arg<char> {
+  return {s};
+}
+#  endif
+}  // namespace literals
+#endif  // FMT_USE_USER_DEFINED_LITERALS
+
+template <typename Locale, FMT_ENABLE_IF(detail::is_locale<Locale>::value)>
+inline auto vformat(const Locale& loc, string_view fmt, format_args args)
+    -> std::string {
+  return detail::vformat(loc, fmt, args);
+}
+
+template <typename Locale, typename... T,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value)>
+inline auto format(const Locale& loc, format_string<T...> fmt, T&&... args)
+    -> std::string {
+  return vformat(loc, string_view(fmt), fmt::make_format_args(args...));
+}
+
+template <typename OutputIt, typename Locale,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value&&
+                            detail::is_locale<Locale>::value)>
+auto vformat_to(OutputIt out, const Locale& loc, string_view fmt,
+                format_args args) -> OutputIt {
+  using detail::get_buffer;
+  auto&& buf = get_buffer<char>(out);
+  detail::vformat_to(buf, fmt, args, detail::locale_ref(loc));
+  return detail::get_iterator(buf);
+}
+
+template <typename OutputIt, typename Locale, typename... T,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value&&
+                            detail::is_locale<Locale>::value)>
+FMT_INLINE auto format_to(OutputIt out, const Locale& loc,
+                          format_string<T...> fmt, T&&... args) -> OutputIt {
+  return vformat_to(out, loc, fmt, fmt::make_format_args(args...));
+}
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#ifdef FMT_HEADER_ONLY
+#  define FMT_FUNC inline
+#  include "format-inl.h"
+#else
+#  define FMT_FUNC
+#endif
+
+#endif  // FMT_FORMAT_H_
diff --git a/libfuse/lib/fmt/os.h b/libfuse/lib/fmt/os.h
new file mode 100644
index 00000000..d82be112
--- /dev/null
+++ b/libfuse/lib/fmt/os.h
@@ -0,0 +1,478 @@
+// Formatting library for C++ - optional OS-specific functionality
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_OS_H_
+#define FMT_OS_H_
+
+#include <cerrno>
+#include <cstddef>
+#include <cstdio>
+#include <system_error>  // std::system_error
+
+#if defined __APPLE__ || defined(__FreeBSD__)
+#  include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
+#endif
+
+#include "format.h"
+
+#ifndef FMT_USE_FCNTL
+// UWP doesn't provide _pipe.
+#  if FMT_HAS_INCLUDE("winapifamily.h")
+#    include <winapifamily.h>
+#  endif
+#  if (FMT_HAS_INCLUDE(<fcntl.h>) || defined(__APPLE__) || \
+       defined(__linux__)) &&                              \
+      (!defined(WINAPI_FAMILY) ||                          \
+       (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+#    include <fcntl.h>  // for O_RDONLY
+#    define FMT_USE_FCNTL 1
+#  else
+#    define FMT_USE_FCNTL 0
+#  endif
+#endif
+
+#ifndef FMT_POSIX
+#  if defined(_WIN32) && !defined(__MINGW32__)
+// Fix warnings about deprecated symbols.
+#    define FMT_POSIX(call) _##call
+#  else
+#    define FMT_POSIX(call) call
+#  endif
+#endif
+
+// Calls to system functions are wrapped in FMT_SYSTEM for testability.
+#ifdef FMT_SYSTEM
+#  define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
+#else
+#  define FMT_SYSTEM(call) ::call
+#  ifdef _WIN32
+// Fix warnings about deprecated symbols.
+#    define FMT_POSIX_CALL(call) ::_##call
+#  else
+#    define FMT_POSIX_CALL(call) ::call
+#  endif
+#endif
+
+// Retries the expression while it evaluates to error_result and errno
+// equals to EINTR.
+#ifndef _WIN32
+#  define FMT_RETRY_VAL(result, expression, error_result) \
+    do {                                                  \
+      (result) = (expression);                            \
+    } while ((result) == (error_result) && errno == EINTR)
+#else
+#  define FMT_RETRY_VAL(result, expression, error_result) result = (expression)
+#endif
+
+#define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  \rst
+  A reference to a null-terminated string. It can be constructed from a C
+  string or ``std::string``.
+
+  You can use one of the following type aliases for common character types:
+
+  +---------------+-----------------------------+
+  | Type          | Definition                  |
+  +===============+=============================+
+  | cstring_view  | basic_cstring_view<char>    |
+  +---------------+-----------------------------+
+  | wcstring_view | basic_cstring_view<wchar_t> |
+  +---------------+-----------------------------+
+
+  This class is most useful as a parameter type to allow passing
+  different types of strings to a function, for example::
+
+    template <typename... Args>
+    std::string format(cstring_view format_str, const Args & ... args);
+
+    format("{}", 42);
+    format(std::string("{}"), 42);
+  \endrst
+ */
+template <typename Char> class basic_cstring_view {
+ private:
+  const Char* data_;
+
+ public:
+  /** Constructs a string reference object from a C string. */
+  basic_cstring_view(const Char* s) : data_(s) {}
+
+  /**
+    \rst
+    Constructs a string reference from an ``std::string`` object.
+    \endrst
+   */
+  basic_cstring_view(const std::basic_string<Char>& s) : data_(s.c_str()) {}
+
+  /** Returns the pointer to a C string. */
+  const Char* c_str() const { return data_; }
+};
+
+using cstring_view = basic_cstring_view<char>;
+using wcstring_view = basic_cstring_view<wchar_t>;
+
+template <typename Char> struct formatter<std::error_code, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  FMT_CONSTEXPR auto format(const std::error_code& ec, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::write_bytes(out, ec.category().name(),
+                              basic_format_specs<Char>());
+    out = detail::write<Char>(out, Char(':'));
+    out = detail::write<Char>(out, ec.value());
+    return out;
+  }
+};
+
+#ifdef _WIN32
+FMT_API const std::error_category& system_category() noexcept;
+
+FMT_BEGIN_DETAIL_NAMESPACE
+// A converter from UTF-16 to UTF-8.
+// It is only provided for Windows since other systems support UTF-8 natively.
+class utf16_to_utf8 {
+ private:
+  memory_buffer buffer_;
+
+ public:
+  utf16_to_utf8() {}
+  FMT_API explicit utf16_to_utf8(basic_string_view<wchar_t> s);
+  operator string_view() const { return string_view(&buffer_[0], size()); }
+  size_t size() const { return buffer_.size() - 1; }
+  const char* c_str() const { return &buffer_[0]; }
+  std::string str() const { return std::string(&buffer_[0], size()); }
+
+  // Performs conversion returning a system error code instead of
+  // throwing exception on conversion error. This method may still throw
+  // in case of memory allocation error.
+  FMT_API int convert(basic_string_view<wchar_t> s);
+};
+
+FMT_API void format_windows_error(buffer<char>& out, int error_code,
+                                  const char* message) noexcept;
+FMT_END_DETAIL_NAMESPACE
+
+FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
+                                         format_args args);
+
+/**
+ \rst
+ Constructs a :class:`std::system_error` object with the description
+ of the form
+
+ .. parsed-literal::
+   *<message>*: *<system-message>*
+
+ where *<message>* is the formatted message and *<system-message>* is the
+ system message corresponding to the error code.
+ *error_code* is a Windows error code as given by ``GetLastError``.
+ If *error_code* is not a valid error code such as -1, the system message
+ will look like "error -1".
+
+ **Example**::
+
+   // This throws a system_error with the description
+   //   cannot open file 'madeup': The system cannot find the file specified.
+   // or similar (system message may vary).
+   const char *filename = "madeup";
+   LPOFSTRUCT of = LPOFSTRUCT();
+   HFILE file = OpenFile(filename, &of, OF_READ);
+   if (file == HFILE_ERROR) {
+     throw fmt::windows_error(GetLastError(),
+                              "cannot open file '{}'", filename);
+   }
+ \endrst
+*/
+template <typename... Args>
+std::system_error windows_error(int error_code, string_view message,
+                                const Args&... args) {
+  return vwindows_error(error_code, message, fmt::make_format_args(args...));
+}
+
+// Reports a Windows error without throwing an exception.
+// Can be used to report errors from destructors.
+FMT_API void report_windows_error(int error_code, const char* message) noexcept;
+#else
+inline const std::error_category& system_category() noexcept {
+  return std::system_category();
+}
+#endif  // _WIN32
+
+// std::system is not available on some platforms such as iOS (#2248).
+#ifdef __OSX__
+template <typename S, typename... Args, typename Char = char_t<S>>
+void say(const S& format_str, Args&&... args) {
+  std::system(format("say \"{}\"", format(format_str, args...)).c_str());
+}
+#endif
+
+// A buffered file.
+class buffered_file {
+ private:
+  FILE* file_;
+
+  friend class file;
+
+  explicit buffered_file(FILE* f) : file_(f) {}
+
+ public:
+  buffered_file(const buffered_file&) = delete;
+  void operator=(const buffered_file&) = delete;
+
+  // Constructs a buffered_file object which doesn't represent any file.
+  buffered_file() noexcept : file_(nullptr) {}
+
+  // Destroys the object closing the file it represents if any.
+  FMT_API ~buffered_file() noexcept;
+
+ public:
+  buffered_file(buffered_file&& other) noexcept : file_(other.file_) {
+    other.file_ = nullptr;
+  }
+
+  buffered_file& operator=(buffered_file&& other) {
+    close();
+    file_ = other.file_;
+    other.file_ = nullptr;
+    return *this;
+  }
+
+  // Opens a file.
+  FMT_API buffered_file(cstring_view filename, cstring_view mode);
+
+  // Closes the file.
+  FMT_API void close();
+
+  // Returns the pointer to a FILE object representing this file.
+  FILE* get() const noexcept { return file_; }
+
+  FMT_API int descriptor() const;
+
+  void vprint(string_view format_str, format_args args) {
+    fmt::vprint(file_, format_str, args);
+  }
+
+  template <typename... Args>
+  inline void print(string_view format_str, const Args&... args) {
+    vprint(format_str, fmt::make_format_args(args...));
+  }
+};
+
+#if FMT_USE_FCNTL
+// A file. Closed file is represented by a file object with descriptor -1.
+// Methods that are not declared with noexcept may throw
+// fmt::system_error in case of failure. Note that some errors such as
+// closing the file multiple times will cause a crash on Windows rather
+// than an exception. You can get standard behavior by overriding the
+// invalid parameter handler with _set_invalid_parameter_handler.
+class FMT_API file {
+ private:
+  int fd_;  // File descriptor.
+
+  // Constructs a file object with a given descriptor.
+  explicit file(int fd) : fd_(fd) {}
+
+ public:
+  // Possible values for the oflag argument to the constructor.
+  enum {
+    RDONLY = FMT_POSIX(O_RDONLY),  // Open for reading only.
+    WRONLY = FMT_POSIX(O_WRONLY),  // Open for writing only.
+    RDWR = FMT_POSIX(O_RDWR),      // Open for reading and writing.
+    CREATE = FMT_POSIX(O_CREAT),   // Create if the file doesn't exist.
+    APPEND = FMT_POSIX(O_APPEND),  // Open in append mode.
+    TRUNC = FMT_POSIX(O_TRUNC)     // Truncate the content of the file.
+  };
+
+  // Constructs a file object which doesn't represent any file.
+  file() noexcept : fd_(-1) {}
+
+  // Opens a file and constructs a file object representing this file.
+  file(cstring_view path, int oflag);
+
+ public:
+  file(const file&) = delete;
+  void operator=(const file&) = delete;
+
+  file(file&& other) noexcept : fd_(other.fd_) { other.fd_ = -1; }
+
+  // Move assignment is not noexcept because close may throw.
+  file& operator=(file&& other) {
+    close();
+    fd_ = other.fd_;
+    other.fd_ = -1;
+    return *this;
+  }
+
+  // Destroys the object closing the file it represents if any.
+  ~file() noexcept;
+
+  // Returns the file descriptor.
+  int descriptor() const noexcept { return fd_; }
+
+  // Closes the file.
+  void close();
+
+  // Returns the file size. The size has signed type for consistency with
+  // stat::st_size.
+  long long size() const;
+
+  // Attempts to read count bytes from the file into the specified buffer.
+  size_t read(void* buffer, size_t count);
+
+  // Attempts to write count bytes from the specified buffer to the file.
+  size_t write(const void* buffer, size_t count);
+
+  // Duplicates a file descriptor with the dup function and returns
+  // the duplicate as a file object.
+  static file dup(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  void dup2(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  void dup2(int fd, std::error_code& ec) noexcept;
+
+  // Creates a pipe setting up read_end and write_end file objects for reading
+  // and writing respectively.
+  static void pipe(file& read_end, file& write_end);
+
+  // Creates a buffered_file object associated with this file and detaches
+  // this file object from the file.
+  buffered_file fdopen(const char* mode);
+};
+
+// Returns the memory page size.
+long getpagesize();
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+struct buffer_size {
+  buffer_size() = default;
+  size_t value = 0;
+  buffer_size operator=(size_t val) const {
+    auto bs = buffer_size();
+    bs.value = val;
+    return bs;
+  }
+};
+
+struct ostream_params {
+  int oflag = file::WRONLY | file::CREATE | file::TRUNC;
+  size_t buffer_size = BUFSIZ > 32768 ? BUFSIZ : 32768;
+
+  ostream_params() {}
+
+  template <typename... T>
+  ostream_params(T... params, int new_oflag) : ostream_params(params...) {
+    oflag = new_oflag;
+  }
+
+  template <typename... T>
+  ostream_params(T... params, detail::buffer_size bs)
+      : ostream_params(params...) {
+    this->buffer_size = bs.value;
+  }
+
+// Intel has a bug that results in failure to deduce a constructor
+// for empty parameter packs.
+#  if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 2000
+  ostream_params(int new_oflag) : oflag(new_oflag) {}
+  ostream_params(detail::buffer_size bs) : buffer_size(bs.value) {}
+#  endif
+};
+
+FMT_END_DETAIL_NAMESPACE
+
+// Added {} below to work around default constructor error known to
+// occur in Xcode versions 7.2.1 and 8.2.1.
+constexpr detail::buffer_size buffer_size{};
+
+/** A fast output stream which is not thread-safe. */
+class FMT_API ostream final : private detail::buffer<char> {
+ private:
+  file file_;
+
+  void grow(size_t) override;
+
+  ostream(cstring_view path, const detail::ostream_params& params)
+      : file_(path, params.oflag) {
+    set(new char[params.buffer_size], params.buffer_size);
+  }
+
+ public:
+  ostream(ostream&& other)
+      : detail::buffer<char>(other.data(), other.size(), other.capacity()),
+        file_(std::move(other.file_)) {
+    other.clear();
+    other.set(nullptr, 0);
+  }
+  ~ostream() {
+    flush();
+    delete[] data();
+  }
+
+  void flush() {
+    if (size() == 0) return;
+    file_.write(data(), size());
+    clear();
+  }
+
+  template <typename... T>
+  friend ostream output_file(cstring_view path, T... params);
+
+  void close() {
+    flush();
+    file_.close();
+  }
+
+  /**
+    Formats ``args`` according to specifications in ``fmt`` and writes the
+    output to the file.
+   */
+  template <typename... T> void print(format_string<T...> fmt, T&&... args) {
+    vformat_to(detail::buffer_appender<char>(*this), fmt,
+               fmt::make_format_args(args...));
+  }
+};
+
+/**
+  \rst
+  Opens a file for writing. Supported parameters passed in *params*:
+
+  * ``<integer>``: Flags passed to `open
+    <https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html>`_
+    (``file::WRONLY | file::CREATE | file::TRUNC`` by default)
+  * ``buffer_size=<integer>``: Output buffer size
+
+  **Example**::
+
+    auto out = fmt::output_file("guide.txt");
+    out.print("Don't {}", "Panic");
+  \endrst
+ */
+template <typename... T>
+inline ostream output_file(cstring_view path, T... params) {
+  return {path, detail::ostream_params(params...)};
+}
+#endif  // FMT_USE_FCNTL
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_OS_H_
diff --git a/libfuse/lib/fmt/ostream.h b/libfuse/lib/fmt/ostream.h
new file mode 100644
index 00000000..c3cdd4a6
--- /dev/null
+++ b/libfuse/lib/fmt/ostream.h
@@ -0,0 +1,237 @@
+// Formatting library for C++ - std::ostream support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_OSTREAM_H_
+#define FMT_OSTREAM_H_
+
+#include <fstream>
+#include <ostream>
+#if defined(_WIN32) && defined(__GLIBCXX__)
+#  include <ext/stdio_filebuf.h>
+#  include <ext/stdio_sync_filebuf.h>
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+#  include <__std_stream>
+#endif
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+
+template <typename OutputIt, typename Char> class basic_printf_context;
+
+namespace detail {
+
+// Checks if T has a user-defined operator<<.
+template <typename T, typename Char, typename Enable = void>
+class is_streamable {
+ private:
+  template <typename U>
+  static auto test(int)
+      -> bool_constant<sizeof(std::declval<std::basic_ostream<Char>&>()
+                              << std::declval<U>()) != 0>;
+
+  template <typename> static auto test(...) -> std::false_type;
+
+  using result = decltype(test<T>(0));
+
+ public:
+  is_streamable() = default;
+
+  static const bool value = result::value;
+};
+
+// Formatting of built-in types and arrays is intentionally disabled because
+// it's handled by standard (non-ostream) formatters.
+template <typename T, typename Char>
+struct is_streamable<
+    T, Char,
+    enable_if_t<
+        std::is_arithmetic<T>::value || std::is_array<T>::value ||
+        std::is_pointer<T>::value || std::is_same<T, char8_type>::value ||
+        std::is_convertible<T, fmt::basic_string_view<Char>>::value ||
+        std::is_same<T, std_string_view<Char>>::value ||
+        (std::is_convertible<T, int>::value && !std::is_enum<T>::value)>>
+    : std::false_type {};
+
+// Generate a unique explicit instantion in every translation unit using a tag
+// type in an anonymous namespace.
+namespace {
+struct file_access_tag {};
+}  // namespace
+template <class Tag, class BufType, FILE* BufType::*FileMemberPtr>
+class file_access {
+  friend auto get_file(BufType& obj) -> FILE* { return obj.*FileMemberPtr; }
+};
+
+#if FMT_MSC_VERSION
+template class file_access<file_access_tag, std::filebuf,
+                           &std::filebuf::_Myfile>;
+auto get_file(std::filebuf&) -> FILE*;
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+template class file_access<file_access_tag, std::__stdoutbuf<char>,
+                           &std::__stdoutbuf<char>::__file_>;
+auto get_file(std::__stdoutbuf<char>&) -> FILE*;
+#endif
+
+inline bool write_ostream_unicode(std::ostream& os, fmt::string_view data) {
+#if FMT_MSC_VERSION
+  if (auto* buf = dynamic_cast<std::filebuf*>(os.rdbuf()))
+    if (FILE* f = get_file(*buf)) return write_console(f, data);
+#elif defined(_WIN32) && defined(__GLIBCXX__)
+  auto* rdbuf = os.rdbuf();
+  FILE* c_file;
+  if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_sync_filebuf<char>*>(rdbuf))
+    c_file = fbuf->file();
+  else if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_filebuf<char>*>(rdbuf))
+    c_file = fbuf->file();
+  else
+    return false;
+  if (c_file) return write_console(c_file, data);
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+  if (auto* buf = dynamic_cast<std::__stdoutbuf<char>*>(os.rdbuf()))
+    if (FILE* f = get_file(*buf)) return write_console(f, data);
+#else
+  ignore_unused(os, data);
+#endif
+  return false;
+}
+inline bool write_ostream_unicode(std::wostream&,
+                                  fmt::basic_string_view<wchar_t>) {
+  return false;
+}
+
+// Write the content of buf to os.
+// It is a separate function rather than a part of vprint to simplify testing.
+template <typename Char>
+void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
+  const Char* buf_data = buf.data();
+  using unsigned_streamsize = std::make_unsigned<std::streamsize>::type;
+  unsigned_streamsize size = buf.size();
+  unsigned_streamsize max_size = to_unsigned(max_value<std::streamsize>());
+  do {
+    unsigned_streamsize n = size <= max_size ? size : max_size;
+    os.write(buf_data, static_cast<std::streamsize>(n));
+    buf_data += n;
+    size -= n;
+  } while (size != 0);
+}
+
+template <typename Char, typename T>
+void format_value(buffer<Char>& buf, const T& value,
+                  locale_ref loc = locale_ref()) {
+  auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
+  auto&& output = std::basic_ostream<Char>(&format_buf);
+#if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
+  if (loc) output.imbue(loc.get<std::locale>());
+#endif
+  output << value;
+  output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
+}
+
+template <typename T> struct streamed_view { const T& value; };
+
+}  // namespace detail
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename Char>
+struct basic_ostream_formatter : formatter<basic_string_view<Char>, Char> {
+  void set_debug_format() = delete;
+
+  template <typename T, typename OutputIt>
+  auto format(const T& value, basic_format_context<OutputIt, Char>& ctx) const
+      -> OutputIt {
+    auto buffer = basic_memory_buffer<Char>();
+    format_value(buffer, value, ctx.locale());
+    return formatter<basic_string_view<Char>, Char>::format(
+        {buffer.data(), buffer.size()}, ctx);
+  }
+};
+
+using ostream_formatter = basic_ostream_formatter<char>;
+
+template <typename T, typename Char>
+struct formatter<detail::streamed_view<T>, Char>
+    : basic_ostream_formatter<Char> {
+  template <typename OutputIt>
+  auto format(detail::streamed_view<T> view,
+              basic_format_context<OutputIt, Char>& ctx) const -> OutputIt {
+    return basic_ostream_formatter<Char>::format(view.value, ctx);
+  }
+};
+
+/**
+  \rst
+  Returns a view that formats `value` via an ostream ``operator<<``.
+
+  **Example**::
+
+    fmt::print("Current thread id: {}\n",
+               fmt::streamed(std::this_thread::get_id()));
+  \endrst
+ */
+template <typename T>
+auto streamed(const T& value) -> detail::streamed_view<T> {
+  return {value};
+}
+
+namespace detail {
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename T, typename Char>
+struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
+    : basic_ostream_formatter<Char> {
+  using basic_ostream_formatter<Char>::format;
+};
+
+inline void vprint_directly(std::ostream& os, string_view format_str,
+                            format_args args) {
+  auto buffer = memory_buffer();
+  detail::vformat_to(buffer, format_str, args);
+  detail::write_buffer(os, buffer);
+}
+
+}  // namespace detail
+
+FMT_MODULE_EXPORT template <typename Char>
+void vprint(std::basic_ostream<Char>& os,
+            basic_string_view<type_identity_t<Char>> format_str,
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  auto buffer = basic_memory_buffer<Char>();
+  detail::vformat_to(buffer, format_str, args);
+  if (detail::write_ostream_unicode(os, {buffer.data(), buffer.size()})) return;
+  detail::write_buffer(os, buffer);
+}
+
+/**
+  \rst
+  Prints formatted data to the stream *os*.
+
+  **Example**::
+
+    fmt::print(cerr, "Don't {}!", "panic");
+  \endrst
+ */
+FMT_MODULE_EXPORT template <typename... T>
+void print(std::ostream& os, format_string<T...> fmt, T&&... args) {
+  const auto& vargs = fmt::make_format_args(args...);
+  if (detail::is_utf8())
+    vprint(os, fmt, vargs);
+  else
+    detail::vprint_directly(os, fmt, vargs);
+}
+
+FMT_MODULE_EXPORT
+template <typename... Args>
+void print(std::wostream& os,
+           basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
+           Args&&... args) {
+  vprint(os, fmt, fmt::make_format_args<buffer_context<wchar_t>>(args...));
+}
+
+FMT_END_NAMESPACE
+
+#endif  // FMT_OSTREAM_H_
diff --git a/libfuse/lib/fmt/printf.h b/libfuse/lib/fmt/printf.h
new file mode 100644
index 00000000..70a592dc
--- /dev/null
+++ b/libfuse/lib/fmt/printf.h
@@ -0,0 +1,640 @@
+// Formatting library for C++ - legacy printf implementation
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_PRINTF_H_
+#define FMT_PRINTF_H_
+
+#include <algorithm>  // std::max
+#include <limits>     // std::numeric_limits
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+template <typename T> struct printf_formatter { printf_formatter() = delete; };
+
+template <typename Char>
+class basic_printf_parse_context : public basic_format_parse_context<Char> {
+  using basic_format_parse_context<Char>::basic_format_parse_context;
+};
+
+template <typename OutputIt, typename Char> class basic_printf_context {
+ private:
+  OutputIt out_;
+  basic_format_args<basic_printf_context> args_;
+
+ public:
+  using char_type = Char;
+  using format_arg = basic_format_arg<basic_printf_context>;
+  using parse_context_type = basic_printf_parse_context<Char>;
+  template <typename T> using formatter_type = printf_formatter<T>;
+
+  /**
+    \rst
+    Constructs a ``printf_context`` object. References to the arguments are
+    stored in the context object so make sure they have appropriate lifetimes.
+    \endrst
+   */
+  basic_printf_context(OutputIt out,
+                       basic_format_args<basic_printf_context> args)
+      : out_(out), args_(args) {}
+
+  OutputIt out() { return out_; }
+  void advance_to(OutputIt it) { out_ = it; }
+
+  detail::locale_ref locale() { return {}; }
+
+  format_arg arg(int id) const { return args_.get(id); }
+
+  FMT_CONSTEXPR void on_error(const char* message) {
+    detail::error_handler().on_error(message);
+  }
+};
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+// Checks if a value fits in int - used to avoid warnings about comparing
+// signed and unsigned integers.
+template <bool IsSigned> struct int_checker {
+  template <typename T> static bool fits_in_int(T value) {
+    unsigned max = max_value<int>();
+    return value <= max;
+  }
+  static bool fits_in_int(bool) { return true; }
+};
+
+template <> struct int_checker<true> {
+  template <typename T> static bool fits_in_int(T value) {
+    return value >= (std::numeric_limits<int>::min)() &&
+           value <= max_value<int>();
+  }
+  static bool fits_in_int(int) { return true; }
+};
+
+class printf_precision_handler {
+ public:
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  int operator()(T value) {
+    if (!int_checker<std::numeric_limits<T>::is_signed>::fits_in_int(value))
+      FMT_THROW(format_error("number is too big"));
+    return (std::max)(static_cast<int>(value), 0);
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  int operator()(T) {
+    FMT_THROW(format_error("precision is not integer"));
+    return 0;
+  }
+};
+
+// An argument visitor that returns true iff arg is a zero integer.
+class is_zero_int {
+ public:
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  bool operator()(T value) {
+    return value == 0;
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  bool operator()(T) {
+    return false;
+  }
+};
+
+template <typename T> struct make_unsigned_or_bool : std::make_unsigned<T> {};
+
+template <> struct make_unsigned_or_bool<bool> { using type = bool; };
+
+template <typename T, typename Context> class arg_converter {
+ private:
+  using char_type = typename Context::char_type;
+
+  basic_format_arg<Context>& arg_;
+  char_type type_;
+
+ public:
+  arg_converter(basic_format_arg<Context>& arg, char_type type)
+      : arg_(arg), type_(type) {}
+
+  void operator()(bool value) {
+    if (type_ != 's') operator()<bool>(value);
+  }
+
+  template <typename U, FMT_ENABLE_IF(std::is_integral<U>::value)>
+  void operator()(U value) {
+    bool is_signed = type_ == 'd' || type_ == 'i';
+    using target_type = conditional_t<std::is_same<T, void>::value, U, T>;
+    if (const_check(sizeof(target_type) <= sizeof(int))) {
+      // Extra casts are used to silence warnings.
+      if (is_signed) {
+        arg_ = detail::make_arg<Context>(
+            static_cast<int>(static_cast<target_type>(value)));
+      } else {
+        using unsigned_type = typename make_unsigned_or_bool<target_type>::type;
+        arg_ = detail::make_arg<Context>(
+            static_cast<unsigned>(static_cast<unsigned_type>(value)));
+      }
+    } else {
+      if (is_signed) {
+        // glibc's printf doesn't sign extend arguments of smaller types:
+        //   std::printf("%lld", -42);  // prints "4294967254"
+        // but we don't have to do the same because it's a UB.
+        arg_ = detail::make_arg<Context>(static_cast<long long>(value));
+      } else {
+        arg_ = detail::make_arg<Context>(
+            static_cast<typename make_unsigned_or_bool<U>::type>(value));
+      }
+    }
+  }
+
+  template <typename U, FMT_ENABLE_IF(!std::is_integral<U>::value)>
+  void operator()(U) {}  // No conversion needed for non-integral types.
+};
+
+// Converts an integer argument to T for printf, if T is an integral type.
+// If T is void, the argument is converted to corresponding signed or unsigned
+// type depending on the type specifier: 'd' and 'i' - signed, other -
+// unsigned).
+template <typename T, typename Context, typename Char>
+void convert_arg(basic_format_arg<Context>& arg, Char type) {
+  visit_format_arg(arg_converter<T, Context>(arg, type), arg);
+}
+
+// Converts an integer argument to char for printf.
+template <typename Context> class char_converter {
+ private:
+  basic_format_arg<Context>& arg_;
+
+ public:
+  explicit char_converter(basic_format_arg<Context>& arg) : arg_(arg) {}
+
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  void operator()(T value) {
+    arg_ = detail::make_arg<Context>(
+        static_cast<typename Context::char_type>(value));
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  void operator()(T) {}  // No conversion needed for non-integral types.
+};
+
+// An argument visitor that return a pointer to a C string if argument is a
+// string or null otherwise.
+template <typename Char> struct get_cstring {
+  template <typename T> const Char* operator()(T) { return nullptr; }
+  const Char* operator()(const Char* s) { return s; }
+};
+
+// Checks if an argument is a valid printf width specifier and sets
+// left alignment if it is negative.
+template <typename Char> class printf_width_handler {
+ private:
+  using format_specs = basic_format_specs<Char>;
+
+  format_specs& specs_;
+
+ public:
+  explicit printf_width_handler(format_specs& specs) : specs_(specs) {}
+
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  unsigned operator()(T value) {
+    auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
+    if (detail::is_negative(value)) {
+      specs_.align = align::left;
+      width = 0 - width;
+    }
+    unsigned int_max = max_value<int>();
+    if (width > int_max) FMT_THROW(format_error("number is too big"));
+    return static_cast<unsigned>(width);
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  unsigned operator()(T) {
+    FMT_THROW(format_error("width is not integer"));
+    return 0;
+  }
+};
+
+// The ``printf`` argument formatter.
+template <typename OutputIt, typename Char>
+class printf_arg_formatter : public arg_formatter<Char> {
+ private:
+  using base = arg_formatter<Char>;
+  using context_type = basic_printf_context<OutputIt, Char>;
+  using format_specs = basic_format_specs<Char>;
+
+  context_type& context_;
+
+  OutputIt write_null_pointer(bool is_string = false) {
+    auto s = this->specs;
+    s.type = presentation_type::none;
+    return write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
+  }
+
+ public:
+  printf_arg_formatter(OutputIt iter, format_specs& s, context_type& ctx)
+      : base{iter, s, locale_ref()}, context_(ctx) {}
+
+  OutputIt operator()(monostate value) { return base::operator()(value); }
+
+  template <typename T, FMT_ENABLE_IF(detail::is_integral<T>::value)>
+  OutputIt operator()(T value) {
+    // MSVC2013 fails to compile separate overloads for bool and Char so use
+    // std::is_same instead.
+    if (std::is_same<T, Char>::value) {
+      format_specs fmt_specs = this->specs;
+      if (fmt_specs.type != presentation_type::none &&
+          fmt_specs.type != presentation_type::chr) {
+        return (*this)(static_cast<int>(value));
+      }
+      fmt_specs.sign = sign::none;
+      fmt_specs.alt = false;
+      fmt_specs.fill[0] = ' ';  // Ignore '0' flag for char types.
+      // align::numeric needs to be overwritten here since the '0' flag is
+      // ignored for non-numeric types
+      if (fmt_specs.align == align::none || fmt_specs.align == align::numeric)
+        fmt_specs.align = align::right;
+      return write<Char>(this->out, static_cast<Char>(value), fmt_specs);
+    }
+    return base::operator()(value);
+  }
+
+  template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
+  OutputIt operator()(T value) {
+    return base::operator()(value);
+  }
+
+  /** Formats a null-terminated C string. */
+  OutputIt operator()(const char* value) {
+    if (value) return base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
+  }
+
+  /** Formats a null-terminated wide C string. */
+  OutputIt operator()(const wchar_t* value) {
+    if (value) return base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
+  }
+
+  OutputIt operator()(basic_string_view<Char> value) {
+    return base::operator()(value);
+  }
+
+  /** Formats a pointer. */
+  OutputIt operator()(const void* value) {
+    return value ? base::operator()(value) : write_null_pointer();
+  }
+
+  /** Formats an argument of a custom (user-defined) type. */
+  OutputIt operator()(typename basic_format_arg<context_type>::handle handle) {
+    auto parse_ctx =
+        basic_printf_parse_context<Char>(basic_string_view<Char>());
+    handle.format(parse_ctx, context_);
+    return this->out;
+  }
+};
+
+template <typename Char>
+void parse_flags(basic_format_specs<Char>& specs, const Char*& it,
+                 const Char* end) {
+  for (; it != end; ++it) {
+    switch (*it) {
+    case '-':
+      specs.align = align::left;
+      break;
+    case '+':
+      specs.sign = sign::plus;
+      break;
+    case '0':
+      specs.fill[0] = '0';
+      break;
+    case ' ':
+      if (specs.sign != sign::plus) {
+        specs.sign = sign::space;
+      }
+      break;
+    case '#':
+      specs.alt = true;
+      break;
+    default:
+      return;
+    }
+  }
+}
+
+template <typename Char, typename GetArg>
+int parse_header(const Char*& it, const Char* end,
+                 basic_format_specs<Char>& specs, GetArg get_arg) {
+  int arg_index = -1;
+  Char c = *it;
+  if (c >= '0' && c <= '9') {
+    // Parse an argument index (if followed by '$') or a width possibly
+    // preceded with '0' flag(s).
+    int value = parse_nonnegative_int(it, end, -1);
+    if (it != end && *it == '$') {  // value is an argument index
+      ++it;
+      arg_index = value != -1 ? value : max_value<int>();
+    } else {
+      if (c == '0') specs.fill[0] = '0';
+      if (value != 0) {
+        // Nonzero value means that we parsed width and don't need to
+        // parse it or flags again, so return now.
+        if (value == -1) FMT_THROW(format_error("number is too big"));
+        specs.width = value;
+        return arg_index;
+      }
+    }
+  }
+  parse_flags(specs, it, end);
+  // Parse width.
+  if (it != end) {
+    if (*it >= '0' && *it <= '9') {
+      specs.width = parse_nonnegative_int(it, end, -1);
+      if (specs.width == -1) FMT_THROW(format_error("number is too big"));
+    } else if (*it == '*') {
+      ++it;
+      specs.width = static_cast<int>(visit_format_arg(
+          detail::printf_width_handler<Char>(specs), get_arg(-1)));
+    }
+  }
+  return arg_index;
+}
+
+template <typename Char, typename Context>
+void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
+             basic_format_args<Context> args) {
+  using OutputIt = buffer_appender<Char>;
+  auto out = OutputIt(buf);
+  auto context = basic_printf_context<OutputIt, Char>(out, args);
+  auto parse_ctx = basic_printf_parse_context<Char>(format);
+
+  // Returns the argument with specified index or, if arg_index is -1, the next
+  // argument.
+  auto get_arg = [&](int arg_index) {
+    if (arg_index < 0)
+      arg_index = parse_ctx.next_arg_id();
+    else
+      parse_ctx.check_arg_id(--arg_index);
+    return detail::get_arg(context, arg_index);
+  };
+
+  const Char* start = parse_ctx.begin();
+  const Char* end = parse_ctx.end();
+  auto it = start;
+  while (it != end) {
+    if (!detail::find<false, Char>(it, end, '%', it)) {
+      it = end;  // detail::find leaves it == nullptr if it doesn't find '%'
+      break;
+    }
+    Char c = *it++;
+    if (it != end && *it == c) {
+      out = detail::write(
+          out, basic_string_view<Char>(start, detail::to_unsigned(it - start)));
+      start = ++it;
+      continue;
+    }
+    out = detail::write(out, basic_string_view<Char>(
+                                 start, detail::to_unsigned(it - 1 - start)));
+
+    basic_format_specs<Char> specs;
+    specs.align = align::right;
+
+    // Parse argument index, flags and width.
+    int arg_index = parse_header(it, end, specs, get_arg);
+    if (arg_index == 0) parse_ctx.on_error("argument not found");
+
+    // Parse precision.
+    if (it != end && *it == '.') {
+      ++it;
+      c = it != end ? *it : 0;
+      if ('0' <= c && c <= '9') {
+        specs.precision = parse_nonnegative_int(it, end, 0);
+      } else if (c == '*') {
+        ++it;
+        specs.precision = static_cast<int>(
+            visit_format_arg(detail::printf_precision_handler(), get_arg(-1)));
+      } else {
+        specs.precision = 0;
+      }
+    }
+
+    auto arg = get_arg(arg_index);
+    // For d, i, o, u, x, and X conversion specifiers, if a precision is
+    // specified, the '0' flag is ignored
+    if (specs.precision >= 0 && arg.is_integral())
+      specs.fill[0] =
+          ' ';  // Ignore '0' flag for non-numeric types or if '-' present.
+    if (specs.precision >= 0 && arg.type() == detail::type::cstring_type) {
+      auto str = visit_format_arg(detail::get_cstring<Char>(), arg);
+      auto str_end = str + specs.precision;
+      auto nul = std::find(str, str_end, Char());
+      arg = detail::make_arg<basic_printf_context<OutputIt, Char>>(
+          basic_string_view<Char>(
+              str, detail::to_unsigned(nul != str_end ? nul - str
+                                                      : specs.precision)));
+    }
+    if (specs.alt && visit_format_arg(detail::is_zero_int(), arg))
+      specs.alt = false;
+    if (specs.fill[0] == '0') {
+      if (arg.is_arithmetic() && specs.align != align::left)
+        specs.align = align::numeric;
+      else
+        specs.fill[0] = ' ';  // Ignore '0' flag for non-numeric types or if '-'
+                              // flag is also present.
+    }
+
+    // Parse length and convert the argument to the required type.
+    c = it != end ? *it++ : 0;
+    Char t = it != end ? *it : 0;
+    using detail::convert_arg;
+    switch (c) {
+    case 'h':
+      if (t == 'h') {
+        ++it;
+        t = it != end ? *it : 0;
+        convert_arg<signed char>(arg, t);
+      } else {
+        convert_arg<short>(arg, t);
+      }
+      break;
+    case 'l':
+      if (t == 'l') {
+        ++it;
+        t = it != end ? *it : 0;
+        convert_arg<long long>(arg, t);
+      } else {
+        convert_arg<long>(arg, t);
+      }
+      break;
+    case 'j':
+      convert_arg<intmax_t>(arg, t);
+      break;
+    case 'z':
+      convert_arg<size_t>(arg, t);
+      break;
+    case 't':
+      convert_arg<std::ptrdiff_t>(arg, t);
+      break;
+    case 'L':
+      // printf produces garbage when 'L' is omitted for long double, no
+      // need to do the same.
+      break;
+    default:
+      --it;
+      convert_arg<void>(arg, c);
+    }
+
+    // Parse type.
+    if (it == end) FMT_THROW(format_error("invalid format string"));
+    char type = static_cast<char>(*it++);
+    if (arg.is_integral()) {
+      // Normalize type.
+      switch (type) {
+      case 'i':
+      case 'u':
+        type = 'd';
+        break;
+      case 'c':
+        visit_format_arg(
+            detail::char_converter<basic_printf_context<OutputIt, Char>>(arg),
+            arg);
+        break;
+      }
+    }
+    specs.type = parse_presentation_type(type);
+    if (specs.type == presentation_type::none)
+      parse_ctx.on_error("invalid type specifier");
+
+    start = it;
+
+    // Format argument.
+    out = visit_format_arg(
+        detail::printf_arg_formatter<OutputIt, Char>(out, specs, context), arg);
+  }
+  detail::write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
+}
+FMT_END_DETAIL_NAMESPACE
+
+template <typename Char>
+using basic_printf_context_t =
+    basic_printf_context<detail::buffer_appender<Char>, Char>;
+
+using printf_context = basic_printf_context_t<char>;
+using wprintf_context = basic_printf_context_t<wchar_t>;
+
+using printf_args = basic_format_args<printf_context>;
+using wprintf_args = basic_format_args<wprintf_context>;
+
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::printf_args`.
+  \endrst
+ */
+template <typename... T>
+inline auto make_printf_args(const T&... args)
+    -> format_arg_store<printf_context, T...> {
+  return {args...};
+}
+
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::wprintf_args`.
+  \endrst
+ */
+template <typename... T>
+inline auto make_wprintf_args(const T&... args)
+    -> format_arg_store<wprintf_context, T...> {
+  return {args...};
+}
+
+template <typename S, typename Char = char_t<S>>
+inline auto vsprintf(
+    const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  basic_memory_buffer<Char> buffer;
+  vprintf(buffer, detail::to_string_view(fmt), args);
+  return to_string(buffer);
+}
+
+/**
+  \rst
+  Formats arguments and returns the result as a string.
+
+  **Example**::
+
+    std::string message = fmt::sprintf("The answer is %d", 42);
+  \endrst
+*/
+template <typename S, typename... T,
+          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
+inline auto sprintf(const S& fmt, const T&... args) -> std::basic_string<Char> {
+  using context = basic_printf_context_t<Char>;
+  return vsprintf(detail::to_string_view(fmt),
+                  fmt::make_format_args<context>(args...));
+}
+
+template <typename S, typename Char = char_t<S>>
+inline auto vfprintf(
+    std::FILE* f, const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
+  basic_memory_buffer<Char> buffer;
+  vprintf(buffer, detail::to_string_view(fmt), args);
+  size_t size = buffer.size();
+  return std::fwrite(buffer.data(), sizeof(Char), size, f) < size
+             ? -1
+             : static_cast<int>(size);
+}
+
+/**
+  \rst
+  Prints formatted data to the file *f*.
+
+  **Example**::
+
+    fmt::fprintf(stderr, "Don't %s!", "panic");
+  \endrst
+ */
+template <typename S, typename... T, typename Char = char_t<S>>
+inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
+  using context = basic_printf_context_t<Char>;
+  return vfprintf(f, detail::to_string_view(fmt),
+                  fmt::make_format_args<context>(args...));
+}
+
+template <typename S, typename Char = char_t<S>>
+inline auto vprintf(
+    const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
+  return vfprintf(stdout, detail::to_string_view(fmt), args);
+}
+
+/**
+  \rst
+  Prints formatted data to ``stdout``.
+
+  **Example**::
+
+    fmt::printf("Elapsed time: %.2f seconds", 1.23);
+  \endrst
+ */
+template <typename S, typename... T, FMT_ENABLE_IF(detail::is_string<S>::value)>
+inline auto printf(const S& fmt, const T&... args) -> int {
+  return vprintf(
+      detail::to_string_view(fmt),
+      fmt::make_format_args<basic_printf_context_t<char_t<S>>>(args...));
+}
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_PRINTF_H_
diff --git a/libfuse/lib/fmt/ranges.h b/libfuse/lib/fmt/ranges.h
new file mode 100644
index 00000000..dea7d60d
--- /dev/null
+++ b/libfuse/lib/fmt/ranges.h
@@ -0,0 +1,722 @@
+// Formatting library for C++ - experimental range support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+//
+// Copyright (c) 2018 - present, Remotion (Igor Schulz)
+// All Rights Reserved
+// {fmt} support for ranges, containers and types tuple interface.
+
+#ifndef FMT_RANGES_H_
+#define FMT_RANGES_H_
+
+#include <initializer_list>
+#include <tuple>
+#include <type_traits>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename RangeT, typename OutputIterator>
+OutputIterator copy(const RangeT& range, OutputIterator out) {
+  for (auto it = range.begin(), end = range.end(); it != end; ++it)
+    *out++ = *it;
+  return out;
+}
+
+template <typename OutputIterator>
+OutputIterator copy(const char* str, OutputIterator out) {
+  while (*str) *out++ = *str++;
+  return out;
+}
+
+template <typename OutputIterator>
+OutputIterator copy(char ch, OutputIterator out) {
+  *out++ = ch;
+  return out;
+}
+
+template <typename OutputIterator>
+OutputIterator copy(wchar_t ch, OutputIterator out) {
+  *out++ = ch;
+  return out;
+}
+
+// Returns true if T has a std::string-like interface, like std::string_view.
+template <typename T> class is_std_string_like {
+  template <typename U>
+  static auto check(U* p)
+      -> decltype((void)p->find('a'), p->length(), (void)p->data(), int());
+  template <typename> static void check(...);
+
+ public:
+  static constexpr const bool value =
+      is_string<T>::value ||
+      std::is_convertible<T, std_string_view<char>>::value ||
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+};
+
+template <typename Char>
+struct is_std_string_like<fmt::basic_string_view<Char>> : std::true_type {};
+
+template <typename T> class is_map {
+  template <typename U> static auto check(U*) -> typename U::mapped_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_MAP_AS_LIST
+  static constexpr const bool value = false;
+#else
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+#endif
+};
+
+template <typename T> class is_set {
+  template <typename U> static auto check(U*) -> typename U::key_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_SET_AS_LIST
+  static constexpr const bool value = false;
+#else
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value && !is_map<T>::value;
+#endif
+};
+
+template <typename... Ts> struct conditional_helper {};
+
+template <typename T, typename _ = void> struct is_range_ : std::false_type {};
+
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION > 1800
+
+#  define FMT_DECLTYPE_RETURN(val)  \
+    ->decltype(val) { return val; } \
+    static_assert(                  \
+        true, "")  // This makes it so that a semicolon is required after the
+                   // macro, which helps clang-format handle the formatting.
+
+// C array overload
+template <typename T, std::size_t N>
+auto range_begin(const T (&arr)[N]) -> const T* {
+  return arr;
+}
+template <typename T, std::size_t N>
+auto range_end(const T (&arr)[N]) -> const T* {
+  return arr + N;
+}
+
+template <typename T, typename Enable = void>
+struct has_member_fn_begin_end_t : std::false_type {};
+
+template <typename T>
+struct has_member_fn_begin_end_t<T, void_t<decltype(std::declval<T>().begin()),
+                                           decltype(std::declval<T>().end())>>
+    : std::true_type {};
+
+// Member function overload
+template <typename T>
+auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).begin());
+template <typename T>
+auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).end());
+
+// ADL overload. Only participates in overload resolution if member functions
+// are not found.
+template <typename T>
+auto range_begin(T&& rng)
+    -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                   decltype(begin(static_cast<T&&>(rng)))> {
+  return begin(static_cast<T&&>(rng));
+}
+template <typename T>
+auto range_end(T&& rng) -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                                       decltype(end(static_cast<T&&>(rng)))> {
+  return end(static_cast<T&&>(rng));
+}
+
+template <typename T, typename Enable = void>
+struct has_const_begin_end : std::false_type {};
+template <typename T, typename Enable = void>
+struct has_mutable_begin_end : std::false_type {};
+
+template <typename T>
+struct has_const_begin_end<
+    T,
+    void_t<
+        decltype(detail::range_begin(std::declval<const remove_cvref_t<T>&>())),
+        decltype(detail::range_end(std::declval<const remove_cvref_t<T>&>()))>>
+    : std::true_type {};
+
+template <typename T>
+struct has_mutable_begin_end<
+    T, void_t<decltype(detail::range_begin(std::declval<T>())),
+              decltype(detail::range_end(std::declval<T>())),
+              enable_if_t<std::is_copy_constructible<T>::value>>>
+    : std::true_type {};
+
+template <typename T>
+struct is_range_<T, void>
+    : std::integral_constant<bool, (has_const_begin_end<T>::value ||
+                                    has_mutable_begin_end<T>::value)> {};
+#  undef FMT_DECLTYPE_RETURN
+#endif
+
+// tuple_size and tuple_element check.
+template <typename T> class is_tuple_like_ {
+  template <typename U>
+  static auto check(U* p) -> decltype(std::tuple_size<U>::value, int());
+  template <typename> static void check(...);
+
+ public:
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+};
+
+// Check for integer_sequence
+#if defined(__cpp_lib_integer_sequence) || FMT_MSC_VERSION >= 1900
+template <typename T, T... N>
+using integer_sequence = std::integer_sequence<T, N...>;
+template <size_t... N> using index_sequence = std::index_sequence<N...>;
+template <size_t N> using make_index_sequence = std::make_index_sequence<N>;
+#else
+template <typename T, T... N> struct integer_sequence {
+  using value_type = T;
+
+  static FMT_CONSTEXPR size_t size() { return sizeof...(N); }
+};
+
+template <size_t... N> using index_sequence = integer_sequence<size_t, N...>;
+
+template <typename T, size_t N, T... Ns>
+struct make_integer_sequence : make_integer_sequence<T, N - 1, N - 1, Ns...> {};
+template <typename T, T... Ns>
+struct make_integer_sequence<T, 0, Ns...> : integer_sequence<T, Ns...> {};
+
+template <size_t N>
+using make_index_sequence = make_integer_sequence<size_t, N>;
+#endif
+
+template <typename T>
+using tuple_index_sequence = make_index_sequence<std::tuple_size<T>::value>;
+
+template <typename T, typename C, bool = is_tuple_like_<T>::value>
+class is_tuple_formattable_ {
+ public:
+  static constexpr const bool value = false;
+};
+template <typename T, typename C> class is_tuple_formattable_<T, C, true> {
+  template <std::size_t... I>
+  static std::true_type check2(index_sequence<I...>,
+                               integer_sequence<bool, (I == I)...>);
+  static std::false_type check2(...);
+  template <std::size_t... I>
+  static decltype(check2(
+      index_sequence<I...>{},
+      integer_sequence<
+          bool, (is_formattable<typename std::tuple_element<I, T>::type,
+                                C>::value)...>{})) check(index_sequence<I...>);
+
+ public:
+  static constexpr const bool value =
+      decltype(check(tuple_index_sequence<T>{}))::value;
+};
+
+template <class Tuple, class F, size_t... Is>
+void for_each(index_sequence<Is...>, Tuple&& tup, F&& f) noexcept {
+  using std::get;
+  // using free function get<I>(T) now.
+  const int _[] = {0, ((void)f(get<Is>(tup)), 0)...};
+  (void)_;  // blocks warnings
+}
+
+template <class T>
+FMT_CONSTEXPR make_index_sequence<std::tuple_size<T>::value> get_indexes(
+    T const&) {
+  return {};
+}
+
+template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) {
+  const auto indexes = get_indexes(tup);
+  for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f));
+}
+
+#if FMT_MSC_VERSION && FMT_MSC_VERSION < 1920
+// Older MSVC doesn't get the reference type correctly for arrays.
+template <typename R> struct range_reference_type_impl {
+  using type = decltype(*detail::range_begin(std::declval<R&>()));
+};
+
+template <typename T, std::size_t N> struct range_reference_type_impl<T[N]> {
+  using type = T&;
+};
+
+template <typename T>
+using range_reference_type = typename range_reference_type_impl<T>::type;
+#else
+template <typename Range>
+using range_reference_type =
+    decltype(*detail::range_begin(std::declval<Range&>()));
+#endif
+
+// We don't use the Range's value_type for anything, but we do need the Range's
+// reference type, with cv-ref stripped.
+template <typename Range>
+using uncvref_type = remove_cvref_t<range_reference_type<Range>>;
+
+template <typename Range>
+using uncvref_first_type =
+    remove_cvref_t<decltype(std::declval<range_reference_type<Range>>().first)>;
+
+template <typename Range>
+using uncvref_second_type = remove_cvref_t<
+    decltype(std::declval<range_reference_type<Range>>().second)>;
+
+template <typename OutputIt> OutputIt write_delimiter(OutputIt out) {
+  *out++ = ',';
+  *out++ = ' ';
+  return out;
+}
+
+template <typename Char, typename OutputIt>
+auto write_range_entry(OutputIt out, basic_string_view<Char> str) -> OutputIt {
+  return write_escaped_string(out, str);
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_convertible<T, std_string_view<char>>::value)>
+inline auto write_range_entry(OutputIt out, const T& str) -> OutputIt {
+  auto sv = std_string_view<Char>(str);
+  return write_range_entry<Char>(out, basic_string_view<Char>(sv));
+}
+
+template <typename Char, typename OutputIt, typename Arg,
+          FMT_ENABLE_IF(std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg v) {
+  return write_escaped_char(out, v);
+}
+
+template <
+    typename Char, typename OutputIt, typename Arg,
+    FMT_ENABLE_IF(!is_std_string_like<typename std::decay<Arg>::type>::value &&
+                  !std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg& v) {
+  return write<Char>(out, v);
+}
+
+}  // namespace detail
+
+template <typename T> struct is_tuple_like {
+  static constexpr const bool value =
+      detail::is_tuple_like_<T>::value && !detail::is_range_<T>::value;
+};
+
+template <typename T, typename C> struct is_tuple_formattable {
+  static constexpr const bool value =
+      detail::is_tuple_formattable_<T, C>::value;
+};
+
+template <typename TupleT, typename Char>
+struct formatter<TupleT, Char,
+                 enable_if_t<fmt::is_tuple_like<TupleT>::value &&
+                             fmt::is_tuple_formattable<TupleT, Char>::value>> {
+ private:
+  basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
+  basic_string_view<Char> opening_bracket_ =
+      detail::string_literal<Char, '('>{};
+  basic_string_view<Char> closing_bracket_ =
+      detail::string_literal<Char, ')'>{};
+
+  // C++11 generic lambda for format().
+  template <typename FormatContext> struct format_each {
+    template <typename T> void operator()(const T& v) {
+      if (i > 0) out = detail::copy_str<Char>(separator, out);
+      out = detail::write_range_entry<Char>(out, v);
+      ++i;
+    }
+    int i;
+    typename FormatContext::iterator& out;
+    basic_string_view<Char> separator;
+  };
+
+ public:
+  FMT_CONSTEXPR formatter() {}
+
+  FMT_CONSTEXPR void set_separator(basic_string_view<Char> sep) {
+    separator_ = sep;
+  }
+
+  FMT_CONSTEXPR void set_brackets(basic_string_view<Char> open,
+                                  basic_string_view<Char> close) {
+    opening_bracket_ = open;
+    closing_bracket_ = close;
+  }
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext = format_context>
+  auto format(const TupleT& values, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::copy_str<Char>(opening_bracket_, out);
+    detail::for_each(values, format_each<FormatContext>{0, out, separator_});
+    out = detail::copy_str<Char>(closing_bracket_, out);
+    return out;
+  }
+};
+
+template <typename T, typename Char> struct is_range {
+  static constexpr const bool value =
+      detail::is_range_<T>::value && !detail::is_std_string_like<T>::value &&
+      !std::is_convertible<T, std::basic_string<Char>>::value &&
+      !std::is_convertible<T, detail::std_string_view<Char>>::value;
+};
+
+namespace detail {
+template <typename Context> struct range_mapper {
+  using mapper = arg_mapper<Context>;
+
+  template <typename T,
+            FMT_ENABLE_IF(has_formatter<remove_cvref_t<T>, Context>::value)>
+  static auto map(T&& value) -> T&& {
+    return static_cast<T&&>(value);
+  }
+  template <typename T,
+            FMT_ENABLE_IF(!has_formatter<remove_cvref_t<T>, Context>::value)>
+  static auto map(T&& value)
+      -> decltype(mapper().map(static_cast<T&&>(value))) {
+    return mapper().map(static_cast<T&&>(value));
+  }
+};
+
+template <typename Char, typename Element>
+using range_formatter_type = conditional_t<
+    is_formattable<Element, Char>::value,
+    formatter<remove_cvref_t<decltype(range_mapper<buffer_context<Char>>{}.map(
+                  std::declval<Element>()))>,
+              Char>,
+    fallback_formatter<Element, Char>>;
+
+template <typename R>
+using maybe_const_range =
+    conditional_t<has_const_begin_end<R>::value, const R, R>;
+
+// Workaround a bug in MSVC 2015 and earlier.
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
+template <typename R, typename Char>
+struct is_formattable_delayed
+    : disjunction<
+          is_formattable<uncvref_type<maybe_const_range<R>>, Char>,
+          has_fallback_formatter<uncvref_type<maybe_const_range<R>>, Char>> {};
+#endif
+
+}  // namespace detail
+
+template <typename T, typename Char, typename Enable = void>
+struct range_formatter;
+
+template <typename T, typename Char>
+struct range_formatter<
+    T, Char,
+    enable_if_t<conjunction<
+        std::is_same<T, remove_cvref_t<T>>,
+        disjunction<is_formattable<T, Char>,
+                    detail::has_fallback_formatter<T, Char>>>::value>> {
+ private:
+  detail::range_formatter_type<Char, T> underlying_;
+  bool custom_specs_ = false;
+  basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
+  basic_string_view<Char> opening_bracket_ =
+      detail::string_literal<Char, '['>{};
+  basic_string_view<Char> closing_bracket_ =
+      detail::string_literal<Char, ']'>{};
+
+  template <class U>
+  FMT_CONSTEXPR static auto maybe_set_debug_format(U& u, int)
+      -> decltype(u.set_debug_format()) {
+    u.set_debug_format();
+  }
+
+  template <class U>
+  FMT_CONSTEXPR static void maybe_set_debug_format(U&, ...) {}
+
+  FMT_CONSTEXPR void maybe_set_debug_format() {
+    maybe_set_debug_format(underlying_, 0);
+  }
+
+ public:
+  FMT_CONSTEXPR range_formatter() {}
+
+  FMT_CONSTEXPR auto underlying() -> detail::range_formatter_type<Char, T>& {
+    return underlying_;
+  }
+
+  FMT_CONSTEXPR void set_separator(basic_string_view<Char> sep) {
+    separator_ = sep;
+  }
+
+  FMT_CONSTEXPR void set_brackets(basic_string_view<Char> open,
+                                  basic_string_view<Char> close) {
+    opening_bracket_ = open;
+    closing_bracket_ = close;
+  }
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    auto it = ctx.begin();
+    auto end = ctx.end();
+    if (it == end || *it == '}') {
+      maybe_set_debug_format();
+      return it;
+    }
+
+    if (*it == 'n') {
+      set_brackets({}, {});
+      ++it;
+    }
+
+    if (*it == '}') {
+      maybe_set_debug_format();
+      return it;
+    }
+
+    if (*it != ':')
+      FMT_THROW(format_error("no other top-level range formatters supported"));
+
+    custom_specs_ = true;
+    ++it;
+    ctx.advance_to(it);
+    return underlying_.parse(ctx);
+  }
+
+  template <typename R, class FormatContext>
+  auto format(R&& range, FormatContext& ctx) const -> decltype(ctx.out()) {
+    detail::range_mapper<buffer_context<Char>> mapper;
+    auto out = ctx.out();
+    out = detail::copy_str<Char>(opening_bracket_, out);
+    int i = 0;
+    auto it = detail::range_begin(range);
+    auto end = detail::range_end(range);
+    for (; it != end; ++it) {
+      if (i > 0) out = detail::copy_str<Char>(separator_, out);
+      ;
+      ctx.advance_to(out);
+      out = underlying_.format(mapper.map(*it), ctx);
+      ++i;
+    }
+    out = detail::copy_str<Char>(closing_bracket_, out);
+    return out;
+  }
+};
+
+enum class range_format { disabled, map, set, sequence, string, debug_string };
+
+namespace detail {
+template <typename T> struct range_format_kind_ {
+  static constexpr auto value = std::is_same<range_reference_type<T>, T>::value
+                                    ? range_format::disabled
+                                : is_map<T>::value ? range_format::map
+                                : is_set<T>::value ? range_format::set
+                                                   : range_format::sequence;
+};
+
+template <range_format K, typename R, typename Char, typename Enable = void>
+struct range_default_formatter;
+
+template <range_format K>
+using range_format_constant = std::integral_constant<range_format, K>;
+
+template <range_format K, typename R, typename Char>
+struct range_default_formatter<
+    K, R, Char,
+    enable_if_t<(K == range_format::sequence || K == range_format::map ||
+                 K == range_format::set)>> {
+  using range_type = detail::maybe_const_range<R>;
+  range_formatter<detail::uncvref_type<range_type>, Char> underlying_;
+
+  FMT_CONSTEXPR range_default_formatter() { init(range_format_constant<K>()); }
+
+  FMT_CONSTEXPR void init(range_format_constant<range_format::set>) {
+    underlying_.set_brackets(detail::string_literal<Char, '{'>{},
+                             detail::string_literal<Char, '}'>{});
+  }
+
+  FMT_CONSTEXPR void init(range_format_constant<range_format::map>) {
+    underlying_.set_brackets(detail::string_literal<Char, '{'>{},
+                             detail::string_literal<Char, '}'>{});
+    underlying_.underlying().set_brackets({}, {});
+    underlying_.underlying().set_separator(
+        detail::string_literal<Char, ':', ' '>{});
+  }
+
+  FMT_CONSTEXPR void init(range_format_constant<range_format::sequence>) {}
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return underlying_.parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(range_type& range, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return underlying_.format(range, ctx);
+  }
+};
+}  // namespace detail
+
+template <typename T, typename Char, typename Enable = void>
+struct range_format_kind
+    : conditional_t<
+          is_range<T, Char>::value, detail::range_format_kind_<T>,
+          std::integral_constant<range_format, range_format::disabled>> {};
+
+template <typename R, typename Char>
+struct formatter<
+    R, Char,
+    enable_if_t<conjunction<bool_constant<range_format_kind<R, Char>::value !=
+                                          range_format::disabled>
+// Workaround a bug in MSVC 2015 and earlier.
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
+                            ,
+                            detail::is_formattable_delayed<R, Char>
+#endif
+                            >::value>>
+    : detail::range_default_formatter<range_format_kind<R, Char>::value, R,
+                                      Char> {
+};
+
+template <typename Char, typename... T> struct tuple_join_view : detail::view {
+  const std::tuple<T...>& tuple;
+  basic_string_view<Char> sep;
+
+  tuple_join_view(const std::tuple<T...>& t, basic_string_view<Char> s)
+      : tuple(t), sep{s} {}
+};
+
+template <typename Char, typename... T>
+using tuple_arg_join = tuple_join_view<Char, T...>;
+
+// Define FMT_TUPLE_JOIN_SPECIFIERS to enable experimental format specifiers
+// support in tuple_join. It is disabled by default because of issues with
+// the dynamic width and precision.
+#ifndef FMT_TUPLE_JOIN_SPECIFIERS
+#  define FMT_TUPLE_JOIN_SPECIFIERS 0
+#endif
+
+template <typename Char, typename... T>
+struct formatter<tuple_join_view<Char, T...>, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return do_parse(ctx, std::integral_constant<size_t, sizeof...(T)>());
+  }
+
+  template <typename FormatContext>
+  auto format(const tuple_join_view<Char, T...>& value,
+              FormatContext& ctx) const -> typename FormatContext::iterator {
+    return do_format(value, ctx,
+                     std::integral_constant<size_t, sizeof...(T)>());
+  }
+
+ private:
+  std::tuple<formatter<typename std::decay<T>::type, Char>...> formatters_;
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, 0>)
+      -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename ParseContext, size_t N>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, N>)
+      -> decltype(ctx.begin()) {
+    auto end = ctx.begin();
+#if FMT_TUPLE_JOIN_SPECIFIERS
+    end = std::get<sizeof...(T) - N>(formatters_).parse(ctx);
+    if (N > 1) {
+      auto end1 = do_parse(ctx, std::integral_constant<size_t, N - 1>());
+      if (end != end1)
+        FMT_THROW(format_error("incompatible format specs for tuple elements"));
+    }
+#endif
+    return end;
+  }
+
+  template <typename FormatContext>
+  auto do_format(const tuple_join_view<Char, T...>&, FormatContext& ctx,
+                 std::integral_constant<size_t, 0>) const ->
+      typename FormatContext::iterator {
+    return ctx.out();
+  }
+
+  template <typename FormatContext, size_t N>
+  auto do_format(const tuple_join_view<Char, T...>& value, FormatContext& ctx,
+                 std::integral_constant<size_t, N>) const ->
+      typename FormatContext::iterator {
+    auto out = std::get<sizeof...(T) - N>(formatters_)
+                   .format(std::get<sizeof...(T) - N>(value.tuple), ctx);
+    if (N > 1) {
+      out = std::copy(value.sep.begin(), value.sep.end(), out);
+      ctx.advance_to(out);
+      return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
+    }
+    return out;
+  }
+};
+
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  \rst
+  Returns an object that formats `tuple` with elements separated by `sep`.
+
+  **Example**::
+
+    std::tuple<int, char> t = {1, 'a'};
+    fmt::print("{}", fmt::join(t, ", "));
+    // Output: "1, a"
+  \endrst
+ */
+template <typename... T>
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple, string_view sep)
+    -> tuple_join_view<char, T...> {
+  return {tuple, sep};
+}
+
+template <typename... T>
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple,
+                        basic_string_view<wchar_t> sep)
+    -> tuple_join_view<wchar_t, T...> {
+  return {tuple, sep};
+}
+
+/**
+  \rst
+  Returns an object that formats `initializer_list` with elements separated by
+  `sep`.
+
+  **Example**::
+
+    fmt::print("{}", fmt::join({1, 2, 3}, ", "));
+    // Output: "1, 2, 3"
+  \endrst
+ */
+template <typename T>
+auto join(std::initializer_list<T> list, string_view sep)
+    -> join_view<const T*, const T*> {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_RANGES_H_
diff --git a/libfuse/lib/fmt/std.h b/libfuse/lib/fmt/std.h
new file mode 100644
index 00000000..41d2b283
--- /dev/null
+++ b/libfuse/lib/fmt/std.h
@@ -0,0 +1,171 @@
+// Formatting library for C++ - formatters for standard library types
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_STD_H_
+#define FMT_STD_H_
+
+#include <thread>
+#include <type_traits>
+#include <utility>
+
+#include "ostream.h"
+
+#if FMT_HAS_INCLUDE(<version>)
+#  include <version>
+#endif
+// Checking FMT_CPLUSPLUS for warning suppression in MSVC.
+#if FMT_CPLUSPLUS >= 201703L
+#  if FMT_HAS_INCLUDE(<filesystem>)
+#    include <filesystem>
+#  endif
+#  if FMT_HAS_INCLUDE(<variant>)
+#    include <variant>
+#  endif
+#endif
+
+#ifdef __cpp_lib_filesystem
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename Char>
+void write_escaped_path(basic_memory_buffer<Char>& quoted,
+                        const std::filesystem::path& p) {
+  write_escaped_string<Char>(std::back_inserter(quoted), p.string<Char>());
+}
+#  ifdef _WIN32
+template <>
+inline void write_escaped_path<char>(basic_memory_buffer<char>& quoted,
+                                     const std::filesystem::path& p) {
+  auto s = p.u8string();
+  write_escaped_string<char>(
+      std::back_inserter(quoted),
+      string_view(reinterpret_cast<const char*>(s.c_str()), s.size()));
+}
+#  endif
+template <>
+inline void write_escaped_path<std::filesystem::path::value_type>(
+    basic_memory_buffer<std::filesystem::path::value_type>& quoted,
+    const std::filesystem::path& p) {
+  write_escaped_string<std::filesystem::path::value_type>(
+      std::back_inserter(quoted), p.native());
+}
+
+}  // namespace detail
+
+template <typename Char>
+struct formatter<std::filesystem::path, Char>
+    : formatter<basic_string_view<Char>> {
+  template <typename FormatContext>
+  auto format(const std::filesystem::path& p, FormatContext& ctx) const ->
+      typename FormatContext::iterator {
+    basic_memory_buffer<Char> quoted;
+    detail::write_escaped_path(quoted, p);
+    return formatter<basic_string_view<Char>>::format(
+        basic_string_view<Char>(quoted.data(), quoted.size()), ctx);
+  }
+};
+FMT_END_NAMESPACE
+#endif
+
+FMT_BEGIN_NAMESPACE
+template <typename Char>
+struct formatter<std::thread::id, Char> : basic_ostream_formatter<Char> {};
+FMT_END_NAMESPACE
+
+#ifdef __cpp_lib_variant
+FMT_BEGIN_NAMESPACE
+template <typename Char> struct formatter<std::monostate, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const std::monostate&, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::write<Char>(out, "monostate");
+    return out;
+  }
+};
+
+namespace detail {
+
+template <typename T>
+using variant_index_sequence =
+    std::make_index_sequence<std::variant_size<T>::value>;
+
+// variant_size and variant_alternative check.
+template <typename T, typename U = void>
+struct is_variant_like_ : std::false_type {};
+template <typename T>
+struct is_variant_like_<T, std::void_t<decltype(std::variant_size<T>::value)>>
+    : std::true_type {};
+
+// formattable element check
+template <typename T, typename C> class is_variant_formattable_ {
+  template <std::size_t... I>
+  static std::conjunction<
+      is_formattable<std::variant_alternative_t<I, T>, C>...>
+      check(std::index_sequence<I...>);
+
+ public:
+  static constexpr const bool value =
+      decltype(check(variant_index_sequence<T>{}))::value;
+};
+
+template <typename Char, typename OutputIt, typename T>
+auto write_variant_alternative(OutputIt out, const T& v) -> OutputIt {
+  if constexpr (is_string<T>::value)
+    return write_escaped_string<Char>(out, detail::to_string_view(v));
+  else if constexpr (std::is_same_v<T, Char>)
+    return write_escaped_char(out, v);
+  else
+    return write<Char>(out, v);
+}
+
+}  // namespace detail
+
+template <typename T> struct is_variant_like {
+  static constexpr const bool value = detail::is_variant_like_<T>::value;
+};
+
+template <typename T, typename C> struct is_variant_formattable {
+  static constexpr const bool value =
+      detail::is_variant_formattable_<T, C>::value;
+};
+
+template <typename Variant, typename Char>
+struct formatter<
+    Variant, Char,
+    std::enable_if_t<std::conjunction_v<
+        is_variant_like<Variant>, is_variant_formattable<Variant, Char>>>> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const Variant& value, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+
+    out = detail::write<Char>(out, "variant(");
+    std::visit(
+        [&](const auto& v) {
+          out = detail::write_variant_alternative<Char>(out, v);
+        },
+        value);
+    *out++ = ')';
+    return out;
+  }
+};
+FMT_END_NAMESPACE
+#endif
+
+#endif  // FMT_STD_H_
diff --git a/libfuse/lib/fmt/xchar.h b/libfuse/lib/fmt/xchar.h
new file mode 100644
index 00000000..3b5bc15c
--- /dev/null
+++ b/libfuse/lib/fmt/xchar.h
@@ -0,0 +1,229 @@
+// Formatting library for C++ - optional wchar_t and exotic character support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_XCHAR_H_
+#define FMT_XCHAR_H_
+
+#include <cwchar>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+template <typename T>
+using is_exotic_char = bool_constant<!std::is_same<T, char>::value>;
+}
+
+FMT_MODULE_EXPORT_BEGIN
+
+using wstring_view = basic_string_view<wchar_t>;
+using wformat_parse_context = basic_format_parse_context<wchar_t>;
+using wformat_context = buffer_context<wchar_t>;
+using wformat_args = basic_format_args<wformat_context>;
+using wmemory_buffer = basic_memory_buffer<wchar_t>;
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+// Workaround broken conversion on older gcc.
+template <typename... Args> using wformat_string = wstring_view;
+inline auto runtime(wstring_view s) -> wstring_view { return s; }
+#else
+template <typename... Args>
+using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>;
+inline auto runtime(wstring_view s) -> basic_runtime<wchar_t> { return {{s}}; }
+#endif
+
+template <> struct is_char<wchar_t> : std::true_type {};
+template <> struct is_char<detail::char8_type> : std::true_type {};
+template <> struct is_char<char16_t> : std::true_type {};
+template <> struct is_char<char32_t> : std::true_type {};
+
+template <typename... Args>
+constexpr format_arg_store<wformat_context, Args...> make_wformat_args(
+    const Args&... args) {
+  return {args...};
+}
+
+inline namespace literals {
+#if FMT_USE_USER_DEFINED_LITERALS && !FMT_USE_NONTYPE_TEMPLATE_ARGS
+constexpr detail::udl_arg<wchar_t> operator"" _a(const wchar_t* s, size_t) {
+  return {s};
+}
+#endif
+}  // namespace literals
+
+template <typename It, typename Sentinel>
+auto join(It begin, Sentinel end, wstring_view sep)
+    -> join_view<It, Sentinel, wchar_t> {
+  return {begin, end, sep};
+}
+
+template <typename Range>
+auto join(Range&& range, wstring_view sep)
+    -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>,
+                 wchar_t> {
+  return join(std::begin(range), std::end(range), sep);
+}
+
+template <typename T>
+auto join(std::initializer_list<T> list, wstring_view sep)
+    -> join_view<const T*, const T*, wchar_t> {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+template <typename Char, FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto vformat(basic_string_view<Char> format_str,
+             basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  basic_memory_buffer<Char> buffer;
+  detail::vformat_to(buffer, format_str, args);
+  return to_string(buffer);
+}
+
+template <typename... T>
+auto format(wformat_string<T...> fmt, T&&... args) -> std::wstring {
+  return vformat(fmt::wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+// Pass char_t as a default template parameter instead of using
+// std::basic_string<char_t<S>> to reduce the symbol size.
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(!std::is_same<Char, char>::value &&
+                        !std::is_same<Char, wchar_t>::value)>
+auto format(const S& format_str, Args&&... args) -> std::basic_string<Char> {
+  return vformat(detail::to_string_view(format_str),
+                 fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename Locale, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat(
+    const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, detail::to_string_view(format_str), args);
+}
+
+template <typename Locale, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format(const Locale& loc, const S& format_str, Args&&... args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, detail::to_string_view(format_str),
+                         fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename OutputIt, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+auto vformat_to(OutputIt out, const S& format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, detail::to_string_view(format_str), args);
+  return detail::get_iterator(buf);
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to(OutputIt out, const S& fmt, Args&&... args) -> OutputIt {
+  return vformat_to(out, detail::to_string_view(fmt),
+                    fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename Locale, typename S, typename OutputIt, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_locale<Locale>::value&&
+                                detail::is_exotic_char<Char>::value)>
+inline auto vformat_to(
+    OutputIt out, const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  vformat_to(buf, detail::to_string_view(format_str), args,
+             detail::locale_ref(loc));
+  return detail::get_iterator(buf);
+}
+
+template <
+    typename OutputIt, typename Locale, typename S, typename... Args,
+    typename Char = char_t<S>,
+    bool enable = detail::is_output_iterator<OutputIt, Char>::value&&
+        detail::is_locale<Locale>::value&& detail::is_exotic_char<Char>::value>
+inline auto format_to(OutputIt out, const Locale& loc, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  return vformat_to(out, loc, to_string_view(format_str),
+                    fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename OutputIt, typename Char, typename... Args,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat_to_n(
+    OutputIt out, size_t n, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> format_to_n_result<OutputIt> {
+  detail::iterator_buffer<OutputIt, Char, detail::fixed_buffer_traits> buf(out,
+                                                                           n);
+  detail::vformat_to(buf, format_str, args);
+  return {buf.out(), buf.count()};
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to_n(OutputIt out, size_t n, const S& fmt,
+                        const Args&... args) -> format_to_n_result<OutputIt> {
+  return vformat_to_n(out, n, detail::to_string_view(fmt),
+                      fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
+inline auto formatted_size(const S& fmt, Args&&... args) -> size_t {
+  detail::counting_buffer<Char> buf;
+  detail::vformat_to(buf, detail::to_string_view(fmt),
+                     fmt::make_format_args<buffer_context<Char>>(args...));
+  return buf.count();
+}
+
+inline void vprint(std::FILE* f, wstring_view fmt, wformat_args args) {
+  wmemory_buffer buffer;
+  detail::vformat_to(buffer, fmt, args);
+  buffer.push_back(L'\0');
+  if (std::fputws(buffer.data(), f) == -1)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+inline void vprint(wstring_view fmt, wformat_args args) {
+  vprint(stdout, fmt, args);
+}
+
+template <typename... T>
+void print(std::FILE* f, wformat_string<T...> fmt, T&&... args) {
+  return vprint(f, wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+template <typename... T> void print(wformat_string<T...> fmt, T&&... args) {
+  return vprint(wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+/**
+  Converts *value* to ``std::wstring`` using the default format for type *T*.
+ */
+template <typename T> inline auto to_wstring(const T& value) -> std::wstring {
+  return format(FMT_STRING(L"{}"), value);
+}
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_XCHAR_H_
diff --git a/libfuse/lib/format.cpp b/libfuse/lib/format.cpp
new file mode 100644
index 00000000..99b7e9dd
--- /dev/null
+++ b/libfuse/lib/format.cpp
@@ -0,0 +1,47 @@
+// Formatting library for C++
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include "fmt/format-inl.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+
+template FMT_API auto dragonbox::to_decimal(float x) noexcept
+    -> dragonbox::decimal_fp<float>;
+template FMT_API auto dragonbox::to_decimal(double x) noexcept
+    -> dragonbox::decimal_fp<double>;
+
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+template FMT_API locale_ref::locale_ref(const std::locale& loc);
+template FMT_API auto locale_ref::get<std::locale>() const -> std::locale;
+#endif
+
+// Explicit instantiations for char.
+
+template FMT_API auto thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<char>;
+template FMT_API auto decimal_point_impl(locale_ref) -> char;
+
+template FMT_API void buffer<char>::append(const char*, const char*);
+
+// DEPRECATED!
+// There is no correspondent extern template in format.h because of
+// incompatibility between clang and gcc (#2377).
+template FMT_API void vformat_to(buffer<char>&, string_view,
+                                 basic_format_args<FMT_BUFFER_CONTEXT(char)>,
+                                 locale_ref);
+
+// Explicit instantiations for wchar_t.
+
+template FMT_API auto thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<wchar_t>;
+template FMT_API auto decimal_point_impl(locale_ref) -> wchar_t;
+
+template FMT_API void buffer<wchar_t>::append(const wchar_t*, const wchar_t*);
+
+}  // namespace detail
+FMT_END_NAMESPACE
diff --git a/libfuse/lib/fuse.c b/libfuse/lib/fuse.c
index b8ff3055..d3acce55 100644
--- a/libfuse/lib/fuse.c
+++ b/libfuse/lib/fuse.c
@@ -73,6 +73,7 @@ struct fuse_config
   int help;
   int read_thread_count;
   int process_thread_count;
+  char *pin_threads;
 };
 
 struct fuse_fs
@@ -3667,6 +3668,7 @@ static const struct fuse_opt fuse_lib_opts[] =
    FUSE_LIB_OPT("threads=%d",         read_thread_count,0),
    FUSE_LIB_OPT("read-thread-count=%d", read_thread_count,0),
    FUSE_LIB_OPT("process-thread-count=%d", process_thread_count,-1),
+   FUSE_LIB_OPT("pin-threads=%s",     pin_threads, 0),
    FUSE_OPT_END
   };
 
@@ -4035,6 +4037,13 @@ fuse_config_process_thread_count(const struct fuse *f_)
   return f_->conf.process_thread_count;
 }
 
+const
+char*
+fuse_config_pin_threads(const struct fuse *f_)
+{
+  return f_->conf.pin_threads;
+}
+
 void
 fuse_log_metrics_set(int log_)
 {
diff --git a/libfuse/lib/fuse_loop_mt.cpp b/libfuse/lib/fuse_loop_mt.cpp
index c1c9b931..f62a0745 100644
--- a/libfuse/lib/fuse_loop_mt.cpp
+++ b/libfuse/lib/fuse_loop_mt.cpp
@@ -1,4 +1,10 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
 #include "thread_pool.hpp"
+#include "cpu.hpp"
+#include "fmt/core.h"
 
 #include "fuse_i.h"
 #include "fuse_kernel.h"
@@ -9,6 +15,7 @@
 #include "fuse_ll.hpp"
 
 #include <errno.h>
+#include <pthread.h>
 #include <semaphore.h>
 #include <signal.h>
 #include <stdio.h>
@@ -208,16 +215,230 @@ process_msgbuf_async(fuse_worker_data_t *wd_,
   wd_->tp->enqueue_work(func);
 }
 
+static
+void
+pin_threads_R1L(const CPU::ThreadIdVec read_threads_)
+{
+  CPU::CPUVec cpus;
+
+  cpus = CPU::cpus();
+  if(cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,cpus.front());
+}
+
+static
+void
+pin_threads_R1P(const CPU::ThreadIdVec read_threads_)
+{
+  CPU::Core2CPUsMap core2cpus;
+
+  core2cpus = CPU::core2cpus();
+  if(core2cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+}
+
+static
+void
+pin_threads_RP1L(const CPU::ThreadIdVec read_threads_,
+                 const CPU::ThreadIdVec process_threads_)
+{
+  CPU::CPUVec cpus;
+
+  cpus = CPU::cpus();
+  if(cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,cpus.front());
+  for(auto const thread_id : process_threads_)
+    CPU::setaffinity(thread_id,cpus.front());
+}
+
+static
+void
+pin_threads_RP1P(const CPU::ThreadIdVec read_threads_,
+                 const CPU::ThreadIdVec process_threads_)
+{
+  CPU::Core2CPUsMap core2cpus;
+
+  core2cpus = CPU::core2cpus();
+  if(core2cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+  for(auto const thread_id : process_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+}
+
+static
+void
+pin_threads_R1LP1L(const std::vector<pthread_t> read_threads_,
+                   const std::vector<pthread_t> process_threads_)
+{
+  CPU::CPUVec cpus;
+
+  cpus = CPU::cpus();
+  if(cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,cpus.front());
+
+  for(auto const thread_id : process_threads_)
+    CPU::setaffinity(thread_id,cpus.back());
+}
+
+static
+void
+pin_threads_R1PP1P(const std::vector<pthread_t> read_threads_,
+                   const std::vector<pthread_t> process_threads_)
+{
+  CPU::Core2CPUsMap core2cpus;
+
+  core2cpus = CPU::core2cpus();
+  if(core2cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+
+  if(core2cpus.size() > 1)
+    core2cpus.erase(core2cpus.begin());
+
+  for(auto const thread_id : process_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+}
+
+static
+void
+pin_threads_RPSL(const std::vector<pthread_t> read_threads_,
+                 const std::vector<pthread_t> process_threads_)
+{
+  CPU::CPUVec cpus;
+
+  cpus = CPU::cpus();
+  if(cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    {
+      if(cpus.empty())
+        cpus = CPU::cpus();
+      CPU::setaffinity(thread_id,cpus.back());
+      cpus.pop_back();
+    }
+
+  for(auto const thread_id : process_threads_)
+    {
+      if(cpus.empty())
+        cpus = CPU::cpus();
+      CPU::setaffinity(thread_id,cpus.back());
+      cpus.pop_back();
+    }
+}
+
+static
+void
+pin_threads_RPSP(const std::vector<pthread_t> read_threads_,
+                 const std::vector<pthread_t> process_threads_)
+{
+  CPU::Core2CPUsMap core2cpus;
+
+  core2cpus = CPU::core2cpus();
+  if(core2cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    {
+      if(core2cpus.empty())
+        core2cpus = CPU::core2cpus();
+      CPU::setaffinity(thread_id,core2cpus.begin()->second);
+      core2cpus.erase(core2cpus.begin());
+    }
+
+  for(auto const thread_id : process_threads_)
+    {
+      if(core2cpus.empty())
+        core2cpus = CPU::core2cpus();
+      CPU::setaffinity(thread_id,core2cpus.begin()->second);
+      core2cpus.erase(core2cpus.begin());
+    }
+}
+
+static
+void
+pin_threads_R1PPSP(const std::vector<pthread_t> read_threads_,
+                   const std::vector<pthread_t> process_threads_)
+{
+  CPU::Core2CPUsMap core2cpus;
+  CPU::Core2CPUsMap leftover;
+
+  core2cpus = CPU::core2cpus();
+  if(core2cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+
+  core2cpus.erase(core2cpus.begin());
+  if(core2cpus.empty())
+    core2cpus = CPU::core2cpus();
+  leftover = core2cpus;
+
+  for(auto const thread_id : process_threads_)
+    {
+      if(core2cpus.empty())
+        core2cpus = leftover;
+      CPU::setaffinity(thread_id,core2cpus.begin()->second);
+      core2cpus.erase(core2cpus.begin());
+    }
+}
+
+static
+void
+pin_threads(const std::vector<pthread_t>  read_threads_,
+            const std::vector<pthread_t>  process_threads_,
+            const std::string             type_)
+{
+  if(type_ == "R1L")
+    return ::pin_threads_R1L(read_threads_);
+  if(type_ == "R1P")
+    return ::pin_threads_R1P(read_threads_);
+  if(type_ == "RP1L")
+    return ::pin_threads_RP1L(read_threads_,process_threads_);
+  if(type_ == "RP1P")
+    return ::pin_threads_RP1P(read_threads_,process_threads_);
+  if(type_ == "R1LP1L")
+    return ::pin_threads_R1LP1L(read_threads_,process_threads_);
+  if(type_ == "R1PP1P")
+    return ::pin_threads_R1PP1P(read_threads_,process_threads_);
+  if(type_ == "RPSL")
+    return ::pin_threads_RPSL(read_threads_,process_threads_);
+  if(type_ == "RPSP")
+    return ::pin_threads_RPSP(read_threads_,process_threads_);
+  if(type_ == "R1PPSP")
+    return ::pin_threads_R1PPSP(read_threads_,process_threads_);
+}
+
 int
 fuse_session_loop_mt(struct fuse_session *se_,
                      const int            raw_read_thread_count_,
-                     const int            raw_process_thread_count_)
+                     const int            raw_process_thread_count_,
+                     const char          *pin_threads_type_)
 {
   int err;
   int read_thread_count;
   int process_thread_count;
   fuse_worker_data_t wd = {0};
-  std::vector<pthread_t> threads;
+  std::vector<pthread_t> read_threads;
+  std::vector<pthread_t> process_threads;
 
   read_thread_count    = raw_read_thread_count_;
   process_thread_count = raw_process_thread_count_;
@@ -227,6 +448,7 @@ fuse_session_loop_mt(struct fuse_session *se_,
     {
       wd.tp = std::make_shared<ThreadPool>(process_thread_count);
       wd.msgbuf_processor = process_msgbuf_async;
+      process_threads = wd.tp->threads();
     }
   else
     {
@@ -244,19 +466,22 @@ fuse_session_loop_mt(struct fuse_session *se_,
       pthread_t thread_id;
       err = fuse_start_thread(&thread_id,fuse_do_work,&wd);
       assert(err == 0);
-      threads.push_back(thread_id);
+      read_threads.push_back(thread_id);
     }
 
+  if(pin_threads_type_ != NULL)
+    ::pin_threads(read_threads,process_threads,pin_threads_type_);
+
   if(!err)
     {
       /* sem_wait() is interruptible */
       while(!fuse_session_exited(se_))
         sem_wait(&wd.finished);
 
-      for(const auto &thread_id : threads)
+      for(const auto &thread_id : read_threads)
         pthread_cancel(thread_id);
 
-      for(const auto &thread_id : threads)
+      for(const auto &thread_id : read_threads)
         pthread_join(thread_id,NULL);
     }
 
diff --git a/libfuse/lib/fuse_mt.c b/libfuse/lib/fuse_mt.c
index 1752bef5..03812a29 100644
--- a/libfuse/lib/fuse_mt.c
+++ b/libfuse/lib/fuse_mt.c
@@ -28,7 +28,8 @@ fuse_loop_mt(struct fuse *f)
 
   res = fuse_session_loop_mt(fuse_get_session(f),
                              fuse_config_read_thread_count(f),
-                             fuse_config_process_thread_count(f));
+                             fuse_config_process_thread_count(f),
+                             fuse_config_pin_threads(f));
 
   fuse_stop_maintenance_thread(f);
 
diff --git a/libfuse/lib/ghc/filesystem.hpp b/libfuse/lib/ghc/filesystem.hpp
new file mode 100644
index 00000000..9540b440
--- /dev/null
+++ b/libfuse/lib/ghc/filesystem.hpp
@@ -0,0 +1,6049 @@
+//---------------------------------------------------------------------------------------
+//
+// ghc::filesystem - A C++17-like filesystem implementation for C++11/C++14/C++17/C++20
+//
+//---------------------------------------------------------------------------------------
+//
+// Copyright (c) 2018, Steffen Schümann <s.schuemann@pobox.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+//---------------------------------------------------------------------------------------
+//
+// To dynamically select std::filesystem where available on most platforms,
+// you could use:
+//
+// #if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || (defined(__cplusplus) && __cplusplus >= 201703L)) && defined(__has_include)
+// #if __has_include(<filesystem>) && (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101500)
+// #define GHC_USE_STD_FS
+// #include <filesystem>
+// namespace fs = std::filesystem;
+// #endif
+// #endif
+// #ifndef GHC_USE_STD_FS
+// #include <ghc/filesystem.hpp>
+// namespace fs = ghc::filesystem;
+// #endif
+//
+//---------------------------------------------------------------------------------------
+#ifndef GHC_FILESYSTEM_H
+#define GHC_FILESYSTEM_H
+
+// #define BSD manifest constant only in
+// sys/param.h
+#ifndef _WIN32
+#include <sys/param.h>
+#endif
+
+#ifndef GHC_OS_DETECTED
+#if defined(__APPLE__) && defined(__MACH__)
+#define GHC_OS_MACOS
+#elif defined(__linux__)
+#define GHC_OS_LINUX
+#if defined(__ANDROID__)
+#define GHC_OS_ANDROID
+#endif
+#elif defined(_WIN64)
+#define GHC_OS_WINDOWS
+#define GHC_OS_WIN64
+#elif defined(_WIN32)
+#define GHC_OS_WINDOWS
+#define GHC_OS_WIN32
+#elif defined(__CYGWIN__)
+#define GHC_OS_CYGWIN
+#elif defined(__sun) && defined(__SVR4)
+#define GHC_OS_SOLARIS
+#elif defined(__svr4__)
+#define GHC_OS_SYS5R4
+#elif defined(BSD)
+#define GHC_OS_BSD
+#elif defined(__EMSCRIPTEN__)
+#define GHC_OS_WEB
+#include <wasi/api.h>
+#elif defined(__QNX__)
+#define GHC_OS_QNX
+#else
+#error "Operating system currently not supported!"
+#endif
+#define GHC_OS_DETECTED
+#if (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
+#if _MSVC_LANG == 201703L
+#define GHC_FILESYSTEM_RUNNING_CPP17
+#else
+#define GHC_FILESYSTEM_RUNNING_CPP20
+#endif
+#elif (defined(__cplusplus) && __cplusplus >= 201703L)
+#if __cplusplus == 201703L
+#define GHC_FILESYSTEM_RUNNING_CPP17
+#else
+#define GHC_FILESYSTEM_RUNNING_CPP20
+#endif
+#endif
+#endif
+
+#if defined(GHC_FILESYSTEM_IMPLEMENTATION)
+#define GHC_EXPAND_IMPL
+#define GHC_INLINE
+#ifdef GHC_OS_WINDOWS
+#ifndef GHC_FS_API
+#define GHC_FS_API
+#endif
+#ifndef GHC_FS_API_CLASS
+#define GHC_FS_API_CLASS
+#endif
+#else
+#ifndef GHC_FS_API
+#define GHC_FS_API __attribute__((visibility("default")))
+#endif
+#ifndef GHC_FS_API_CLASS
+#define GHC_FS_API_CLASS __attribute__((visibility("default")))
+#endif
+#endif
+#elif defined(GHC_FILESYSTEM_FWD)
+#define GHC_INLINE
+#ifdef GHC_OS_WINDOWS
+#ifndef GHC_FS_API
+#define GHC_FS_API extern
+#endif
+#ifndef GHC_FS_API_CLASS
+#define GHC_FS_API_CLASS
+#endif
+#else
+#ifndef GHC_FS_API
+#define GHC_FS_API extern
+#endif
+#ifndef GHC_FS_API_CLASS
+#define GHC_FS_API_CLASS
+#endif
+#endif
+#else
+#define GHC_EXPAND_IMPL
+#define GHC_INLINE inline
+#ifndef GHC_FS_API
+#define GHC_FS_API
+#endif
+#ifndef GHC_FS_API_CLASS
+#define GHC_FS_API_CLASS
+#endif
+#endif
+
+#ifdef GHC_EXPAND_IMPL
+
+#ifdef GHC_OS_WINDOWS
+#include <windows.h>
+// additional includes
+#include <shellapi.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <wchar.h>
+#include <winioctl.h>
+#else
+#include <dirent.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#ifdef GHC_OS_ANDROID
+#include <android/api-level.h>
+#if __ANDROID_API__ < 12
+#include <sys/syscall.h>
+#endif
+#include <sys/vfs.h>
+#define statvfs statfs
+#else
+#include <sys/statvfs.h>
+#endif
+#ifdef GHC_OS_CYGWIN
+#include <strings.h>
+#endif
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 26
+#include <langinfo.h>
+#endif
+#endif
+#ifdef GHC_OS_MACOS
+#include <Availability.h>
+#endif
+
+#if defined(__cpp_impl_three_way_comparison) && defined(__has_include)
+#if __has_include(<compare>)
+#define GHC_HAS_THREEWAY_COMP
+#include <compare>
+#endif
+#endif
+
+#include <algorithm>
+#include <cctype>
+#include <chrono>
+#include <clocale>
+#include <cstdlib>
+#include <cstring>
+#include <fstream>
+#include <functional>
+#include <memory>
+#include <stack>
+#include <stdexcept>
+#include <string>
+#include <system_error>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#else  // GHC_EXPAND_IMPL
+
+#if defined(__cpp_impl_three_way_comparison) && defined(__has_include)
+#if __has_include(<compare>)
+#define GHC_HAS_THREEWAY_COMP
+#include <compare>
+#endif
+#endif
+#include <chrono>
+#include <fstream>
+#include <memory>
+#include <stack>
+#include <stdexcept>
+#include <string>
+#include <system_error>
+#ifdef GHC_OS_WINDOWS
+#include <vector>
+#endif
+#endif  // GHC_EXPAND_IMPL
+
+// After standard library includes.
+// Standard library support for std::string_view.
+#if defined(__cpp_lib_string_view)
+#define GHC_HAS_STD_STRING_VIEW
+#elif defined(_LIBCPP_VERSION) && (_LIBCPP_VERSION >= 4000) && (__cplusplus >= 201402)
+#define GHC_HAS_STD_STRING_VIEW
+#elif defined(_GLIBCXX_RELEASE) && (_GLIBCXX_RELEASE >= 7) && (__cplusplus >= 201703)
+#define GHC_HAS_STD_STRING_VIEW
+#elif defined(_MSC_VER) && (_MSC_VER >= 1910 && _MSVC_LANG >= 201703)
+#define GHC_HAS_STD_STRING_VIEW
+#endif
+
+// Standard library support for std::experimental::string_view.
+#if defined(_LIBCPP_VERSION) && (_LIBCPP_VERSION >= 3700 && _LIBCPP_VERSION < 7000) && (__cplusplus >= 201402)
+#define GHC_HAS_STD_EXPERIMENTAL_STRING_VIEW
+#elif defined(__GNUC__) && (((__GNUC__ == 4) && (__GNUC_MINOR__ >= 9)) || (__GNUC__ > 4)) && (__cplusplus >= 201402)
+#define GHC_HAS_STD_EXPERIMENTAL_STRING_VIEW
+#elif defined(__GLIBCXX__) && defined(_GLIBCXX_USE_DUAL_ABI) && (__cplusplus >= 201402)
+// macro _GLIBCXX_USE_DUAL_ABI is always defined in libstdc++ from gcc-5 and newer
+#define GHC_HAS_STD_EXPERIMENTAL_STRING_VIEW
+#endif
+
+#if defined(GHC_HAS_STD_STRING_VIEW)
+#include <string_view>
+#elif defined(GHC_HAS_STD_EXPERIMENTAL_STRING_VIEW)
+#include <experimental/string_view>
+#endif
+
+#if !defined(GHC_OS_WINDOWS) && !defined(PATH_MAX)
+#define PATH_MAX 4096
+#endif
+
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// Behaviour Switches (see README.md, should match the config in test/filesystem_test.cpp):
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// Enforce C++17 API where possible when compiling for C++20, handles the following cases:
+// * fs::path::u8string() returns std::string instead of std::u8string
+// #define GHC_FILESYSTEM_ENFORCE_CPP17_API
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// LWG #2682 disables the since then invalid use of the copy option create_symlinks on directories
+// configure LWG conformance ()
+#define LWG_2682_BEHAVIOUR
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// LWG #2395 makes crate_directory/create_directories not emit an error if there is a regular
+// file with that name, it is superseded by P1164R1, so only activate if really needed
+// #define LWG_2935_BEHAVIOUR
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// LWG #2936 enables new element wise (more expensive) path comparison
+// * if this->root_name().native().compare(p.root_name().native()) != 0 return result
+// * if this->has_root_directory() and !p.has_root_directory() return -1
+// * if !this->has_root_directory() and p.has_root_directory() return -1
+// * else result of element wise comparison of path iteration where first comparison is != 0 or 0
+//   if all comparisons are 0 (on Windows this implementation does case-insensitive root_name()
+//   comparison)
+#define LWG_2936_BEHAVIOUR
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// LWG #2937 enforces that fs::equivalent emits an error, if !fs::exists(p1)||!exists(p2)
+#define LWG_2937_BEHAVIOUR
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// UTF8-Everywhere is the original behaviour of ghc::filesystem. But since v1.5 the Windows
+// version defaults to std::wstring storage backend. Still all std::string will be interpreted
+// as UTF-8 encoded. With this define you can enforce the old behavior on Windows, using
+// std::string as backend and for fs::path::native() and char for fs::path::c_str(). This
+// needs more conversions, so it is (and was before v1.5) slower, bot might help keeping source
+// homogeneous in a multi-platform project.
+// #define GHC_WIN_DISABLE_WSTRING_STORAGE_TYPE
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// Raise errors/exceptions when invalid unicode codepoints or UTF-8 sequences are found,
+// instead of replacing them with the unicode replacement character (U+FFFD).
+// #define GHC_RAISE_UNICODE_ERRORS
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// Automatic prefix windows path with "\\?\" if they would break the MAX_PATH length.
+// instead of replacing them with the unicode replacement character (U+FFFD).
+#ifndef GHC_WIN_DISABLE_AUTO_PREFIXES
+#define GHC_WIN_AUTO_PREFIX_LONG_PATH
+#endif  // GHC_WIN_DISABLE_AUTO_PREFIXES
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+// ghc::filesystem version in decimal (major * 10000 + minor * 100 + patch)
+#define GHC_FILESYSTEM_VERSION 10512L
+
+#if !defined(GHC_WITH_EXCEPTIONS) && (defined(__EXCEPTIONS) || defined(__cpp_exceptions) || defined(_CPPUNWIND))
+#define GHC_WITH_EXCEPTIONS
+#endif
+#if !defined(GHC_WITH_EXCEPTIONS) && defined(GHC_RAISE_UNICODE_ERRORS)
+#error "Can't raise unicode errors with exception support disabled"
+#endif
+
+namespace ghc {
+namespace filesystem {
+
+#if defined(GHC_HAS_CUSTOM_STRING_VIEW)
+#define GHC_WITH_STRING_VIEW
+#elif defined(GHC_HAS_STD_STRING_VIEW)
+#define GHC_WITH_STRING_VIEW
+using std::basic_string_view;
+#elif defined(GHC_HAS_STD_EXPERIMENTAL_STRING_VIEW)
+#define GHC_WITH_STRING_VIEW
+using std::experimental::basic_string_view;
+#endif
+
+// temporary existing exception type for yet unimplemented parts
+class GHC_FS_API_CLASS not_implemented_exception : public std::logic_error
+{
+public:
+    not_implemented_exception()
+        : std::logic_error("function not implemented yet.")
+    {
+    }
+};
+
+template <typename char_type>
+class path_helper_base
+{
+public:
+    using value_type = char_type;
+#ifdef GHC_OS_WINDOWS
+    static constexpr value_type preferred_separator = '\\';
+#else
+    static constexpr value_type preferred_separator = '/';
+#endif
+};
+
+#if __cplusplus < 201703L
+template <typename char_type>
+constexpr char_type path_helper_base<char_type>::preferred_separator;
+#endif
+
+#ifdef GHC_OS_WINDOWS
+class path;
+namespace detail {
+bool has_executable_extension(const path& p);
+}
+#endif
+
+// [fs.class.path] class path
+class GHC_FS_API_CLASS path
+#if defined(GHC_OS_WINDOWS) && !defined(GHC_WIN_DISABLE_WSTRING_STORAGE_TYPE)
+#define GHC_USE_WCHAR_T
+#define GHC_NATIVEWP(p) p.c_str()
+#define GHC_PLATFORM_LITERAL(str) L##str
+    : private path_helper_base<std::wstring::value_type>
+{
+public:
+    using path_helper_base<std::wstring::value_type>::value_type;
+#else
+#define GHC_NATIVEWP(p) p.wstring().c_str()
+#define GHC_PLATFORM_LITERAL(str) str
+    : private path_helper_base<std::string::value_type>
+{
+public:
+    using path_helper_base<std::string::value_type>::value_type;
+#endif
+    using string_type = std::basic_string<value_type>;
+    using path_helper_base<value_type>::preferred_separator;
+
+    // [fs.enum.path.format] enumeration format
+    /// The path format in which the constructor argument is given.
+    enum format {
+        generic_format,  ///< The generic format, internally used by
+                         ///< ghc::filesystem::path with slashes
+        native_format,   ///< The format native to the current platform this code
+                         ///< is build for
+        auto_format,     ///< Try to auto-detect the format, fallback to native
+    };
+
+    template <class T>
+    struct _is_basic_string : std::false_type
+    {
+    };
+    template <class CharT, class Traits, class Alloc>
+    struct _is_basic_string<std::basic_string<CharT, Traits, Alloc>> : std::true_type
+    {
+    };
+    template <class CharT>
+    struct _is_basic_string<std::basic_string<CharT, std::char_traits<CharT>, std::allocator<CharT>>> : std::true_type
+    {
+    };
+#ifdef GHC_WITH_STRING_VIEW
+    template <class CharT, class Traits>
+    struct _is_basic_string<basic_string_view<CharT, Traits>> : std::true_type
+    {
+    };
+    template <class CharT>
+    struct _is_basic_string<basic_string_view<CharT, std::char_traits<CharT>>> : std::true_type
+    {
+    };
+#endif
+
+    template <typename T1, typename T2 = void>
+    using path_type = typename std::enable_if<!std::is_same<path, T1>::value, path>::type;
+    template <typename T>
+#if defined(__cpp_lib_char8_t) && !defined(GHC_FILESYSTEM_ENFORCE_CPP17_API)
+    using path_from_string =
+        typename std::enable_if<_is_basic_string<T>::value || std::is_same<char const*, typename std::decay<T>::type>::value || std::is_same<char*, typename std::decay<T>::type>::value || std::is_same<char8_t const*, typename std::decay<T>::type>::value ||
+                                    std::is_same<char8_t*, typename std::decay<T>::type>::value || std::is_same<char16_t const*, typename std::decay<T>::type>::value || std::is_same<char16_t*, typename std::decay<T>::type>::value ||
+                                    std::is_same<char32_t const*, typename std::decay<T>::type>::value || std::is_same<char32_t*, typename std::decay<T>::type>::value || std::is_same<wchar_t const*, typename std::decay<T>::type>::value ||
+                                    std::is_same<wchar_t*, typename std::decay<T>::type>::value,
+                                path>::type;
+    template <typename T>
+    using path_type_EcharT = typename std::enable_if<std::is_same<T, char>::value || std::is_same<T, char8_t>::value || std::is_same<T, char16_t>::value || std::is_same<T, char32_t>::value || std::is_same<T, wchar_t>::value, path>::type;
+#else
+    using path_from_string =
+        typename std::enable_if<_is_basic_string<T>::value || std::is_same<char const*, typename std::decay<T>::type>::value || std::is_same<char*, typename std::decay<T>::type>::value ||
+                                    std::is_same<char16_t const*, typename std::decay<T>::type>::value || std::is_same<char16_t*, typename std::decay<T>::type>::value || std::is_same<char32_t const*, typename std::decay<T>::type>::value ||
+                                    std::is_same<char32_t*, typename std::decay<T>::type>::value || std::is_same<wchar_t const*, typename std::decay<T>::type>::value || std::is_same<wchar_t*, typename std::decay<T>::type>::value,
+                                path>::type;
+    template <typename T>
+    using path_type_EcharT = typename std::enable_if<std::is_same<T, char>::value || std::is_same<T, char16_t>::value || std::is_same<T, char32_t>::value || std::is_same<T, wchar_t>::value, path>::type;
+#endif
+    // [fs.path.construct] constructors and destructor
+    path() noexcept;
+    path(const path& p);
+    path(path&& p) noexcept;
+    path(string_type&& source, format fmt = auto_format);
+    template <class Source, typename = path_from_string<Source>>
+    path(const Source& source, format fmt = auto_format);
+    template <class InputIterator>
+    path(InputIterator first, InputIterator last, format fmt = auto_format);
+#ifdef GHC_WITH_EXCEPTIONS
+    template <class Source, typename = path_from_string<Source>>
+    path(const Source& source, const std::locale& loc, format fmt = auto_format);
+    template <class InputIterator>
+    path(InputIterator first, InputIterator last, const std::locale& loc, format fmt = auto_format);
+#endif
+    ~path();
+
+    // [fs.path.assign] assignments
+    path& operator=(const path& p);
+    path& operator=(path&& p) noexcept;
+    path& operator=(string_type&& source);
+    path& assign(string_type&& source);
+    template <class Source>
+    path& operator=(const Source& source);
+    template <class Source>
+    path& assign(const Source& source);
+    template <class InputIterator>
+    path& assign(InputIterator first, InputIterator last);
+
+    // [fs.path.append] appends
+    path& operator/=(const path& p);
+    template <class Source>
+    path& operator/=(const Source& source);
+    template <class Source>
+    path& append(const Source& source);
+    template <class InputIterator>
+    path& append(InputIterator first, InputIterator last);
+
+    // [fs.path.concat] concatenation
+    path& operator+=(const path& x);
+    path& operator+=(const string_type& x);
+#ifdef GHC_WITH_STRING_VIEW
+    path& operator+=(basic_string_view<value_type> x);
+#endif
+    path& operator+=(const value_type* x);
+    path& operator+=(value_type x);
+    template <class Source>
+    path_from_string<Source>& operator+=(const Source& x);
+    template <class EcharT>
+    path_type_EcharT<EcharT>& operator+=(EcharT x);
+    template <class Source>
+    path& concat(const Source& x);
+    template <class InputIterator>
+    path& concat(InputIterator first, InputIterator last);
+
+    // [fs.path.modifiers] modifiers
+    void clear() noexcept;
+    path& make_preferred();
+    path& remove_filename();
+    path& replace_filename(const path& replacement);
+    path& replace_extension(const path& replacement = path());
+    void swap(path& rhs) noexcept;
+
+    // [fs.path.native.obs] native format observers
+    const string_type& native() const noexcept;
+    const value_type* c_str() const noexcept;
+    operator string_type() const;
+    template <class EcharT, class traits = std::char_traits<EcharT>, class Allocator = std::allocator<EcharT>>
+    std::basic_string<EcharT, traits, Allocator> string(const Allocator& a = Allocator()) const;
+    std::string string() const;
+    std::wstring wstring() const;
+#if defined(__cpp_lib_char8_t) && !defined(GHC_FILESYSTEM_ENFORCE_CPP17_API)
+    std::u8string u8string() const;
+#else
+    std::string u8string() const;
+#endif
+    std::u16string u16string() const;
+    std::u32string u32string() const;
+
+    // [fs.path.generic.obs] generic format observers
+    template <class EcharT, class traits = std::char_traits<EcharT>, class Allocator = std::allocator<EcharT>>
+    std::basic_string<EcharT, traits, Allocator> generic_string(const Allocator& a = Allocator()) const;
+    std::string generic_string() const;
+    std::wstring generic_wstring() const;
+#if defined(__cpp_lib_char8_t) && !defined(GHC_FILESYSTEM_ENFORCE_CPP17_API)
+    std::u8string generic_u8string() const;
+#else
+    std::string generic_u8string() const;
+#endif
+    std::u16string generic_u16string() const;
+    std::u32string generic_u32string() const;
+
+    // [fs.path.compare] compare
+    int compare(const path& p) const noexcept;
+    int compare(const string_type& s) const;
+#ifdef GHC_WITH_STRING_VIEW
+    int compare(basic_string_view<value_type> s) const;
+#endif
+    int compare(const value_type* s) const;
+
+    // [fs.path.decompose] decomposition
+    path root_name() const;
+    path root_directory() const;
+    path root_path() const;
+    path relative_path() const;
+    path parent_path() const;
+    path filename() const;
+    path stem() const;
+    path extension() const;
+
+    // [fs.path.query] query
+    bool empty() const noexcept;
+    bool has_root_name() const;
+    bool has_root_directory() const;
+    bool has_root_path() const;
+    bool has_relative_path() const;
+    bool has_parent_path() const;
+    bool has_filename() const;
+    bool has_stem() const;
+    bool has_extension() const;
+    bool is_absolute() const;
+    bool is_relative() const;
+
+    // [fs.path.gen] generation
+    path lexically_normal() const;
+    path lexically_relative(const path& base) const;
+    path lexically_proximate(const path& base) const;
+
+    // [fs.path.itr] iterators
+    class iterator;
+    using const_iterator = iterator;
+    iterator begin() const;
+    iterator end() const;
+
+private:
+    using impl_value_type = value_type;
+    using impl_string_type = std::basic_string<impl_value_type>;
+    friend class directory_iterator;
+    void append_name(const value_type* name);
+    static constexpr impl_value_type generic_separator = '/';
+    template <typename InputIterator>
+    class input_iterator_range
+    {
+    public:
+        typedef InputIterator iterator;
+        typedef InputIterator const_iterator;
+        typedef typename InputIterator::difference_type difference_type;
+
+        input_iterator_range(const InputIterator& first, const InputIterator& last)
+            : _first(first)
+            , _last(last)
+        {
+        }
+
+        InputIterator begin() const { return _first; }
+        InputIterator end() const { return _last; }
+
+    private:
+        InputIterator _first;
+        InputIterator _last;
+    };
+    friend void swap(path& lhs, path& rhs) noexcept;
+    friend size_t hash_value(const path& p) noexcept;
+    friend path canonical(const path& p, std::error_code& ec);
+    friend bool create_directories(const path& p, std::error_code& ec) noexcept;
+    string_type::size_type root_name_length() const noexcept;
+    void postprocess_path_with_format(format fmt);
+    void check_long_path();
+    impl_string_type _path;
+#ifdef GHC_OS_WINDOWS
+    void handle_prefixes();
+    friend bool detail::has_executable_extension(const path& p);
+#ifdef GHC_WIN_AUTO_PREFIX_LONG_PATH
+    string_type::size_type _prefixLength{0};
+#else   // GHC_WIN_AUTO_PREFIX_LONG_PATH
+    static const string_type::size_type _prefixLength{0};
+#endif  // GHC_WIN_AUTO_PREFIX_LONG_PATH
+#else
+    static const string_type::size_type _prefixLength{0};
+#endif
+};
+
+// [fs.path.nonmember] path non-member functions
+GHC_FS_API void swap(path& lhs, path& rhs) noexcept;
+GHC_FS_API size_t hash_value(const path& p) noexcept;
+#ifdef GHC_HAS_THREEWAY_COMP
+GHC_FS_API std::strong_ordering operator<=>(const path& lhs, const path& rhs) noexcept;
+#endif
+GHC_FS_API bool operator==(const path& lhs, const path& rhs) noexcept;
+GHC_FS_API bool operator!=(const path& lhs, const path& rhs) noexcept;
+GHC_FS_API bool operator<(const path& lhs, const path& rhs) noexcept;
+GHC_FS_API bool operator<=(const path& lhs, const path& rhs) noexcept;
+GHC_FS_API bool operator>(const path& lhs, const path& rhs) noexcept;
+GHC_FS_API bool operator>=(const path& lhs, const path& rhs) noexcept;
+GHC_FS_API path operator/(const path& lhs, const path& rhs);
+
+// [fs.path.io] path inserter and extractor
+template <class charT, class traits>
+std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& os, const path& p);
+template <class charT, class traits>
+std::basic_istream<charT, traits>& operator>>(std::basic_istream<charT, traits>& is, path& p);
+
+// [pfs.path.factory] path factory functions
+template <class Source, typename = path::path_from_string<Source>>
+#if defined(__cpp_lib_char8_t) && !defined(GHC_FILESYSTEM_ENFORCE_CPP17_API)
+[[deprecated("use ghc::filesystem::path::path() with std::u8string instead")]]
+#endif
+path u8path(const Source& source);
+template <class InputIterator>
+#if defined(__cpp_lib_char8_t) && !defined(GHC_FILESYSTEM_ENFORCE_CPP17_API)
+[[deprecated("use ghc::filesystem::path::path() with std::u8string instead")]]
+#endif
+path u8path(InputIterator first, InputIterator last);
+
+// [fs.class.filesystem_error] class filesystem_error
+class GHC_FS_API_CLASS filesystem_error : public std::system_error
+{
+public:
+    filesystem_error(const std::string& what_arg, std::error_code ec);
+    filesystem_error(const std::string& what_arg, const path& p1, std::error_code ec);
+    filesystem_error(const std::string& what_arg, const path& p1, const path& p2, std::error_code ec);
+    const path& path1() const noexcept;
+    const path& path2() const noexcept;
+    const char* what() const noexcept override;
+
+private:
+    std::string _what_arg;
+    std::error_code _ec;
+    path _p1, _p2;
+};
+
+class GHC_FS_API_CLASS path::iterator
+{
+public:
+    using value_type = const path;
+    using difference_type = std::ptrdiff_t;
+    using pointer = const path*;
+    using reference = const path&;
+    using iterator_category = std::bidirectional_iterator_tag;
+
+    iterator();
+    iterator(const path& p, const impl_string_type::const_iterator& pos);
+    iterator& operator++();
+    iterator operator++(int);
+    iterator& operator--();
+    iterator operator--(int);
+    bool operator==(const iterator& other) const;
+    bool operator!=(const iterator& other) const;
+    reference operator*() const;
+    pointer operator->() const;
+
+private:
+    friend class path;
+    impl_string_type::const_iterator increment(const impl_string_type::const_iterator& pos) const;
+    impl_string_type::const_iterator decrement(const impl_string_type::const_iterator& pos) const;
+    void updateCurrent();
+    impl_string_type::const_iterator _first;
+    impl_string_type::const_iterator _last;
+    impl_string_type::const_iterator _prefix;
+    impl_string_type::const_iterator _root;
+    impl_string_type::const_iterator _iter;
+    path _current;
+};
+
+struct space_info
+{
+    uintmax_t capacity;
+    uintmax_t free;
+    uintmax_t available;
+};
+
+// [fs.enum] enumerations
+// [fs.enum.file_type]
+enum class file_type {
+    none,
+    not_found,
+    regular,
+    directory,
+    symlink,
+    block,
+    character,
+    fifo,
+    socket,
+    unknown,
+};
+
+// [fs.enum.perms]
+enum class perms : uint16_t {
+    none = 0,
+
+    owner_read = 0400,
+    owner_write = 0200,
+    owner_exec = 0100,
+    owner_all = 0700,
+
+    group_read = 040,
+    group_write = 020,
+    group_exec = 010,
+    group_all = 070,
+
+    others_read = 04,
+    others_write = 02,
+    others_exec = 01,
+    others_all = 07,
+
+    all = 0777,
+    set_uid = 04000,
+    set_gid = 02000,
+    sticky_bit = 01000,
+
+    mask = 07777,
+    unknown = 0xffff
+};
+
+// [fs.enum.perm.opts]
+enum class perm_options : uint16_t {
+    replace = 3,
+    add = 1,
+    remove = 2,
+    nofollow = 4,
+};
+
+// [fs.enum.copy.opts]
+enum class copy_options : uint16_t {
+    none = 0,
+
+    skip_existing = 1,
+    overwrite_existing = 2,
+    update_existing = 4,
+
+    recursive = 8,
+
+    copy_symlinks = 0x10,
+    skip_symlinks = 0x20,
+
+    directories_only = 0x40,
+    create_symlinks = 0x80,
+#ifndef GHC_OS_WEB
+    create_hard_links = 0x100
+#endif
+};
+
+// [fs.enum.dir.opts]
+enum class directory_options : uint16_t {
+    none = 0,
+    follow_directory_symlink = 1,
+    skip_permission_denied = 2,
+};
+
+// [fs.class.file_status] class file_status
+class GHC_FS_API_CLASS file_status
+{
+public:
+    // [fs.file_status.cons] constructors and destructor
+    file_status() noexcept;
+    explicit file_status(file_type ft, perms prms = perms::unknown) noexcept;
+    file_status(const file_status&) noexcept;
+    file_status(file_status&&) noexcept;
+    ~file_status();
+    // assignments:
+    file_status& operator=(const file_status&) noexcept;
+    file_status& operator=(file_status&&) noexcept;
+    // [fs.file_status.mods] modifiers
+    void type(file_type ft) noexcept;
+    void permissions(perms prms) noexcept;
+    // [fs.file_status.obs] observers
+    file_type type() const noexcept;
+    perms permissions() const noexcept;
+    friend bool operator==(const file_status& lhs, const file_status& rhs) noexcept { return lhs.type() == rhs.type() && lhs.permissions() == rhs.permissions(); }
+
+private:
+    file_type _type;
+    perms _perms;
+};
+
+using file_time_type = std::chrono::time_point<std::chrono::system_clock>;
+
+// [fs.class.directory_entry] Class directory_entry
+class GHC_FS_API_CLASS directory_entry
+{
+public:
+    // [fs.dir.entry.cons] constructors and destructor
+    directory_entry() noexcept = default;
+    directory_entry(const directory_entry&) = default;
+    directory_entry(directory_entry&&) noexcept = default;
+#ifdef GHC_WITH_EXCEPTIONS
+    explicit directory_entry(const path& p);
+#endif
+    directory_entry(const path& p, std::error_code& ec);
+    ~directory_entry();
+
+    // assignments:
+    directory_entry& operator=(const directory_entry&) = default;
+    directory_entry& operator=(directory_entry&&) noexcept = default;
+
+    // [fs.dir.entry.mods] modifiers
+#ifdef GHC_WITH_EXCEPTIONS
+    void assign(const path& p);
+    void replace_filename(const path& p);
+    void refresh();
+#endif
+    void assign(const path& p, std::error_code& ec);
+    void replace_filename(const path& p, std::error_code& ec);
+    void refresh(std::error_code& ec) noexcept;
+
+    // [fs.dir.entry.obs] observers
+    const filesystem::path& path() const noexcept;
+    operator const filesystem::path&() const noexcept;
+#ifdef GHC_WITH_EXCEPTIONS
+    bool exists() const;
+    bool is_block_file() const;
+    bool is_character_file() const;
+    bool is_directory() const;
+    bool is_fifo() const;
+    bool is_other() const;
+    bool is_regular_file() const;
+    bool is_socket() const;
+    bool is_symlink() const;
+    uintmax_t file_size() const;
+    file_time_type last_write_time() const;
+    file_status status() const;
+    file_status symlink_status() const;
+#endif
+    bool exists(std::error_code& ec) const noexcept;
+    bool is_block_file(std::error_code& ec) const noexcept;
+    bool is_character_file(std::error_code& ec) const noexcept;
+    bool is_directory(std::error_code& ec) const noexcept;
+    bool is_fifo(std::error_code& ec) const noexcept;
+    bool is_other(std::error_code& ec) const noexcept;
+    bool is_regular_file(std::error_code& ec) const noexcept;
+    bool is_socket(std::error_code& ec) const noexcept;
+    bool is_symlink(std::error_code& ec) const noexcept;
+    uintmax_t file_size(std::error_code& ec) const noexcept;
+    file_time_type last_write_time(std::error_code& ec) const noexcept;
+    file_status status(std::error_code& ec) const noexcept;
+    file_status symlink_status(std::error_code& ec) const noexcept;
+
+#ifndef GHC_OS_WEB
+#ifdef GHC_WITH_EXCEPTIONS
+    uintmax_t hard_link_count() const;
+#endif
+    uintmax_t hard_link_count(std::error_code& ec) const noexcept;
+#endif
+
+#ifdef GHC_HAS_THREEWAY_COMP
+    std::strong_ordering operator<=>(const directory_entry& rhs) const noexcept;
+#endif
+    bool operator<(const directory_entry& rhs) const noexcept;
+    bool operator==(const directory_entry& rhs) const noexcept;
+    bool operator!=(const directory_entry& rhs) const noexcept;
+    bool operator<=(const directory_entry& rhs) const noexcept;
+    bool operator>(const directory_entry& rhs) const noexcept;
+    bool operator>=(const directory_entry& rhs) const noexcept;
+
+private:
+    friend class directory_iterator;
+#ifdef GHC_WITH_EXCEPTIONS
+    file_type status_file_type() const;
+#endif
+    file_type status_file_type(std::error_code& ec) const noexcept;
+    filesystem::path _path;
+    file_status _status;
+    file_status _symlink_status;
+    uintmax_t _file_size = static_cast<uintmax_t>(-1);
+#ifndef GHC_OS_WINDOWS
+    uintmax_t _hard_link_count = static_cast<uintmax_t>(-1);
+#endif
+    time_t _last_write_time = 0;
+};
+
+// [fs.class.directory.iterator] Class directory_iterator
+class GHC_FS_API_CLASS directory_iterator
+{
+public:
+    class GHC_FS_API_CLASS proxy
+    {
+    public:
+        const directory_entry& operator*() const& noexcept { return _dir_entry; }
+        directory_entry operator*() && noexcept { return std::move(_dir_entry); }
+
+    private:
+        explicit proxy(const directory_entry& dir_entry)
+            : _dir_entry(dir_entry)
+        {
+        }
+        friend class directory_iterator;
+        friend class recursive_directory_iterator;
+        directory_entry _dir_entry;
+    };
+    using iterator_category = std::input_iterator_tag;
+    using value_type = directory_entry;
+    using difference_type = std::ptrdiff_t;
+    using pointer = const directory_entry*;
+    using reference = const directory_entry&;
+
+    // [fs.dir.itr.members] member functions
+    directory_iterator() noexcept;
+#ifdef GHC_WITH_EXCEPTIONS
+    explicit directory_iterator(const path& p);
+    directory_iterator(const path& p, directory_options options);
+#endif
+    directory_iterator(const path& p, std::error_code& ec) noexcept;
+    directory_iterator(const path& p, directory_options options, std::error_code& ec) noexcept;
+    directory_iterator(const directory_iterator& rhs);
+    directory_iterator(directory_iterator&& rhs) noexcept;
+    ~directory_iterator();
+    directory_iterator& operator=(const directory_iterator& rhs);
+    directory_iterator& operator=(directory_iterator&& rhs) noexcept;
+    const directory_entry& operator*() const;
+    const directory_entry* operator->() const;
+#ifdef GHC_WITH_EXCEPTIONS
+    directory_iterator& operator++();
+#endif
+    directory_iterator& increment(std::error_code& ec) noexcept;
+
+    // other members as required by [input.iterators]
+#ifdef GHC_WITH_EXCEPTIONS
+    proxy operator++(int)
+    {
+        proxy p{**this};
+        ++*this;
+        return p;
+    }
+#endif
+    bool operator==(const directory_iterator& rhs) const;
+    bool operator!=(const directory_iterator& rhs) const;
+
+private:
+    friend class recursive_directory_iterator;
+    class impl;
+    std::shared_ptr<impl> _impl;
+};
+
+// [fs.dir.itr.nonmembers] directory_iterator non-member functions
+GHC_FS_API directory_iterator begin(directory_iterator iter) noexcept;
+GHC_FS_API directory_iterator end(const directory_iterator&) noexcept;
+
+// [fs.class.re.dir.itr] class recursive_directory_iterator
+class GHC_FS_API_CLASS recursive_directory_iterator
+{
+public:
+    using iterator_category = std::input_iterator_tag;
+    using value_type = directory_entry;
+    using difference_type = std::ptrdiff_t;
+    using pointer = const directory_entry*;
+    using reference = const directory_entry&;
+
+    // [fs.rec.dir.itr.members] constructors and destructor
+    recursive_directory_iterator() noexcept;
+#ifdef GHC_WITH_EXCEPTIONS
+    explicit recursive_directory_iterator(const path& p);
+    recursive_directory_iterator(const path& p, directory_options options);
+#endif
+    recursive_directory_iterator(const path& p, directory_options options, std::error_code& ec) noexcept;
+    recursive_directory_iterator(const path& p, std::error_code& ec) noexcept;
+    recursive_directory_iterator(const recursive_directory_iterator& rhs);
+    recursive_directory_iterator(recursive_directory_iterator&& rhs) noexcept;
+    ~recursive_directory_iterator();
+
+    // [fs.rec.dir.itr.members] observers
+    directory_options options() const;
+    int depth() const;
+    bool recursion_pending() const;
+
+    const directory_entry& operator*() const;
+    const directory_entry* operator->() const;
+
+    // [fs.rec.dir.itr.members] modifiers recursive_directory_iterator&
+    recursive_directory_iterator& operator=(const recursive_directory_iterator& rhs);
+    recursive_directory_iterator& operator=(recursive_directory_iterator&& rhs) noexcept;
+#ifdef GHC_WITH_EXCEPTIONS
+    recursive_directory_iterator& operator++();
+#endif
+    recursive_directory_iterator& increment(std::error_code& ec) noexcept;
+
+#ifdef GHC_WITH_EXCEPTIONS
+    void pop();
+#endif
+    void pop(std::error_code& ec);
+    void disable_recursion_pending();
+
+    // other members as required by [input.iterators]
+#ifdef GHC_WITH_EXCEPTIONS
+    directory_iterator::proxy operator++(int)
+    {
+        directory_iterator::proxy proxy{**this};
+        ++*this;
+        return proxy;
+    }
+#endif
+    bool operator==(const recursive_directory_iterator& rhs) const;
+    bool operator!=(const recursive_directory_iterator& rhs) const;
+
+private:
+    struct recursive_directory_iterator_impl
+    {
+        directory_options _options;
+        bool _recursion_pending;
+        std::stack<directory_iterator> _dir_iter_stack;
+        recursive_directory_iterator_impl(directory_options options, bool recursion_pending)
+            : _options(options)
+            , _recursion_pending(recursion_pending)
+        {
+        }
+    };
+    std::shared_ptr<recursive_directory_iterator_impl> _impl;
+};
+
+// [fs.rec.dir.itr.nonmembers] directory_iterator non-member functions
+GHC_FS_API recursive_directory_iterator begin(recursive_directory_iterator iter) noexcept;
+GHC_FS_API recursive_directory_iterator end(const recursive_directory_iterator&) noexcept;
+
+// [fs.op.funcs] filesystem operations
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_FS_API path absolute(const path& p);
+GHC_FS_API path canonical(const path& p);
+GHC_FS_API void copy(const path& from, const path& to);
+GHC_FS_API void copy(const path& from, const path& to, copy_options options);
+GHC_FS_API bool copy_file(const path& from, const path& to);
+GHC_FS_API bool copy_file(const path& from, const path& to, copy_options option);
+GHC_FS_API void copy_symlink(const path& existing_symlink, const path& new_symlink);
+GHC_FS_API bool create_directories(const path& p);
+GHC_FS_API bool create_directory(const path& p);
+GHC_FS_API bool create_directory(const path& p, const path& attributes);
+GHC_FS_API void create_directory_symlink(const path& to, const path& new_symlink);
+GHC_FS_API void create_symlink(const path& to, const path& new_symlink);
+GHC_FS_API path current_path();
+GHC_FS_API void current_path(const path& p);
+GHC_FS_API bool exists(const path& p);
+GHC_FS_API bool equivalent(const path& p1, const path& p2);
+GHC_FS_API uintmax_t file_size(const path& p);
+GHC_FS_API bool is_block_file(const path& p);
+GHC_FS_API bool is_character_file(const path& p);
+GHC_FS_API bool is_directory(const path& p);
+GHC_FS_API bool is_empty(const path& p);
+GHC_FS_API bool is_fifo(const path& p);
+GHC_FS_API bool is_other(const path& p);
+GHC_FS_API bool is_regular_file(const path& p);
+GHC_FS_API bool is_socket(const path& p);
+GHC_FS_API bool is_symlink(const path& p);
+GHC_FS_API file_time_type last_write_time(const path& p);
+GHC_FS_API void last_write_time(const path& p, file_time_type new_time);
+GHC_FS_API void permissions(const path& p, perms prms, perm_options opts = perm_options::replace);
+GHC_FS_API path proximate(const path& p, const path& base = current_path());
+GHC_FS_API path read_symlink(const path& p);
+GHC_FS_API path relative(const path& p, const path& base = current_path());
+GHC_FS_API bool remove(const path& p);
+GHC_FS_API uintmax_t remove_all(const path& p);
+GHC_FS_API void rename(const path& from, const path& to);
+GHC_FS_API void resize_file(const path& p, uintmax_t size);
+GHC_FS_API space_info space(const path& p);
+GHC_FS_API file_status status(const path& p);
+GHC_FS_API file_status symlink_status(const path& p);
+GHC_FS_API path temp_directory_path();
+GHC_FS_API path weakly_canonical(const path& p);
+#endif
+GHC_FS_API path absolute(const path& p, std::error_code& ec);
+GHC_FS_API path canonical(const path& p, std::error_code& ec);
+GHC_FS_API void copy(const path& from, const path& to, std::error_code& ec) noexcept;
+GHC_FS_API void copy(const path& from, const path& to, copy_options options, std::error_code& ec) noexcept;
+GHC_FS_API bool copy_file(const path& from, const path& to, std::error_code& ec) noexcept;
+GHC_FS_API bool copy_file(const path& from, const path& to, copy_options option, std::error_code& ec) noexcept;
+GHC_FS_API void copy_symlink(const path& existing_symlink, const path& new_symlink, std::error_code& ec) noexcept;
+GHC_FS_API bool create_directories(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool create_directory(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool create_directory(const path& p, const path& attributes, std::error_code& ec) noexcept;
+GHC_FS_API void create_directory_symlink(const path& to, const path& new_symlink, std::error_code& ec) noexcept;
+GHC_FS_API void create_symlink(const path& to, const path& new_symlink, std::error_code& ec) noexcept;
+GHC_FS_API path current_path(std::error_code& ec);
+GHC_FS_API void current_path(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool exists(file_status s) noexcept;
+GHC_FS_API bool exists(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool equivalent(const path& p1, const path& p2, std::error_code& ec) noexcept;
+GHC_FS_API uintmax_t file_size(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool is_block_file(file_status s) noexcept;
+GHC_FS_API bool is_block_file(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool is_character_file(file_status s) noexcept;
+GHC_FS_API bool is_character_file(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool is_directory(file_status s) noexcept;
+GHC_FS_API bool is_directory(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool is_empty(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool is_fifo(file_status s) noexcept;
+GHC_FS_API bool is_fifo(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool is_other(file_status s) noexcept;
+GHC_FS_API bool is_other(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool is_regular_file(file_status s) noexcept;
+GHC_FS_API bool is_regular_file(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool is_socket(file_status s) noexcept;
+GHC_FS_API bool is_socket(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool is_symlink(file_status s) noexcept;
+GHC_FS_API bool is_symlink(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API file_time_type last_write_time(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API void last_write_time(const path& p, file_time_type new_time, std::error_code& ec) noexcept;
+GHC_FS_API void permissions(const path& p, perms prms, std::error_code& ec) noexcept;
+GHC_FS_API void permissions(const path& p, perms prms, perm_options opts, std::error_code& ec) noexcept;
+GHC_FS_API path proximate(const path& p, std::error_code& ec);
+GHC_FS_API path proximate(const path& p, const path& base, std::error_code& ec);
+GHC_FS_API path read_symlink(const path& p, std::error_code& ec);
+GHC_FS_API path relative(const path& p, std::error_code& ec);
+GHC_FS_API path relative(const path& p, const path& base, std::error_code& ec);
+GHC_FS_API bool remove(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API uintmax_t remove_all(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API void rename(const path& from, const path& to, std::error_code& ec) noexcept;
+GHC_FS_API void resize_file(const path& p, uintmax_t size, std::error_code& ec) noexcept;
+GHC_FS_API space_info space(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API file_status status(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API bool status_known(file_status s) noexcept;
+GHC_FS_API file_status symlink_status(const path& p, std::error_code& ec) noexcept;
+GHC_FS_API path temp_directory_path(std::error_code& ec) noexcept;
+GHC_FS_API path weakly_canonical(const path& p, std::error_code& ec) noexcept;
+
+#ifndef GHC_OS_WEB
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_FS_API void create_hard_link(const path& to, const path& new_hard_link);
+GHC_FS_API uintmax_t hard_link_count(const path& p);
+#endif
+GHC_FS_API void create_hard_link(const path& to, const path& new_hard_link, std::error_code& ec) noexcept;
+GHC_FS_API uintmax_t hard_link_count(const path& p, std::error_code& ec) noexcept;
+#endif
+
+// Non-C++17 add-on std::fstream wrappers with path
+template <class charT, class traits = std::char_traits<charT>>
+class basic_filebuf : public std::basic_filebuf<charT, traits>
+{
+public:
+    basic_filebuf() {}
+    ~basic_filebuf() override {}
+    basic_filebuf(const basic_filebuf&) = delete;
+    const basic_filebuf& operator=(const basic_filebuf&) = delete;
+    basic_filebuf<charT, traits>* open(const path& p, std::ios_base::openmode mode)
+    {
+#if defined(GHC_OS_WINDOWS) && !defined(__GLIBCXX__)
+        return std::basic_filebuf<charT, traits>::open(p.wstring().c_str(), mode) ? this : 0;
+#else
+        return std::basic_filebuf<charT, traits>::open(p.string().c_str(), mode) ? this : 0;
+#endif
+    }
+};
+
+template <class charT, class traits = std::char_traits<charT>>
+class basic_ifstream : public std::basic_ifstream<charT, traits>
+{
+public:
+    basic_ifstream() {}
+#if defined(GHC_OS_WINDOWS) && !defined(__GLIBCXX__)
+    explicit basic_ifstream(const path& p, std::ios_base::openmode mode = std::ios_base::in)
+        : std::basic_ifstream<charT, traits>(p.wstring().c_str(), mode)
+    {
+    }
+    void open(const path& p, std::ios_base::openmode mode = std::ios_base::in) { std::basic_ifstream<charT, traits>::open(p.wstring().c_str(), mode); }
+#else
+    explicit basic_ifstream(const path& p, std::ios_base::openmode mode = std::ios_base::in)
+        : std::basic_ifstream<charT, traits>(p.string().c_str(), mode)
+    {
+    }
+    void open(const path& p, std::ios_base::openmode mode = std::ios_base::in) { std::basic_ifstream<charT, traits>::open(p.string().c_str(), mode); }
+#endif
+    basic_ifstream(const basic_ifstream&) = delete;
+    const basic_ifstream& operator=(const basic_ifstream&) = delete;
+    ~basic_ifstream() override {}
+};
+
+template <class charT, class traits = std::char_traits<charT>>
+class basic_ofstream : public std::basic_ofstream<charT, traits>
+{
+public:
+    basic_ofstream() {}
+#if defined(GHC_OS_WINDOWS) && !defined(__GLIBCXX__)
+    explicit basic_ofstream(const path& p, std::ios_base::openmode mode = std::ios_base::out)
+        : std::basic_ofstream<charT, traits>(p.wstring().c_str(), mode)
+    {
+    }
+    void open(const path& p, std::ios_base::openmode mode = std::ios_base::out) { std::basic_ofstream<charT, traits>::open(p.wstring().c_str(), mode); }
+#else
+    explicit basic_ofstream(const path& p, std::ios_base::openmode mode = std::ios_base::out)
+        : std::basic_ofstream<charT, traits>(p.string().c_str(), mode)
+    {
+    }
+    void open(const path& p, std::ios_base::openmode mode = std::ios_base::out) { std::basic_ofstream<charT, traits>::open(p.string().c_str(), mode); }
+#endif
+    basic_ofstream(const basic_ofstream&) = delete;
+    const basic_ofstream& operator=(const basic_ofstream&) = delete;
+    ~basic_ofstream() override {}
+};
+
+template <class charT, class traits = std::char_traits<charT>>
+class basic_fstream : public std::basic_fstream<charT, traits>
+{
+public:
+    basic_fstream() {}
+#if defined(GHC_OS_WINDOWS) && !defined(__GLIBCXX__)
+    explicit basic_fstream(const path& p, std::ios_base::openmode mode = std::ios_base::in | std::ios_base::out)
+        : std::basic_fstream<charT, traits>(p.wstring().c_str(), mode)
+    {
+    }
+    void open(const path& p, std::ios_base::openmode mode = std::ios_base::in | std::ios_base::out) { std::basic_fstream<charT, traits>::open(p.wstring().c_str(), mode); }
+#else
+    explicit basic_fstream(const path& p, std::ios_base::openmode mode = std::ios_base::in | std::ios_base::out)
+        : std::basic_fstream<charT, traits>(p.string().c_str(), mode)
+    {
+    }
+    void open(const path& p, std::ios_base::openmode mode = std::ios_base::in | std::ios_base::out) { std::basic_fstream<charT, traits>::open(p.string().c_str(), mode); }
+#endif
+    basic_fstream(const basic_fstream&) = delete;
+    const basic_fstream& operator=(const basic_fstream&) = delete;
+    ~basic_fstream() override {}
+};
+
+typedef basic_filebuf<char> filebuf;
+typedef basic_filebuf<wchar_t> wfilebuf;
+typedef basic_ifstream<char> ifstream;
+typedef basic_ifstream<wchar_t> wifstream;
+typedef basic_ofstream<char> ofstream;
+typedef basic_ofstream<wchar_t> wofstream;
+typedef basic_fstream<char> fstream;
+typedef basic_fstream<wchar_t> wfstream;
+
+class GHC_FS_API_CLASS u8arguments
+{
+public:
+    u8arguments(int& argc, char**& argv);
+    ~u8arguments()
+    {
+        _refargc = _argc;
+        _refargv = _argv;
+    }
+
+    bool valid() const { return _isvalid; }
+
+private:
+    int _argc;
+    char** _argv;
+    int& _refargc;
+    char**& _refargv;
+    bool _isvalid;
+#ifdef GHC_OS_WINDOWS
+    std::vector<std::string> _args;
+    std::vector<char*> _argp;
+#endif
+};
+
+//-------------------------------------------------------------------------------------------------
+//  Implementation
+//-------------------------------------------------------------------------------------------------
+
+namespace detail {
+enum utf8_states_t { S_STRT = 0, S_RJCT = 8 };
+GHC_FS_API void appendUTF8(std::string& str, uint32_t unicode);
+GHC_FS_API bool is_surrogate(uint32_t c);
+GHC_FS_API bool is_high_surrogate(uint32_t c);
+GHC_FS_API bool is_low_surrogate(uint32_t c);
+GHC_FS_API unsigned consumeUtf8Fragment(const unsigned state, const uint8_t fragment, uint32_t& codepoint);
+enum class portable_error {
+    none = 0,
+    exists,
+    not_found,
+    not_supported,
+    not_implemented,
+    invalid_argument,
+    is_a_directory,
+};
+GHC_FS_API std::error_code make_error_code(portable_error err);
+#ifdef GHC_OS_WINDOWS
+GHC_FS_API std::error_code make_system_error(uint32_t err = 0);
+#else
+GHC_FS_API std::error_code make_system_error(int err = 0);
+
+template <typename T, typename = int>
+struct has_d_type : std::false_type{};
+
+template <typename T>
+struct has_d_type<T, decltype((void)T::d_type, 0)> : std::true_type {};
+
+template <typename T>
+GHC_INLINE file_type file_type_from_dirent_impl(const T&, std::false_type)
+{
+    return file_type::none;
+}
+
+template <typename T>
+GHC_INLINE file_type file_type_from_dirent_impl(const T& t, std::true_type)
+{
+    switch (t.d_type) {
+#ifdef DT_BLK
+        case DT_BLK:
+            return file_type::block;
+#endif
+#ifdef DT_CHR
+        case DT_CHR:
+            return file_type::character;
+#endif
+#ifdef DT_DIR
+        case DT_DIR:
+            return file_type::directory;
+#endif
+#ifdef DT_FIFO
+        case DT_FIFO:
+            return file_type::fifo;
+#endif
+#ifdef DT_LNK
+        case DT_LNK:
+            return file_type::symlink;
+#endif
+#ifdef DT_REG
+        case DT_REG:
+            return file_type::regular;
+#endif
+#ifdef DT_SOCK
+        case DT_SOCK:
+            return file_type::socket;
+#endif
+#ifdef DT_UNKNOWN
+        case DT_UNKNOWN:
+            return file_type::none;
+#endif
+        default:
+            return file_type::unknown;
+    }
+}
+
+template <class T>
+GHC_INLINE file_type file_type_from_dirent(const T& t)
+{
+    return file_type_from_dirent_impl(t, has_d_type<T>{});
+}
+#endif
+}  // namespace detail
+
+namespace detail {
+
+#ifdef GHC_EXPAND_IMPL
+
+GHC_INLINE std::error_code make_error_code(portable_error err)
+{
+#ifdef GHC_OS_WINDOWS
+    switch (err) {
+        case portable_error::none:
+            return std::error_code();
+        case portable_error::exists:
+            return std::error_code(ERROR_ALREADY_EXISTS, std::system_category());
+        case portable_error::not_found:
+            return std::error_code(ERROR_PATH_NOT_FOUND, std::system_category());
+        case portable_error::not_supported:
+            return std::error_code(ERROR_NOT_SUPPORTED, std::system_category());
+        case portable_error::not_implemented:
+            return std::error_code(ERROR_CALL_NOT_IMPLEMENTED, std::system_category());
+        case portable_error::invalid_argument:
+            return std::error_code(ERROR_INVALID_PARAMETER, std::system_category());
+        case portable_error::is_a_directory:
+#ifdef ERROR_DIRECTORY_NOT_SUPPORTED
+            return std::error_code(ERROR_DIRECTORY_NOT_SUPPORTED, std::system_category());
+#else
+            return std::error_code(ERROR_NOT_SUPPORTED, std::system_category());
+#endif
+    }
+#else
+    switch (err) {
+        case portable_error::none:
+            return std::error_code();
+        case portable_error::exists:
+            return std::error_code(EEXIST, std::system_category());
+        case portable_error::not_found:
+            return std::error_code(ENOENT, std::system_category());
+        case portable_error::not_supported:
+            return std::error_code(ENOTSUP, std::system_category());
+        case portable_error::not_implemented:
+            return std::error_code(ENOSYS, std::system_category());
+        case portable_error::invalid_argument:
+            return std::error_code(EINVAL, std::system_category());
+        case portable_error::is_a_directory:
+            return std::error_code(EISDIR, std::system_category());
+    }
+#endif
+    return std::error_code();
+}
+
+#ifdef GHC_OS_WINDOWS
+GHC_INLINE std::error_code make_system_error(uint32_t err)
+{
+    return std::error_code(err ? static_cast<int>(err) : static_cast<int>(::GetLastError()), std::system_category());
+}
+#else
+GHC_INLINE std::error_code make_system_error(int err)
+{
+    return std::error_code(err ? err : errno, std::system_category());
+}
+#endif
+
+#endif  // GHC_EXPAND_IMPL
+
+template <typename Enum>
+using EnableBitmask = typename std::enable_if<std::is_same<Enum, perms>::value || std::is_same<Enum, perm_options>::value || std::is_same<Enum, copy_options>::value || std::is_same<Enum, directory_options>::value, Enum>::type;
+}  // namespace detail
+
+template <typename Enum>
+constexpr detail::EnableBitmask<Enum> operator&(Enum X, Enum Y)
+{
+    using underlying = typename std::underlying_type<Enum>::type;
+    return static_cast<Enum>(static_cast<underlying>(X) & static_cast<underlying>(Y));
+}
+
+template <typename Enum>
+constexpr detail::EnableBitmask<Enum> operator|(Enum X, Enum Y)
+{
+    using underlying = typename std::underlying_type<Enum>::type;
+    return static_cast<Enum>(static_cast<underlying>(X) | static_cast<underlying>(Y));
+}
+
+template <typename Enum>
+constexpr detail::EnableBitmask<Enum> operator^(Enum X, Enum Y)
+{
+    using underlying = typename std::underlying_type<Enum>::type;
+    return static_cast<Enum>(static_cast<underlying>(X) ^ static_cast<underlying>(Y));
+}
+
+template <typename Enum>
+constexpr detail::EnableBitmask<Enum> operator~(Enum X)
+{
+    using underlying = typename std::underlying_type<Enum>::type;
+    return static_cast<Enum>(~static_cast<underlying>(X));
+}
+
+template <typename Enum>
+detail::EnableBitmask<Enum>& operator&=(Enum& X, Enum Y)
+{
+    X = X & Y;
+    return X;
+}
+
+template <typename Enum>
+detail::EnableBitmask<Enum>& operator|=(Enum& X, Enum Y)
+{
+    X = X | Y;
+    return X;
+}
+
+template <typename Enum>
+detail::EnableBitmask<Enum>& operator^=(Enum& X, Enum Y)
+{
+    X = X ^ Y;
+    return X;
+}
+
+#ifdef GHC_EXPAND_IMPL
+
+namespace detail {
+
+GHC_INLINE bool in_range(uint32_t c, uint32_t lo, uint32_t hi)
+{
+    return (static_cast<uint32_t>(c - lo) < (hi - lo + 1));
+}
+
+GHC_INLINE bool is_surrogate(uint32_t c)
+{
+    return in_range(c, 0xd800, 0xdfff);
+}
+
+GHC_INLINE bool is_high_surrogate(uint32_t c)
+{
+    return (c & 0xfffffc00) == 0xd800;
+}
+
+GHC_INLINE bool is_low_surrogate(uint32_t c)
+{
+    return (c & 0xfffffc00) == 0xdc00;
+}
+
+GHC_INLINE void appendUTF8(std::string& str, uint32_t unicode)
+{
+    if (unicode <= 0x7f) {
+        str.push_back(static_cast<char>(unicode));
+    }
+    else if (unicode >= 0x80 && unicode <= 0x7ff) {
+        str.push_back(static_cast<char>((unicode >> 6) + 192));
+        str.push_back(static_cast<char>((unicode & 0x3f) + 128));
+    }
+    else if ((unicode >= 0x800 && unicode <= 0xd7ff) || (unicode >= 0xe000 && unicode <= 0xffff)) {
+        str.push_back(static_cast<char>((unicode >> 12) + 224));
+        str.push_back(static_cast<char>(((unicode & 0xfff) >> 6) + 128));
+        str.push_back(static_cast<char>((unicode & 0x3f) + 128));
+    }
+    else if (unicode >= 0x10000 && unicode <= 0x10ffff) {
+        str.push_back(static_cast<char>((unicode >> 18) + 240));
+        str.push_back(static_cast<char>(((unicode & 0x3ffff) >> 12) + 128));
+        str.push_back(static_cast<char>(((unicode & 0xfff) >> 6) + 128));
+        str.push_back(static_cast<char>((unicode & 0x3f) + 128));
+    }
+    else {
+#ifdef GHC_RAISE_UNICODE_ERRORS
+        throw filesystem_error("Illegal code point for unicode character.", str, std::make_error_code(std::errc::illegal_byte_sequence));
+#else
+        appendUTF8(str, 0xfffd);
+#endif
+    }
+}
+
+// Thanks to Bjoern Hoehrmann (https://bjoern.hoehrmann.de/utf-8/decoder/dfa/)
+// and Taylor R Campbell for the ideas to this DFA approach of UTF-8 decoding;
+// Generating debugging and shrinking my own DFA from scratch was a day of fun!
+GHC_INLINE unsigned consumeUtf8Fragment(const unsigned state, const uint8_t fragment, uint32_t& codepoint)
+{
+    static const uint32_t utf8_state_info[] = {
+        // encoded states
+        0x11111111u, 0x11111111u, 0x77777777u, 0x77777777u, 0x88888888u, 0x88888888u, 0x88888888u, 0x88888888u, 0x22222299u, 0x22222222u, 0x22222222u, 0x22222222u, 0x3333333au, 0x33433333u, 0x9995666bu, 0x99999999u,
+        0x88888880u, 0x22818108u, 0x88888881u, 0x88888882u, 0x88888884u, 0x88888887u, 0x88888886u, 0x82218108u, 0x82281108u, 0x88888888u, 0x88888883u, 0x88888885u, 0u,          0u,          0u,          0u,
+    };
+    uint8_t category = fragment < 128 ? 0 : (utf8_state_info[(fragment >> 3) & 0xf] >> ((fragment & 7) << 2)) & 0xf;
+    codepoint = (state ? (codepoint << 6) | (fragment & 0x3fu) : (0xffu >> category) & fragment);
+    return state == S_RJCT ? static_cast<unsigned>(S_RJCT) : static_cast<unsigned>((utf8_state_info[category + 16] >> (state << 2)) & 0xf);
+}
+
+GHC_INLINE bool validUtf8(const std::string& utf8String)
+{
+    std::string::const_iterator iter = utf8String.begin();
+    unsigned utf8_state = S_STRT;
+    std::uint32_t codepoint = 0;
+    while (iter < utf8String.end()) {
+        if ((utf8_state = consumeUtf8Fragment(utf8_state, static_cast<uint8_t>(*iter++), codepoint)) == S_RJCT) {
+            return false;
+        }
+    }
+    if (utf8_state) {
+        return false;
+    }
+    return true;
+}
+
+}  // namespace detail
+
+#endif
+
+namespace detail {
+
+template <class StringType, class Utf8String, typename std::enable_if<path::_is_basic_string<Utf8String>::value && (sizeof(typename Utf8String::value_type) == 1) && (sizeof(typename StringType::value_type) == 1)>::type* = nullptr>
+inline StringType fromUtf8(const Utf8String& utf8String, const typename StringType::allocator_type& alloc = typename StringType::allocator_type())
+{
+    return StringType(utf8String.begin(), utf8String.end(), alloc);
+}
+
+template <class StringType, class Utf8String, typename std::enable_if<path::_is_basic_string<Utf8String>::value && (sizeof(typename Utf8String::value_type) == 1) && (sizeof(typename StringType::value_type) == 2)>::type* = nullptr>
+inline StringType fromUtf8(const Utf8String& utf8String, const typename StringType::allocator_type& alloc = typename StringType::allocator_type())
+{
+    StringType result(alloc);
+    result.reserve(utf8String.length());
+    auto iter = utf8String.cbegin();
+    unsigned utf8_state = S_STRT;
+    std::uint32_t codepoint = 0;
+    while (iter < utf8String.cend()) {
+        if ((utf8_state = consumeUtf8Fragment(utf8_state, static_cast<uint8_t>(*iter++), codepoint)) == S_STRT) {
+            if (codepoint <= 0xffff) {
+                result += static_cast<typename StringType::value_type>(codepoint);
+            }
+            else {
+                codepoint -= 0x10000;
+                result += static_cast<typename StringType::value_type>((codepoint >> 10) + 0xd800);
+                result += static_cast<typename StringType::value_type>((codepoint & 0x3ff) + 0xdc00);
+            }
+            codepoint = 0;
+        }
+        else if (utf8_state == S_RJCT) {
+#ifdef GHC_RAISE_UNICODE_ERRORS
+            throw filesystem_error("Illegal byte sequence for unicode character.", utf8String, std::make_error_code(std::errc::illegal_byte_sequence));
+#else
+            result += static_cast<typename StringType::value_type>(0xfffd);
+            utf8_state = S_STRT;
+            codepoint = 0;
+#endif
+        }
+    }
+    if (utf8_state) {
+#ifdef GHC_RAISE_UNICODE_ERRORS
+        throw filesystem_error("Illegal byte sequence for unicode character.", utf8String, std::make_error_code(std::errc::illegal_byte_sequence));
+#else
+        result += static_cast<typename StringType::value_type>(0xfffd);
+#endif
+    }
+    return result;
+}
+
+template <class StringType, class Utf8String, typename std::enable_if<path::_is_basic_string<Utf8String>::value && (sizeof(typename Utf8String::value_type) == 1) && (sizeof(typename StringType::value_type) == 4)>::type* = nullptr>
+inline StringType fromUtf8(const Utf8String& utf8String, const typename StringType::allocator_type& alloc = typename StringType::allocator_type())
+{
+    StringType result(alloc);
+    result.reserve(utf8String.length());
+    auto iter = utf8String.cbegin();
+    unsigned utf8_state = S_STRT;
+    std::uint32_t codepoint = 0;
+    while (iter < utf8String.cend()) {
+        if ((utf8_state = consumeUtf8Fragment(utf8_state, static_cast<uint8_t>(*iter++), codepoint)) == S_STRT) {
+            result += static_cast<typename StringType::value_type>(codepoint);
+            codepoint = 0;
+        }
+        else if (utf8_state == S_RJCT) {
+#ifdef GHC_RAISE_UNICODE_ERRORS
+            throw filesystem_error("Illegal byte sequence for unicode character.", utf8String, std::make_error_code(std::errc::illegal_byte_sequence));
+#else
+            result += static_cast<typename StringType::value_type>(0xfffd);
+            utf8_state = S_STRT;
+            codepoint = 0;
+#endif
+        }
+    }
+    if (utf8_state) {
+#ifdef GHC_RAISE_UNICODE_ERRORS
+        throw filesystem_error("Illegal byte sequence for unicode character.", utf8String, std::make_error_code(std::errc::illegal_byte_sequence));
+#else
+        result += static_cast<typename StringType::value_type>(0xfffd);
+#endif
+    }
+    return result;
+}
+
+template <class StringType, typename charT, std::size_t N>
+inline StringType fromUtf8(const charT (&utf8String)[N])
+{
+#ifdef GHC_WITH_STRING_VIEW
+    return fromUtf8<StringType>(basic_string_view<charT>(utf8String, N - 1));
+#else
+    return fromUtf8<StringType>(std::basic_string<charT>(utf8String, N - 1));
+#endif
+}
+
+template <typename strT, typename std::enable_if<path::_is_basic_string<strT>::value && (sizeof(typename strT::value_type) == 1), int>::type size = 1>
+inline std::string toUtf8(const strT& unicodeString)
+{
+    return std::string(unicodeString.begin(), unicodeString.end());
+}
+
+template <typename strT, typename std::enable_if<path::_is_basic_string<strT>::value && (sizeof(typename strT::value_type) == 2), int>::type size = 2>
+inline std::string toUtf8(const strT& unicodeString)
+{
+    std::string result;
+    for (auto iter = unicodeString.begin(); iter != unicodeString.end(); ++iter) {
+        char32_t c = *iter;
+        if (is_surrogate(c)) {
+            ++iter;
+            if (iter != unicodeString.end() && is_high_surrogate(c) && is_low_surrogate(*iter)) {
+                appendUTF8(result, (char32_t(c) << 10) + *iter - 0x35fdc00);
+            }
+            else {
+#ifdef GHC_RAISE_UNICODE_ERRORS
+                throw filesystem_error("Illegal code point for unicode character.", result, std::make_error_code(std::errc::illegal_byte_sequence));
+#else
+                appendUTF8(result, 0xfffd);
+                if (iter == unicodeString.end()) {
+                    break;
+                }
+#endif
+            }
+        }
+        else {
+            appendUTF8(result, c);
+        }
+    }
+    return result;
+}
+
+template <typename strT, typename std::enable_if<path::_is_basic_string<strT>::value && (sizeof(typename strT::value_type) == 4), int>::type size = 4>
+inline std::string toUtf8(const strT& unicodeString)
+{
+    std::string result;
+    for (auto c : unicodeString) {
+        appendUTF8(result, static_cast<uint32_t>(c));
+    }
+    return result;
+}
+
+template <typename charT>
+inline std::string toUtf8(const charT* unicodeString)
+{
+#ifdef GHC_WITH_STRING_VIEW
+    return toUtf8(basic_string_view<charT, std::char_traits<charT>>(unicodeString));
+#else
+    return toUtf8(std::basic_string<charT, std::char_traits<charT>>(unicodeString));
+#endif
+}
+
+#ifdef GHC_USE_WCHAR_T
+template <class StringType, class WString, typename std::enable_if<path::_is_basic_string<WString>::value && (sizeof(typename WString::value_type) == 2) && (sizeof(typename StringType::value_type) == 1), bool>::type = false>
+inline StringType fromWChar(const WString& wString, const typename StringType::allocator_type& alloc = typename StringType::allocator_type())
+{
+    auto temp = toUtf8(wString);
+    return StringType(temp.begin(), temp.end(), alloc);
+}
+
+template <class StringType, class WString, typename std::enable_if<path::_is_basic_string<WString>::value && (sizeof(typename WString::value_type) == 2) && (sizeof(typename StringType::value_type) == 2), bool>::type = false>
+inline StringType fromWChar(const WString& wString, const typename StringType::allocator_type& alloc = typename StringType::allocator_type())
+{
+    return StringType(wString.begin(), wString.end(), alloc);
+}
+
+template <class StringType, class WString, typename std::enable_if<path::_is_basic_string<WString>::value && (sizeof(typename WString::value_type) == 2) && (sizeof(typename StringType::value_type) == 4), bool>::type = false>
+inline StringType fromWChar(const WString& wString, const typename StringType::allocator_type& alloc = typename StringType::allocator_type())
+{
+    auto temp = toUtf8(wString);
+    return fromUtf8<StringType>(temp, alloc);
+}
+
+template <typename strT, typename std::enable_if<path::_is_basic_string<strT>::value && (sizeof(typename strT::value_type) == 1), bool>::type = false>
+inline std::wstring toWChar(const strT& unicodeString)
+{
+    return fromUtf8<std::wstring>(unicodeString);
+}
+
+template <typename strT, typename std::enable_if<path::_is_basic_string<strT>::value && (sizeof(typename strT::value_type) == 2), bool>::type = false>
+inline std::wstring toWChar(const strT& unicodeString)
+{
+    return std::wstring(unicodeString.begin(), unicodeString.end());
+}
+
+template <typename strT, typename std::enable_if<path::_is_basic_string<strT>::value && (sizeof(typename strT::value_type) == 4), bool>::type = false>
+inline std::wstring toWChar(const strT& unicodeString)
+{
+    auto temp = toUtf8(unicodeString);
+    return fromUtf8<std::wstring>(temp);
+}
+
+template <typename charT>
+inline std::wstring toWChar(const charT* unicodeString)
+{
+#ifdef GHC_WITH_STRING_VIEW
+    return toWChar(basic_string_view<charT, std::char_traits<charT>>(unicodeString));
+#else
+    return toWChar(std::basic_string<charT, std::char_traits<charT>>(unicodeString));
+#endif
+}
+#endif  // GHC_USE_WCHAR_T
+
+}  // namespace detail
+
+#ifdef GHC_EXPAND_IMPL
+
+namespace detail {
+
+template <typename strT, typename std::enable_if<path::_is_basic_string<strT>::value, bool>::type = true>
+GHC_INLINE bool startsWith(const strT& what, const strT& with)
+{
+    return with.length() <= what.length() && equal(with.begin(), with.end(), what.begin());
+}
+
+template <typename strT, typename std::enable_if<path::_is_basic_string<strT>::value, bool>::type = true>
+GHC_INLINE bool endsWith(const strT& what, const strT& with)
+{
+    return with.length() <= what.length() && what.compare(what.length() - with.length(), with.size(), with) == 0;
+}
+
+}  // namespace detail
+
+GHC_INLINE void path::check_long_path()
+{
+#if defined(GHC_OS_WINDOWS) && defined(GHC_WIN_AUTO_PREFIX_LONG_PATH)
+    if (is_absolute() && _path.length() >= MAX_PATH - 12 && !detail::startsWith(_path, impl_string_type(GHC_PLATFORM_LITERAL("\\\\?\\")))) {
+        postprocess_path_with_format(native_format);
+    }
+#endif
+}
+
+GHC_INLINE void path::postprocess_path_with_format(path::format fmt)
+{
+#ifdef GHC_RAISE_UNICODE_ERRORS
+    if (!detail::validUtf8(_path)) {
+        path t;
+        t._path = _path;
+        throw filesystem_error("Illegal byte sequence for unicode character.", t, std::make_error_code(std::errc::illegal_byte_sequence));
+    }
+#endif
+    switch (fmt) {
+#ifdef GHC_OS_WINDOWS
+        case path::native_format:
+        case path::auto_format:
+        case path::generic_format:
+            for (auto& c : _path) {
+                if (c == generic_separator) {
+                    c = preferred_separator;
+                }
+            }
+#ifdef GHC_WIN_AUTO_PREFIX_LONG_PATH
+            if (is_absolute() && _path.length() >= MAX_PATH - 12 && !detail::startsWith(_path, impl_string_type(GHC_PLATFORM_LITERAL("\\\\?\\")))) {
+                _path = GHC_PLATFORM_LITERAL("\\\\?\\") + _path;
+            }
+#endif
+            handle_prefixes();
+            break;
+#else
+        case path::auto_format:
+        case path::native_format:
+        case path::generic_format:
+            // nothing to do
+            break;
+#endif
+    }
+    if (_path.length() > _prefixLength + 2 && _path[_prefixLength] == preferred_separator && _path[_prefixLength + 1] == preferred_separator && _path[_prefixLength + 2] != preferred_separator) {
+        impl_string_type::iterator new_end = std::unique(_path.begin() + static_cast<string_type::difference_type>(_prefixLength) + 2, _path.end(), [](path::value_type lhs, path::value_type rhs) { return lhs == rhs && lhs == preferred_separator; });
+        _path.erase(new_end, _path.end());
+    }
+    else {
+        impl_string_type::iterator new_end = std::unique(_path.begin() + static_cast<string_type::difference_type>(_prefixLength), _path.end(), [](path::value_type lhs, path::value_type rhs) { return lhs == rhs && lhs == preferred_separator; });
+        _path.erase(new_end, _path.end());
+    }
+}
+
+#endif  // GHC_EXPAND_IMPL
+
+template <class Source, typename>
+inline path::path(const Source& source, format fmt)
+#ifdef GHC_USE_WCHAR_T
+    : _path(detail::toWChar(source))
+#else
+    : _path(detail::toUtf8(source))
+#endif
+{
+    postprocess_path_with_format(fmt);
+}
+
+template <class Source, typename>
+inline path u8path(const Source& source)
+{
+    return path(source);
+}
+template <class InputIterator>
+inline path u8path(InputIterator first, InputIterator last)
+{
+    return path(first, last);
+}
+
+template <class InputIterator>
+inline path::path(InputIterator first, InputIterator last, format fmt)
+    : path(std::basic_string<typename std::iterator_traits<InputIterator>::value_type>(first, last), fmt)
+{
+    // delegated
+}
+
+#ifdef GHC_EXPAND_IMPL
+
+namespace detail {
+
+GHC_INLINE bool equals_simple_insensitive(const path::value_type* str1, const path::value_type* str2)
+{
+#ifdef GHC_OS_WINDOWS
+#ifdef __GNUC__
+    while (::tolower((unsigned char)*str1) == ::tolower((unsigned char)*str2++)) {
+        if (*str1++ == 0)
+            return true;
+    }
+    return false;
+#else  // __GNUC__
+#ifdef GHC_USE_WCHAR_T
+    return 0 == ::_wcsicmp(str1, str2);
+#else   // GHC_USE_WCHAR_T
+    return 0 == ::_stricmp(str1, str2);
+#endif  // GHC_USE_WCHAR_T
+#endif  // __GNUC__
+#else   // GHC_OS_WINDOWS
+    return 0 == ::strcasecmp(str1, str2);
+#endif  // GHC_OS_WINDOWS
+}
+
+GHC_INLINE int compare_simple_insensitive(const path::value_type* str1, size_t len1, const path::value_type* str2, size_t len2)
+{
+    while (len1 > 0 && len2 > 0 && ::tolower(static_cast<unsigned char>(*str1)) == ::tolower(static_cast<unsigned char>(*str2))) {
+        --len1;
+        --len2;
+        ++str1;
+        ++str2;
+    }
+    if (len1 && len2) {
+        return *str1 < *str2 ? -1 : 1;
+    }
+    if (len1 == 0 && len2 == 0) {
+        return 0;
+    }
+    return len1 == 0 ? -1 : 1;
+}
+
+GHC_INLINE const char* strerror_adapter(char* gnu, char*)
+{
+    return gnu;
+}
+
+GHC_INLINE const char* strerror_adapter(int posix, char* buffer)
+{
+    if (posix) {
+        return "Error in strerror_r!";
+    }
+    return buffer;
+}
+
+template <typename ErrorNumber>
+GHC_INLINE std::string systemErrorText(ErrorNumber code = 0)
+{
+#if defined(GHC_OS_WINDOWS)
+    LPVOID msgBuf;
+    DWORD dw = code ? static_cast<DWORD>(code) : ::GetLastError();
+    FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, dw, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPWSTR)&msgBuf, 0, NULL);
+    std::string msg = toUtf8(std::wstring((LPWSTR)msgBuf));
+    LocalFree(msgBuf);
+    return msg;
+#else
+    char buffer[512];
+    return strerror_adapter(strerror_r(code ? code : errno, buffer, sizeof(buffer)), buffer);
+#endif
+}
+
+#ifdef GHC_OS_WINDOWS
+using CreateSymbolicLinkW_fp = BOOLEAN(WINAPI*)(LPCWSTR, LPCWSTR, DWORD);
+using CreateHardLinkW_fp = BOOLEAN(WINAPI*)(LPCWSTR, LPCWSTR, LPSECURITY_ATTRIBUTES);
+
+GHC_INLINE void create_symlink(const path& target_name, const path& new_symlink, bool to_directory, std::error_code& ec)
+{
+    std::error_code tec;
+    auto fs = status(target_name, tec);
+    if ((fs.type() == file_type::directory && !to_directory) || (fs.type() == file_type::regular && to_directory)) {
+        ec = detail::make_error_code(detail::portable_error::not_supported);
+        return;
+    }
+#if defined(__GNUC__) && __GNUC__ >= 8
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-function-type"
+#endif
+    static CreateSymbolicLinkW_fp api_call = reinterpret_cast<CreateSymbolicLinkW_fp>(GetProcAddress(GetModuleHandleW(L"kernel32.dll"), "CreateSymbolicLinkW"));
+#if defined(__GNUC__) && __GNUC__ >= 8
+#pragma GCC diagnostic pop
+#endif
+    if (api_call) {
+        if (api_call(GHC_NATIVEWP(new_symlink), GHC_NATIVEWP(target_name), to_directory ? 1 : 0) == 0) {
+            auto result = ::GetLastError();
+            if (result == ERROR_PRIVILEGE_NOT_HELD && api_call(GHC_NATIVEWP(new_symlink), GHC_NATIVEWP(target_name), to_directory ? 3 : 2) != 0) {
+                return;
+            }
+            ec = detail::make_system_error(result);
+        }
+    }
+    else {
+        ec = detail::make_system_error(ERROR_NOT_SUPPORTED);
+    }
+}
+
+GHC_INLINE void create_hardlink(const path& target_name, const path& new_hardlink, std::error_code& ec)
+{
+#if defined(__GNUC__) && __GNUC__ >= 8
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-function-type"
+#endif
+    static CreateHardLinkW_fp api_call = reinterpret_cast<CreateHardLinkW_fp>(GetProcAddress(GetModuleHandleW(L"kernel32.dll"), "CreateHardLinkW"));
+#if defined(__GNUC__) && __GNUC__ >= 8
+#pragma GCC diagnostic pop
+#endif
+    if (api_call) {
+        if (api_call(GHC_NATIVEWP(new_hardlink), GHC_NATIVEWP(target_name), NULL) == 0) {
+            ec = detail::make_system_error();
+        }
+    }
+    else {
+        ec = detail::make_system_error(ERROR_NOT_SUPPORTED);
+    }
+}
+
+GHC_INLINE path getFullPathName(const wchar_t* p, std::error_code& ec)
+{
+    ULONG size = ::GetFullPathNameW(p, 0, 0, 0);
+    if (size) {
+        std::vector<wchar_t> buf(size, 0);
+        ULONG s2 = GetFullPathNameW(p, size, buf.data(), nullptr);
+        if (s2 && s2 < size) {
+            return path(std::wstring(buf.data(), s2));
+        }
+    }
+    ec = detail::make_system_error();
+    return path();
+}
+
+#else
+GHC_INLINE void create_symlink(const path& target_name, const path& new_symlink, bool, std::error_code& ec)
+{
+    if (::symlink(target_name.c_str(), new_symlink.c_str()) != 0) {
+        ec = detail::make_system_error();
+    }
+}
+
+#ifndef GHC_OS_WEB
+GHC_INLINE void create_hardlink(const path& target_name, const path& new_hardlink, std::error_code& ec)
+{
+    if (::link(target_name.c_str(), new_hardlink.c_str()) != 0) {
+        ec = detail::make_system_error();
+    }
+}
+#endif
+#endif
+
+template <typename T>
+GHC_INLINE file_status file_status_from_st_mode(T mode)
+{
+#ifdef GHC_OS_WINDOWS
+    file_type ft = file_type::unknown;
+    if ((mode & _S_IFDIR) == _S_IFDIR) {
+        ft = file_type::directory;
+    }
+    else if ((mode & _S_IFREG) == _S_IFREG) {
+        ft = file_type::regular;
+    }
+    else if ((mode & _S_IFCHR) == _S_IFCHR) {
+        ft = file_type::character;
+    }
+    perms prms = static_cast<perms>(mode & 0xfff);
+    return file_status(ft, prms);
+#else
+    file_type ft = file_type::unknown;
+    if (S_ISDIR(mode)) {
+        ft = file_type::directory;
+    }
+    else if (S_ISREG(mode)) {
+        ft = file_type::regular;
+    }
+    else if (S_ISCHR(mode)) {
+        ft = file_type::character;
+    }
+    else if (S_ISBLK(mode)) {
+        ft = file_type::block;
+    }
+    else if (S_ISFIFO(mode)) {
+        ft = file_type::fifo;
+    }
+    else if (S_ISLNK(mode)) {
+        ft = file_type::symlink;
+    }
+    else if (S_ISSOCK(mode)) {
+        ft = file_type::socket;
+    }
+    perms prms = static_cast<perms>(mode & 0xfff);
+    return file_status(ft, prms);
+#endif
+}
+
+#ifdef GHC_OS_WINDOWS
+
+class unique_handle
+{
+public:
+    typedef HANDLE element_type;
+
+    unique_handle() noexcept
+        : _handle(INVALID_HANDLE_VALUE)
+    {
+    }
+    explicit unique_handle(element_type h) noexcept
+        : _handle(h)
+    {
+    }
+    unique_handle(unique_handle&& u) noexcept
+        : _handle(u.release())
+    {
+    }
+    ~unique_handle() { reset(); }
+    unique_handle& operator=(unique_handle&& u) noexcept
+    {
+        reset(u.release());
+        return *this;
+    }
+    element_type get() const noexcept { return _handle; }
+    explicit operator bool() const noexcept { return _handle != INVALID_HANDLE_VALUE; }
+    element_type release() noexcept
+    {
+        element_type tmp = _handle;
+        _handle = INVALID_HANDLE_VALUE;
+        return tmp;
+    }
+    void reset(element_type h = INVALID_HANDLE_VALUE) noexcept
+    {
+        element_type tmp = _handle;
+        _handle = h;
+        if (tmp != INVALID_HANDLE_VALUE) {
+            CloseHandle(tmp);
+        }
+    }
+    void swap(unique_handle& u) noexcept { std::swap(_handle, u._handle); }
+
+private:
+    element_type _handle;
+};
+
+#ifndef REPARSE_DATA_BUFFER_HEADER_SIZE
+typedef struct _REPARSE_DATA_BUFFER
+{
+    ULONG ReparseTag;
+    USHORT ReparseDataLength;
+    USHORT Reserved;
+    union
+    {
+        struct
+        {
+            USHORT SubstituteNameOffset;
+            USHORT SubstituteNameLength;
+            USHORT PrintNameOffset;
+            USHORT PrintNameLength;
+            ULONG Flags;
+            WCHAR PathBuffer[1];
+        } SymbolicLinkReparseBuffer;
+        struct
+        {
+            USHORT SubstituteNameOffset;
+            USHORT SubstituteNameLength;
+            USHORT PrintNameOffset;
+            USHORT PrintNameLength;
+            WCHAR PathBuffer[1];
+        } MountPointReparseBuffer;
+        struct
+        {
+            UCHAR DataBuffer[1];
+        } GenericReparseBuffer;
+    } DUMMYUNIONNAME;
+} REPARSE_DATA_BUFFER;
+#ifndef MAXIMUM_REPARSE_DATA_BUFFER_SIZE
+#define MAXIMUM_REPARSE_DATA_BUFFER_SIZE (16 * 1024)
+#endif
+#endif
+
+template <class T>
+struct free_deleter
+{
+    void operator()(T* p) const { std::free(p); }
+};
+
+GHC_INLINE std::unique_ptr<REPARSE_DATA_BUFFER, free_deleter<REPARSE_DATA_BUFFER>> getReparseData(const path& p, std::error_code& ec)
+{
+    unique_handle file(CreateFileW(GHC_NATIVEWP(p), 0, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, 0, OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, 0));
+    if (!file) {
+        ec = detail::make_system_error();
+        return nullptr;
+    }
+
+    std::unique_ptr<REPARSE_DATA_BUFFER, free_deleter<REPARSE_DATA_BUFFER>> reparseData(reinterpret_cast<REPARSE_DATA_BUFFER*>(std::calloc(1, MAXIMUM_REPARSE_DATA_BUFFER_SIZE)));
+    ULONG bufferUsed;
+    if (DeviceIoControl(file.get(), FSCTL_GET_REPARSE_POINT, 0, 0, reparseData.get(), MAXIMUM_REPARSE_DATA_BUFFER_SIZE, &bufferUsed, 0)) {
+        return reparseData;
+    }
+    else {
+        ec = detail::make_system_error();
+    }
+    return nullptr;
+}
+#endif
+
+GHC_INLINE path resolveSymlink(const path& p, std::error_code& ec)
+{
+#ifdef GHC_OS_WINDOWS
+    path result;
+    auto reparseData = detail::getReparseData(p, ec);
+    if (!ec) {
+        if (reparseData && IsReparseTagMicrosoft(reparseData->ReparseTag)) {
+            switch (reparseData->ReparseTag) {
+                case IO_REPARSE_TAG_SYMLINK: {
+                    auto printName = std::wstring(&reparseData->SymbolicLinkReparseBuffer.PathBuffer[reparseData->SymbolicLinkReparseBuffer.PrintNameOffset / sizeof(WCHAR)], reparseData->SymbolicLinkReparseBuffer.PrintNameLength / sizeof(WCHAR));
+                    auto substituteName =
+                        std::wstring(&reparseData->SymbolicLinkReparseBuffer.PathBuffer[reparseData->SymbolicLinkReparseBuffer.SubstituteNameOffset / sizeof(WCHAR)], reparseData->SymbolicLinkReparseBuffer.SubstituteNameLength / sizeof(WCHAR));
+                    if (detail::endsWith(substituteName, printName) && detail::startsWith(substituteName, std::wstring(L"\\??\\"))) {
+                        result = printName;
+                    }
+                    else {
+                        result = substituteName;
+                    }
+                    if (reparseData->SymbolicLinkReparseBuffer.Flags & 0x1 /*SYMLINK_FLAG_RELATIVE*/) {
+                        result = p.parent_path() / result;
+                    }
+                    break;
+                }
+                case IO_REPARSE_TAG_MOUNT_POINT:
+                    result = detail::getFullPathName(GHC_NATIVEWP(p), ec);
+                    // result = std::wstring(&reparseData->MountPointReparseBuffer.PathBuffer[reparseData->MountPointReparseBuffer.SubstituteNameOffset / sizeof(WCHAR)], reparseData->MountPointReparseBuffer.SubstituteNameLength / sizeof(WCHAR));
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+    return result;
+#else
+    size_t bufferSize = 256;
+    while (true) {
+        std::vector<char> buffer(bufferSize, static_cast<char>(0));
+        auto rc = ::readlink(p.c_str(), buffer.data(), buffer.size());
+        if (rc < 0) {
+            ec = detail::make_system_error();
+            return path();
+        }
+        else if (rc < static_cast<int>(bufferSize)) {
+            return path(std::string(buffer.data(), static_cast<std::string::size_type>(rc)));
+        }
+        bufferSize *= 2;
+    }
+    return path();
+#endif
+}
+
+#ifdef GHC_OS_WINDOWS
+GHC_INLINE time_t timeFromFILETIME(const FILETIME& ft)
+{
+    ULARGE_INTEGER ull;
+    ull.LowPart = ft.dwLowDateTime;
+    ull.HighPart = ft.dwHighDateTime;
+    return static_cast<time_t>(ull.QuadPart / 10000000ULL - 11644473600ULL);
+}
+
+GHC_INLINE void timeToFILETIME(time_t t, FILETIME& ft)
+{
+    LONGLONG ll;
+    ll = Int32x32To64(t, 10000000) + 116444736000000000;
+    ft.dwLowDateTime = static_cast<DWORD>(ll);
+    ft.dwHighDateTime = static_cast<DWORD>(ll >> 32);
+}
+
+template <typename INFO>
+GHC_INLINE uintmax_t hard_links_from_INFO(const INFO* info)
+{
+    return static_cast<uintmax_t>(-1);
+}
+
+template <>
+GHC_INLINE uintmax_t hard_links_from_INFO<BY_HANDLE_FILE_INFORMATION>(const BY_HANDLE_FILE_INFORMATION* info)
+{
+    return info->nNumberOfLinks;
+}
+
+template <typename INFO>
+GHC_INLINE DWORD reparse_tag_from_INFO(const INFO*)
+{
+    return 0;
+}
+
+template <>
+GHC_INLINE DWORD reparse_tag_from_INFO(const WIN32_FIND_DATAW* info)
+{
+    return info->dwReserved0;
+}
+
+template <typename INFO>
+GHC_INLINE file_status status_from_INFO(const path& p, const INFO* info, std::error_code& ec, uintmax_t* sz = nullptr, time_t* lwt = nullptr)
+{
+    file_type ft = file_type::unknown;
+    if (sizeof(INFO) == sizeof(WIN32_FIND_DATAW)) {
+        if (detail::reparse_tag_from_INFO(info) == IO_REPARSE_TAG_SYMLINK) {
+            ft = file_type::symlink;
+        }
+    }
+    else {
+        if ((info->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
+            auto reparseData = detail::getReparseData(p, ec);
+            if (!ec && reparseData && IsReparseTagMicrosoft(reparseData->ReparseTag) && reparseData->ReparseTag == IO_REPARSE_TAG_SYMLINK) {
+                ft = file_type::symlink;
+            }
+        }
+    }
+    if (ft == file_type::unknown) {
+        if ((info->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) {
+            ft = file_type::directory;
+        }
+        else {
+            ft = file_type::regular;
+        }
+    }
+    perms prms = perms::owner_read | perms::group_read | perms::others_read;
+    if (!(info->dwFileAttributes & FILE_ATTRIBUTE_READONLY)) {
+        prms = prms | perms::owner_write | perms::group_write | perms::others_write;
+    }
+    if (has_executable_extension(p)) {
+        prms = prms | perms::owner_exec | perms::group_exec | perms::others_exec;
+    }
+    if (sz) {
+        *sz = static_cast<uintmax_t>(info->nFileSizeHigh) << (sizeof(info->nFileSizeHigh) * 8) | info->nFileSizeLow;
+    }
+    if (lwt) {
+        *lwt = detail::timeFromFILETIME(info->ftLastWriteTime);
+    }
+    return file_status(ft, prms);
+}
+
+#endif
+
+GHC_INLINE bool is_not_found_error(std::error_code& ec)
+{
+#ifdef GHC_OS_WINDOWS
+    return ec.value() == ERROR_FILE_NOT_FOUND || ec.value() == ERROR_PATH_NOT_FOUND || ec.value() == ERROR_INVALID_NAME;
+#else
+    return ec.value() == ENOENT || ec.value() == ENOTDIR;
+#endif
+}
+
+GHC_INLINE file_status symlink_status_ex(const path& p, std::error_code& ec, uintmax_t* sz = nullptr, uintmax_t* nhl = nullptr, time_t* lwt = nullptr) noexcept
+{
+#ifdef GHC_OS_WINDOWS
+    file_status fs;
+    WIN32_FILE_ATTRIBUTE_DATA attr;
+    if (!GetFileAttributesExW(GHC_NATIVEWP(p), GetFileExInfoStandard, &attr)) {
+        ec = detail::make_system_error();
+    }
+    else {
+        ec.clear();
+        fs = detail::status_from_INFO(p, &attr, ec, sz, lwt);
+        if (nhl) {
+            *nhl = 0;
+        }
+    }
+    if (detail::is_not_found_error(ec)) {
+        return file_status(file_type::not_found);
+    }
+    return ec ? file_status(file_type::none) : fs;
+#else
+    (void)sz;
+    (void)nhl;
+    (void)lwt;
+    struct ::stat fs;
+    auto result = ::lstat(p.c_str(), &fs);
+    if (result == 0) {
+        ec.clear();
+        file_status f_s = detail::file_status_from_st_mode(fs.st_mode);
+        return f_s;
+    }
+    ec = detail::make_system_error();
+    if (detail::is_not_found_error(ec)) {
+        return file_status(file_type::not_found, perms::unknown);
+    }
+    return file_status(file_type::none);
+#endif
+}
+
+GHC_INLINE file_status status_ex(const path& p, std::error_code& ec, file_status* sls = nullptr, uintmax_t* sz = nullptr, uintmax_t* nhl = nullptr, time_t* lwt = nullptr, int recurse_count = 0) noexcept
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    if (recurse_count > 16) {
+        ec = detail::make_system_error(0x2A9 /*ERROR_STOPPED_ON_SYMLINK*/);
+        return file_status(file_type::unknown);
+    }
+    WIN32_FILE_ATTRIBUTE_DATA attr;
+    if (!::GetFileAttributesExW(GHC_NATIVEWP(p), GetFileExInfoStandard, &attr)) {
+        ec = detail::make_system_error();
+    }
+    else if (attr.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
+        auto reparseData = detail::getReparseData(p, ec);
+        if (!ec && reparseData && IsReparseTagMicrosoft(reparseData->ReparseTag) && reparseData->ReparseTag == IO_REPARSE_TAG_SYMLINK) {
+            path target = resolveSymlink(p, ec);
+            file_status result;
+            if (!ec && !target.empty()) {
+                if (sls) {
+                    *sls = status_from_INFO(p, &attr, ec);
+                }
+                return detail::status_ex(target, ec, nullptr, sz, nhl, lwt, recurse_count + 1);
+            }
+            return file_status(file_type::unknown);
+        }
+    }
+    if (ec) {
+        if (detail::is_not_found_error(ec)) {
+            return file_status(file_type::not_found);
+        }
+        return file_status(file_type::none);
+    }
+    if (nhl) {
+        *nhl = 0;
+    }
+    return detail::status_from_INFO(p, &attr, ec, sz, lwt);
+#else
+    (void)recurse_count;
+    struct ::stat st;
+    auto result = ::lstat(p.c_str(), &st);
+    if (result == 0) {
+        ec.clear();
+        file_status fs = detail::file_status_from_st_mode(st.st_mode);
+        if (sls) {
+            *sls = fs;
+        }
+        if (fs.type() == file_type::symlink) {
+            result = ::stat(p.c_str(), &st);
+            if (result == 0) {
+                fs = detail::file_status_from_st_mode(st.st_mode);
+            }
+            else {
+                ec = detail::make_system_error();
+                if (detail::is_not_found_error(ec)) {
+                    return file_status(file_type::not_found, perms::unknown);
+                }
+                return file_status(file_type::none);
+            }
+        }
+        if (sz) {
+            *sz = static_cast<uintmax_t>(st.st_size);
+        }
+        if (nhl) {
+            *nhl = st.st_nlink;
+        }
+        if (lwt) {
+            *lwt = st.st_mtime;
+        }
+        return fs;
+    }
+    else {
+        ec = detail::make_system_error();
+        if (detail::is_not_found_error(ec)) {
+            return file_status(file_type::not_found, perms::unknown);
+        }
+        return file_status(file_type::none);
+    }
+#endif
+}
+
+}  // namespace detail
+
+GHC_INLINE u8arguments::u8arguments(int& argc, char**& argv)
+    : _argc(argc)
+    , _argv(argv)
+    , _refargc(argc)
+    , _refargv(argv)
+    , _isvalid(false)
+{
+#ifdef GHC_OS_WINDOWS
+    LPWSTR* p;
+    p = ::CommandLineToArgvW(::GetCommandLineW(), &argc);
+    _args.reserve(static_cast<size_t>(argc));
+    _argp.reserve(static_cast<size_t>(argc));
+    for (size_t i = 0; i < static_cast<size_t>(argc); ++i) {
+        _args.push_back(detail::toUtf8(std::wstring(p[i])));
+        _argp.push_back((char*)_args[i].data());
+    }
+    argv = _argp.data();
+    ::LocalFree(p);
+    _isvalid = true;
+#else
+    std::setlocale(LC_ALL, "");
+#if defined(__ANDROID__) && __ANDROID_API__ < 26
+    _isvalid = true;
+#else
+    if (detail::equals_simple_insensitive(::nl_langinfo(CODESET), "UTF-8")) {
+        _isvalid = true;
+    }
+#endif
+#endif
+}
+
+//-----------------------------------------------------------------------------
+// [fs.path.construct] constructors and destructor
+
+GHC_INLINE path::path() noexcept {}
+
+GHC_INLINE path::path(const path& p)
+    : _path(p._path)
+#if defined(GHC_OS_WINDOWS) && defined(GHC_WIN_AUTO_PREFIX_LONG_PATH)
+    , _prefixLength(p._prefixLength)
+#endif
+{
+}
+
+GHC_INLINE path::path(path&& p) noexcept
+    : _path(std::move(p._path))
+#if defined(GHC_OS_WINDOWS) && defined(GHC_WIN_AUTO_PREFIX_LONG_PATH)
+    , _prefixLength(p._prefixLength)
+#endif
+{
+}
+
+GHC_INLINE path::path(string_type&& source, format fmt)
+    : _path(std::move(source))
+{
+    postprocess_path_with_format(fmt);
+}
+
+#endif  // GHC_EXPAND_IMPL
+
+#ifdef GHC_WITH_EXCEPTIONS
+template <class Source, typename>
+inline path::path(const Source& source, const std::locale& loc, format fmt)
+    : path(source, fmt)
+{
+    std::string locName = loc.name();
+    if (!(locName.length() >= 5 && (locName.substr(locName.length() - 5) == "UTF-8" || locName.substr(locName.length() - 5) == "utf-8"))) {
+        throw filesystem_error("This implementation only supports UTF-8 locales!", path(_path), detail::make_error_code(detail::portable_error::not_supported));
+    }
+}
+
+template <class InputIterator>
+inline path::path(InputIterator first, InputIterator last, const std::locale& loc, format fmt)
+    : path(std::basic_string<typename std::iterator_traits<InputIterator>::value_type>(first, last), fmt)
+{
+    std::string locName = loc.name();
+    if (!(locName.length() >= 5 && (locName.substr(locName.length() - 5) == "UTF-8" || locName.substr(locName.length() - 5) == "utf-8"))) {
+        throw filesystem_error("This implementation only supports UTF-8 locales!", path(_path), detail::make_error_code(detail::portable_error::not_supported));
+    }
+}
+#endif
+
+#ifdef GHC_EXPAND_IMPL
+
+GHC_INLINE path::~path() {}
+
+//-----------------------------------------------------------------------------
+// [fs.path.assign] assignments
+
+GHC_INLINE path& path::operator=(const path& p)
+{
+    _path = p._path;
+#if defined(GHC_OS_WINDOWS) && defined(GHC_WIN_AUTO_PREFIX_LONG_PATH)
+    _prefixLength = p._prefixLength;
+#endif
+    return *this;
+}
+
+GHC_INLINE path& path::operator=(path&& p) noexcept
+{
+    _path = std::move(p._path);
+#if defined(GHC_OS_WINDOWS) && defined(GHC_WIN_AUTO_PREFIX_LONG_PATH)
+    _prefixLength = p._prefixLength;
+#endif
+    return *this;
+}
+
+GHC_INLINE path& path::operator=(path::string_type&& source)
+{
+    return assign(source);
+}
+
+GHC_INLINE path& path::assign(path::string_type&& source)
+{
+    _path = std::move(source);
+    postprocess_path_with_format(native_format);
+    return *this;
+}
+
+#endif  // GHC_EXPAND_IMPL
+
+template <class Source>
+inline path& path::operator=(const Source& source)
+{
+    return assign(source);
+}
+
+template <class Source>
+inline path& path::assign(const Source& source)
+{
+#ifdef GHC_USE_WCHAR_T
+    _path.assign(detail::toWChar(source));
+#else
+    _path.assign(detail::toUtf8(source));
+#endif
+    postprocess_path_with_format(native_format);
+    return *this;
+}
+
+template <>
+inline path& path::assign<path>(const path& source)
+{
+    _path = source._path;
+#if defined(GHC_OS_WINDOWS) && defined(GHC_WIN_AUTO_PREFIX_LONG_PATH)
+    _prefixLength = source._prefixLength;
+#endif
+    return *this;
+}
+
+template <class InputIterator>
+inline path& path::assign(InputIterator first, InputIterator last)
+{
+    _path.assign(first, last);
+    postprocess_path_with_format(native_format);
+    return *this;
+}
+
+#ifdef GHC_EXPAND_IMPL
+
+//-----------------------------------------------------------------------------
+// [fs.path.append] appends
+
+GHC_INLINE path& path::operator/=(const path& p)
+{
+    if (p.empty()) {
+        // was: if ((!has_root_directory() && is_absolute()) || has_filename())
+        if (!_path.empty() && _path[_path.length() - 1] != preferred_separator && _path[_path.length() - 1] != ':') {
+            _path += preferred_separator;
+        }
+        return *this;
+    }
+    if ((p.is_absolute() && (_path != root_name()._path || p._path != "/")) || (p.has_root_name() && p.root_name() != root_name())) {
+        assign(p);
+        return *this;
+    }
+    if (p.has_root_directory()) {
+        assign(root_name());
+    }
+    else if ((!has_root_directory() && is_absolute()) || has_filename()) {
+        _path += preferred_separator;
+    }
+    auto iter = p.begin();
+    bool first = true;
+    if (p.has_root_name()) {
+        ++iter;
+    }
+    while (iter != p.end()) {
+        if (!first && !(!_path.empty() && _path[_path.length() - 1] == preferred_separator)) {
+            _path += preferred_separator;
+        }
+        first = false;
+        _path += (*iter++).native();
+    }
+    check_long_path();
+    return *this;
+}
+
+GHC_INLINE void path::append_name(const value_type* name)
+{
+    if (_path.empty()) {
+        this->operator/=(path(name));
+    }
+    else {
+        if (_path.back() != path::preferred_separator) {
+            _path.push_back(path::preferred_separator);
+        }
+        _path += name;
+        check_long_path();
+    }
+}
+
+#endif  // GHC_EXPAND_IMPL
+
+template <class Source>
+inline path& path::operator/=(const Source& source)
+{
+    return append(source);
+}
+
+template <class Source>
+inline path& path::append(const Source& source)
+{
+    return this->operator/=(path(source));
+}
+
+template <>
+inline path& path::append<path>(const path& p)
+{
+    return this->operator/=(p);
+}
+
+template <class InputIterator>
+inline path& path::append(InputIterator first, InputIterator last)
+{
+    std::basic_string<typename std::iterator_traits<InputIterator>::value_type> part(first, last);
+    return append(part);
+}
+
+#ifdef GHC_EXPAND_IMPL
+
+//-----------------------------------------------------------------------------
+// [fs.path.concat] concatenation
+
+GHC_INLINE path& path::operator+=(const path& x)
+{
+    return concat(x._path);
+}
+
+GHC_INLINE path& path::operator+=(const string_type& x)
+{
+    return concat(x);
+}
+
+#ifdef GHC_WITH_STRING_VIEW
+GHC_INLINE path& path::operator+=(basic_string_view<value_type> x)
+{
+    return concat(x);
+}
+#endif
+
+GHC_INLINE path& path::operator+=(const value_type* x)
+{
+#ifdef GHC_WITH_STRING_VIEW
+    basic_string_view<value_type> part(x);
+#else
+    string_type part(x);
+#endif
+    return concat(part);
+}
+
+GHC_INLINE path& path::operator+=(value_type x)
+{
+#ifdef GHC_OS_WINDOWS
+    if (x == generic_separator) {
+        x = preferred_separator;
+    }
+#endif
+    if (_path.empty() || _path.back() != preferred_separator) {
+        _path += x;
+    }
+    check_long_path();
+    return *this;
+}
+
+#endif  // GHC_EXPAND_IMPL
+
+template <class Source>
+inline path::path_from_string<Source>& path::operator+=(const Source& x)
+{
+    return concat(x);
+}
+
+template <class EcharT>
+inline path::path_type_EcharT<EcharT>& path::operator+=(EcharT x)
+{
+#ifdef GHC_WITH_STRING_VIEW
+    basic_string_view<EcharT> part(&x, 1);
+#else
+    std::basic_string<EcharT> part(1, x);
+#endif
+    concat(part);
+    return *this;
+}
+
+template <class Source>
+inline path& path::concat(const Source& x)
+{
+    path p(x);
+    _path += p._path;
+    postprocess_path_with_format(native_format);
+    return *this;
+}
+template <class InputIterator>
+inline path& path::concat(InputIterator first, InputIterator last)
+{
+    _path.append(first, last);
+    postprocess_path_with_format(native_format);
+    return *this;
+}
+
+#ifdef GHC_EXPAND_IMPL
+
+//-----------------------------------------------------------------------------
+// [fs.path.modifiers] modifiers
+GHC_INLINE void path::clear() noexcept
+{
+    _path.clear();
+#if defined(GHC_OS_WINDOWS) && defined(GHC_WIN_AUTO_PREFIX_LONG_PATH)
+    _prefixLength = 0;
+#endif
+}
+
+GHC_INLINE path& path::make_preferred()
+{
+    // as this filesystem implementation only uses generic_format
+    // internally, this must be a no-op
+    return *this;
+}
+
+GHC_INLINE path& path::remove_filename()
+{
+    if (has_filename()) {
+        _path.erase(_path.size() - filename()._path.size());
+    }
+    return *this;
+}
+
+GHC_INLINE path& path::replace_filename(const path& replacement)
+{
+    remove_filename();
+    return append(replacement);
+}
+
+GHC_INLINE path& path::replace_extension(const path& replacement)
+{
+    if (has_extension()) {
+        _path.erase(_path.size() - extension()._path.size());
+    }
+    if (!replacement.empty() && replacement._path[0] != '.') {
+        _path += '.';
+    }
+    return concat(replacement);
+}
+
+GHC_INLINE void path::swap(path& rhs) noexcept
+{
+    _path.swap(rhs._path);
+#if defined(GHC_OS_WINDOWS) && defined(GHC_WIN_AUTO_PREFIX_LONG_PATH)
+    std::swap(_prefixLength, rhs._prefixLength);
+#endif
+}
+
+//-----------------------------------------------------------------------------
+// [fs.path.native.obs] native format observers
+GHC_INLINE const path::string_type& path::native() const noexcept
+{
+    return _path;
+}
+
+GHC_INLINE const path::value_type* path::c_str() const noexcept
+{
+    return native().c_str();
+}
+
+GHC_INLINE path::operator path::string_type() const
+{
+    return native();
+}
+
+#endif  // GHC_EXPAND_IMPL
+
+template <class EcharT, class traits, class Allocator>
+inline std::basic_string<EcharT, traits, Allocator> path::string(const Allocator& a) const
+{
+#ifdef GHC_USE_WCHAR_T
+    return detail::fromWChar<std::basic_string<EcharT, traits, Allocator>>(_path, a);
+#else
+    return detail::fromUtf8<std::basic_string<EcharT, traits, Allocator>>(_path, a);
+#endif
+}
+
+#ifdef GHC_EXPAND_IMPL
+
+GHC_INLINE std::string path::string() const
+{
+#ifdef GHC_USE_WCHAR_T
+    return detail::toUtf8(native());
+#else
+    return native();
+#endif
+}
+
+GHC_INLINE std::wstring path::wstring() const
+{
+#ifdef GHC_USE_WCHAR_T
+    return native();
+#else
+    return detail::fromUtf8<std::wstring>(native());
+#endif
+}
+
+#if defined(__cpp_lib_char8_t) && !defined(GHC_FILESYSTEM_ENFORCE_CPP17_API)
+GHC_INLINE std::u8string path::u8string() const
+{
+#ifdef GHC_USE_WCHAR_T
+    return std::u8string(reinterpret_cast<const char8_t*>(detail::toUtf8(native()).c_str()));
+#else
+    return std::u8string(reinterpret_cast<const char8_t*>(c_str()));
+#endif
+}
+#else
+GHC_INLINE std::string path::u8string() const
+{
+#ifdef GHC_USE_WCHAR_T
+    return detail::toUtf8(native());
+#else
+    return native();
+#endif
+}
+#endif
+
+GHC_INLINE std::u16string path::u16string() const
+{
+    // TODO: optimize
+    return detail::fromUtf8<std::u16string>(string());
+}
+
+GHC_INLINE std::u32string path::u32string() const
+{
+    // TODO: optimize
+    return detail::fromUtf8<std::u32string>(string());
+}
+
+#endif  // GHC_EXPAND_IMPL
+
+//-----------------------------------------------------------------------------
+// [fs.path.generic.obs] generic format observers
+template <class EcharT, class traits, class Allocator>
+inline std::basic_string<EcharT, traits, Allocator> path::generic_string(const Allocator& a) const
+{
+#ifdef GHC_OS_WINDOWS
+#ifdef GHC_USE_WCHAR_T
+    auto result = detail::fromWChar<std::basic_string<EcharT, traits, Allocator>, path::string_type>(_path, a);
+#else
+    auto result = detail::fromUtf8<std::basic_string<EcharT, traits, Allocator>>(_path, a);
+#endif
+    for (auto& c : result) {
+        if (c == preferred_separator) {
+            c = generic_separator;
+        }
+    }
+    return result;
+#else
+    return detail::fromUtf8<std::basic_string<EcharT, traits, Allocator>>(_path, a);
+#endif
+}
+
+#ifdef GHC_EXPAND_IMPL
+
+GHC_INLINE std::string path::generic_string() const
+{
+#ifdef GHC_OS_WINDOWS
+    return generic_string<std::string::value_type, std::string::traits_type, std::string::allocator_type>();
+#else
+    return _path;
+#endif
+}
+
+GHC_INLINE std::wstring path::generic_wstring() const
+{
+#ifdef GHC_OS_WINDOWS
+    return generic_string<std::wstring::value_type, std::wstring::traits_type, std::wstring::allocator_type>();
+#else
+    return detail::fromUtf8<std::wstring>(_path);
+#endif
+}  // namespace filesystem
+
+#if defined(__cpp_lib_char8_t) && !defined(GHC_FILESYSTEM_ENFORCE_CPP17_API)
+GHC_INLINE std::u8string path::generic_u8string() const
+{
+#ifdef GHC_OS_WINDOWS
+    return generic_string<std::u8string::value_type, std::u8string::traits_type, std::u8string::allocator_type>();
+#else
+    return std::u8string(reinterpret_cast<const char8_t*>(_path.c_str()));
+#endif
+}
+#else
+GHC_INLINE std::string path::generic_u8string() const
+{
+#ifdef GHC_OS_WINDOWS
+    return generic_string<std::string::value_type, std::string::traits_type, std::string::allocator_type>();
+#else
+    return _path;
+#endif
+}
+#endif
+
+GHC_INLINE std::u16string path::generic_u16string() const
+{
+#ifdef GHC_OS_WINDOWS
+    return generic_string<std::u16string::value_type, std::u16string::traits_type, std::u16string::allocator_type>();
+#else
+    return detail::fromUtf8<std::u16string>(_path);
+#endif
+}
+
+GHC_INLINE std::u32string path::generic_u32string() const
+{
+#ifdef GHC_OS_WINDOWS
+    return generic_string<std::u32string::value_type, std::u32string::traits_type, std::u32string::allocator_type>();
+#else
+    return detail::fromUtf8<std::u32string>(_path);
+#endif
+}
+
+//-----------------------------------------------------------------------------
+// [fs.path.compare] compare
+GHC_INLINE int path::compare(const path& p) const noexcept
+{
+#ifdef LWG_2936_BEHAVIOUR
+    auto rnl1 = root_name_length();
+    auto rnl2 = p.root_name_length();
+#ifdef GHC_OS_WINDOWS
+    auto rnc = detail::compare_simple_insensitive(_path.c_str(), rnl1, p._path.c_str(), rnl2);
+#else
+    auto rnc = _path.compare(0, rnl1, p._path, 0, (std::min(rnl1, rnl2)));
+#endif
+    if (rnc) {
+        return rnc;
+    }
+    bool hrd1 = has_root_directory(), hrd2 = p.has_root_directory();
+    if (hrd1 != hrd2) {
+        return hrd1 ? 1 : -1;
+    }
+    if (hrd1) {
+        ++rnl1;
+        ++rnl2;
+    }
+    auto iter1 = _path.begin() + static_cast<int>(rnl1);
+    auto iter2 = p._path.begin() + static_cast<int>(rnl2);
+    while (iter1 != _path.end() && iter2 != p._path.end() && *iter1 == *iter2) {
+        ++iter1;
+        ++iter2;
+    }
+    if (iter1 == _path.end()) {
+        return iter2 == p._path.end() ? 0 : -1;
+    }
+    if (iter2 == p._path.end()) {
+        return 1;
+    }
+    if (*iter1 == preferred_separator) {
+        return -1;
+    }
+    if (*iter2 == preferred_separator) {
+        return 1;
+    }
+    return *iter1 < *iter2 ? -1 : 1;
+#else  // LWG_2936_BEHAVIOUR
+#ifdef GHC_OS_WINDOWS
+    auto rnl1 = root_name_length();
+    auto rnl2 = p.root_name_length();
+    auto rnc = detail::compare_simple_insensitive(_path.c_str(), rnl1, p._path.c_str(), rnl2);
+    if (rnc) {
+        return rnc;
+    }
+    return _path.compare(rnl1, std::string::npos, p._path, rnl2, std::string::npos);
+#else
+    return _path.compare(p._path);
+#endif
+#endif
+}
+
+GHC_INLINE int path::compare(const string_type& s) const
+{
+    return compare(path(s));
+}
+
+#ifdef GHC_WITH_STRING_VIEW
+GHC_INLINE int path::compare(basic_string_view<value_type> s) const
+{
+    return compare(path(s));
+}
+#endif
+
+GHC_INLINE int path::compare(const value_type* s) const
+{
+    return compare(path(s));
+}
+
+//-----------------------------------------------------------------------------
+// [fs.path.decompose] decomposition
+#ifdef GHC_OS_WINDOWS
+GHC_INLINE void path::handle_prefixes()
+{
+#if defined(GHC_WIN_AUTO_PREFIX_LONG_PATH)
+    _prefixLength = 0;
+    if (_path.length() >= 6 && _path[2] == '?' && std::toupper(static_cast<unsigned char>(_path[4])) >= 'A' && std::toupper(static_cast<unsigned char>(_path[4])) <= 'Z' && _path[5] == ':') {
+        if (detail::startsWith(_path, impl_string_type(GHC_PLATFORM_LITERAL("\\\\?\\"))) || detail::startsWith(_path, impl_string_type(GHC_PLATFORM_LITERAL("\\??\\")))) {
+            _prefixLength = 4;
+        }
+    }
+#endif  // GHC_WIN_AUTO_PREFIX_LONG_PATH
+}
+#endif
+
+GHC_INLINE path::string_type::size_type path::root_name_length() const noexcept
+{
+#ifdef GHC_OS_WINDOWS
+    if (_path.length() >= _prefixLength + 2 && std::toupper(static_cast<unsigned char>(_path[_prefixLength])) >= 'A' && std::toupper(static_cast<unsigned char>(_path[_prefixLength])) <= 'Z' && _path[_prefixLength + 1] == ':') {
+        return 2;
+    }
+#endif
+    if (_path.length() > _prefixLength + 2 && _path[_prefixLength] == preferred_separator && _path[_prefixLength + 1] == preferred_separator && _path[_prefixLength + 2] != preferred_separator && std::isprint(_path[_prefixLength + 2])) {
+        impl_string_type::size_type pos = _path.find(preferred_separator, _prefixLength + 3);
+        if (pos == impl_string_type::npos) {
+            return _path.length();
+        }
+        else {
+            return pos;
+        }
+    }
+    return 0;
+}
+
+GHC_INLINE path path::root_name() const
+{
+    return path(_path.substr(_prefixLength, root_name_length()), native_format);
+}
+
+GHC_INLINE path path::root_directory() const
+{
+    if (has_root_directory()) {
+        static const path _root_dir(std::string(1, preferred_separator), native_format);
+        return _root_dir;
+    }
+    return path();
+}
+
+GHC_INLINE path path::root_path() const
+{
+    return path(root_name().string() + root_directory().string(), native_format);
+}
+
+GHC_INLINE path path::relative_path() const
+{
+    auto rootPathLen = _prefixLength + root_name_length() + (has_root_directory() ? 1 : 0);
+    return path(_path.substr((std::min)(rootPathLen, _path.length())), generic_format);
+}
+
+GHC_INLINE path path::parent_path() const
+{
+    auto rootPathLen = _prefixLength + root_name_length() + (has_root_directory() ? 1 : 0);
+    if (rootPathLen < _path.length()) {
+        if (empty()) {
+            return path();
+        }
+        else {
+            auto piter = end();
+            auto iter = piter.decrement(_path.end());
+            if (iter > _path.begin() + static_cast<long>(rootPathLen) && *iter != preferred_separator) {
+                --iter;
+            }
+            return path(_path.begin(), iter, native_format);
+        }
+    }
+    else {
+        return *this;
+    }
+}
+
+GHC_INLINE path path::filename() const
+{
+    return !has_relative_path() ? path() : path(*--end());
+}
+
+GHC_INLINE path path::stem() const
+{
+    impl_string_type fn = filename().native();
+    if (fn != "." && fn != "..") {
+        impl_string_type::size_type pos = fn.rfind('.');
+        if (pos != impl_string_type::npos && pos > 0) {
+            return path{fn.substr(0, pos), native_format};
+        }
+    }
+    return path{fn, native_format};
+}
+
+GHC_INLINE path path::extension() const
+{
+    if (has_relative_path()) {
+        auto iter = end();
+        const auto& fn = *--iter;
+        impl_string_type::size_type pos = fn._path.rfind('.');
+        if (pos != std::string::npos && pos > 0) {
+            return path(fn._path.substr(pos), native_format);
+        }
+    }
+    return path();
+}
+
+#ifdef GHC_OS_WINDOWS
+namespace detail {
+GHC_INLINE bool has_executable_extension(const path& p)
+{
+    if (p.has_relative_path()) {
+        auto iter = p.end();
+        const auto& fn = *--iter;
+        auto pos = fn._path.find_last_of('.');
+        if (pos == std::string::npos || pos == 0 || fn._path.length() - pos != 3) {
+            return false;
+        }
+        const path::value_type* ext = fn._path.c_str() + pos + 1;
+        if (detail::equals_simple_insensitive(ext, GHC_PLATFORM_LITERAL("exe")) || detail::equals_simple_insensitive(ext, GHC_PLATFORM_LITERAL("cmd")) || detail::equals_simple_insensitive(ext, GHC_PLATFORM_LITERAL("bat")) ||
+            detail::equals_simple_insensitive(ext, GHC_PLATFORM_LITERAL("com"))) {
+            return true;
+        }
+    }
+    return false;
+}
+}  // namespace detail
+#endif
+
+//-----------------------------------------------------------------------------
+// [fs.path.query] query
+GHC_INLINE bool path::empty() const noexcept
+{
+    return _path.empty();
+}
+
+GHC_INLINE bool path::has_root_name() const
+{
+    return root_name_length() > 0;
+}
+
+GHC_INLINE bool path::has_root_directory() const
+{
+    auto rootLen = _prefixLength + root_name_length();
+    return (_path.length() > rootLen && _path[rootLen] == preferred_separator);
+}
+
+GHC_INLINE bool path::has_root_path() const
+{
+    return has_root_name() || has_root_directory();
+}
+
+GHC_INLINE bool path::has_relative_path() const
+{
+    auto rootPathLen = _prefixLength + root_name_length() + (has_root_directory() ? 1 : 0);
+    return rootPathLen < _path.length();
+}
+
+GHC_INLINE bool path::has_parent_path() const
+{
+    return !parent_path().empty();
+}
+
+GHC_INLINE bool path::has_filename() const
+{
+    return has_relative_path() && !filename().empty();
+}
+
+GHC_INLINE bool path::has_stem() const
+{
+    return !stem().empty();
+}
+
+GHC_INLINE bool path::has_extension() const
+{
+    return !extension().empty();
+}
+
+GHC_INLINE bool path::is_absolute() const
+{
+#ifdef GHC_OS_WINDOWS
+    return has_root_name() && has_root_directory();
+#else
+    return has_root_directory();
+#endif
+}
+
+GHC_INLINE bool path::is_relative() const
+{
+    return !is_absolute();
+}
+
+//-----------------------------------------------------------------------------
+// [fs.path.gen] generation
+GHC_INLINE path path::lexically_normal() const
+{
+    path dest;
+    bool lastDotDot = false;
+    for (string_type s : *this) {
+        if (s == ".") {
+            dest /= "";
+            continue;
+        }
+        else if (s == ".." && !dest.empty()) {
+            auto root = root_path();
+            if (dest == root) {
+                continue;
+            }
+            else if (*(--dest.end()) != "..") {
+                if (dest._path.back() == preferred_separator) {
+                    dest._path.pop_back();
+                }
+                dest.remove_filename();
+                continue;
+            }
+        }
+        if (!(s.empty() && lastDotDot)) {
+            dest /= s;
+        }
+        lastDotDot = s == "..";
+    }
+    if (dest.empty()) {
+        dest = ".";
+    }
+    return dest;
+}
+
+GHC_INLINE path path::lexically_relative(const path& base) const
+{
+    if (root_name() != base.root_name() || is_absolute() != base.is_absolute() || (!has_root_directory() && base.has_root_directory())) {
+        return path();
+    }
+    const_iterator a = begin(), b = base.begin();
+    while (a != end() && b != base.end() && *a == *b) {
+        ++a;
+        ++b;
+    }
+    if (a == end() && b == base.end()) {
+        return path(".");
+    }
+    int count = 0;
+    for (const auto& element : input_iterator_range<const_iterator>(b, base.end())) {
+        if (element != "." && element != "" && element != "..") {
+            ++count;
+        }
+        else if (element == "..") {
+            --count;
+        }
+    }
+    if (count < 0) {
+        return path();
+    }
+    path result;
+    for (int i = 0; i < count; ++i) {
+        result /= "..";
+    }
+    for (const auto& element : input_iterator_range<const_iterator>(a, end())) {
+        result /= element;
+    }
+    return result;
+}
+
+GHC_INLINE path path::lexically_proximate(const path& base) const
+{
+    path result = lexically_relative(base);
+    return result.empty() ? *this : result;
+}
+
+//-----------------------------------------------------------------------------
+// [fs.path.itr] iterators
+GHC_INLINE path::iterator::iterator() {}
+
+GHC_INLINE path::iterator::iterator(const path& p, const impl_string_type::const_iterator& pos)
+    : _first(p._path.begin())
+    , _last(p._path.end())
+    , _prefix(_first + static_cast<string_type::difference_type>(p._prefixLength))
+    , _root(p.has_root_directory() ? _first + static_cast<string_type::difference_type>(p._prefixLength + p.root_name_length()) : _last)
+    , _iter(pos)
+{
+    if (pos != _last) {
+        updateCurrent();
+    }
+}
+
+GHC_INLINE path::impl_string_type::const_iterator path::iterator::increment(const path::impl_string_type::const_iterator& pos) const
+{
+    path::impl_string_type::const_iterator i = pos;
+    bool fromStart = i == _first || i == _prefix;
+    if (i != _last) {
+        if (fromStart && i == _first && _prefix > _first) {
+            i = _prefix;
+        }
+        else if (*i++ == preferred_separator) {
+            // we can only sit on a slash if it is a network name or a root
+            if (i != _last && *i == preferred_separator) {
+                if (fromStart && !(i + 1 != _last && *(i + 1) == preferred_separator)) {
+                    // leadind double slashes detected, treat this and the
+                    // following until a slash as one unit
+                    i = std::find(++i, _last, preferred_separator);
+                }
+                else {
+                    // skip redundant slashes
+                    while (i != _last && *i == preferred_separator) {
+                        ++i;
+                    }
+                }
+            }
+        }
+        else {
+            if (fromStart && i != _last && *i == ':') {
+                ++i;
+            }
+            else {
+                i = std::find(i, _last, preferred_separator);
+            }
+        }
+    }
+    return i;
+}
+
+GHC_INLINE path::impl_string_type::const_iterator path::iterator::decrement(const path::impl_string_type::const_iterator& pos) const
+{
+    path::impl_string_type::const_iterator i = pos;
+    if (i != _first) {
+        --i;
+        // if this is now the root slash or the trailing slash, we are done,
+        // else check for network name
+        if (i != _root && (pos != _last || *i != preferred_separator)) {
+#ifdef GHC_OS_WINDOWS
+            static const impl_string_type seps = GHC_PLATFORM_LITERAL("\\:");
+            i = std::find_first_of(std::reverse_iterator<path::impl_string_type::const_iterator>(i), std::reverse_iterator<path::impl_string_type::const_iterator>(_first), seps.begin(), seps.end()).base();
+            if (i > _first && *i == ':') {
+                i++;
+            }
+#else
+            i = std::find(std::reverse_iterator<path::impl_string_type::const_iterator>(i), std::reverse_iterator<path::impl_string_type::const_iterator>(_first), preferred_separator).base();
+#endif
+            // Now we have to check if this is a network name
+            if (i - _first == 2 && *_first == preferred_separator && *(_first + 1) == preferred_separator) {
+                i -= 2;
+            }
+        }
+    }
+    return i;
+}
+
+GHC_INLINE void path::iterator::updateCurrent()
+{
+    if ((_iter == _last) || (_iter != _first && _iter != _last && (*_iter == preferred_separator && _iter != _root) && (_iter + 1 == _last))) {
+        _current.clear();
+    }
+    else {
+        _current.assign(_iter, increment(_iter));
+    }
+}
+
+GHC_INLINE path::iterator& path::iterator::operator++()
+{
+    _iter = increment(_iter);
+    while (_iter != _last &&                 // we didn't reach the end
+           _iter != _root &&                 // this is not a root position
+           *_iter == preferred_separator &&  // we are on a separator
+           (_iter + 1) != _last              // the slash is not the last char
+    ) {
+        ++_iter;
+    }
+    updateCurrent();
+    return *this;
+}
+
+GHC_INLINE path::iterator path::iterator::operator++(int)
+{
+    path::iterator i{*this};
+    ++(*this);
+    return i;
+}
+
+GHC_INLINE path::iterator& path::iterator::operator--()
+{
+    _iter = decrement(_iter);
+    updateCurrent();
+    return *this;
+}
+
+GHC_INLINE path::iterator path::iterator::operator--(int)
+{
+    auto i = *this;
+    --(*this);
+    return i;
+}
+
+GHC_INLINE bool path::iterator::operator==(const path::iterator& other) const
+{
+    return _iter == other._iter;
+}
+
+GHC_INLINE bool path::iterator::operator!=(const path::iterator& other) const
+{
+    return _iter != other._iter;
+}
+
+GHC_INLINE path::iterator::reference path::iterator::operator*() const
+{
+    return _current;
+}
+
+GHC_INLINE path::iterator::pointer path::iterator::operator->() const
+{
+    return &_current;
+}
+
+GHC_INLINE path::iterator path::begin() const
+{
+    return iterator(*this, _path.begin());
+}
+
+GHC_INLINE path::iterator path::end() const
+{
+    return iterator(*this, _path.end());
+}
+
+//-----------------------------------------------------------------------------
+// [fs.path.nonmember] path non-member functions
+GHC_INLINE void swap(path& lhs, path& rhs) noexcept
+{
+    swap(lhs._path, rhs._path);
+}
+
+GHC_INLINE size_t hash_value(const path& p) noexcept
+{
+    return std::hash<std::string>()(p.generic_string());
+}
+
+#ifdef GHC_HAS_THREEWAY_COMP
+GHC_INLINE std::strong_ordering operator<=>(const path& lhs, const path& rhs) noexcept
+{
+    return lhs.compare(rhs) <=> 0;
+}
+#endif
+
+GHC_INLINE bool operator==(const path& lhs, const path& rhs) noexcept
+{
+    return lhs.compare(rhs) == 0;
+}
+
+GHC_INLINE bool operator!=(const path& lhs, const path& rhs) noexcept
+{
+    return !(lhs == rhs);
+}
+
+GHC_INLINE bool operator<(const path& lhs, const path& rhs) noexcept
+{
+    return lhs.compare(rhs) < 0;
+}
+
+GHC_INLINE bool operator<=(const path& lhs, const path& rhs) noexcept
+{
+    return lhs.compare(rhs) <= 0;
+}
+
+GHC_INLINE bool operator>(const path& lhs, const path& rhs) noexcept
+{
+    return lhs.compare(rhs) > 0;
+}
+
+GHC_INLINE bool operator>=(const path& lhs, const path& rhs) noexcept
+{
+    return lhs.compare(rhs) >= 0;
+}
+
+GHC_INLINE path operator/(const path& lhs, const path& rhs)
+{
+    path result(lhs);
+    result /= rhs;
+    return result;
+}
+
+#endif  // GHC_EXPAND_IMPL
+
+//-----------------------------------------------------------------------------
+// [fs.path.io] path inserter and extractor
+template <class charT, class traits>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& os, const path& p)
+{
+    os << "\"";
+    auto ps = p.string<charT, traits>();
+    for (auto c : ps) {
+        if (c == '"' || c == '\\') {
+            os << '\\';
+        }
+        os << c;
+    }
+    os << "\"";
+    return os;
+}
+
+template <class charT, class traits>
+inline std::basic_istream<charT, traits>& operator>>(std::basic_istream<charT, traits>& is, path& p)
+{
+    std::basic_string<charT, traits> tmp;
+    charT c;
+    is >> c;
+    if (c == '"') {
+        auto sf = is.flags();
+        is >> std::noskipws;
+        while (is) {
+            auto c2 = is.get();
+            if (is) {
+                if (c2 == '\\') {
+                    c2 = is.get();
+                    if (is) {
+                        tmp += static_cast<charT>(c2);
+                    }
+                }
+                else if (c2 == '"') {
+                    break;
+                }
+                else {
+                    tmp += static_cast<charT>(c2);
+                }
+            }
+        }
+        if ((sf & std::ios_base::skipws) == std::ios_base::skipws) {
+            is >> std::skipws;
+        }
+        p = path(tmp);
+    }
+    else {
+        is >> tmp;
+        p = path(static_cast<charT>(c) + tmp);
+    }
+    return is;
+}
+
+#ifdef GHC_EXPAND_IMPL
+
+//-----------------------------------------------------------------------------
+// [fs.class.filesystem_error] Class filesystem_error
+GHC_INLINE filesystem_error::filesystem_error(const std::string& what_arg, std::error_code ec)
+    : std::system_error(ec, what_arg)
+    , _what_arg(what_arg)
+    , _ec(ec)
+{
+}
+
+GHC_INLINE filesystem_error::filesystem_error(const std::string& what_arg, const path& p1, std::error_code ec)
+    : std::system_error(ec, what_arg)
+    , _what_arg(what_arg)
+    , _ec(ec)
+    , _p1(p1)
+{
+    if (!_p1.empty()) {
+        _what_arg += ": '" + _p1.string() + "'";
+    }
+}
+
+GHC_INLINE filesystem_error::filesystem_error(const std::string& what_arg, const path& p1, const path& p2, std::error_code ec)
+    : std::system_error(ec, what_arg)
+    , _what_arg(what_arg)
+    , _ec(ec)
+    , _p1(p1)
+    , _p2(p2)
+{
+    if (!_p1.empty()) {
+        _what_arg += ": '" + _p1.string() + "'";
+    }
+    if (!_p2.empty()) {
+        _what_arg += ", '" + _p2.string() + "'";
+    }
+}
+
+GHC_INLINE const path& filesystem_error::path1() const noexcept
+{
+    return _p1;
+}
+
+GHC_INLINE const path& filesystem_error::path2() const noexcept
+{
+    return _p2;
+}
+
+GHC_INLINE const char* filesystem_error::what() const noexcept
+{
+    return _what_arg.c_str();
+}
+
+//-----------------------------------------------------------------------------
+// [fs.op.funcs] filesystem operations
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE path absolute(const path& p)
+{
+    std::error_code ec;
+    path result = absolute(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE path absolute(const path& p, std::error_code& ec)
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    if (p.empty()) {
+        return absolute(current_path(ec), ec) / "";
+    }
+    ULONG size = ::GetFullPathNameW(GHC_NATIVEWP(p), 0, 0, 0);
+    if (size) {
+        std::vector<wchar_t> buf(size, 0);
+        ULONG s2 = GetFullPathNameW(GHC_NATIVEWP(p), size, buf.data(), nullptr);
+        if (s2 && s2 < size) {
+            path result = path(std::wstring(buf.data(), s2));
+            if (p.filename() == ".") {
+                result /= ".";
+            }
+            return result;
+        }
+    }
+    ec = detail::make_system_error();
+    return path();
+#else
+    path base = current_path(ec);
+    if (!ec) {
+        if (p.empty()) {
+            return base / p;
+        }
+        if (p.has_root_name()) {
+            if (p.has_root_directory()) {
+                return p;
+            }
+            else {
+                return p.root_name() / base.root_directory() / base.relative_path() / p.relative_path();
+            }
+        }
+        else {
+            if (p.has_root_directory()) {
+                return base.root_name() / p;
+            }
+            else {
+                return base / p;
+            }
+        }
+    }
+    ec = detail::make_system_error();
+    return path();
+#endif
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE path canonical(const path& p)
+{
+    std::error_code ec;
+    auto result = canonical(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE path canonical(const path& p, std::error_code& ec)
+{
+    if (p.empty()) {
+        ec = detail::make_error_code(detail::portable_error::not_found);
+        return path();
+    }
+    path work = p.is_absolute() ? p : absolute(p, ec);
+    path result;
+
+    auto fs = status(work, ec);
+    if (ec) {
+        return path();
+    }
+    if (fs.type() == file_type::not_found) {
+        ec = detail::make_error_code(detail::portable_error::not_found);
+        return path();
+    }
+    bool redo;
+    do {
+        auto rootPathLen = work._prefixLength + work.root_name_length() + (work.has_root_directory() ? 1 : 0);
+        redo = false;
+        result.clear();
+        for (auto pe : work) {
+            if (pe.empty() || pe == ".") {
+                continue;
+            }
+            else if (pe == "..") {
+                result = result.parent_path();
+                continue;
+            }
+            else if ((result / pe).string().length() <= rootPathLen) {
+                result /= pe;
+                continue;
+            }
+            auto sls = symlink_status(result / pe, ec);
+            if (ec) {
+                return path();
+            }
+            if (is_symlink(sls)) {
+                redo = true;
+                auto target = read_symlink(result / pe, ec);
+                if (ec) {
+                    return path();
+                }
+                if (target.is_absolute()) {
+                    result = target;
+                    continue;
+                }
+                else {
+                    result /= target;
+                    continue;
+                }
+            }
+            else {
+                result /= pe;
+            }
+        }
+        work = result;
+    } while (redo);
+    ec.clear();
+    return result;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void copy(const path& from, const path& to)
+{
+    copy(from, to, copy_options::none);
+}
+
+GHC_INLINE void copy(const path& from, const path& to, copy_options options)
+{
+    std::error_code ec;
+    copy(from, to, options, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), from, to, ec);
+    }
+}
+#endif
+
+GHC_INLINE void copy(const path& from, const path& to, std::error_code& ec) noexcept
+{
+    copy(from, to, copy_options::none, ec);
+}
+
+GHC_INLINE void copy(const path& from, const path& to, copy_options options, std::error_code& ec) noexcept
+{
+    std::error_code tec;
+    file_status fs_from, fs_to;
+    ec.clear();
+    if ((options & (copy_options::skip_symlinks | copy_options::copy_symlinks | copy_options::create_symlinks)) != copy_options::none) {
+        fs_from = symlink_status(from, ec);
+    }
+    else {
+        fs_from = status(from, ec);
+    }
+    if (!exists(fs_from)) {
+        if (!ec) {
+            ec = detail::make_error_code(detail::portable_error::not_found);
+        }
+        return;
+    }
+    if ((options & (copy_options::skip_symlinks | copy_options::create_symlinks)) != copy_options::none) {
+        fs_to = symlink_status(to, tec);
+    }
+    else {
+        fs_to = status(to, tec);
+    }
+    if (is_other(fs_from) || is_other(fs_to) || (is_directory(fs_from) && is_regular_file(fs_to)) || (exists(fs_to) && equivalent(from, to, ec))) {
+        ec = detail::make_error_code(detail::portable_error::invalid_argument);
+    }
+    else if (is_symlink(fs_from)) {
+        if ((options & copy_options::skip_symlinks) == copy_options::none) {
+            if (!exists(fs_to) && (options & copy_options::copy_symlinks) != copy_options::none) {
+                copy_symlink(from, to, ec);
+            }
+            else {
+                ec = detail::make_error_code(detail::portable_error::invalid_argument);
+            }
+        }
+    }
+    else if (is_regular_file(fs_from)) {
+        if ((options & copy_options::directories_only) == copy_options::none) {
+            if ((options & copy_options::create_symlinks) != copy_options::none) {
+                create_symlink(from.is_absolute() ? from : canonical(from, ec), to, ec);
+            }
+#ifndef GHC_OS_WEB
+            else if ((options & copy_options::create_hard_links) != copy_options::none) {
+                create_hard_link(from, to, ec);
+            }
+#endif
+            else if (is_directory(fs_to)) {
+                copy_file(from, to / from.filename(), options, ec);
+            }
+            else {
+                copy_file(from, to, options, ec);
+            }
+        }
+    }
+#ifdef LWG_2682_BEHAVIOUR
+    else if (is_directory(fs_from) && (options & copy_options::create_symlinks) != copy_options::none) {
+        ec = detail::make_error_code(detail::portable_error::is_a_directory);
+    }
+#endif
+    else if (is_directory(fs_from) && (options == copy_options::none || (options & copy_options::recursive) != copy_options::none)) {
+        if (!exists(fs_to)) {
+            create_directory(to, from, ec);
+            if (ec) {
+                return;
+            }
+        }
+        for (auto iter = directory_iterator(from, ec); iter != directory_iterator(); iter.increment(ec)) {
+            if (!ec) {
+                copy(iter->path(), to / iter->path().filename(), options | static_cast<copy_options>(0x8000), ec);
+            }
+            if (ec) {
+                return;
+            }
+        }
+    }
+    return;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool copy_file(const path& from, const path& to)
+{
+    return copy_file(from, to, copy_options::none);
+}
+
+GHC_INLINE bool copy_file(const path& from, const path& to, copy_options option)
+{
+    std::error_code ec;
+    auto result = copy_file(from, to, option, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), from, to, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE bool copy_file(const path& from, const path& to, std::error_code& ec) noexcept
+{
+    return copy_file(from, to, copy_options::none, ec);
+}
+
+GHC_INLINE bool copy_file(const path& from, const path& to, copy_options options, std::error_code& ec) noexcept
+{
+    std::error_code tecf, tect;
+    auto sf = status(from, tecf);
+    auto st = status(to, tect);
+    bool overwrite = false;
+    ec.clear();
+    if (!is_regular_file(sf)) {
+        ec = tecf;
+        return false;
+    }
+    if (exists(st) && (!is_regular_file(st) || equivalent(from, to, ec) || (options & (copy_options::skip_existing | copy_options::overwrite_existing | copy_options::update_existing)) == copy_options::none)) {
+        ec = tect ? tect : detail::make_error_code(detail::portable_error::exists);
+        return false;
+    }
+    if (exists(st)) {
+        if ((options & copy_options::update_existing) == copy_options::update_existing) {
+            auto from_time = last_write_time(from, ec);
+            if (ec) {
+                ec = detail::make_system_error();
+                return false;
+            }
+            auto to_time = last_write_time(to, ec);
+            if (ec) {
+                ec = detail::make_system_error();
+                return false;
+            }
+            if (from_time <= to_time) {
+                return false;
+            }
+        }
+        overwrite = true;
+    }
+#ifdef GHC_OS_WINDOWS
+    if (!::CopyFileW(GHC_NATIVEWP(from), GHC_NATIVEWP(to), !overwrite)) {
+        ec = detail::make_system_error();
+        return false;
+    }
+    return true;
+#else
+    std::vector<char> buffer(16384, '\0');
+    int in = -1, out = -1;
+    if ((in = ::open(from.c_str(), O_RDONLY)) < 0) {
+        ec = detail::make_system_error();
+        return false;
+    }
+    int mode = O_CREAT | O_WRONLY | O_TRUNC;
+    if (!overwrite) {
+        mode |= O_EXCL;
+    }
+    if ((out = ::open(to.c_str(), mode, static_cast<int>(sf.permissions() & perms::all))) < 0) {
+        ec = detail::make_system_error();
+        ::close(in);
+        return false;
+    }
+    ssize_t br, bw;
+    while ((br = ::read(in, buffer.data(), buffer.size())) > 0) {
+        ssize_t offset = 0;
+        do {
+            if ((bw = ::write(out, buffer.data() + offset, static_cast<size_t>(br))) > 0) {
+                br -= bw;
+                offset += bw;
+            }
+            else if (bw < 0) {
+                ec = detail::make_system_error();
+                ::close(in);
+                ::close(out);
+                return false;
+            }
+        } while (br);
+    }
+    ::close(in);
+    ::close(out);
+    return true;
+#endif
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void copy_symlink(const path& existing_symlink, const path& new_symlink)
+{
+    std::error_code ec;
+    copy_symlink(existing_symlink, new_symlink, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), existing_symlink, new_symlink, ec);
+    }
+}
+#endif
+
+GHC_INLINE void copy_symlink(const path& existing_symlink, const path& new_symlink, std::error_code& ec) noexcept
+{
+    ec.clear();
+    auto to = read_symlink(existing_symlink, ec);
+    if (!ec) {
+        if (exists(to, ec) && is_directory(to, ec)) {
+            create_directory_symlink(to, new_symlink, ec);
+        }
+        else {
+            create_symlink(to, new_symlink, ec);
+        }
+    }
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool create_directories(const path& p)
+{
+    std::error_code ec;
+    auto result = create_directories(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE bool create_directories(const path& p, std::error_code& ec) noexcept
+{
+    path current;
+    ec.clear();
+    bool didCreate = false;
+    auto rootPathLen = p._prefixLength + p.root_name_length() + (p.has_root_directory() ? 1 : 0);
+    current = p.native().substr(0, rootPathLen);
+    path folders(p._path.substr(rootPathLen));
+    for (path::string_type part : folders) {
+        current /= part;
+        std::error_code tec;
+        auto fs = status(current, tec);
+        if (tec && fs.type() != file_type::not_found) {
+            ec = tec;
+            return false;
+        }
+        if (!exists(fs)) {
+            create_directory(current, ec);
+            if (ec) {
+                std::error_code tmp_ec;
+                if (is_directory(current, tmp_ec)) {
+                    ec.clear();
+                }
+                else {
+                    return false;
+                }
+            }
+            didCreate = true;
+        }
+#ifndef LWG_2935_BEHAVIOUR
+        else if (!is_directory(fs)) {
+            ec = detail::make_error_code(detail::portable_error::exists);
+            return false;
+        }
+#endif
+    }
+    return didCreate;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool create_directory(const path& p)
+{
+    std::error_code ec;
+    auto result = create_directory(p, path(), ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE bool create_directory(const path& p, std::error_code& ec) noexcept
+{
+    return create_directory(p, path(), ec);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool create_directory(const path& p, const path& attributes)
+{
+    std::error_code ec;
+    auto result = create_directory(p, attributes, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE bool create_directory(const path& p, const path& attributes, std::error_code& ec) noexcept
+{
+    std::error_code tec;
+    ec.clear();
+    auto fs = status(p, tec);
+#ifdef LWG_2935_BEHAVIOUR
+    if (status_known(fs) && exists(fs)) {
+        return false;
+    }
+#else
+    if (status_known(fs) && exists(fs) && is_directory(fs)) {
+        return false;
+    }
+#endif
+#ifdef GHC_OS_WINDOWS
+    if (!attributes.empty()) {
+        if (!::CreateDirectoryExW(GHC_NATIVEWP(attributes), GHC_NATIVEWP(p), NULL)) {
+            ec = detail::make_system_error();
+            return false;
+        }
+    }
+    else if (!::CreateDirectoryW(GHC_NATIVEWP(p), NULL)) {
+        ec = detail::make_system_error();
+        return false;
+    }
+#else
+    ::mode_t attribs = static_cast<mode_t>(perms::all);
+    if (!attributes.empty()) {
+        struct ::stat fileStat;
+        if (::stat(attributes.c_str(), &fileStat) != 0) {
+            ec = detail::make_system_error();
+            return false;
+        }
+        attribs = fileStat.st_mode;
+    }
+    if (::mkdir(p.c_str(), attribs) != 0) {
+        ec = detail::make_system_error();
+        return false;
+    }
+#endif
+    return true;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void create_directory_symlink(const path& to, const path& new_symlink)
+{
+    std::error_code ec;
+    create_directory_symlink(to, new_symlink, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), to, new_symlink, ec);
+    }
+}
+#endif
+
+GHC_INLINE void create_directory_symlink(const path& to, const path& new_symlink, std::error_code& ec) noexcept
+{
+    detail::create_symlink(to, new_symlink, true, ec);
+}
+
+#ifndef GHC_OS_WEB
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void create_hard_link(const path& to, const path& new_hard_link)
+{
+    std::error_code ec;
+    create_hard_link(to, new_hard_link, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), to, new_hard_link, ec);
+    }
+}
+#endif
+
+GHC_INLINE void create_hard_link(const path& to, const path& new_hard_link, std::error_code& ec) noexcept
+{
+    detail::create_hardlink(to, new_hard_link, ec);
+}
+#endif
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void create_symlink(const path& to, const path& new_symlink)
+{
+    std::error_code ec;
+    create_symlink(to, new_symlink, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), to, new_symlink, ec);
+    }
+}
+#endif
+
+GHC_INLINE void create_symlink(const path& to, const path& new_symlink, std::error_code& ec) noexcept
+{
+    detail::create_symlink(to, new_symlink, false, ec);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE path current_path()
+{
+    std::error_code ec;
+    auto result = current_path(ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE path current_path(std::error_code& ec)
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    DWORD pathlen = ::GetCurrentDirectoryW(0, 0);
+    std::unique_ptr<wchar_t[]> buffer(new wchar_t[size_t(pathlen) + 1]);
+    if (::GetCurrentDirectoryW(pathlen, buffer.get()) == 0) {
+        ec = detail::make_system_error();
+        return path();
+    }
+    return path(std::wstring(buffer.get()), path::native_format);
+#else
+    size_t pathlen = static_cast<size_t>(std::max(int(::pathconf(".", _PC_PATH_MAX)), int(PATH_MAX)));
+    std::unique_ptr<char[]> buffer(new char[pathlen + 1]);
+    if (::getcwd(buffer.get(), pathlen) == nullptr) {
+        ec = detail::make_system_error();
+        return path();
+    }
+    return path(buffer.get());
+#endif
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void current_path(const path& p)
+{
+    std::error_code ec;
+    current_path(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+}
+#endif
+
+GHC_INLINE void current_path(const path& p, std::error_code& ec) noexcept
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    if (!::SetCurrentDirectoryW(GHC_NATIVEWP(p))) {
+        ec = detail::make_system_error();
+    }
+#else
+    if (::chdir(p.string().c_str()) == -1) {
+        ec = detail::make_system_error();
+    }
+#endif
+}
+
+GHC_INLINE bool exists(file_status s) noexcept
+{
+    return status_known(s) && s.type() != file_type::not_found;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool exists(const path& p)
+{
+    return exists(status(p));
+}
+#endif
+
+GHC_INLINE bool exists(const path& p, std::error_code& ec) noexcept
+{
+    file_status s = status(p, ec);
+    if (status_known(s)) {
+        ec.clear();
+    }
+    return exists(s);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool equivalent(const path& p1, const path& p2)
+{
+    std::error_code ec;
+    bool result = equivalent(p1, p2, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p1, p2, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE bool equivalent(const path& p1, const path& p2, std::error_code& ec) noexcept
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    detail::unique_handle file1(::CreateFileW(GHC_NATIVEWP(p1), 0, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, 0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0));
+    auto e1 = ::GetLastError();
+    detail::unique_handle file2(::CreateFileW(GHC_NATIVEWP(p2), 0, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, 0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0));
+    if (!file1 || !file2) {
+#ifdef LWG_2937_BEHAVIOUR
+        ec = detail::make_system_error(e1 ? e1 : ::GetLastError());
+#else
+        if (file1 == file2) {
+            ec = detail::make_system_error(e1 ? e1 : ::GetLastError());
+        }
+#endif
+        return false;
+    }
+    BY_HANDLE_FILE_INFORMATION inf1, inf2;
+    if (!::GetFileInformationByHandle(file1.get(), &inf1)) {
+        ec = detail::make_system_error();
+        return false;
+    }
+    if (!::GetFileInformationByHandle(file2.get(), &inf2)) {
+        ec = detail::make_system_error();
+        return false;
+    }
+    return inf1.ftLastWriteTime.dwLowDateTime == inf2.ftLastWriteTime.dwLowDateTime && inf1.ftLastWriteTime.dwHighDateTime == inf2.ftLastWriteTime.dwHighDateTime && inf1.nFileIndexHigh == inf2.nFileIndexHigh && inf1.nFileIndexLow == inf2.nFileIndexLow &&
+           inf1.nFileSizeHigh == inf2.nFileSizeHigh && inf1.nFileSizeLow == inf2.nFileSizeLow && inf1.dwVolumeSerialNumber == inf2.dwVolumeSerialNumber;
+#else
+    struct ::stat s1, s2;
+    auto rc1 = ::stat(p1.c_str(), &s1);
+    auto e1 = errno;
+    auto rc2 = ::stat(p2.c_str(), &s2);
+    if (rc1 || rc2) {
+#ifdef LWG_2937_BEHAVIOUR
+        ec = detail::make_system_error(e1 ? e1 : errno);
+#else
+        if (rc1 && rc2) {
+            ec = detail::make_system_error(e1 ? e1 : errno);
+        }
+#endif
+        return false;
+    }
+    return s1.st_dev == s2.st_dev && s1.st_ino == s2.st_ino && s1.st_size == s2.st_size && s1.st_mtime == s2.st_mtime;
+#endif
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE uintmax_t file_size(const path& p)
+{
+    std::error_code ec;
+    auto result = file_size(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE uintmax_t file_size(const path& p, std::error_code& ec) noexcept
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    WIN32_FILE_ATTRIBUTE_DATA attr;
+    if (!GetFileAttributesExW(GHC_NATIVEWP(p), GetFileExInfoStandard, &attr)) {
+        ec = detail::make_system_error();
+        return static_cast<uintmax_t>(-1);
+    }
+    return static_cast<uintmax_t>(attr.nFileSizeHigh) << (sizeof(attr.nFileSizeHigh) * 8) | attr.nFileSizeLow;
+#else
+    struct ::stat fileStat;
+    if (::stat(p.c_str(), &fileStat) == -1) {
+        ec = detail::make_system_error();
+        return static_cast<uintmax_t>(-1);
+    }
+    return static_cast<uintmax_t>(fileStat.st_size);
+#endif
+}
+
+#ifndef GHC_OS_WEB
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE uintmax_t hard_link_count(const path& p)
+{
+    std::error_code ec;
+    auto result = hard_link_count(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE uintmax_t hard_link_count(const path& p, std::error_code& ec) noexcept
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    uintmax_t result = static_cast<uintmax_t>(-1);
+    detail::unique_handle file(::CreateFileW(GHC_NATIVEWP(p), 0, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, 0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0));
+    BY_HANDLE_FILE_INFORMATION inf;
+    if (!file) {
+        ec = detail::make_system_error();
+    }
+    else {
+        if (!::GetFileInformationByHandle(file.get(), &inf)) {
+            ec = detail::make_system_error();
+        }
+        else {
+            result = inf.nNumberOfLinks;
+        }
+    }
+    return result;
+#else
+    uintmax_t result = 0;
+    file_status fs = detail::status_ex(p, ec, nullptr, nullptr, &result, nullptr);
+    if (fs.type() == file_type::not_found) {
+        ec = detail::make_error_code(detail::portable_error::not_found);
+    }
+    return ec ? static_cast<uintmax_t>(-1) : result;
+#endif
+}
+#endif
+
+GHC_INLINE bool is_block_file(file_status s) noexcept
+{
+    return s.type() == file_type::block;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool is_block_file(const path& p)
+{
+    return is_block_file(status(p));
+}
+#endif
+
+GHC_INLINE bool is_block_file(const path& p, std::error_code& ec) noexcept
+{
+    return is_block_file(status(p, ec));
+}
+
+GHC_INLINE bool is_character_file(file_status s) noexcept
+{
+    return s.type() == file_type::character;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool is_character_file(const path& p)
+{
+    return is_character_file(status(p));
+}
+#endif
+
+GHC_INLINE bool is_character_file(const path& p, std::error_code& ec) noexcept
+{
+    return is_character_file(status(p, ec));
+}
+
+GHC_INLINE bool is_directory(file_status s) noexcept
+{
+    return s.type() == file_type::directory;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool is_directory(const path& p)
+{
+    return is_directory(status(p));
+}
+#endif
+
+GHC_INLINE bool is_directory(const path& p, std::error_code& ec) noexcept
+{
+    return is_directory(status(p, ec));
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool is_empty(const path& p)
+{
+    if (is_directory(p)) {
+        return directory_iterator(p) == directory_iterator();
+    }
+    else {
+        return file_size(p) == 0;
+    }
+}
+#endif
+
+GHC_INLINE bool is_empty(const path& p, std::error_code& ec) noexcept
+{
+    auto fs = status(p, ec);
+    if (ec) {
+        return false;
+    }
+    if (is_directory(fs)) {
+        directory_iterator iter(p, ec);
+        if (ec) {
+            return false;
+        }
+        return iter == directory_iterator();
+    }
+    else {
+        auto sz = file_size(p, ec);
+        if (ec) {
+            return false;
+        }
+        return sz == 0;
+    }
+}
+
+GHC_INLINE bool is_fifo(file_status s) noexcept
+{
+    return s.type() == file_type::fifo;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool is_fifo(const path& p)
+{
+    return is_fifo(status(p));
+}
+#endif
+
+GHC_INLINE bool is_fifo(const path& p, std::error_code& ec) noexcept
+{
+    return is_fifo(status(p, ec));
+}
+
+GHC_INLINE bool is_other(file_status s) noexcept
+{
+    return exists(s) && !is_regular_file(s) && !is_directory(s) && !is_symlink(s);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool is_other(const path& p)
+{
+    return is_other(status(p));
+}
+#endif
+
+GHC_INLINE bool is_other(const path& p, std::error_code& ec) noexcept
+{
+    return is_other(status(p, ec));
+}
+
+GHC_INLINE bool is_regular_file(file_status s) noexcept
+{
+    return s.type() == file_type::regular;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool is_regular_file(const path& p)
+{
+    return is_regular_file(status(p));
+}
+#endif
+
+GHC_INLINE bool is_regular_file(const path& p, std::error_code& ec) noexcept
+{
+    return is_regular_file(status(p, ec));
+}
+
+GHC_INLINE bool is_socket(file_status s) noexcept
+{
+    return s.type() == file_type::socket;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool is_socket(const path& p)
+{
+    return is_socket(status(p));
+}
+#endif
+
+GHC_INLINE bool is_socket(const path& p, std::error_code& ec) noexcept
+{
+    return is_socket(status(p, ec));
+}
+
+GHC_INLINE bool is_symlink(file_status s) noexcept
+{
+    return s.type() == file_type::symlink;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool is_symlink(const path& p)
+{
+    return is_symlink(symlink_status(p));
+}
+#endif
+
+GHC_INLINE bool is_symlink(const path& p, std::error_code& ec) noexcept
+{
+    return is_symlink(symlink_status(p, ec));
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE file_time_type last_write_time(const path& p)
+{
+    std::error_code ec;
+    auto result = last_write_time(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE file_time_type last_write_time(const path& p, std::error_code& ec) noexcept
+{
+    time_t result = 0;
+    ec.clear();
+    file_status fs = detail::status_ex(p, ec, nullptr, nullptr, nullptr, &result);
+    return ec ? (file_time_type::min)() : std::chrono::system_clock::from_time_t(result);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void last_write_time(const path& p, file_time_type new_time)
+{
+    std::error_code ec;
+    last_write_time(p, new_time, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+}
+#endif
+
+GHC_INLINE void last_write_time(const path& p, file_time_type new_time, std::error_code& ec) noexcept
+{
+    ec.clear();
+    auto d = new_time.time_since_epoch();
+#ifdef GHC_OS_WINDOWS
+    detail::unique_handle file(::CreateFileW(GHC_NATIVEWP(p), FILE_WRITE_ATTRIBUTES, FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL));
+    FILETIME ft;
+    auto tt = std::chrono::duration_cast<std::chrono::microseconds>(d).count() * 10 + 116444736000000000;
+    ft.dwLowDateTime = static_cast<DWORD>(tt);
+    ft.dwHighDateTime = static_cast<DWORD>(tt >> 32);
+    if (!::SetFileTime(file.get(), 0, 0, &ft)) {
+        ec = detail::make_system_error();
+    }
+#elif defined(GHC_OS_MACOS)
+#ifdef __MAC_OS_X_VERSION_MIN_REQUIRED
+#if __MAC_OS_X_VERSION_MIN_REQUIRED < 101300
+    struct ::stat fs;
+    if (::stat(p.c_str(), &fs) == 0) {
+        struct ::timeval tv[2];
+        tv[0].tv_sec = fs.st_atimespec.tv_sec;
+        tv[0].tv_usec = static_cast<int>(fs.st_atimespec.tv_nsec / 1000);
+        tv[1].tv_sec = std::chrono::duration_cast<std::chrono::seconds>(d).count();
+        tv[1].tv_usec = static_cast<int>(std::chrono::duration_cast<std::chrono::microseconds>(d).count() % 1000000);
+        if (::utimes(p.c_str(), tv) == 0) {
+            return;
+        }
+    }
+    ec = detail::make_system_error();
+    return;
+#else
+    struct ::timespec times[2];
+    times[0].tv_sec = 0;
+    times[0].tv_nsec = UTIME_OMIT;
+    times[1].tv_sec = std::chrono::duration_cast<std::chrono::seconds>(d).count();
+    times[1].tv_nsec = 0;  // std::chrono::duration_cast<std::chrono::nanoseconds>(d).count() % 1000000000;
+    if (::utimensat(AT_FDCWD, p.c_str(), times, AT_SYMLINK_NOFOLLOW) != 0) {
+        ec = detail::make_system_error();
+    }
+    return;
+#endif
+#endif
+#else
+#ifndef UTIME_OMIT
+#define UTIME_OMIT ((1l << 30) - 2l)
+#endif
+    struct ::timespec times[2];
+    times[0].tv_sec = 0;
+    times[0].tv_nsec = UTIME_OMIT;
+    times[1].tv_sec = static_cast<decltype(times[1].tv_sec)>(std::chrono::duration_cast<std::chrono::seconds>(d).count());
+    times[1].tv_nsec = static_cast<decltype(times[1].tv_nsec)>(std::chrono::duration_cast<std::chrono::nanoseconds>(d).count() % 1000000000);
+#if defined(__ANDROID_API__) && __ANDROID_API__ < 12
+    if (syscall(__NR_utimensat, AT_FDCWD, p.c_str(), times, AT_SYMLINK_NOFOLLOW) != 0) {
+#else
+    if (::utimensat((int)AT_FDCWD, p.c_str(), times, AT_SYMLINK_NOFOLLOW) != 0) {
+#endif
+        ec = detail::make_system_error();
+    }
+    return;
+#endif
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void permissions(const path& p, perms prms, perm_options opts)
+{
+    std::error_code ec;
+    permissions(p, prms, opts, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+}
+#endif
+
+GHC_INLINE void permissions(const path& p, perms prms, std::error_code& ec) noexcept
+{
+    permissions(p, prms, perm_options::replace, ec);
+}
+
+GHC_INLINE void permissions(const path& p, perms prms, perm_options opts, std::error_code& ec) noexcept
+{
+    if (static_cast<int>(opts & (perm_options::replace | perm_options::add | perm_options::remove)) == 0) {
+        ec = detail::make_error_code(detail::portable_error::invalid_argument);
+        return;
+    }
+    auto fs = symlink_status(p, ec);
+    if ((opts & perm_options::replace) != perm_options::replace) {
+        if ((opts & perm_options::add) == perm_options::add) {
+            prms = fs.permissions() | prms;
+        }
+        else {
+            prms = fs.permissions() & ~prms;
+        }
+    }
+#ifdef GHC_OS_WINDOWS
+#ifdef __GNUC__
+    auto oldAttr = GetFileAttributesW(GHC_NATIVEWP(p));
+    if (oldAttr != INVALID_FILE_ATTRIBUTES) {
+        DWORD newAttr = ((prms & perms::owner_write) == perms::owner_write) ? oldAttr & ~(static_cast<DWORD>(FILE_ATTRIBUTE_READONLY)) : oldAttr | FILE_ATTRIBUTE_READONLY;
+        if (oldAttr == newAttr || SetFileAttributesW(GHC_NATIVEWP(p), newAttr)) {
+            return;
+        }
+    }
+    ec = detail::make_system_error();
+#else
+    int mode = 0;
+    if ((prms & perms::owner_read) == perms::owner_read) {
+        mode |= _S_IREAD;
+    }
+    if ((prms & perms::owner_write) == perms::owner_write) {
+        mode |= _S_IWRITE;
+    }
+    if (::_wchmod(p.wstring().c_str(), mode) != 0) {
+        ec = detail::make_system_error();
+    }
+#endif
+#else
+    if ((opts & perm_options::nofollow) != perm_options::nofollow) {
+        if (::chmod(p.c_str(), static_cast<mode_t>(prms)) != 0) {
+            ec = detail::make_system_error();
+        }
+    }
+#endif
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE path proximate(const path& p, std::error_code& ec)
+{
+    auto cp = current_path(ec);
+    if (!ec) {
+        return proximate(p, cp, ec);
+    }
+    return path();
+}
+#endif
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE path proximate(const path& p, const path& base)
+{
+    return weakly_canonical(p).lexically_proximate(weakly_canonical(base));
+}
+#endif
+
+GHC_INLINE path proximate(const path& p, const path& base, std::error_code& ec)
+{
+    return weakly_canonical(p, ec).lexically_proximate(weakly_canonical(base, ec));
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE path read_symlink(const path& p)
+{
+    std::error_code ec;
+    auto result = read_symlink(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE path read_symlink(const path& p, std::error_code& ec)
+{
+    file_status fs = symlink_status(p, ec);
+    if (fs.type() != file_type::symlink) {
+        ec = detail::make_error_code(detail::portable_error::invalid_argument);
+        return path();
+    }
+    auto result = detail::resolveSymlink(p, ec);
+    return ec ? path() : result;
+}
+
+GHC_INLINE path relative(const path& p, std::error_code& ec)
+{
+    return relative(p, current_path(ec), ec);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE path relative(const path& p, const path& base)
+{
+    return weakly_canonical(p).lexically_relative(weakly_canonical(base));
+}
+#endif
+
+GHC_INLINE path relative(const path& p, const path& base, std::error_code& ec)
+{
+    return weakly_canonical(p, ec).lexically_relative(weakly_canonical(base, ec));
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool remove(const path& p)
+{
+    std::error_code ec;
+    auto result = remove(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE bool remove(const path& p, std::error_code& ec) noexcept
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+#ifdef GHC_USE_WCHAR_T
+    auto cstr = p.c_str();
+#else
+    std::wstring np = detail::fromUtf8<std::wstring>(p.u8string());
+    auto cstr = np.c_str();
+#endif
+    DWORD attr = GetFileAttributesW(cstr);
+    if (attr == INVALID_FILE_ATTRIBUTES) {
+        auto error = ::GetLastError();
+        if (error == ERROR_FILE_NOT_FOUND || error == ERROR_PATH_NOT_FOUND) {
+            return false;
+        }
+        ec = detail::make_system_error(error);
+    }
+    else if (attr & FILE_ATTRIBUTE_READONLY) {
+        auto new_attr = attr & ~static_cast<DWORD>(FILE_ATTRIBUTE_READONLY);
+        if (!SetFileAttributesW(cstr, new_attr)) {
+            auto error = ::GetLastError();
+            ec = detail::make_system_error(error);
+        }
+    }
+    if (!ec) {
+        if (attr & FILE_ATTRIBUTE_DIRECTORY) {
+            if (!RemoveDirectoryW(cstr)) {
+                ec = detail::make_system_error();
+            }
+        }
+        else {
+            if (!DeleteFileW(cstr)) {
+                ec = detail::make_system_error();
+            }
+        }
+    }
+#else
+    if (::remove(p.c_str()) == -1) {
+        auto error = errno;
+        if (error == ENOENT) {
+            return false;
+        }
+        ec = detail::make_system_error();
+    }
+#endif
+    return ec ? false : true;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE uintmax_t remove_all(const path& p)
+{
+    std::error_code ec;
+    auto result = remove_all(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE uintmax_t remove_all(const path& p, std::error_code& ec) noexcept
+{
+    ec.clear();
+    uintmax_t count = 0;
+    if (p == "/") {
+        ec = detail::make_error_code(detail::portable_error::not_supported);
+        return static_cast<uintmax_t>(-1);
+    }
+    std::error_code tec;
+    auto fs = symlink_status(p, tec);
+    if (exists(fs) && is_directory(fs)) {
+        for (auto iter = directory_iterator(p, ec); iter != directory_iterator(); iter.increment(ec)) {
+            if (ec && !detail::is_not_found_error(ec)) {
+                break;
+            }
+            bool is_symlink_result = iter->is_symlink(ec);
+            if (ec)
+                return static_cast<uintmax_t>(-1);
+            if (!is_symlink_result && iter->is_directory(ec)) {
+                count += remove_all(iter->path(), ec);
+                if (ec) {
+                    return static_cast<uintmax_t>(-1);
+                }
+            }
+            else {
+                if (!ec) {
+                    remove(iter->path(), ec);
+                }
+                if (ec) {
+                    return static_cast<uintmax_t>(-1);
+                }
+                ++count;
+            }
+        }
+    }
+    if (!ec) {
+        if (remove(p, ec)) {
+            ++count;
+        }
+    }
+    if (ec) {
+        return static_cast<uintmax_t>(-1);
+    }
+    return count;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void rename(const path& from, const path& to)
+{
+    std::error_code ec;
+    rename(from, to, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), from, to, ec);
+    }
+}
+#endif
+
+GHC_INLINE void rename(const path& from, const path& to, std::error_code& ec) noexcept
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    if (from != to) {
+        if (!MoveFileExW(GHC_NATIVEWP(from), GHC_NATIVEWP(to), (DWORD)MOVEFILE_REPLACE_EXISTING)) {
+            ec = detail::make_system_error();
+        }
+    }
+#else
+    if (from != to) {
+        if (::rename(from.c_str(), to.c_str()) != 0) {
+            ec = detail::make_system_error();
+        }
+    }
+#endif
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void resize_file(const path& p, uintmax_t size)
+{
+    std::error_code ec;
+    resize_file(p, size, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+}
+#endif
+
+GHC_INLINE void resize_file(const path& p, uintmax_t size, std::error_code& ec) noexcept
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    LARGE_INTEGER lisize;
+    lisize.QuadPart = static_cast<LONGLONG>(size);
+    if (lisize.QuadPart < 0) {
+#ifdef ERROR_FILE_TOO_LARGE
+        ec = detail::make_system_error(ERROR_FILE_TOO_LARGE);
+#else
+        ec = detail::make_system_error(223);
+#endif
+        return;
+    }
+    detail::unique_handle file(CreateFileW(GHC_NATIVEWP(p), GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL));
+    if (!file) {
+        ec = detail::make_system_error();
+    }
+    else if (SetFilePointerEx(file.get(), lisize, NULL, FILE_BEGIN) == 0 || SetEndOfFile(file.get()) == 0) {
+        ec = detail::make_system_error();
+    }
+#else
+    if (::truncate(p.c_str(), static_cast<off_t>(size)) != 0) {
+        ec = detail::make_system_error();
+    }
+#endif
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE space_info space(const path& p)
+{
+    std::error_code ec;
+    auto result = space(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE space_info space(const path& p, std::error_code& ec) noexcept
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    ULARGE_INTEGER freeBytesAvailableToCaller = {{ 0, 0 }};
+    ULARGE_INTEGER totalNumberOfBytes = {{ 0, 0 }};
+    ULARGE_INTEGER totalNumberOfFreeBytes = {{ 0, 0 }};
+    if (!GetDiskFreeSpaceExW(GHC_NATIVEWP(p), &freeBytesAvailableToCaller, &totalNumberOfBytes, &totalNumberOfFreeBytes)) {
+        ec = detail::make_system_error();
+        return {static_cast<uintmax_t>(-1), static_cast<uintmax_t>(-1), static_cast<uintmax_t>(-1)};
+    }
+    return {static_cast<uintmax_t>(totalNumberOfBytes.QuadPart), static_cast<uintmax_t>(totalNumberOfFreeBytes.QuadPart), static_cast<uintmax_t>(freeBytesAvailableToCaller.QuadPart)};
+#else
+    struct ::statvfs sfs;
+    if (::statvfs(p.c_str(), &sfs) != 0) {
+        ec = detail::make_system_error();
+        return {static_cast<uintmax_t>(-1), static_cast<uintmax_t>(-1), static_cast<uintmax_t>(-1)};
+    }
+    return {static_cast<uintmax_t>(sfs.f_blocks) * static_cast<uintmax_t>(sfs.f_frsize), static_cast<uintmax_t>(sfs.f_bfree) * static_cast<uintmax_t>(sfs.f_frsize), static_cast<uintmax_t>(sfs.f_bavail) * static_cast<uintmax_t>(sfs.f_frsize)};
+#endif
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE file_status status(const path& p)
+{
+    std::error_code ec;
+    auto result = status(p, ec);
+    if (result.type() == file_type::none) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE file_status status(const path& p, std::error_code& ec) noexcept
+{
+    return detail::status_ex(p, ec);
+}
+
+GHC_INLINE bool status_known(file_status s) noexcept
+{
+    return s.type() != file_type::none;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE file_status symlink_status(const path& p)
+{
+    std::error_code ec;
+    auto result = symlink_status(p, ec);
+    if (result.type() == file_type::none) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE file_status symlink_status(const path& p, std::error_code& ec) noexcept
+{
+    return detail::symlink_status_ex(p, ec);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE path temp_directory_path()
+{
+    std::error_code ec;
+    path result = temp_directory_path(ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE path temp_directory_path(std::error_code& ec) noexcept
+{
+    ec.clear();
+#ifdef GHC_OS_WINDOWS
+    wchar_t buffer[512];
+    auto rc = GetTempPathW(511, buffer);
+    if (!rc || rc > 511) {
+        ec = detail::make_system_error();
+        return path();
+    }
+    return path(std::wstring(buffer));
+#else
+    static const char* temp_vars[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR", nullptr};
+    const char* temp_path = nullptr;
+    for (auto temp_name = temp_vars; *temp_name != nullptr; ++temp_name) {
+        temp_path = std::getenv(*temp_name);
+        if (temp_path) {
+            return path(temp_path);
+        }
+    }
+    return path("/tmp");
+#endif
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE path weakly_canonical(const path& p)
+{
+    std::error_code ec;
+    auto result = weakly_canonical(p, ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), p, ec);
+    }
+    return result;
+}
+#endif
+
+GHC_INLINE path weakly_canonical(const path& p, std::error_code& ec) noexcept
+{
+    path result;
+    ec.clear();
+    bool scan = true;
+    for (auto pe : p) {
+        if (scan) {
+            std::error_code tec;
+            if (exists(result / pe, tec)) {
+                result /= pe;
+            }
+            else {
+                if (ec) {
+                    return path();
+                }
+                scan = false;
+                if (!result.empty()) {
+                    result = canonical(result, ec) / pe;
+                    if (ec) {
+                        break;
+                    }
+                }
+                else {
+                    result /= pe;
+                }
+            }
+        }
+        else {
+            result /= pe;
+        }
+    }
+    if (scan) {
+        if (!result.empty()) {
+            result = canonical(result, ec);
+        }
+    }
+    return ec ? path() : result.lexically_normal();
+}
+
+//-----------------------------------------------------------------------------
+// [fs.class.file_status] class file_status
+// [fs.file_status.cons] constructors and destructor
+GHC_INLINE file_status::file_status() noexcept
+    : file_status(file_type::none)
+{
+}
+
+GHC_INLINE file_status::file_status(file_type ft, perms prms) noexcept
+    : _type(ft)
+    , _perms(prms)
+{
+}
+
+GHC_INLINE file_status::file_status(const file_status& other) noexcept
+    : _type(other._type)
+    , _perms(other._perms)
+{
+}
+
+GHC_INLINE file_status::file_status(file_status&& other) noexcept
+    : _type(other._type)
+    , _perms(other._perms)
+{
+}
+
+GHC_INLINE file_status::~file_status() {}
+
+// assignments:
+GHC_INLINE file_status& file_status::operator=(const file_status& rhs) noexcept
+{
+    _type = rhs._type;
+    _perms = rhs._perms;
+    return *this;
+}
+
+GHC_INLINE file_status& file_status::operator=(file_status&& rhs) noexcept
+{
+    _type = rhs._type;
+    _perms = rhs._perms;
+    return *this;
+}
+
+// [fs.file_status.mods] modifiers
+GHC_INLINE void file_status::type(file_type ft) noexcept
+{
+    _type = ft;
+}
+
+GHC_INLINE void file_status::permissions(perms prms) noexcept
+{
+    _perms = prms;
+}
+
+// [fs.file_status.obs] observers
+GHC_INLINE file_type file_status::type() const noexcept
+{
+    return _type;
+}
+
+GHC_INLINE perms file_status::permissions() const noexcept
+{
+    return _perms;
+}
+
+//-----------------------------------------------------------------------------
+// [fs.class.directory_entry] class directory_entry
+// [fs.dir.entry.cons] constructors and destructor
+// directory_entry::directory_entry() noexcept = default;
+// directory_entry::directory_entry(const directory_entry&) = default;
+// directory_entry::directory_entry(directory_entry&&) noexcept = default;
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE directory_entry::directory_entry(const filesystem::path& p)
+    : _path(p)
+    , _file_size(static_cast<uintmax_t>(-1))
+#ifndef GHC_OS_WINDOWS
+    , _hard_link_count(static_cast<uintmax_t>(-1))
+#endif
+    , _last_write_time(0)
+{
+    refresh();
+}
+#endif
+
+GHC_INLINE directory_entry::directory_entry(const filesystem::path& p, std::error_code& ec)
+    : _path(p)
+    , _file_size(static_cast<uintmax_t>(-1))
+#ifndef GHC_OS_WINDOWS
+    , _hard_link_count(static_cast<uintmax_t>(-1))
+#endif
+    , _last_write_time(0)
+{
+    refresh(ec);
+}
+
+GHC_INLINE directory_entry::~directory_entry() {}
+
+// assignments:
+// directory_entry& directory_entry::operator=(const directory_entry&) = default;
+// directory_entry& directory_entry::operator=(directory_entry&&) noexcept = default;
+
+// [fs.dir.entry.mods] directory_entry modifiers
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void directory_entry::assign(const filesystem::path& p)
+{
+    _path = p;
+    refresh();
+}
+#endif
+
+GHC_INLINE void directory_entry::assign(const filesystem::path& p, std::error_code& ec)
+{
+    _path = p;
+    refresh(ec);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void directory_entry::replace_filename(const filesystem::path& p)
+{
+    _path.replace_filename(p);
+    refresh();
+}
+#endif
+
+GHC_INLINE void directory_entry::replace_filename(const filesystem::path& p, std::error_code& ec)
+{
+    _path.replace_filename(p);
+    refresh(ec);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void directory_entry::refresh()
+{
+    std::error_code ec;
+    refresh(ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), _path, ec);
+    }
+}
+#endif
+
+GHC_INLINE void directory_entry::refresh(std::error_code& ec) noexcept
+{
+#ifdef GHC_OS_WINDOWS
+    _status = detail::status_ex(_path, ec, &_symlink_status, &_file_size, nullptr, &_last_write_time);
+#else
+    _status = detail::status_ex(_path, ec, &_symlink_status, &_file_size, &_hard_link_count, &_last_write_time);
+#endif
+}
+
+// [fs.dir.entry.obs] directory_entry observers
+GHC_INLINE const filesystem::path& directory_entry::path() const noexcept
+{
+    return _path;
+}
+
+GHC_INLINE directory_entry::operator const filesystem::path&() const noexcept
+{
+    return _path;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE file_type directory_entry::status_file_type() const
+{
+    return _status.type() != file_type::none ? _status.type() : filesystem::status(path()).type();
+}
+#endif
+
+GHC_INLINE file_type directory_entry::status_file_type(std::error_code& ec) const noexcept
+{
+    if (_status.type() != file_type::none) {
+        ec.clear();
+        return _status.type();
+    }
+    return filesystem::status(path(), ec).type();
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool directory_entry::exists() const
+{
+    return status_file_type() != file_type::not_found;
+}
+#endif
+
+GHC_INLINE bool directory_entry::exists(std::error_code& ec) const noexcept
+{
+    return status_file_type(ec) != file_type::not_found;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool directory_entry::is_block_file() const
+{
+    return status_file_type() == file_type::block;
+}
+#endif
+GHC_INLINE bool directory_entry::is_block_file(std::error_code& ec) const noexcept
+{
+    return status_file_type(ec) == file_type::block;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool directory_entry::is_character_file() const
+{
+    return status_file_type() == file_type::character;
+}
+#endif
+
+GHC_INLINE bool directory_entry::is_character_file(std::error_code& ec) const noexcept
+{
+    return status_file_type(ec) == file_type::character;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool directory_entry::is_directory() const
+{
+    return status_file_type() == file_type::directory;
+}
+#endif
+
+GHC_INLINE bool directory_entry::is_directory(std::error_code& ec) const noexcept
+{
+    return status_file_type(ec) == file_type::directory;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool directory_entry::is_fifo() const
+{
+    return status_file_type() == file_type::fifo;
+}
+#endif
+
+GHC_INLINE bool directory_entry::is_fifo(std::error_code& ec) const noexcept
+{
+    return status_file_type(ec) == file_type::fifo;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool directory_entry::is_other() const
+{
+    auto ft = status_file_type();
+    return ft != file_type::none && ft != file_type::not_found && ft != file_type::regular && ft != file_type::directory && !is_symlink();
+}
+#endif
+
+GHC_INLINE bool directory_entry::is_other(std::error_code& ec) const noexcept
+{
+    auto ft = status_file_type(ec);
+    bool other = ft != file_type::none && ft != file_type::not_found && ft != file_type::regular && ft != file_type::directory && !is_symlink(ec);
+    return !ec && other;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool directory_entry::is_regular_file() const
+{
+    return status_file_type() == file_type::regular;
+}
+#endif
+
+GHC_INLINE bool directory_entry::is_regular_file(std::error_code& ec) const noexcept
+{
+    return status_file_type(ec) == file_type::regular;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool directory_entry::is_socket() const
+{
+    return status_file_type() == file_type::socket;
+}
+#endif
+
+GHC_INLINE bool directory_entry::is_socket(std::error_code& ec) const noexcept
+{
+    return status_file_type(ec) == file_type::socket;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE bool directory_entry::is_symlink() const
+{
+    return _symlink_status.type() != file_type::none ? _symlink_status.type() == file_type::symlink : filesystem::is_symlink(symlink_status());
+}
+#endif
+
+GHC_INLINE bool directory_entry::is_symlink(std::error_code& ec) const noexcept
+{
+    if (_symlink_status.type() != file_type::none) {
+        ec.clear();
+        return _symlink_status.type() == file_type::symlink;
+    }
+    return filesystem::is_symlink(symlink_status(ec));
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE uintmax_t directory_entry::file_size() const
+{
+    if (_file_size != static_cast<uintmax_t>(-1)) {
+        return _file_size;
+    }
+    return filesystem::file_size(path());
+}
+#endif
+
+GHC_INLINE uintmax_t directory_entry::file_size(std::error_code& ec) const noexcept
+{
+    if (_file_size != static_cast<uintmax_t>(-1)) {
+        ec.clear();
+        return _file_size;
+    }
+    return filesystem::file_size(path(), ec);
+}
+
+#ifndef GHC_OS_WEB
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE uintmax_t directory_entry::hard_link_count() const
+{
+#ifndef GHC_OS_WINDOWS
+    if (_hard_link_count != static_cast<uintmax_t>(-1)) {
+        return _hard_link_count;
+    }
+#endif
+    return filesystem::hard_link_count(path());
+}
+#endif
+
+GHC_INLINE uintmax_t directory_entry::hard_link_count(std::error_code& ec) const noexcept
+{
+#ifndef GHC_OS_WINDOWS
+    if (_hard_link_count != static_cast<uintmax_t>(-1)) {
+        ec.clear();
+        return _hard_link_count;
+    }
+#endif
+    return filesystem::hard_link_count(path(), ec);
+}
+#endif
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE file_time_type directory_entry::last_write_time() const
+{
+    if (_last_write_time != 0) {
+        return std::chrono::system_clock::from_time_t(_last_write_time);
+    }
+    return filesystem::last_write_time(path());
+}
+#endif
+
+GHC_INLINE file_time_type directory_entry::last_write_time(std::error_code& ec) const noexcept
+{
+    if (_last_write_time != 0) {
+        ec.clear();
+        return std::chrono::system_clock::from_time_t(_last_write_time);
+    }
+    return filesystem::last_write_time(path(), ec);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE file_status directory_entry::status() const
+{
+    if (_status.type() != file_type::none && _status.permissions() != perms::unknown) {
+        return _status;
+    }
+    return filesystem::status(path());
+}
+#endif
+
+GHC_INLINE file_status directory_entry::status(std::error_code& ec) const noexcept
+{
+    if (_status.type() != file_type::none && _status.permissions() != perms::unknown) {
+        ec.clear();
+        return _status;
+    }
+    return filesystem::status(path(), ec);
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE file_status directory_entry::symlink_status() const
+{
+    if (_symlink_status.type() != file_type::none && _symlink_status.permissions() != perms::unknown) {
+        return _symlink_status;
+    }
+    return filesystem::symlink_status(path());
+}
+#endif
+
+GHC_INLINE file_status directory_entry::symlink_status(std::error_code& ec) const noexcept
+{
+    if (_symlink_status.type() != file_type::none && _symlink_status.permissions() != perms::unknown) {
+        ec.clear();
+        return _symlink_status;
+    }
+    return filesystem::symlink_status(path(), ec);
+}
+
+#ifdef GHC_HAS_THREEWAY_COMP
+GHC_INLINE std::strong_ordering directory_entry::operator<=>(const directory_entry& rhs) const noexcept
+{
+    return _path <=> rhs._path;
+}
+#endif
+
+GHC_INLINE bool directory_entry::operator<(const directory_entry& rhs) const noexcept
+{
+    return _path < rhs._path;
+}
+
+GHC_INLINE bool directory_entry::operator==(const directory_entry& rhs) const noexcept
+{
+    return _path == rhs._path;
+}
+
+GHC_INLINE bool directory_entry::operator!=(const directory_entry& rhs) const noexcept
+{
+    return _path != rhs._path;
+}
+
+GHC_INLINE bool directory_entry::operator<=(const directory_entry& rhs) const noexcept
+{
+    return _path <= rhs._path;
+}
+
+GHC_INLINE bool directory_entry::operator>(const directory_entry& rhs) const noexcept
+{
+    return _path > rhs._path;
+}
+
+GHC_INLINE bool directory_entry::operator>=(const directory_entry& rhs) const noexcept
+{
+    return _path >= rhs._path;
+}
+
+//-----------------------------------------------------------------------------
+// [fs.class.directory_iterator] class directory_iterator
+
+#ifdef GHC_OS_WINDOWS
+class directory_iterator::impl
+{
+public:
+    impl(const path& p, directory_options options)
+        : _base(p)
+        , _options(options)
+        , _dirHandle(INVALID_HANDLE_VALUE)
+    {
+        if (!_base.empty()) {
+            ZeroMemory(&_findData, sizeof(WIN32_FIND_DATAW));
+            if ((_dirHandle = FindFirstFileW(GHC_NATIVEWP((_base / "*")), &_findData)) != INVALID_HANDLE_VALUE) {
+                if (std::wstring(_findData.cFileName) == L"." || std::wstring(_findData.cFileName) == L"..") {
+                    increment(_ec);
+                }
+                else {
+                    _dir_entry._path = _base / std::wstring(_findData.cFileName);
+                    copyToDirEntry(_ec);
+                }
+            }
+            else {
+                auto error = ::GetLastError();
+                _base = filesystem::path();
+                if (error != ERROR_ACCESS_DENIED || (options & directory_options::skip_permission_denied) == directory_options::none) {
+                    _ec = detail::make_system_error();
+                }
+            }
+        }
+    }
+    impl(const impl& other) = delete;
+    ~impl()
+    {
+        if (_dirHandle != INVALID_HANDLE_VALUE) {
+            FindClose(_dirHandle);
+            _dirHandle = INVALID_HANDLE_VALUE;
+        }
+    }
+    void increment(std::error_code& ec)
+    {
+        if (_dirHandle != INVALID_HANDLE_VALUE) {
+            do {
+                if (FindNextFileW(_dirHandle, &_findData)) {
+                    _dir_entry._path = _base;
+#ifdef GHC_USE_WCHAR_T
+                    _dir_entry._path.append_name(_findData.cFileName);
+#else
+#ifdef GHC_RAISE_UNICODE_ERRORS
+                    try {
+                        _dir_entry._path.append_name(detail::toUtf8(_findData.cFileName).c_str());
+                    }
+                    catch (filesystem_error& fe) {
+                        ec = fe.code();
+                        return;
+                    }
+#else
+                    _dir_entry._path.append_name(detail::toUtf8(_findData.cFileName).c_str());
+#endif
+#endif
+                    copyToDirEntry(ec);
+                }
+                else {
+                    auto err = ::GetLastError();
+                    if (err != ERROR_NO_MORE_FILES) {
+                        _ec = ec = detail::make_system_error(err);
+                    }
+                    FindClose(_dirHandle);
+                    _dirHandle = INVALID_HANDLE_VALUE;
+                    _dir_entry._path.clear();
+                    break;
+                }
+            } while (std::wstring(_findData.cFileName) == L"." || std::wstring(_findData.cFileName) == L"..");
+        }
+        else {
+            ec = _ec;
+        }
+    }
+    void copyToDirEntry(std::error_code& ec)
+    {
+        if (_findData.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
+            _dir_entry._status = detail::status_ex(_dir_entry._path, ec, &_dir_entry._symlink_status, &_dir_entry._file_size, nullptr, &_dir_entry._last_write_time);
+        }
+        else {
+            _dir_entry._status = detail::status_from_INFO(_dir_entry._path, &_findData, ec, &_dir_entry._file_size, &_dir_entry._last_write_time);
+            _dir_entry._symlink_status = _dir_entry._status;
+        }
+        if (ec) {
+            if (_dir_entry._status.type() != file_type::none && _dir_entry._symlink_status.type() != file_type::none) {
+                ec.clear();
+            }
+            else {
+                _dir_entry._file_size = static_cast<uintmax_t>(-1);
+                _dir_entry._last_write_time = 0;
+            }
+        }
+    }
+    path _base;
+    directory_options _options;
+    WIN32_FIND_DATAW _findData;
+    HANDLE _dirHandle;
+    directory_entry _dir_entry;
+    std::error_code _ec;
+};
+#else
+// POSIX implementation
+class directory_iterator::impl
+{
+public:
+    impl(const path& path, directory_options options)
+        : _base(path)
+        , _options(options)
+        , _dir(nullptr)
+        , _entry(nullptr)
+    {
+        if (!path.empty()) {
+            _dir = ::opendir(path.native().c_str());
+            if (!_dir) {
+                auto error = errno;
+                _base = filesystem::path();
+                if ((error != EACCES && error != EPERM) || (options & directory_options::skip_permission_denied) == directory_options::none) {
+                    _ec = detail::make_system_error();
+                }
+            }
+            else {
+                increment(_ec);
+            }
+        }
+    }
+    impl(const impl& other) = delete;
+    ~impl()
+    {
+        if (_dir) {
+            ::closedir(_dir);
+        }
+    }
+    void increment(std::error_code& ec)
+    {
+        if (_dir) {
+            bool skip;
+            do {
+                skip = false;
+                errno = 0;
+                _entry = ::readdir(_dir);
+                if (_entry) {
+                    _dir_entry._path = _base;
+                    _dir_entry._path.append_name(_entry->d_name);
+                    copyToDirEntry();
+                    if (ec && (ec.value() == EACCES || ec.value() == EPERM) && (_options & directory_options::skip_permission_denied) == directory_options::skip_permission_denied) {
+                        ec.clear();
+                        skip = true;
+                    }
+                }
+                else {
+                    ::closedir(_dir);
+                    _dir = nullptr;
+                    _dir_entry._path.clear();
+                    if (errno) {
+                        ec = detail::make_system_error();
+                    }
+                    break;
+                }
+            } while (skip || std::strcmp(_entry->d_name, ".") == 0 || std::strcmp(_entry->d_name, "..") == 0);
+        }
+    }
+
+    void copyToDirEntry()
+    {
+        _dir_entry._symlink_status.permissions(perms::unknown);
+        auto ft = detail::file_type_from_dirent(*_entry);
+        _dir_entry._symlink_status.type(ft);
+        if (ft != file_type::symlink) {
+            _dir_entry._status = _dir_entry._symlink_status;
+        }
+        else {
+            _dir_entry._status.type(file_type::none);
+            _dir_entry._status.permissions(perms::unknown);
+        }
+        _dir_entry._file_size = static_cast<uintmax_t>(-1);
+        _dir_entry._hard_link_count = static_cast<uintmax_t>(-1);
+        _dir_entry._last_write_time = 0;
+    }
+    path _base;
+    directory_options _options;
+    DIR* _dir;
+    struct ::dirent* _entry;
+    directory_entry _dir_entry;
+    std::error_code _ec;
+};
+#endif
+
+// [fs.dir.itr.members] member functions
+GHC_INLINE directory_iterator::directory_iterator() noexcept
+    : _impl(new impl(path(), directory_options::none))
+{
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE directory_iterator::directory_iterator(const path& p)
+    : _impl(new impl(p, directory_options::none))
+{
+    if (_impl->_ec) {
+        throw filesystem_error(detail::systemErrorText(_impl->_ec.value()), p, _impl->_ec);
+    }
+    _impl->_ec.clear();
+}
+
+GHC_INLINE directory_iterator::directory_iterator(const path& p, directory_options options)
+    : _impl(new impl(p, options))
+{
+    if (_impl->_ec) {
+        throw filesystem_error(detail::systemErrorText(_impl->_ec.value()), p, _impl->_ec);
+    }
+}
+#endif
+
+GHC_INLINE directory_iterator::directory_iterator(const path& p, std::error_code& ec) noexcept
+    : _impl(new impl(p, directory_options::none))
+{
+    if (_impl->_ec) {
+        ec = _impl->_ec;
+    }
+}
+
+GHC_INLINE directory_iterator::directory_iterator(const path& p, directory_options options, std::error_code& ec) noexcept
+    : _impl(new impl(p, options))
+{
+    if (_impl->_ec) {
+        ec = _impl->_ec;
+    }
+}
+
+GHC_INLINE directory_iterator::directory_iterator(const directory_iterator& rhs)
+    : _impl(rhs._impl)
+{
+}
+
+GHC_INLINE directory_iterator::directory_iterator(directory_iterator&& rhs) noexcept
+    : _impl(std::move(rhs._impl))
+{
+}
+
+GHC_INLINE directory_iterator::~directory_iterator() {}
+
+GHC_INLINE directory_iterator& directory_iterator::operator=(const directory_iterator& rhs)
+{
+    _impl = rhs._impl;
+    return *this;
+}
+
+GHC_INLINE directory_iterator& directory_iterator::operator=(directory_iterator&& rhs) noexcept
+{
+    _impl = std::move(rhs._impl);
+    return *this;
+}
+
+GHC_INLINE const directory_entry& directory_iterator::operator*() const
+{
+    return _impl->_dir_entry;
+}
+
+GHC_INLINE const directory_entry* directory_iterator::operator->() const
+{
+    return &_impl->_dir_entry;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE directory_iterator& directory_iterator::operator++()
+{
+    std::error_code ec;
+    _impl->increment(ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), _impl->_dir_entry._path, ec);
+    }
+    return *this;
+}
+#endif
+
+GHC_INLINE directory_iterator& directory_iterator::increment(std::error_code& ec) noexcept
+{
+    _impl->increment(ec);
+    return *this;
+}
+
+GHC_INLINE bool directory_iterator::operator==(const directory_iterator& rhs) const
+{
+    return _impl->_dir_entry._path == rhs._impl->_dir_entry._path;
+}
+
+GHC_INLINE bool directory_iterator::operator!=(const directory_iterator& rhs) const
+{
+    return _impl->_dir_entry._path != rhs._impl->_dir_entry._path;
+}
+
+// [fs.dir.itr.nonmembers] directory_iterator non-member functions
+
+GHC_INLINE directory_iterator begin(directory_iterator iter) noexcept
+{
+    return iter;
+}
+
+GHC_INLINE directory_iterator end(const directory_iterator&) noexcept
+{
+    return directory_iterator();
+}
+
+//-----------------------------------------------------------------------------
+// [fs.class.rec.dir.itr] class recursive_directory_iterator
+
+GHC_INLINE recursive_directory_iterator::recursive_directory_iterator() noexcept
+    : _impl(new recursive_directory_iterator_impl(directory_options::none, true))
+{
+    _impl->_dir_iter_stack.push(directory_iterator());
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE recursive_directory_iterator::recursive_directory_iterator(const path& p)
+    : _impl(new recursive_directory_iterator_impl(directory_options::none, true))
+{
+    _impl->_dir_iter_stack.push(directory_iterator(p));
+}
+
+GHC_INLINE recursive_directory_iterator::recursive_directory_iterator(const path& p, directory_options options)
+    : _impl(new recursive_directory_iterator_impl(options, true))
+{
+    _impl->_dir_iter_stack.push(directory_iterator(p, options));
+}
+#endif
+
+GHC_INLINE recursive_directory_iterator::recursive_directory_iterator(const path& p, directory_options options, std::error_code& ec) noexcept
+    : _impl(new recursive_directory_iterator_impl(options, true))
+{
+    _impl->_dir_iter_stack.push(directory_iterator(p, options, ec));
+}
+
+GHC_INLINE recursive_directory_iterator::recursive_directory_iterator(const path& p, std::error_code& ec) noexcept
+    : _impl(new recursive_directory_iterator_impl(directory_options::none, true))
+{
+    _impl->_dir_iter_stack.push(directory_iterator(p, ec));
+}
+
+GHC_INLINE recursive_directory_iterator::recursive_directory_iterator(const recursive_directory_iterator& rhs)
+    : _impl(rhs._impl)
+{
+}
+
+GHC_INLINE recursive_directory_iterator::recursive_directory_iterator(recursive_directory_iterator&& rhs) noexcept
+    : _impl(std::move(rhs._impl))
+{
+}
+
+GHC_INLINE recursive_directory_iterator::~recursive_directory_iterator() {}
+
+// [fs.rec.dir.itr.members] observers
+GHC_INLINE directory_options recursive_directory_iterator::options() const
+{
+    return _impl->_options;
+}
+
+GHC_INLINE int recursive_directory_iterator::depth() const
+{
+    return static_cast<int>(_impl->_dir_iter_stack.size() - 1);
+}
+
+GHC_INLINE bool recursive_directory_iterator::recursion_pending() const
+{
+    return _impl->_recursion_pending;
+}
+
+GHC_INLINE const directory_entry& recursive_directory_iterator::operator*() const
+{
+    return *(_impl->_dir_iter_stack.top());
+}
+
+GHC_INLINE const directory_entry* recursive_directory_iterator::operator->() const
+{
+    return &(*(_impl->_dir_iter_stack.top()));
+}
+
+// [fs.rec.dir.itr.members] modifiers recursive_directory_iterator&
+GHC_INLINE recursive_directory_iterator& recursive_directory_iterator::operator=(const recursive_directory_iterator& rhs)
+{
+    _impl = rhs._impl;
+    return *this;
+}
+
+GHC_INLINE recursive_directory_iterator& recursive_directory_iterator::operator=(recursive_directory_iterator&& rhs) noexcept
+{
+    _impl = std::move(rhs._impl);
+    return *this;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE recursive_directory_iterator& recursive_directory_iterator::operator++()
+{
+    std::error_code ec;
+    increment(ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), _impl->_dir_iter_stack.empty() ? path() : _impl->_dir_iter_stack.top()->path(), ec);
+    }
+    return *this;
+}
+#endif
+
+GHC_INLINE recursive_directory_iterator& recursive_directory_iterator::increment(std::error_code& ec) noexcept
+{
+    bool isSymLink = (*this)->is_symlink(ec);
+    bool isDir = !ec && (*this)->is_directory(ec);
+    if (isSymLink && detail::is_not_found_error(ec)) {
+        ec.clear();
+    }
+    if (!ec) {
+        if (recursion_pending() && isDir && (!isSymLink || (options() & directory_options::follow_directory_symlink) != directory_options::none)) {
+            _impl->_dir_iter_stack.push(directory_iterator((*this)->path(), _impl->_options, ec));
+        }
+        else {
+            _impl->_dir_iter_stack.top().increment(ec);
+        }
+        if (!ec) {
+            while (depth() && _impl->_dir_iter_stack.top() == directory_iterator()) {
+                _impl->_dir_iter_stack.pop();
+                _impl->_dir_iter_stack.top().increment(ec);
+            }
+        }
+        else if (!_impl->_dir_iter_stack.empty()) {
+            _impl->_dir_iter_stack.pop();
+        }
+        _impl->_recursion_pending = true;
+    }
+    return *this;
+}
+
+#ifdef GHC_WITH_EXCEPTIONS
+GHC_INLINE void recursive_directory_iterator::pop()
+{
+    std::error_code ec;
+    pop(ec);
+    if (ec) {
+        throw filesystem_error(detail::systemErrorText(ec.value()), _impl->_dir_iter_stack.empty() ? path() : _impl->_dir_iter_stack.top()->path(), ec);
+    }
+}
+#endif
+
+GHC_INLINE void recursive_directory_iterator::pop(std::error_code& ec)
+{
+    if (depth() == 0) {
+        *this = recursive_directory_iterator();
+    }
+    else {
+        do {
+            _impl->_dir_iter_stack.pop();
+            _impl->_dir_iter_stack.top().increment(ec);
+        } while (depth() && _impl->_dir_iter_stack.top() == directory_iterator());
+    }
+}
+
+GHC_INLINE void recursive_directory_iterator::disable_recursion_pending()
+{
+    _impl->_recursion_pending = false;
+}
+
+// other members as required by [input.iterators]
+GHC_INLINE bool recursive_directory_iterator::operator==(const recursive_directory_iterator& rhs) const
+{
+    return _impl->_dir_iter_stack.top() == rhs._impl->_dir_iter_stack.top();
+}
+
+GHC_INLINE bool recursive_directory_iterator::operator!=(const recursive_directory_iterator& rhs) const
+{
+    return _impl->_dir_iter_stack.top() != rhs._impl->_dir_iter_stack.top();
+}
+
+// [fs.rec.dir.itr.nonmembers] directory_iterator non-member functions
+GHC_INLINE recursive_directory_iterator begin(recursive_directory_iterator iter) noexcept
+{
+    return iter;
+}
+
+GHC_INLINE recursive_directory_iterator end(const recursive_directory_iterator&) noexcept
+{
+    return recursive_directory_iterator();
+}
+
+#endif  // GHC_EXPAND_IMPL
+
+}  // namespace filesystem
+}  // namespace ghc
+
+// cleanup some macros
+#undef GHC_INLINE
+#undef GHC_EXPAND_IMPL
+
+#endif  // GHC_FILESYSTEM_H
diff --git a/libfuse/lib/os.cpp b/libfuse/lib/os.cpp
new file mode 100644
index 00000000..f388ead0
--- /dev/null
+++ b/libfuse/lib/os.cpp
@@ -0,0 +1,361 @@
+// Formatting library for C++ - optional OS-specific functionality
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+// Disable bogus MSVC warnings.
+#if !defined(_CRT_SECURE_NO_WARNINGS) && defined(_MSC_VER)
+#  define _CRT_SECURE_NO_WARNINGS
+#endif
+
+#include "fmt/os.h"
+
+#include <climits>
+
+#if FMT_USE_FCNTL
+#  include <sys/stat.h>
+#  include <sys/types.h>
+
+#  ifndef _WIN32
+#    include <unistd.h>
+#  else
+#    ifndef WIN32_LEAN_AND_MEAN
+#      define WIN32_LEAN_AND_MEAN
+#    endif
+#    include <io.h>
+
+#    ifndef S_IRUSR
+#      define S_IRUSR _S_IREAD
+#    endif
+#    ifndef S_IWUSR
+#      define S_IWUSR _S_IWRITE
+#    endif
+#    ifndef S_IRGRP
+#      define S_IRGRP 0
+#    endif
+#    ifndef S_IWGRP
+#      define S_IWGRP 0
+#    endif
+#    ifndef S_IROTH
+#      define S_IROTH 0
+#    endif
+#    ifndef S_IWOTH
+#      define S_IWOTH 0
+#    endif
+#  endif  // _WIN32
+#endif    // FMT_USE_FCNTL
+
+#ifdef _WIN32
+#  include <windows.h>
+#endif
+
+namespace {
+#ifdef _WIN32
+// Return type of read and write functions.
+using rwresult = int;
+
+// On Windows the count argument to read and write is unsigned, so convert
+// it from size_t preventing integer overflow.
+inline unsigned convert_rwcount(std::size_t count) {
+  return count <= UINT_MAX ? static_cast<unsigned>(count) : UINT_MAX;
+}
+#elif FMT_USE_FCNTL
+// Return type of read and write functions.
+using rwresult = ssize_t;
+
+inline std::size_t convert_rwcount(std::size_t count) { return count; }
+#endif
+}  // namespace
+
+FMT_BEGIN_NAMESPACE
+
+#ifdef _WIN32
+detail::utf16_to_utf8::utf16_to_utf8(basic_string_view<wchar_t> s) {
+  if (int error_code = convert(s)) {
+    FMT_THROW(windows_error(error_code,
+                            "cannot convert string from UTF-16 to UTF-8"));
+  }
+}
+
+int detail::utf16_to_utf8::convert(basic_string_view<wchar_t> s) {
+  if (s.size() > INT_MAX) return ERROR_INVALID_PARAMETER;
+  int s_size = static_cast<int>(s.size());
+  if (s_size == 0) {
+    // WideCharToMultiByte does not support zero length, handle separately.
+    buffer_.resize(1);
+    buffer_[0] = 0;
+    return 0;
+  }
+
+  int length = WideCharToMultiByte(CP_UTF8, 0, s.data(), s_size, nullptr, 0,
+                                   nullptr, nullptr);
+  if (length == 0) return GetLastError();
+  buffer_.resize(length + 1);
+  length = WideCharToMultiByte(CP_UTF8, 0, s.data(), s_size, &buffer_[0],
+                               length, nullptr, nullptr);
+  if (length == 0) return GetLastError();
+  buffer_[length] = 0;
+  return 0;
+}
+
+namespace detail {
+
+class system_message {
+  system_message(const system_message&) = delete;
+  void operator=(const system_message&) = delete;
+
+  unsigned long result_;
+  wchar_t* message_;
+
+  static bool is_whitespace(wchar_t c) noexcept {
+    return c == L' ' || c == L'\n' || c == L'\r' || c == L'\t' || c == L'\0';
+  }
+
+ public:
+  explicit system_message(unsigned long error_code)
+      : result_(0), message_(nullptr) {
+    result_ = FormatMessageW(
+        FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
+            FORMAT_MESSAGE_IGNORE_INSERTS,
+        nullptr, error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+        reinterpret_cast<wchar_t*>(&message_), 0, nullptr);
+    if (result_ != 0) {
+      while (result_ != 0 && is_whitespace(message_[result_ - 1])) {
+        --result_;
+      }
+    }
+  }
+  ~system_message() { LocalFree(message_); }
+  explicit operator bool() const noexcept { return result_ != 0; }
+  operator basic_string_view<wchar_t>() const noexcept {
+    return basic_string_view<wchar_t>(message_, result_);
+  }
+};
+
+class utf8_system_category final : public std::error_category {
+ public:
+  const char* name() const noexcept override { return "system"; }
+  std::string message(int error_code) const override {
+    system_message msg(error_code);
+    if (msg) {
+      utf16_to_utf8 utf8_message;
+      if (utf8_message.convert(msg) == ERROR_SUCCESS) {
+        return utf8_message.str();
+      }
+    }
+    return "unknown error";
+  }
+};
+
+}  // namespace detail
+
+FMT_API const std::error_category& system_category() noexcept {
+  static const detail::utf8_system_category category;
+  return category;
+}
+
+std::system_error vwindows_error(int err_code, string_view format_str,
+                                 format_args args) {
+  auto ec = std::error_code(err_code, system_category());
+  return std::system_error(ec, vformat(format_str, args));
+}
+
+void detail::format_windows_error(detail::buffer<char>& out, int error_code,
+                                  const char* message) noexcept {
+  FMT_TRY {
+    system_message msg(error_code);
+    if (msg) {
+      utf16_to_utf8 utf8_message;
+      if (utf8_message.convert(msg) == ERROR_SUCCESS) {
+        fmt::format_to(buffer_appender<char>(out), "{}: {}", message, utf8_message);
+        return;
+      }
+    }
+  }
+  FMT_CATCH(...) {}
+  format_error_code(out, error_code, message);
+}
+
+void report_windows_error(int error_code, const char* message) noexcept {
+  report_error(detail::format_windows_error, error_code, message);
+}
+#endif  // _WIN32
+
+buffered_file::~buffered_file() noexcept {
+  if (file_ && FMT_SYSTEM(fclose(file_)) != 0)
+    report_system_error(errno, "cannot close file");
+}
+
+buffered_file::buffered_file(cstring_view filename, cstring_view mode) {
+  FMT_RETRY_VAL(file_, FMT_SYSTEM(fopen(filename.c_str(), mode.c_str())),
+                nullptr);
+  if (!file_)
+    FMT_THROW(system_error(errno, "cannot open file {}", filename.c_str()));
+}
+
+void buffered_file::close() {
+  if (!file_) return;
+  int result = FMT_SYSTEM(fclose(file_));
+  file_ = nullptr;
+  if (result != 0) FMT_THROW(system_error(errno, "cannot close file"));
+}
+
+int buffered_file::descriptor() const {
+  int fd = FMT_POSIX_CALL(fileno(file_));
+  if (fd == -1) FMT_THROW(system_error(errno, "cannot get file descriptor"));
+  return fd;
+}
+
+#if FMT_USE_FCNTL
+file::file(cstring_view path, int oflag) {
+#  ifdef _WIN32
+  using mode_t = int;
+#  endif
+  constexpr mode_t mode =
+      S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
+#  if defined(_WIN32) && !defined(__MINGW32__)
+  fd_ = -1;
+  FMT_POSIX_CALL(sopen_s(&fd_, path.c_str(), oflag, _SH_DENYNO, mode));
+#  else
+  FMT_RETRY(fd_, FMT_POSIX_CALL(open(path.c_str(), oflag, mode)));
+#  endif
+  if (fd_ == -1)
+    FMT_THROW(system_error(errno, "cannot open file {}", path.c_str()));
+}
+
+file::~file() noexcept {
+  // Don't retry close in case of EINTR!
+  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
+  if (fd_ != -1 && FMT_POSIX_CALL(close(fd_)) != 0)
+    report_system_error(errno, "cannot close file");
+}
+
+void file::close() {
+  if (fd_ == -1) return;
+  // Don't retry close in case of EINTR!
+  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
+  int result = FMT_POSIX_CALL(close(fd_));
+  fd_ = -1;
+  if (result != 0) FMT_THROW(system_error(errno, "cannot close file"));
+}
+
+long long file::size() const {
+#  ifdef _WIN32
+  // Use GetFileSize instead of GetFileSizeEx for the case when _WIN32_WINNT
+  // is less than 0x0500 as is the case with some default MinGW builds.
+  // Both functions support large file sizes.
+  DWORD size_upper = 0;
+  HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd_));
+  DWORD size_lower = FMT_SYSTEM(GetFileSize(handle, &size_upper));
+  if (size_lower == INVALID_FILE_SIZE) {
+    DWORD error = GetLastError();
+    if (error != NO_ERROR)
+      FMT_THROW(windows_error(GetLastError(), "cannot get file size"));
+  }
+  unsigned long long long_size = size_upper;
+  return (long_size << sizeof(DWORD) * CHAR_BIT) | size_lower;
+#  else
+  using Stat = struct stat;
+  Stat file_stat = Stat();
+  if (FMT_POSIX_CALL(fstat(fd_, &file_stat)) == -1)
+    FMT_THROW(system_error(errno, "cannot get file attributes"));
+  static_assert(sizeof(long long) >= sizeof(file_stat.st_size),
+                "return type of file::size is not large enough");
+  return file_stat.st_size;
+#  endif
+}
+
+std::size_t file::read(void* buffer, std::size_t count) {
+  rwresult result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(read(fd_, buffer, convert_rwcount(count))));
+  if (result < 0) FMT_THROW(system_error(errno, "cannot read from file"));
+  return detail::to_unsigned(result);
+}
+
+std::size_t file::write(const void* buffer, std::size_t count) {
+  rwresult result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(write(fd_, buffer, convert_rwcount(count))));
+  if (result < 0) FMT_THROW(system_error(errno, "cannot write to file"));
+  return detail::to_unsigned(result);
+}
+
+file file::dup(int fd) {
+  // Don't retry as dup doesn't return EINTR.
+  // http://pubs.opengroup.org/onlinepubs/009695399/functions/dup.html
+  int new_fd = FMT_POSIX_CALL(dup(fd));
+  if (new_fd == -1)
+    FMT_THROW(system_error(errno, "cannot duplicate file descriptor {}", fd));
+  return file(new_fd);
+}
+
+void file::dup2(int fd) {
+  int result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
+  if (result == -1) {
+    FMT_THROW(system_error(errno, "cannot duplicate file descriptor {} to {}",
+                           fd_, fd));
+  }
+}
+
+void file::dup2(int fd, std::error_code& ec) noexcept {
+  int result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
+  if (result == -1) ec = std::error_code(errno, std::generic_category());
+}
+
+void file::pipe(file& read_end, file& write_end) {
+  // Close the descriptors first to make sure that assignments don't throw
+  // and there are no leaks.
+  read_end.close();
+  write_end.close();
+  int fds[2] = {};
+#  ifdef _WIN32
+  // Make the default pipe capacity same as on Linux 2.6.11+.
+  enum { DEFAULT_CAPACITY = 65536 };
+  int result = FMT_POSIX_CALL(pipe(fds, DEFAULT_CAPACITY, _O_BINARY));
+#  else
+  // Don't retry as the pipe function doesn't return EINTR.
+  // http://pubs.opengroup.org/onlinepubs/009696799/functions/pipe.html
+  int result = FMT_POSIX_CALL(pipe(fds));
+#  endif
+  if (result != 0) FMT_THROW(system_error(errno, "cannot create pipe"));
+  // The following assignments don't throw because read_fd and write_fd
+  // are closed.
+  read_end = file(fds[0]);
+  write_end = file(fds[1]);
+}
+
+buffered_file file::fdopen(const char* mode) {
+// Don't retry as fdopen doesn't return EINTR.
+#  if defined(__MINGW32__) && defined(_POSIX_)
+  FILE* f = ::fdopen(fd_, mode);
+#  else
+  FILE* f = FMT_POSIX_CALL(fdopen(fd_, mode));
+#  endif
+  if (!f)
+    FMT_THROW(
+        system_error(errno, "cannot associate stream with file descriptor"));
+  buffered_file bf(f);
+  fd_ = -1;
+  return bf;
+}
+
+long getpagesize() {
+#  ifdef _WIN32
+  SYSTEM_INFO si;
+  GetSystemInfo(&si);
+  return si.dwPageSize;
+#  else
+  long size = FMT_POSIX_CALL(sysconf(_SC_PAGESIZE));
+  if (size < 0) FMT_THROW(system_error(errno, "cannot get memory page size"));
+  return size;
+#  endif
+}
+
+FMT_API void ostream::grow(size_t) {
+  if (this->size() == this->capacity()) flush();
+}
+#endif  // FMT_USE_FCNTL
+FMT_END_NAMESPACE
diff --git a/libfuse/lib/thread_pool.hpp b/libfuse/lib/thread_pool.hpp
index 1599bef9..c8b5ac32 100644
--- a/libfuse/lib/thread_pool.hpp
+++ b/libfuse/lib/thread_pool.hpp
@@ -95,6 +95,18 @@ public:
     return future;
   }
 
+public:
+  std::vector<pthread_t>
+  threads()
+  {
+    std::vector<pthread_t> rv;
+
+    for(auto &thread : _threads)
+      rv.push_back(thread.native_handle());
+
+    return rv;
+  }
+
 private:
   using Proc   = std::function<void(void)>;
   using Queue  = UnboundedQueue<Proc>;
diff --git a/man/mergerfs.1 b/man/mergerfs.1
index 08ea8a6d..7bec5f79 100644
--- a/man/mergerfs.1
+++ b/man/mergerfs.1
@@ -1,7 +1,7 @@
 .\"t
 .\" Automatically generated by Pandoc 2.9.2.1
 .\"
-.TH "mergerfs" "1" "2023-01-29" "mergerfs user manual" ""
+.TH "mergerfs" "1" "2023-02-19" "mergerfs user manual" ""
 .hy
 .SH NAME
 .PP
@@ -148,8 +148,9 @@ Selects the inode calculation algorithm.
 \f[B]dropcacheonclose=BOOL\f[R]: When a file is requested to be closed
 call \f[C]posix_fadvise\f[R] on it first to instruct the kernel that we
 no longer need the data and it can drop its cache.
-Recommended when \f[B]cache.files=partial|full|auto-full\f[R] to limit
-double caching.
+Recommended when
+\f[B]cache.files=partial|full|auto-full|per-process\f[R] to limit double
+caching.
 (default: false)
 .IP \[bu] 2
 \f[B]symlinkify=BOOL\f[R]: When enabled and a file is not writable and
@@ -268,6 +269,9 @@ reading FUSE messages which are dispatched to process threads.
 -1 means disabled otherwise acts like \f[C]read-thread-count\f[R].
 (default: -1)
 .IP \[bu] 2
+\f[B]pin-threads=STR\f[R]: Selects a strategy to pin threads to CPUs
+(default: unset)
+.IP \[bu] 2
 \f[B]scheduling-priority=INT\f[R]: Set mergerfs\[cq] scheduling
 priority.
 Valid values range from -20 to 19.
@@ -314,8 +318,13 @@ the search category.
 timeout in seconds.
 (default: 0)
 .IP \[bu] 2
-\f[B]cache.files=libfuse|off|partial|full|auto-full\f[R]: File page
-caching mode (default: libfuse)
+\f[B]cache.files=libfuse|off|partial|full|auto-full|per-process\f[R]:
+File page caching mode (default: libfuse)
+.IP \[bu] 2
+\f[B]cache.files.process-names=LIST\f[R]: A pipe | delimited list of
+process comm (https://man7.org/linux/man-pages/man5/proc.5.html) names
+to enable page caching for when \f[C]cache.files=per-process\f[R].
+(default: \[lq]rtorrent|qbittorrent-nox\[rq])
 .IP \[bu] 2
 \f[B]cache.writeback=BOOL\f[R]: Enable kernel writeback caching
 (default: false)
@@ -360,7 +369,7 @@ UINT = [0,MAX_INT]
 .IP \[bu] 2
 SIZE = `NNM'; NN = INT, M = `K' | `M' | `G' | `T'
 .IP \[bu] 2
-STR = string
+STR = string (may refer to an enumerated value, see details of argument)
 .IP \[bu] 2
 FUNC = filesystem function
 .IP \[bu] 2
@@ -530,6 +539,33 @@ and the kernel use internally (also called the \[dq]nodeid\[dq]).
 .PP
 As of version 2.35.0 the \f[C]use_ino\f[R] option has been removed.
 mergerfs should always be managing inode values.
+.SS pin-threads
+.PP
+Simple strategies for pinning read and/or process threads.
+If process threads are not enabled than the strategy simply works on the
+read threads.
+Invalid values are ignored.
+.IP \[bu] 2
+R1L: All read threads pinned to a single logical CPU.
+.IP \[bu] 2
+R1P: All read threads pinned to a single physical CPU.
+.IP \[bu] 2
+RP1L: All read and process threads pinned to a single logical CPU.
+.IP \[bu] 2
+RP1P: All read and process threads pinned to a single physical CPU.
+.IP \[bu] 2
+R1LP1L: All read threads pinned to a single logical CPU, all process
+threads pinned to a (if possible) different logical CPU.
+.IP \[bu] 2
+R1PP1P: All read threads pinned to a single physical CPU, all process
+threads pinned to a (if possible) different logical CPU.
+.IP \[bu] 2
+RPSL: All read and process threads are spread across all logical CPUs.
+.IP \[bu] 2
+RPSP: All read and process threads are spread across all physical CPUs.
+.IP \[bu] 2
+R1PPSP: All read threads are pinned to a single physical CPU while
+process threads are spread across all other phsycial CPUs.
 .SS fuse_msg_size
 .PP
 FUSE applications communicate with the kernel over a special character
@@ -1449,18 +1485,26 @@ blocks and find the files using those blocks
 .SS page caching
 .PP
 https://en.wikipedia.org/wiki/Page_cache
-.PP
-tl;dr: * cache.files=off: Disables page caching.
+.IP \[bu] 2
+cache.files=off: Disables page caching.
 Underlying files cached, mergerfs files are not.
-* cache.files=partial: Enables page caching.
+.IP \[bu] 2
+cache.files=partial: Enables page caching.
 Underlying files cached, mergerfs files cached while open.
-* cache.files=full: Enables page caching.
+.IP \[bu] 2
+cache.files=full: Enables page caching.
 Underlying files cached, mergerfs files cached across opens.
-* cache.files=auto-full: Enables page caching.
+.IP \[bu] 2
+cache.files=auto-full: Enables page caching.
 Underlying files cached, mergerfs files cached across opens if mtime and
 size are unchanged since previous open.
-* cache.files=libfuse: follow traditional libfuse \f[C]direct_io\f[R],
+.IP \[bu] 2
+cache.files=libfuse: follow traditional libfuse \f[C]direct_io\f[R],
 \f[C]kernel_cache\f[R], and \f[C]auto_cache\f[R] arguments.
+.IP \[bu] 2
+cache.files=per-process: Enable page caching only for processes which
+`comm' name matches one of the values defined in
+\f[C]cache.files.process-names\f[R].
 .PP
 FUSE, which mergerfs uses, offers a number of page caching modes.
 mergerfs tries to simplify their use via the \f[C]cache.files\f[R]