Remove iterator methods from Branches class

src/branches.hpp

@@ -85,13 +85,6 @@ public:
   operator Ptr()   const { return std::atomic_load(&_impl); }
   Ptr operator->() const { return std::atomic_load(&_impl); }
 
-public:
-  Impl::iterator begin() { return _impl->begin(); }
-  Impl::iterator end() { return _impl->end(); }
-  Impl::const_iterator begin() const { return _impl->begin(); }
-  Impl::const_iterator end() const { return _impl->end(); }
-
-
 public:
   void find_and_set_mode_ro();
 };