Issues with C++ 17 support: The specified type does not meet the requirements of Cpp17MoveInsertable

[pavel-odintsov]

Hey!

I received report from mzar at IRC with following error code:

In file included from /usr/include/c++/v1/__memory/ranges_uninitialized_algorithms.h:22:
4:12 PM 
/usr/include/c++/v1/__memory/uninitialized_algorithms.h:605:17: error: static assertion failed due to requirement '__is_cpp17_move_insertable<std::allocator<dynamic_binary_buffer_t>, void>::value': The specified type does not meet the requirements of Cpp17MoveInsertable
4:12 PM 
  605 |   static_assert(__is_cpp17_move_insertable<_Alloc>::value,
4:13 PM 
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4:13 PM 
/usr/include/c++/v1/vector:990:25: note: in instantiation of function template specialization 'std::__uninitialized_allocator_move_if_noexcept<std::allocator<dynamic_binary_buffer_t>, std::reverse_iterator<dynamic_binary_buffer_t *>, std::reverse_iterator<dynamic_binary_buffer_t *>, std::reverse_iterator<dynamic_binary_buffer_t *>>' requested here
4:13 PM 
  990 |   __v.__begin_   = std::__uninitialized_allocator_move_if_noexcept(
4:13 PM 
      |                         ^
4:13 PM 
/usr/include/c++/v1/vector:1455:3: note: in instantiation of member function 'std::vector<dynamic_binary_buffer_t>::__swap_out_circular_buffer' requested here
4:13 PM 
 1455 |   __swap_out_circular_buffer(__v);
4:13 PM 
      |   ^
4:13 PM 
/usr/include/c++/v1/vector:1467:13: note: in instantiation of function template specialization 'std::vector<dynamic_binary_buffer_t>::__push_back_slow_path<const dynamic_binary_buffer_t &>' requested here
4:13 PM 
 1467 |     __end = __push_back_slow_path(__x);
4:13 PM 
      |             ^
4:13 PM 
/wrkdirs/overlays/local/net-mgmt/fastnetmon-devel/work/fastnetmon-7f0ad9c6cd2db3856607aeed04b5e8125fad3124/src/bgp_protocol.hpp:595:25: note: in instantiation of member function 'std::vector<dynamic_binary_buffer_t>::push_back' requested here
4:13 PM 
The specified type does not meet the requirements of Cpp17MoveInsertable
4:13 PM 
  595 |         attributes_list.push_back(origin_as_binary_array);
4:13 PM 
      |                         ^

[cho-m]

Seeing this with 1.2.8 release in Homebrew macOS builds

• fastnetmon 1.2.8 Homebrew/homebrew-core#201366

Seems like LLVM implementation doesn't like the lack of move constructor. May need to check if this matches C++ spec (haven't checked on scenario for falling back to copy constructor to meet MoveInsertable).

fastnetmon/src/dynamic_binary_buffer.hpp

Lines 11 to 12 in 28cf165

	// Explicitly removed it as we need to implement it properly when needed
	dynamic_binary_buffer_t(dynamic_binary_buffer_t&& that) = delete;