[Bug libstdc++/121946] [missing optimization] std::vector does not use memcpy for the trivially copyable/destructible type

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121946

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
That should be:

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wc++17-extensions"
      if constexpr (__is_trivially_destructible(_ValueType))
        {
          __result = std::__uninitialized_move_a(__first, __last, __result,
                                                 __alloc);
          std::_Destroy(__first, __last, __alloc);
          return __result;
        }
#pragma GCC diagnostic pop