[libcxx-commits] [libcxx] [libc++] LWG3187: P0591R4 reverted DR 2586 fixes to `scoped_allocator_adaptor::construct()` (PR #152424)

[A. Jiang via libcxx-commits]

================
@@ -189,19 +281,34 @@ struct __uses_allocator_construction_args<_Type, __enable_if_t<!__is_cv_std_pair
 };
 
 template <class _Type, class _Alloc, class... _Args>
-_LIBCPP_HIDE_FROM_ABI constexpr _Type __make_obj_using_allocator(const _Alloc& __alloc, _Args&&... __args) {
-  return std::make_from_tuple<_Type>(
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 _Type
+__make_obj_using_allocator(const _Alloc& __alloc, _Args&&... __args) {
+  return __uses_allocator_detail::__make_from_tuple<_Type>(
       __uses_allocator_construction_args<_Type>::__apply(__alloc, std::forward<_Args>(__args)...));
 }
 
+#endif // _LIBCPP_STD_VER >= 14
+
+#if _LIBCPP_STD_VER >= 17
+
 template <class _Type, class _Alloc, class... _Args>
-_LIBCPP_HIDE_FROM_ABI constexpr _Type*
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Type*
 __uninitialized_construct_using_allocator(_Type* __ptr, const _Alloc& __alloc, _Args&&... __args) {
   return std::apply(
       [&__ptr](auto&&... __xs) { return std::__construct_at(__ptr, std::forward<decltype(__xs)>(__xs)...); },
       __uses_allocator_construction_args<_Type>::__apply(__alloc, std::forward<_Args>(__args)...));
 }
 
+template <class _Type, class _Alloc, class... _Args>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Type*
+__uninitialized_construct_using_allocator_nocv(_Type* __ptr, const _Alloc& __alloc, _Args&&... __args) {
----------------
frederick-vs-ja wrote:

`nocv` is unfortunately intended. I submitted [LWG4311](https://cplusplus.github.io/LWG/issue4311) for this, but in C++17 perhaps we still need to drop cv-qualification.

https://github.com/llvm/llvm-project/pull/152424