[libcxx-commits] [libcxx] [libc++] Reland LWG2921 and LWG2976 (PR #107960)

[Louis Dionne via libcxx-commits]

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@@ -1460,8 +1460,10 @@ public:
   _LIBCPP_HIDE_FROM_ABI __packaged_task_function() _NOEXCEPT : __f_(nullptr) {}
   template <class _Fp>
   _LIBCPP_HIDE_FROM_ABI __packaged_task_function(_Fp&& __f);
+#  if _LIBCPP_STD_VER <= 14
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ldionne wrote:

Since this is an implementation detail, we can provide it unconditionally IMO. We can guard only the public part of the API under a `_LIBCPP_STD_VER` check.

https://github.com/llvm/llvm-project/pull/107960