[libcxx-commits] [libcxx] [libc++] Implement P0528R3 `std::atomic` CAS for types with paddings (PR #76180)

[Louis Dionne via libcxx-commits]

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@@ -30,11 +31,26 @@ struct __cxx_atomic_base_impl {
   _LIBCPP_HIDE_FROM_ABI
 #ifndef _LIBCPP_CXX03_LANG
   __cxx_atomic_base_impl() _NOEXCEPT = default;
+
+#  if _LIBCPP_STD_VER >= 20 && __has_builtin(__builtin_clear_padding)
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ldionne wrote:

This `#if` is going to hinge on the DR question.

https://github.com/llvm/llvm-project/pull/76180