[libcxx-commits] [libcxx] [libc++] Introduce unversioned namespace macros (PR #133009)

[Louis Dionne via libcxx-commits]

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@@ -577,15 +577,17 @@ typedef __char32_t char32_t;
 #    define _LIBCPP_POP_EXTENSION_DIAGNOSTICS
 #  endif
 
-// Inline namespaces are available in Clang/GCC/MSVC regardless of C++ dialect.
 // clang-format off
-#  define _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS                                               \
-                                      namespace _LIBCPP_TYPE_VISIBILITY_DEFAULT std {                                  \
-                               inline namespace _LIBCPP_ABI_NAMESPACE {
-#  define _LIBCPP_END_NAMESPACE_STD }} _LIBCPP_POP_EXTENSION_DIAGNOSTICS
+#  define _LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD                                                                      \
+    _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS namespace _LIBCPP_TYPE_VISIBILITY_DEFAULT std {
 
-#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL namespace std { namespace experimental {
-#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL }}
+#  define _LIBCPP_END_UNVERSIONED_NAMESPACE_STD } _LIBCPP_POP_EXTENSION_DIAGNOSTICS
+
+#  define _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD inline namespace _LIBCPP_ABI_NAMESPACE {
+#  define _LIBCPP_END_NAMESPACE_STD } _LIBCPP_END_UNVERSIONED_NAMESPACE_STD
+
+#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL _LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD namespace experimental {
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ldionne wrote:

I'd add a TODO to move this to the versioned namespace. We can do that in a follow-up patch.

https://github.com/llvm/llvm-project/pull/133009