[libcxx-commits] [libcxx] [libc++][modules] Uses _LIBCPP_USING_IF_EXISTS. (PR #90409)

[Nikolas Klauser via libcxx-commits]

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@@ -8,10 +8,10 @@
 //===----------------------------------------------------------------------===//
 
 export {
-  using ::max_align_t;
+  using ::max_align_t _LIBCPP_USING_IF_EXISTS;
   using ::nullptr_t;
-  using ::ptrdiff_t;
-  using ::size_t;
+  using ::ptrdiff_t _LIBCPP_USING_IF_EXISTS;
+  using ::size_t _LIBCPP_USING_IF_EXISTS;
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philnik777 wrote:

I feel like `size_t` and `ptrdiff_t` shouldn't have these macros. Reality breaks if these don't exist. (No action required, since they are also marked in the headers.)

https://github.com/llvm/llvm-project/pull/90409