[Libc++] Use #pragma push_macro/pop_macro to better handle min/max on Windows
Summary:
This patch improves how libc++ handles min/max macros within the headers. Previously libc++ would undef them and emit a warning.
This patch changes libc++ to use `#pragma push_macro` to save the macro before undefining it, and `#pragma pop_macro` to restore the macros and the end of the header.
Reviewers: mclow.lists, bcraig, compnerd, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits, krytarowski
Differential Revision: https://reviews.llvm.org/D33080
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@304357 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/memory b/include/memory
index 31dc73d..b12b46a 100644
--- a/include/memory
+++ b/include/memory
@@ -658,12 +658,14 @@
# include <atomic>
#endif
-#include <__undef_min_max>
-
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _ValueType>
@@ -5574,4 +5576,6 @@
_LIBCPP_END_NAMESPACE_STD
+_LIBCPP_POP_MACROS
+
#endif // _LIBCPP_MEMORY