[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
llvm-svn: 304357
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: a016efb1dcda61e606e527b73791fbacf1bc9c86
diff --git a/include/experimental/functional b/include/experimental/functional
index 75fc8e9..a136cbb 100644
--- a/include/experimental/functional
+++ b/include/experimental/functional
@@ -89,21 +89,22 @@
#include <experimental/__config>
#include <functional>
-
#include <algorithm>
#include <type_traits>
#include <vector>
#include <array>
#include <unordered_map>
-#include <__undef_min_max>
-
#include <__debug>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+
_LIBCPP_BEGIN_NAMESPACE_LFTS
#if _LIBCPP_STD_VER > 11
@@ -456,4 +457,6 @@
_LIBCPP_END_NAMESPACE_LFTS
+_LIBCPP_POP_MACROS
+
#endif /* _LIBCPP_EXPERIMENTAL_FUNCTIONAL */