This is an initial commit of constexpr support as proposed by Richard Smith. This by no means completes constexpr support. Indeed, it hardly scratches the surface. All it does is lay the foundation in <__config> and changes those few places in the library that are already using that foundation.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@153856 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__config b/include/__config
index 6b29014..7cd01dc 100644
--- a/include/__config
+++ b/include/__config
@@ -384,7 +384,9 @@
#endif
#ifdef _LIBCPP_HAS_NO_CONSTEXPR
-#define constexpr const
+#define _LIBCPP_CONSTEXPR
+#else
+#define _LIBCPP_CONSTEXPR constexpr
#endif
#ifndef __has_feature