Index: head/contrib/libc++/include/__config
===================================================================
--- head/contrib/libc++/include/__config
+++ head/contrib/libc++/include/__config
@@ -374,6 +374,7 @@
 #define _LIBCPP_HAS_NO_VARIADICS
 #define _LIBCPP_HAS_NO_RVALUE_REFERENCES
 #define _LIBCPP_HAS_NO_ALWAYS_INLINE_VARIADICS
+#define _LIBCPP_HAS_NO_STRONG_ENUMS
 
 #else  // __GXX_EXPERIMENTAL_CXX0X__