Fix PR10509: http://llvm.org/bugs/show_bug.cgi?id=10509

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@136247 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/utility b/include/utility
index d0aee55..358fe76 100644
--- a/include/utility
+++ b/include/utility
@@ -226,9 +226,12 @@
 
     template<class _U1, class _U2>
         _LIBCPP_INLINE_VISIBILITY
-        pair(const pair<_U1, _U2>& __p,
-                 typename enable_if<is_constructible<_T1, _U1>::value &&
-                                    is_constructible<_T2, _U2>::value>::type* = 0)
+        pair(const pair<_U1, _U2>& __p
+#ifndef _LIBCPP_HAS_NO_ADVANCED_SFINAE
+                 ,typename enable_if<is_constructible<_T1, _U1>::value &&
+                                    is_constructible<_T2, _U2>::value>::type* = 0
+#endif
+                                      )
             : first(__p.first), second(__p.second) {}
 
     _LIBCPP_INLINE_VISIBILITY