--- a/include/string	2015/07/13 20:04:56	242056
+++ b/include/string	2015/07/18 20:40:46	242623
@@ -1936,7 +1936,12 @@
 template <class _CharT, class _Traits, class _Allocator>
 inline _LIBCPP_INLINE_VISIBILITY
 basic_string<_CharT, _Traits, _Allocator>::basic_string(const allocator_type& __a)
-    : __r_(__a)
+#if _LIBCPP_STD_VER <= 14
+        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
+#else
+        _NOEXCEPT
+#endif
+: __r_(__a)
 {
 #if _LIBCPP_DEBUG_LEVEL >= 2
     __get_db()->__insert_c(this);