1Index: include/std/type_traits 2=================================================================== 3--- include/std/type_traits (revision 185724) 4+++ include/std/type_traits (working copy) 5@@ -1746,7 +1746,7 @@ 6 7 template<typename _Tp, typename _Up> 8 struct common_type<_Tp, _Up> 9- { typedef decltype(true ? declval<_Tp>() : declval<_Up>()) type; }; 10+ { typedef typename decay<decltype(true ? declval<_Tp>() : declval<_Up>())>::type type; }; 11 12 template<typename _Tp, typename _Up, typename... _Vp> 13 struct common_type<_Tp, _Up, _Vp...> 14