1 // PR c++/44969 2 3 template<bool, typename T = void> struct enable_if { typedef T type; }; 4 template<typename T> struct enable_if<false, T> { }; 5 6 template<typename Tp, typename Arg1, typename Arg2> 7 class mini_is_constructible 8 { 9 typedef char one; 10 typedef struct { char arr[2]; } two; 11 12 template<typename Tp1, typename Arg1_, typename Arg2_> 13 static typename 14 enable_if<(sizeof(Tp1(Arg1_(), Arg2_()), 1) > 0), one>::type 15 test(int); 16 17 template<typename, typename, typename> 18 static two test(...); 19 20 public: 21 static const bool value = sizeof(test<Tp, Arg1, Arg2>(0)) == 1; 22 }; 23 24 class A { }; 25 26 int Test[mini_is_constructible<int, A, A>::value ? -1 : 1]; 27