1 // PR c++/56611
2 // { dg-do compile { target c++11 } }
3 
4 template<class T> struct remove_reference     { typedef T type; };
5 template<class T> struct remove_reference<T&> { typedef T type; };
6 template<class T> T declval() { return T(); }
7 
8 int f(int, int){return 0;}
9 struct Func{};
10 
11 template<class... Args> using result2
12 = decltype(f(declval<typename remove_reference<Args>::type>()...));
13 
14 template<class Sig> struct R;
15 template<class This, class... Args> struct R< This(Args...) >
16 {
17   typedef result2<Args...> type;
18 };
19 
20 typedef R< Func(int, int) >::type R_type;
21