1 // PR c++/52440 2 // { dg-do compile { target c++11 } } 3 4 template<bool> 5 struct V 6 { 7 typedef void type; 8 }; 9 10 template<typename T> 11 struct X 12 { 13 template<typename> always_trueX14 static constexpr bool always_true() 15 { 16 return true; 17 } 18 19 template<typename U, 20 typename = typename V<always_true<U>()>::type> XX21 X(U &&) {} 22 }; 23 main()24int main() 25 { 26 X<int> x(42); 27 } 28