// { dg-options "-std=c++1z -fconcepts" } | |
template<typename T> | |
concept bool C() { return __is_class(T); } | |
template<typename T> | |
struct S1 { | |
template<C U> | |
S1(U x) { } | |
}; | |
template<typename T> | |
struct S2 : S1<T> { | |
using S1<T>::S1; | |
}; | |
struct X { } x; | |
int main() { | |
S2<X> s = x; | |
} |