1 // { dg-do run} 2 // { dg-options "-std=c++17 -fconcepts" } 3 4 5 template<typename T> C()6 concept bool C() { return __is_class(T); } 7 8 template<typename T> D()9 concept bool D() { return __is_empty(T); } 10 11 struct X { } x; 12 struct Y { int n; } y; 13 14 int called = 0; 15 16 // Test constrained member definitions 17 template<typename T> 18 struct S1 { // { dg-message "defined here" } f1S119 void f1() requires C<T>() { } 20 void g1() requires C<T>() and true; h1S121 template<C U> void h1(U u) { called = 1; } 22 23 void g2() requires C<T>(); // { dg-message "candidate" } 24 }; 25 26 template<typename T> g2()27 void S1<T>::g2() requires D<T>() { } // { dg-error "no declaration matches" } 28 main()29int main() { 30 S1<X> sx; 31 S1<Y> sy; 32 S1<int> si; 33 34 si.f1(); // { dg-error "matching" } 35 si.g1(); // { dg-error "matching" } 36 si.h1(0); // { dg-error "matching" } 37 } 38