1 // { dg-options "-std=c++17 -fconcepts" } 2 3 template<typename T1, typename T2> 4 concept bool C1 = true; 5 6 template<typename T1, typename T2, typename T3> 7 concept bool C2 = true; 8 9 10 template<C1 T> // { dg-error "not a type" } f1()11constexpr bool f1( ) { return true; } 12 13 template<C2<int> T> // { dg-error "expected|not a type" } f2()14constexpr bool f2( ) { return true; } 15