// { dg-do compile { target c++20 } } struct S { concept S(); // { dg-error "3:a constructor cannot be .concept." } // { dg-error "concept definition syntax" "" { target *-*-* } .-1 } concept int s = 1; // { dg-error "3:non-static data member .s. declared .concept." } // { dg-error "concept definition syntax" "" { target *-*-* } .-1 } concept void foo(); // { dg-error "3:a concept cannot be a member function" } // { dg-error "concept definition syntax" "" { target *-*-* } .-1 } concept ~S(); // { dg-error "3:a destructor cannot be .concept." } // { dg-error "concept definition syntax" "" { target *-*-* } .-1 } }; typedef concept int my_int; // { dg-error "9:.concept. cannot appear in a typedef declaration" } // { dg-error "concept definition syntax" "" { target *-*-* } .-1 } void bar(concept int); // { dg-error "10:a parameter cannot be declared .concept." } // { dg-error "concept definition syntax" "" { target *-*-* } .-1 } concept int i = 0; // { dg-error "1:a non-template variable cannot be .concept." } // { dg-error "concept definition syntax" "" { target *-*-* } .-1 }