1 // PR c++/42057 2 3 struct A; // { dg-message "forward declaration" } 4 5 struct B 6 { 7 virtual B* foo(A); 8 }; 9 10 struct C : virtual B 11 { fooC12 virtual C* foo(A) { return 0; } // { dg-error "incomplete type" } 13 }; 14 15 C c; 16