/* { dg-do run { target *-*-darwin* } } */ #include #include typedef struct MyWidget { int a; } MyWidget; MyWidget gWidget = { 17 }; @protocol MyProto - (MyWidget *)widget; @end @interface Foo: Object @end @interface Bar: Foo @end @interface Container: Object + (MyWidget *)elementForView:(Foo *)view; @end @implementation Foo @end @implementation Bar - (MyWidget *)widget { return &gWidget; } @end @implementation Container + (MyWidget *)elementForView:(Foo *)view { MyWidget *widget = nil; if ([view conformsTo:@protocol(MyProto)]) { widget = [(Foo *)view widget]; } return widget; } @end int main(void) { id view = [Bar new]; MyWidget *w = [Container elementForView: view]; if (!w || w->a != 17) abort (); return 0; }