#import @interface MyClass : NSObject { }; -(void)test; @end @implementation MyClass -(void)test { printf("%p\n", self); // break here } @end @interface MyOwner : NSObject { @public id ownedThing; // should be id, to test }; @end @implementation MyOwner @end int main (int argc, char const *argv[]) { @autoreleasepool { MyOwner *owner = [[MyOwner alloc] init]; owner->ownedThing = [[MyClass alloc] init]; [(MyClass*)owner->ownedThing test]; } return 0; }