18 lines · c
1template <class T>2struct iterator {3 void Compare(const iterator &x) { return; }4 friend void Check(iterator) { return; }5};6 7template <class T = int> struct Box {8 iterator<T> I;9 10 void test() {11 Check(I);12 I.Compare(I);13 }14};15 16// Force instantiation of Box<int>17Box<> B;18