#include <iostream>

struct A {
    char foo() { return 'A';}
};

template<class T> struct B : public T {
    virtual char foo() {return 'B';}
};

template<class T> struct C : public T {
    virtual char foo() {return 'C';}
};

int main(int argc, char* argv[])
{    
    A* a = new A();
    A* b = new B< A >();
    A* c = new C< A >();
    A* d = new B< C< A > >();

    std::cout << a->foo() << b->foo() << c->foo() << d->foo();

    return 0;
}