Example
struct B { virtual void print() = 0;};
struct D1 : public B { void print() { cout << "I'm a D1" << endl; }};
struct D2 : public B { void print() { cout << "I'm a D2" << endl; }};
int main() { vector V.push_back(new D1); V.push_back(new D2); V.push_back(new D2); V.push_back(new D1); for_each(V.begin(), V.end(), mem_fun(&B::print));}