Main.cpp

#include <iostream>
class First
{
    public:
        First()
        {

        }

        void Update(void)
        {
            A();
        }

        virtual void A(void)
        {
            std::cout << "First::A";
        }


};

class Two : public First
{
    public:
        Two () : First () {};
        void A(void)
        {
            std::cout << "Two::A";
        }
};

int main()
{
    Two *T = new Two;
    T -> Update();
    return 0;
}