#include <iostream>
using namespace std;

class Animal
{
  public:
    void what()
    {
        cout << "I am Animal." << endl;
    }

    virtual void sound()
    {
        cout << "I make animal noises." << endl;
    }

    void identify()
    {
        what();
        sound();
    }
};

class Cat : public Animal
{
  public:
    void what()
    {
        cout << "I am Cat." << endl;
    }

    void sound()
    {
        cout << "I purr." << endl;
    }
};

int main()
{
    Animal animal;
    Cat    cat;

    cout << endl << "After automatic allocation:" << endl;
    animal.identify();
    cat.identify();

    cout << endl << "After animal = cat:" << endl;
    animal = cat;
    animal.identify();

    Animal *animalp = new Animal();
    Cat    *catp    = new Cat();

    cout << endl << "After dynamic allocation:" << endl;
    animalp->identify();
    catp->identify();

    cout << endl << "After animalp = catp:" << endl;
    animalp = catp;
    animalp->identify();

    return 0;
}