#include <iostream>

using namespace std;

​

class Animal {

  public:

    void sound() {

      cout << "Animal sound\n";

    }

};

​

class Dog : public Animal {

  public:

    void sound() {

      cout << "Dog barks\n";

    }

};

​

int main() {

  Animal* a;  // Declare a pointer to the base class (Animal)

  Dog d;  // Create an object of the derived class (Dog)

  a = &d;  // Point the base class pointer to the Dog object

  a->sound(); // Call the sound() function using the pointer. Since sound() is not virtual, this calls Animal's version

  return 0;

}

​