#include <iostream>

using namespace std;

class A{
    public:
         //virtual ~A()=default;
         virtual ~A() {
            cout << "In base class destructor" << endl;
         }
         

         void Method1(void) const {
             cout << "Method 1: In the base class A" << endl;
         }

         virtual void Method2(void) const {
             cout << "Method 2: In the base class A" << endl;
         }

         virtual void Method3(void) const {
             cout << "Method 3: In the base class A" << endl;
         }

         void Method4(void) const {
             cout << "Method 4: In the base class A" << endl;
         }
};

class B :public A{
    public:
         ~B() {
            cout << "In Derived class destructor" << endl;
         }
         void Method1() const {
              cout << "Method 1: In the derived class B" << endl;
         }

         void Method2(void) const override {
             cout << "Method 2: In the derived class B" << endl;
         }
/*
         void Method3(int x) const override {
             cout << "Method 3: In the derived class B" << endl;
         };
*/
};

class C : public B {
    public:
        void Method2(void) const override {
        }
};



int main() {

     A  a;
     B  b;

     A  * ptr1 = new A;
     A  * ptr2 = new B;

     cout << "Calling from an instance of A" << endl;
     a.Method1();
     a.Method2();
     cout << endl;

     cout << "Calling from an instance of B" << endl;
     b.Method1();
     b.Method2();
//     b.Method3();
     b.Method4();
     cout << endl;

     cout << "Calling from a ptr to A, stored as an A*" << endl;
     ptr1->Method1();
     ptr1->Method2();
     cout << endl;

     cout << "Calling from a ptr to B, stored as an A*" << endl;
     ptr2->Method1();
     ptr2->Method2();
     ptr2->Method3();
     ptr2->Method4();
     cout << endl;

     cout << "Deleting Ptr1   A*->A * " << endl;
     delete ptr1;
     cout << "Deleting Ptr2   A*->B * " << endl;
     delete ptr2;

     cout << endl << endl;
     cout << "Exiting the program " << endl;

     return 0;
}