// virtual.cpp

#include <iostream>

class Base
{
    protected:
	int i;
    public:
	Base() { i = 0; }
	Base(int ii) { i = ii; }
	virtual ~Base() {}
	virtual void dothis() const {cout<<"Base function called"<<endl;}
};

class Derived1 : public Base
{
    private:
	float f;
    public:
	Derived1() : Base() { f = 0.0; }
	Derived1(const int ii) : Base (ii) { f = 0.0; }
	~Derived1() {}
	void dothis() const {cout<<"Derived1 function called"<<endl;}
};

class Derived2 : public Base
{
    private:
	double d;
    public:
	Derived2() : Base() { d = 0.0; }
	Derived2(const int ii) : Base (ii) { d = 0.0; }
	~Derived2() {}
	void dothis() const {cout<<"Derived2 function called"<<endl;}
};

main()
{
    Base b(5);
    Derived1 d1(7);
    Derived2 d2(9);

    Base *p = &b;
    Derived1 *p1 = &d1;
    Derived2 *p2 = &d2;
    
    b.dothis();			// static binding
    d1.dothis();		// static binding
    d2.dothis();		// static binding
    cout << endl;

    p->dothis();
    p1->dothis();
    p2->dothis();
    cout << endl;

    Derived2 *ptr;
    ptr = &d2;
    ptr->dothis();
    cout << endl;
    // ptr = &d1;  // error - ptr must be of same or base class

    Base *ptr1;
    ptr1 = &d1;
    ptr1->dothis();
    ptr1 = &d2;
    ptr1->dothis();
    cout << endl;

    return 0;
}