Operator overriding in C++

test.cpp

#include <iostream>
#include <string>

using namespace std;

class A
{
public:
  virtual void operator-(const A& other) const;
};

void A::operator-(const A& other) const {
	cout << "Hello from A::operator-" << endl;
	return;
}

class B : public A
{
public:
	virtual void operator-(const B& other) const;
};

void B::operator-(const B& other) const {
	cout << "Hello from B::operator-" << endl;
	return;
}

int main()
{
	A * a1 = new B();
	B * b = new B();

	(* a1) - (* a1);
	(* b) - (* b);

	delete a1;
	delete b;

	return 0;
}