Overload pre decrement operator

Write a program overload pre decrement operator.

#include<iostream>
using namespace std;
class A
{
	private:
		int x,y;
	public:
		A();
		A(int,int);
		void print();
		//void operator --();
		friend void operator --(A&);
};
#if 0
//using member function
void A :: operator --()
{
	--x,--y;
}
#else
//using friend function
void operator --(A& ob)
{
	--(ob.x),--(ob.y);
}
#endif
A :: A()
{
	cout << "default constructor" << endl;
}
A :: A(int z,int t):x(z),y(t)
{
	cout << "parameterized constructor" << endl;
}
void A :: print()
{
	cout << "x = " << x << " y = " << y << endl;
}
int main()
{
	A obj1(12,57),obj2(34,62);
	obj1.print();
	obj2.print();
	--obj1;//obj1.operator--();
	--obj2;
	obj1.print();
	obj2.print();
	return 0;
}

Output

parameterized constructor
parameterized constructor
x = 12 y = 57
x = 34 y = 62
x = 11 y = 56
x = 33 y = 61