Binary - Overloading

//Binary - Overloading#include <iostream.h>class complex{	int real, imag;	public:		complex(int tr,int ti)		{			real=tr;			imag=ti;		}		complex(){}		void display()		{			cout<<"\nComplex Number = "<<real<<"+i"<<imag;		}		friend complex operator -(complex c1, complex c2);};complex operator -(complex c1, complex c2){	complex result;	result.real=c1.real-c2.real;	result.imag=c1.imag-c2.imag;	return result;}int main(){	complex c1(10,20),c2(5,10);	c1.display();	c2.display();	cout<<"\nResult after Subtraction:\n";	complex result=c1-c2;	result.display();	return 0;}