//write a program to unary operator overload with friend function
#include<iostream.h>
#include<conio.h>
class demo
{
    int a,b;
    public:
    demo()
    {
        a=10;
        b=-20;
    }
    friend void operator -(demo &object)     // Changes Are here
    {
         object.a=-object.a;
         object.b=-object.b;
    }              // Changes Done Replace Friend In Above Void And Create Object
    void display()
    {
        cout<<"\nA ="<<a<<endl;
        cout<<"\nB ="<<b<<endl;
    }
};
void main()
{
    clrscr();
    demo object; // object is a object if you know this allredy then excelent.
    object.display();
    -object; // operator overload finding - sign operator in above void main.
    cout<<"\nOperator Overload Sucessfully Using Friend Function... check below\n";
    object.display();
    getch();
}