Unary - operator overloading using friend function
<p>I have written this code in an attempt to perform overloading on the unary operator - using a friend function. Somehow, there is no effect on the inital values I've passed.</p>

<pre><code>#include&lt;iostream&gt;
//fifty6s
using namespace std;
class invert_position
{
    int x,y;
    public:
        invert_position(int a,int b)
        {
        x=a;
        y=b;
        }
    void show()
        {
            cout&lt;&lt;"\nx="&lt;&lt;x;
            cout&lt;&lt;"\ny="&lt;&lt;y;
        }
    friend void operator -(invert_position);
};
void operator -(invert_position i)
{
    i.x=-i.x;
    i.y=-i.y;
}
int main()
{
    invert_position i(2,3);
    -i;
    i.show();
    return 0;
}
</code></pre>