C++ operator overloading order

Question

Possible Duplicate:
Operator Overloading in C++ as int + obj

I override the * operator as following:

Point Point::operator *(float scale){
    Point point(this->x*scale, this->y*scale);
    return point;
}

How can I fix this:

Point p1 (5.0, 10.0);
Point p2 = p1*4; //works fine
Point p3 = 4*p1  //error: no match for 'operator*'

Look at my (virtually identical) question: http://stackoverflow.com/questions/7651954/overloading-operator-order — Blender, Nov 13 '11 at 07:25

score 5 · Accepted Answer · answered Nov 13 '11 at 07:20

5

Write a free function, like this:

Point operator *(float scale, Point p)
{
    return p * scale;
}

answered Nov 13 '11 at 07:20

Benjamin Lindley

Alok Save · Answer 2 · 2011-11-13T07:26:33.487

4

You overload the operator as a free function and provide both the versions of it instead of overloading it as member function.

Point operator *(float scale, Point p);
Point operator *(Point p, float scale);

With these:

1st version supports:

Point p3 = 4*p1;

and 2nd version supports:

Point p2 = p1*4;

edited Nov 13 '11 at 07:26

answered Nov 13 '11 at 07:20

Alok Save

1

I had a duplicate question and you answered the same thing to mine :P – Blender Nov 13 '11 at 07:24

2 Answers2