Error: taking address of temporary [-fpermissive]

Question

I\'ve been looking into this for a few hours, to no avail. Basically I have

struct rectangle {
    int x, y, w, h;
};

rectangle player::RegionCoordinates() // R         


        

Answer 1

RegionCoordinates() returns an object by value. This means a call to RegionCoordinates() returns a temporary instance of rectangle. As the error says, you're trying to take the address of this temporary object, which is not legal in C++.

Why does IsCollision() take pointers anyway? It would be more natural to take its parameters by const reference:

bool IsCollision (const rectangle &r1, const rectangle &r2) {
if (r1.x < r2.x + r2.w &&
    r1.x + r1.w > r2.x &&
    r1.y < r2.y + r2.h &&
    r1.y + r1.h > r2.y) {
        return true;
    }
        return false;
}
//blah blah main while loop
if (IsCollision(player1.RegionCoordinates(), stick1.RegionCoordinates())) //no error any more
{
player1.score+=10;
stick1.x = rand() % 600+1;
stick1.y = rand() % 400+1;
play_sample(pickup,128,128,1000,false);
}