Regarding drawline You can always define an implicit constructor: Point::Point(const Library::Point &p) Of course, you're now hiding a ticking time

Regarding drawline You can always define an implicit constructor: Point::Point(const Library::Point &p) Of course, you're now hiding a ticking time-bomb from a the next maintainer of that code. If you absolutely want the latter case, overloading is your friend: drawline(int x1, int y1, int x2, int y2); drawline(Point p1, Point p2) { drawline(p1.x, p1.y, p2.x, p2.y); } This, in my opinion, is the most conducive to refactoring (and modularizing code). As an aside, you really should be doing: drawline => drawlines "Where's the one, there's many."