> drawline(Point(vec.x1, vec.y1), Point(vec.x2, vec.y2))

True, though you can usually reduce the pain by implementing appropriate conversion operators and/or implicit constructors.

> Again, it's only inferior until the very common case where you're doing something else with the index, which is pretty common during debugging.

You can use subtraction to obtain the index from the iterators in the better version. In this case, find really is superior.