I'm curious about the choice to make closest, etc, be functions rather than methods

[BenMakesGames]

Just finished watching the introduction video, and was surprised to see

bool result = contains(myRect, myCircle);

rather than

bool result = myRect.contains(myCircle);

Was this a consciously-made decision; if so, what were the pros and cons considered?

Pros of methods/member functions that come to mind:

• More in line with the APIs of standard C++ objects (ex: vector.empty(), string.find(...), etc)
• Discovery via intellisense is easier when you already have shape instances lying around