Does region have any side-effects?

I've been using regions for a long time, but I couldn't find much information about it.

Pros
GetTriggeringRegion() saves a lot of work.
IsUnitInRegion() works really decent, unlike buggy RectContainsUnit().
Shape is not limited to rectangles.

Cons
???

If you have any idea, please let me know.

rect if struct of 4 reals.

region is object

Well, you can't use regions in GUI, only rects which are for some strange reason also named regions. Also, it's kind of hard to make regions, because you have to create rects....... but in general, yes, they don't have any side-effects.

AFAIK rect is also an object, and so is location. Am I wrong?

Region have no coordinates

It is still an object...

Rect is not object, this is data handle, like location.

Everything that cannot affect gameplay by it existance in any way is not object - its data.

Timer = can execute some function
Region = can register leave or enter events
Unit = have mass events on it

That's up to the definition of the object. It may vary. In a programmer's sense, anything instantiable could be an object.

Regions trigger enter events. If timers are an object under that definition regions would as well be objects.

rect != region