[danielweber]

I'm in the midst of something else and can't pull out my C++11 book now, but doesn't C++ have custom types that would let you declare something like "this must be a positive integer"?

I might be confusing this with custom literals.

[AnimalMuppet]

Well, there's unsigned integers. This means that it can't be less than 0. But if you have a 32 bit unsigned integer, and you decrement 0, you get 0xFFFFFFFF. That may or may not be what you want or expect.

You also could create a class that wrapped an integer, that would have a range, and would maintain that range as a class invariant. It could either clip or throw an exception when an attempt was made to go out of the range. But that's just regular class stuff, so I don't think it's what you had in mind...