You'll be comparing against a lot of other things like offsets that aren't naturally unsigned and having everything be of the same type just tends to reduce the

You'll be comparing against a lot of other things like offsets that aren't naturally unsigned and having everything be of the same type just tends to reduce the number of potential corner cases. And it will be a bit faster for certain weird architectures since the overflow behavior of an unsigned is prescribed but signed overflow is undefined. But I really doubt anybody cares about that here.