[cautious_int]

Actually it is misleading by them( and you ) to assume that in C, an unsigned int can represent values larger than the largest signed int value.

In other words, C allows that UINT_MAX == INT_MAX, in which case you will overflow.

If they made that assumption, they should explicitly mention it, but they didn't.

> Update 17 Feb 2008:... ...Now that we've made this change, we know that the program is correct;)

It seems the article is aware of the irony. Another update would be in order.

[dastbe]

Sure, and if you expect your software to run on such a platform with any degree of confidence then you're right to consider it. Even better, tell us about a conforming implementation that you've used in product recently that has UINT_MAX == INT_MAX.

Also I'm not trying to mislead people into thinking that its a good way to implement this. The confounding bit from the article is they started in Java and ended up in C. If you were indexing with signed ints in C, C++, or any language that has unsigned integers then you already have a bug with or without the bad mean check.

[cautious_int]

You got it backwards there. Only if you know your implementation and plan to code only for it, can you even start to consider bending the C Standard, and not the other way around.