Comment by LegionMammal978
1 day ago
> But what about the range? While it’s true that you get twice the range, surprisingly often the code in the range above signed-int max is quite bug-ridden. Any code doing something like (2U * index) / 2U in this range will have quite the surprise coming.
Alas, (2S * signed_index) / 2S will similarly result in surprises the moment the signed_index hits half the signed-int max. There's no free lunch when trying to cheat the integer ranges.
The difference is that in the unsigned case you get a seemingly plausible value, and in the signed case you get a negative value which you can be sure is wrong. This is the problem.
In some languages, the signed version is undefined behavior. You may get a negative value, INT_MAX / 2, or an error. Or the compiler may detect the undefined behavior, which according to the standard cannot happen, and mutilate your code in unexpected ways.