> If you want to blame someone, blame the designers of the C language for doing things like making int the natural idiom to iterate over arrays even when size_t would be better. The fact that C programmers continue to write "for (int i = 0; i < n; i++)" to iterate over an array is why signed overflow is undefined, and it is absolutely a critical optimization in practice.

Well, size_t is unsigned and has defined overflow, so you'd lose the optimization if you switched to it. (Specifically, there's cases where defining overflow means a loop is possibly infinite, which blocks all kinds of optimizations.)

Many languages try to fix this by defaulting to wrap on overflow, but that was a mistake because you rarely actually want that. A better solution is to have a loop iteration statement that doesn't have an explicit "int i" or "i++" written out.