Unsigned types have their own issues, though: they overflow at "small" values like -1, which means that doing things like correctly looping "backwards" over an array with an unsigned index is non-trivial.

> On the other hand, I just wrote a proposal to WG14 to make zero-byte reallocations undefined behavior that was unanimously accepted for C2x.

You're saying that realloc(foo, 0) will no longer free the pointer?