Well, you can compare pointers (to distinct objects) too, but only for equality. (The only in any case not-undefined way of calculating some sort of difference

Well, you can compare pointers (to distinct objects) too, but only for equality. (The only in any case not-undefined way of calculating some sort of difference value between such is with the use of the optional uintptr_t, but I'd guess this isn't a sort of undefined behaviour which triggers unwanted compiler tricks, anyway.)