4 ms·

He covers that in the next section "Signedness" and more thoroughly in "System-Dependent Types" where he recommands (properly) using uintptr_t and intptr_t: Th

• bluetomcat 11y ago
  Correct me if I'm wrong, but in my understanding, the primary purpose of uintptr_t is to type-pun a pointer into a compatible integer, inspect/modify the bits of the integer and then cast it back to a pointer of the same type. I don't feel like it's the right type for simple pointer arithmetic.
  • _kst_ 11y ago
    You're right, using uintptr_t for pointer arithmetic is a bad idea. I've worked on systems (Cray vector machines) where converting a pointer to an integer type, performing arithmetic on the integer, and converting back to a pointer could yield meaningless results. (Hardware addresses were 64-bit addresses of 64-bit words; byte pointers were implemented by storing a 3-bit offset in the high-order bits of the pointer.) Pointer arithmetic works. It causes undefined behavior if it goes outside the address range of the enclosing object, but in those cases converting to uintptr_t and performing arithmetic will give you garbage results anyway.