4 ms·

Is a cast to uintptr_t also OK ? void *oldptr = malloc(73); uintptr_t savedptr = (uintptr_t)oldptr; void *newptr = realloc(oldptr, 42); if (savedptr ==

• munch117 4y ago
  That is OK, at least in the sense that there's no undefined behaviour. I'm not sure it's also OK, because the memcmp suggestion you are replying to seems a bit suspect. There's still the problem that comparing the uintptr_t's is not guaranteed to yield the same result as the pointers they were cast from. But that's merely implementation-specific behaviour, not undefined.
• kazinator 4y ago
  I think it's fine on the assumption that a uintptr_t converted from a pointer cannot be a trap representation, which is the case on mainstream platforms. (An unsigned type can only have trap patterns if it has padding bits. Every combination of the value bits is a valid value according to the pure binary encoding.)