Pointers are 64-bit on 64-bit machines, and so are the largest unsigned ints, hence the problem. On the other hand, you're probably searching at least 4-byte ob

Pointers are 64-bit on 64-bit machines, and so are the largest unsigned ints, hence the problem. On the other hand, you're probably searching at least 4-byte objects, so your actual list length isn't 64 bits but at most 62 bits even if you filled the memory space.