Using intptr_t instead of void*?

Question

Is it a good idea to use intptr_t as a general-purpose storage (to hold pointers and integer values) instead of void*? (As seen here: http://www.cr

Answer 1

No, you can't be guaranteed that any particular type is a reasonable way of storing both pointers and integers, and besides, it makes your code confusing. There is a better way.

If you want to store an integer and a pointer in the same object, the clean and portable method is to use a union:

union foo {
   int integer_foo;
   void *pointer_foo;
};

This is portable and allows you to store both sorts of things in the size of storage needed for the larger of the two. It is guaranteed to always work.