[pcwalton]

You do have to be able to cast from a pointer to an appropriately-sized integer and back, however [1]. This makes the semantics fuzzy and ill-defined in some cases [2].

[1]: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2263.htm#q3...

[2]: https://blog.regehr.org/archives/1621