I'll just take this opportunity to wear the Language Lawyer hat:

There is no requirement that the mapping between integers and pointers
be useful, and indeed, no requirement that there is an integer type
large enough to hold a pointer (and any other cast from a pointer to
an integer is undefined behavior...).

A hostile implementor is allowed to declare that all integers convert
to null pointers.

And yes, if this person hit multiple randomly selected technical lists,,
you still did the right thing; people like that deserve multiple answers,
none of which can possibly work, and none of which they are able to
comprehend well enough to see why it won't work.  :)

-s