How to do sets?

[taylorj at yvax.byu.edu]

This may be a dumb question, but I haven't been able to find anyone yet who
could answer it...

Is there a way to do sets in C (like in Pascal)?  That is, check for set
inclusion (char in ["0".."9"]), and perform unions and intersections.  And the
answer is not "use bitwise operators," I already know how to do that and would
rather not if there's an easier way, especially with large sets requiring 32
bytes or more.

Thanks.