Note that you can also use the C99 fixed-width types perfectly well in Objective-C:
#import <stdint.h>
...
int32_t x; // guaranteed to be 32 bits on any platform
The wikipedia page has a decent description of what's available in this header if you don't have a copy of the C standard (you should, though, since Objective-C is just a tiny extension of C). You may also find the headers limits.h
and inttypes.h
to be useful.