The NSAutoreleasePool class is a thin wrapper around the NSPushAutoreleasePool and NSPopAutoreleasePool functions.
#ifdef __cplusplus
extern "C" void *NSPushAutoreleasePool(void *);
extern "C" void NSPopAutoreleasePool(void *);
#else
void *NSPushAutoreleasePool(void *);
void NSPopAutoreleasePool(void *);
#endif
Example:
static void MyMethod()
{
void *pool = NSPushAutoreleasePool(NULL);
[[[NSObject alloc] init] autorelease];
NSPopAutoreleasePool(pool);
}