#import typedef struct { BOOL fieldOne : 1; BOOL fieldTwo : 1; BOOL fieldThree : 1; BOOL fieldFour : 1; BOOL fieldFive : 1; } BoolBitFields; int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; BOOL yes = YES; BOOL no = NO; BOOL unset = 12; BOOL &yes_ref = yes; BOOL &no_ref = no; BOOL &unset_ref = unset; BOOL* yes_ptr = &yes; BOOL* no_ptr = &no; BOOL* unset_ptr = &unset; BoolBitFields myField = {0}; myField.fieldTwo = YES; myField.fieldFive = YES; [pool drain];// Set break point at this line. return 0; }