How do those bitmasks actually work?
- by mystify
For example, this method from NSCalendar takes a bitmask:
- (NSDate *)dateByAddingComponents:(NSDateComponents *)comps toDate:(NSDate *)date options:(NSUInteger)opts
So options can be like:
NSUInteger options = kCFCalendarUnitYear;
or like:
NSUInteger options = kCFCalendarUnitYear | kCFCalendarUnitMonth | kCFCalendarUnitDay;
What I don't get is, how is this actually done? I mean: How can they pull out those values which are merged into options? If I wanted to program something like this, that can take a bitmask, how would that look?