Equivalent of C++ STL container “pair” in Objective-C?

Question

I\'m new to Objective-C, so please don\'t judge me too much. I was wondering: Is there an equivalent of the C++ STL pair container I can use in Objective-C?

I want to bu

Answer 1

How about a Pair category on NSNumber that uses associated objects, something like the code below (untested, may require iOS4 as I'm not sure when associated objects were introduced).

#import 

@implementation NSNumber(Pair)

#define PAIR_KEY 'p'

- (NSNumber *) pairNumber:(NSNumber *)second
{
    char secondKey = PAIR_KEY;
    objc_setAssociatedObject(self, &secondKey, second, OBJC_ASSOCIATION_RETAIN);
    return self;
}

- (NSNumber *) pairedNumber
{
    char secondKey = PAIR_KEY;
    NSNumber *associatedObject = (NSNumber *)objc_getAssociatedObject(self, &secondKey);    
    return associatedObject;
}

@end

You would use it like so:

BOOL myBool = NO;

NSNumber *storedBool = [NSNumber numberWithBool:myBool];

[myOtherNumber pairNumber:storedBool];

And to get it out:

NSNumber *boolNumber = [myOtherNumber pairedNumber];