Object Association misuse

AssociationMisuse.mm

 
static char ownershipsKey; // one for all objects

@implementation NSObject (Ownerships)

//should not autorelease returned value
- (NSMutableArray *)lazyOwnerships
{
    NSMutableArray *result = objc_getAssociatedObject(self, &ownershipsKey);
    if (!result) {
        result = [NSMutableArray new];
        
        // array instance per object
        objc_setAssociatedObject(self,
                                 &ownershipsKey,
                                 result,
                                 OBJC_ASSOCIATION_RETAIN_NONATOMIC);
    }
    return result;
}