ReactiveCocoa--RACTuple

    [[self rac_signalForSelector:@selector(tableView:didSelectRowAtIndexPath:)
                    fromProtocol:@protocol(UITableViewDelegate)] subscribeNext:^(RACTuple *tuple) {
        NSLog(@"%@", tuple.first);
        NSLog(@"%@", tuple.second);
    }];

    + (instancetype)tupleWithObjectsFromArray:(NSArray *)array;

    + (instancetype)tupleWithObjectsFromArray:(NSArray *)array convertNullsToNils:(BOOL)convert;

    + (instancetype)tupleWithObjects:(id)object, ... NS_REQUIRES_NIL_TERMINATION;

- (NSArray *)allObjects;

- (instancetype)tupleByAddingObject:(id)obj;