Iterating over an NSOrderedSet

Question

I'm trying to iterate over an instance of NSOrderedSet. Something like this:

func myFunc() {
    var orderedSet = NSOrderedSet(array: [ 42, 43, 44])

    for n in orderedSet {
        NSLog("%i", n)
    }
}

...however the for loop line produces this compiler error:

'NSOrderedSet' does not have a member named 'Generator'

Now I could convert it to an array like this:

    for n in orderedSet.array {
        NSLog("%i", n)
    }

...but I wondered if there was a better solution?

I'm also keen to understand why it's possible to iterate over a set but not an ordered set? NSOrderedSet implements NSFastEnumeration, so it should work right?

Answer 1

You can iterate over an ordered set with

let orderedSet = NSOrderedSet(array: [ 42, 43, 44])
orderedSet.enumerateObjectsUsingBlock { (elem, idx, stop) -> Void in
    println("\(idx): \(elem)")
}

UPDATE: As of Swift 1.2 (Xcode 6.3), NSOrderedSet conforms to SequenceType and can be enumerated with for ... in ...:

let orderedSet = NSOrderedSet(array: [ 42, 43, 44])
for elem in orderedSet {
    println(elem)
}