在Swift 3中，当底层枚举有rawValue时，你可以实现Strideable协议。优点是不像其他建议那样创建值数组，并且标准的Swift“for in”循环工作，这是一个很好的语法。

// "Int" to get rawValue, and Strideable so we can iterate
enum MyColorEnum: Int, Strideable {
    case Red
    case Green
    case Blue
    case Black

    // required by Strideable
    typealias Stride = Int

    func advanced(by n:Stride) -> MyColorEnum {
        var next = self.rawValue + n
        if next > MyColorEnum.Black.rawValue {
            next = MyColorEnum.Black.rawValue
        }
        return MyColorEnum(rawValue: next)!
    }

    func distance(to other: MyColorEnum) -> Int {
        return other.rawValue - self.rawValue
    }

    // just for printing
    func simpleDescription() -> String {
        switch self {
        case .Red: return "Red"
        case .Green: return "Green"
        case .Blue: return "Blue"
        case .Black: return "Black"
        }
    }
}

// this is how you use it:
for i in MyColorEnum.Red ... MyColorEnum.Black {
    print("ENUM: \(i)")
}

这看起来像一个黑客，但如果你使用原始值，你可以这样做

enum Suit: Int {  
    case Spades = 0, Hearts, Diamonds, Clubs  
 ...  
}  

var suitIndex = 0  
while var suit = Suit.fromRaw(suitIndex++) {  
   ...  
}  

原则上，如果你不为enum的大小写使用原始值赋值，这样做是可能的:

enum RankEnum: Int {
  case Ace
  case One
  case Two
}

class RankEnumGenerator: Generator {
    var i = 0
    typealias Element = RankEnum
    func next() -> Element? {
        let r = RankEnum.fromRaw(i)
        i += 1
        return r
    }
}

extension RankEnum {
    static func enumerate() -> SequenceOf<RankEnum> {
        return SequenceOf<RankEnum>({ RankEnumGenerator() })
    }
}

for r in RankEnum.enumerate() {
    println("\(r.toRaw())")
}

有时，您可能会处理具有底层原始整数类型的枚举类型，这种类型在整个软件开发生命周期中都会发生变化。下面是一个很适合这种情况的例子:

public class MyClassThatLoadsTexturesEtc
{
    //...

    // Colors used for gems and sectors.
    public enum Color: Int
    {
        // Colors arranged in order of the spectrum.
        case First = 0
        case Red, Orange, Yellow, Green, Blue, Purple, Pink
        // --> Add more colors here, between the first and last markers.
        case Last
    }

    //...

    public func preloadGems()
    {
        // Preload all gems.
        for i in (Color.First.toRaw() + 1) ..< (Color.Last.toRaw())
        {
            let color = Color.fromRaw(i)!
            loadColoredTextures(forKey: color)
        }
    }

    //...
}

我使用了下面的方法，假设我知道哪个是Rank enum中的最后一个值，所有的Rank在Ace之后都有增量值

我喜欢这种方式，因为它干净，小，容易理解

 func cardDeck() -> Card[] {
     var cards: Card[] = []
     let minRank = Rank.Ace.toRaw()
     let maxRank = Rank.King.toRaw()

     for rank in minRank...maxRank {
         if var convertedRank: Rank = Rank.fromRaw(rank) {
             cards.append(Card(rank: convertedRank, suite: Suite.Clubs))
             cards.append(Card(rank: convertedRank, suite: Suite.Diamonds))
             cards.append(Card(rank: convertedRank, suite: Suite.Hearts))
             cards.append(Card(rank: convertedRank, suite: Suite.Spades))
         }
    }

    return cards
}

枚举有toRaw()和fromRaw()方法。所以如果你的原始值是Int，你可以从第一个枚举迭代到最后一个枚举:

enum Suit: Int {
    case Spades = 1
    case Hearts, Diamonds, Clubs
    func simpleDescription() -> String {
        switch self {
        case .Spades:
            return "spades"
        case .Hearts:
            return "hearts"
        case .Diamonds:
            return "diamonds"
        case .Clubs:
            return "clubs"
        }
    }
}

for i in Suit.Spades.toRaw()...Suit.Clubs.toRaw() {
    if let covertedSuit = Suit.fromRaw(i) {
        let description = covertedSuit.simpleDescription()
    }
}

一个问题是在运行simpleDescription方法之前需要测试可选值，因此我们首先将convertedSuit设置为我们的值，然后将常量设置为convertedSuit.simpleDescription()