counting.swift

func enumCount<EnumType:Hashable>(eType : EnumType.Type) -> Int {
    if sizeof(eType) == 0 {return 1} // throw up hands
    if sizeof(eType) > 2 {fatalError("too many enumeration cases.")}
    let singleByte = sizeof(eType) == 1
    let min = singleByte ? 2 : 257
    let max = singleByte ? 2 << 8 : 2 << 16
    for hashIndex in min..<max {
        switch singleByte {
        case true:
            if unsafeBitCast(UInt8(hashIndex), eType).hashValue == 0 {
                return hashIndex
            }
        case false:
            if unsafeBitCast(UInt16(hashIndex), eType).hashValue == 0 {
                return hashIndex
            }
        }
    }
    return max
}

func members<EnumType:Hashable>(eType:EnumType.Type) -> [EnumType] {
    var enumMembers = [EnumType]()
    let singleByte = sizeof(eType) == 1
    for index in 0..<enumCount(EnumType) {
        switch singleByte {
        case true:
            let member = unsafeBitCast(UInt8(index), EnumType.self)
            enumMembers.append(member)
        case false:
            let member = unsafeBitCast(UInt16(index), EnumType.self)
            enumMembers.append(member)
        }
    }
    return enumMembers
}

enum Planets : Int {case Mercury, Venus, Earth, Mars, Jupiter, Saturn, Neptune, Uranus, Pluto}
enum Foo : Int {case i = 1, j = 5, k = 9}
enum Coin {case Heads, Tails}
enum Quark: String {case Up, Down, Top, Bottom, Strange, Charmed}

print(members(Planets))
print(members(Foo))
print(members(Coin))
print(members(Quark))