如何使用Xcode10.2.1/swift 4.2中的'iterateEnum‘函数按照枚举列表中指定的特定顺序对数组中的字符串值进行排序

enum SortOrder: Int {
    case ascending = 1
    case descending = -1
}

func iterateEnum<T: Hashable>(_: T.Type) -> AnyIterator<T> {
    var i = 0
    return AnyIterator {
        let next = withUnsafeBytes(of: &i) { $0.load(as: T.self) }
        if next.hashValue != i { return nil }
        i += 1
        return next
    }
}

let strings = ["apple", "banana", "cherry", "date"]
let sortOrder = SortOrder.ascending

let sortedStrings = strings.sorted {
    (str1, str2) -> Bool in
    let index1 = Array(iterateEnum(SortOrder.self)).firstIndex(of: sortOrder)!
    let index2 = Array(iterateEnum(SortOrder.self)).firstIndex(of: sortOrder)!
    return str1 < str2
}

print(sortedStrings)