After implementing the description property and declaring CustomStringConvertible conformance, the Enum type provides its own custom representation.

enum_description.swift

enum Rank: Int, CustomStringConvertible {
    case ace = 1
    case two, three, four, five, six, seven, eight, nine, ten
    case jack, queen, king

    func simpleDescription() -> String {
        switch self {
            case .ace:
                return "ace"
            case .jack:
                return "jack"
            case .queen:
                return "queen"
            case .king:
                return "king"
            default:
                return String(self.rawValue)
        }
    }
  
  var description: String {
    return "test"
  }
}

let ace = Rank.ace // test
let aceRawValue = ace.rawValue // 1
let ranks: [Rank] = [.ace, .jack, .king] // [test, test, test]