TupleAndMultiParameters.swift

enum Hoge {
    case oneValue(one: String)
    case twoValue(one: String, two: String)

    var description: String {
        switch self {
        case .oneValue(let one): return "\(one)"
        case .twoValue(let one): return "\(one)" // `one` is treated as tuple, unexpectedly
        }
    }
}

let one = Hoge.oneValue(one: "1")
print(one.description) // 1

let two = Hoge.twoValue(one: "1", two: "2")
print(two.description) // "(one: "1", two: "2")"