How to print Optional<Wrapped>

String+Unwrap.swift

fileprivate protocol _Optional {
    func unwrappedString() -> String
}

extension Optional: _Optional {
    fileprivate func unwrappedString() -> String {
        switch self {
        case .some(let wrapped as _Optional): return wrapped.unwrappedString()
        case .some(let wrapped): return String(describing: wrapped)
        case .none: return String(describing: self)
        }
    }
}

postfix operator ~? { }
public postfix func ~? <X> (x: X?) -> String {
    return x.unwrappedString
}



// example

var d: Double? = 12.34
print(d)     // Optional(12.34)
print(d~?)   // 12.34
d = nil
print(d~?)   // nil


let i: Int??? = 5
print(i)              // Optional(Optional(Optional(5)))
print("i: \(i~?)")    // i: 5