OptionalInterpolation.swift

// Based on https://github.com/T-Pham/NoOptionalInterpolation

import Foundation

public
protocol Unwrappable
{
    func unwrap() -> Any?
}

extension Optional: Unwrappable
{
    public
    func unwrap() -> Any?
    {
        switch self
        {
            case nil:
                return nil

            case let unwrappable as Unwrappable:
                return unwrappable.unwrap()

            case let any:
                return any
        }
    }
}

public
extension String
{
    public
    init<T:Unwrappable>(stringInterpolationSegment expr: T)
    {
        guard let unwrapped = expr.unwrap() else { self.init("nil")!; return }
        self.init(reflecting: unwrapped)
    }
}