extensions.swift

// whether or not the string conversions live in the main definition depends on whether
// or not the strings are used for debugging/UI purposes, or have an actual internal role 
// in the program
enum CasualAnswer
{
    case noWay, 
         yeahSure

    // Supported conversions from: Bool
    init(_ value:Bool) 
    {
        self = value ? .yeahSure : .noWay
    }
}
extension CasualAnswer:LosslessStringConvertible 	// String Compatibility
{
    init?(_ description:String) 
    {
        switch description 
        {
            case "no way": 
                self = .noWay
            case "yeah sure": 
                self = .yeahSure
            default: 
                return nil
        }
    }

    var description:String 
    {
        switch self 
        {
            case .noWay: 
                return "no way"
            case .yeahSure: 
                return "yeah sure"
        }
    }
}

// we are modifying a stdlib type to support a conversion to our custom type. 
// this is conceptually different from an opposite conversion from our 
// custom type to a stdlib type. 
// public // why are you making a *public* extension of a stdlib type? this is a *bad* idea
extension Bool 
{
    init(_ value:CasualAnswer) 
    {
        switch value 
        {
            case .noWay: 
                self = false
            case .yeahSure: 
                self = true
        }
    }
}