representable.swift

@propertyWrapper
public struct UserDefault<T>: UserDefaultSpec {
  let key: String
  let defaultValue: T

  public init(_ key: String, defaultValue: T) {
    self.key = key
    self.defaultValue = defaultValue
  }

  public var value: T {
    get {
      UserDefaults.standard[key] ?? defaultValue
    }
    set {
      UserDefaults.standard[key] = newValue
    }
  }
}

// GRRR why don't you work?!
public extension UserDefault where T: RawRepresentable {
  var value: T {
    get {
      if let rawValue = UserDefaults.standard.value(forKey: key) as? T.RawValue {
        return T(rawValue: rawValue)!
      }
      
      return defaultValue
    }
    set {
      UserDefaults.standard.set(newValue.rawValue, forKey: key)
    }
  }
}