title: Map OptionSetType to Array
body: <p>Given the following:</p>
  
  <pre><code>struct Weekdays: OptionSetType {
  
      let rawValue: Int
      init(rawValue: Int) { self.rawValue = rawValue }
  
      static let Monday = Weekdays(rawValue: 1)
      static let Tuesday = Weekdays(rawValue: 2)
      static let Wednesday = Weekdays(rawValue: 4)
      static let Thursday = Weekdays(rawValue: 8)
  
      static let allOptions: [Weekdays] = [.Monday, .Tuesday, .Wednesday, .Thursday]
  
  }
  </code></pre>
  
  <p>I can convert an array of <code>Ints</code> into a <code>Weekdays</code> object by doing this:</p>
  
  <pre><code>let arr = [1, 4]
  let weekdays = arr.reduce(Weekdays()) { $0.union(Weekdays(rawValue: $1)) }
  </code></pre>
  
  <p>My question is, how do I take a <code>Weekdays</code> object and convert it into an array of <code>Ints</code>?</p>