title: Method in an enum is asking for argument when none required in declaration
body: <p>This maybe a terrible n00b question but I'm finally getting to look at Swift properly.
  Imagine I have a simple enum representing a playing card.
  In it I have a method that returns an <code>Array</code> of <code>Card</code>s.
  The method has no arguments, but when I call it the auto-completion and compiler both state it needs one. </p>
  
  <p>Notes:</p>
  
  <ul>
  <li>Rank and Suit are previously defined structs.</li>
  <li>Yes, I know 'nested for-loops considered harmful'. I'll move it to map/reduce later...</li>
  <li>This is running in playground file.</li>
  </ul>
  
  <p>Code:</p>
  
  <pre><code>struct Card {
    var rank: Rank
    var suit: Suit
  
    init(rank: Rank, suit: Suit) {
      self.rank = rank
      self.suit = suit
    }
  
    //internal version
    func deckOfCards() -&gt; [Card] {
      var deck = [Card]()
      for suit in Suit.allSuits {
        for rank in Rank.allRanks {
          deck.append(Card(rank: rank, suit: suit))
        }
      }
      return deck
    }
  }
  
  //external version
  func deckOfCards() -&gt; [Card] {
    var deck = [Card]()
    for suit in Suit.allSuits {
      for rank in Rank.allRanks {
        deck.append(Card(rank: rank, suit: suit))
      }
    }
    return deck
  }
  
  let externalDeck = deckOfCards()
  let internalDeck = Card.deckOfCards() //this has the compiler error: Missing argument for parameter #1
  </code></pre>