title: swift3 Ambiguous reference to member subscript
body: <p>I know this question has been asking countless times but I am still struggling to find an answer to this. This is the simplest example I have in my code even though the rest of my code is also riddled with this error ever since I upgraded to Swift 3.</p>
  
  <pre><code>func generateDummyPlayers(numberOfPlayers: Int32) -&gt; [NSString : Player] {
      var _players = [NSString : Player]()
      if(numberOfPlayers) &gt; 0 {
          for i in 1...numberOfPlayers {
              let name: String = "\(Player.prefix) \(i)";
              let player: Player = Player(name: name);
              _players[name] = player; //Ambiguous reference to member 'subscript'
          }
      }
      return _players;
  }
  </code></pre>