title: TypeScript casting with modules
body: <p>How can I cast the type of a variable with an exported class? Such as this:</p>
  
  <p>GameManager.ts:</p>
  
  <pre><code>export class GameManager {}
  </code></pre>
  
  <p>Player.ts:</p>
  
  <pre><code>private _manager: GameManager;
  </code></pre>
  
  <p>when i use a <code>/// &lt;reference path="GameManager.ts" /&gt;</code>, i get an error saying GameManager is out of scope or something like that. How does this work exactly?</p>