title: Using class constants in Symfony routing
body: <p>I have a route defined with an annotation, like this:</p>
  
  <pre><code>/**
   * @Route("/doSomething/{param}", name="route_name", defaults={"param"=1})
  */
  </code></pre>
  
  <p>Is it possible to use a class constant instead of this hardcoded '1', like:</p>
  
  <pre><code>/**
   * @Route("/doSomething/{param}", name="route_name", defaults={"param"=MyBundle:MyEntity:DEFAULT_TYPE})
  */
  </code></pre>
  
  <p>(of course the above fails)</p>