title: Does Web API 2 support route constraints on query string parameters?
body: <p>In Web API 2, I can put constraints in the route template; for example:</p>
  
  <pre><code>[Route("api/foos/{id:int}")]
  void GetFooWithId(int id, [FromUri] string format = null)
  { ... }
  </code></pre>
  
  <p>Is there a way to constrain query string parameters, such as <code>format</code> in the above example, in a similar manner?</p>
  
  <p>(I know that I could perhaps declare a custom value type for the <code>format</code> parameter and then define a <code>[TypeConverter]</code> on it that fails for invalid values, but I would first like to see whether Web API 2's route constraint mechanism can be employed for query string parameters, too.)</p>