title: How to convert a generic HList to a List
body: <p>I have these:</p>
  
  <pre><code>trait A[T]
  class X
  class Y
  
  object B {
     def method[H :&lt; HList](h: H) = h.toList[A[_]]
  }
  </code></pre>
  
  <p>Parameter <code>h</code> of <code>method</code> will always be a HList of A[T], like new A[X] :: new A[Y] :: HNil.</p>
  
  <p>I would like to convert the HList to a List[A[_]].</p>
  
  <p>How can I get this with generic code, because trait HList doesn't have the toList method()?</p>