title: Can attribute directives transclude?
body: <p>I want slotted transclusion, and I've seen examples of element directives like this:</p>
  
  <pre><code>&lt;my-directive&gt;
      &lt;slot-a&gt;&lt;/slot-a&gt;
      &lt;slot-b&gt;&lt;/slot-b&gt;
  &lt;/my-directive&gt;
  </code></pre>
  
  <p>I want to know if it must be an element directive. I'd like to do something like this:</p>
  
  <pre><code>&lt;div my-directive&gt;
      &lt;slot-a&gt;&lt;/slot-a&gt;
      &lt;slot-b&gt;&lt;/slot-b&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Is this possible? I can't find any documentation saying it can or can't be done.</p>