ng a block of code</p>
</div>
      
    </li>
  
</ul>
<p class="tag_title">Returns:</p>
<ul class="return">
  
    <li>
      
      
        <span class='type'>(<tt>true</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>when not given a block</p>
</div>
      
    </li>
  
    <li>
      
      
        <span class='type'>(<tt>true</tt>, <tt>false</tt>)</span>
      
      
      
        &mdash;
        <div class='inline'><p>the previous value of enable when given a block