 class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term">Returns:</span></p></td>
<td>the <code class="computeroutput">typeid</code> of the
              contained value if instance is non-empty, otherwise
              <code class="computeroutput">typeid(void)</code>.</td>
</tr>
<tr>
<td><p><span