     <p>
                  Assignment operator for nullptr_t.
                </p>
                <p>
                  Assignment operator to create a polymorphic wrapper for the specified
                  executor.
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <a class="link" href="executor/post.html" title="executor::post"><span class="bold"><strong>post</strong></span></a>
                </p>
              </td>
<td>
                <p>
               