             searches sub-directories for matching file names.
                  </p>
                  <p>
                    Returns the total number of matches found.
                  </p>
                  <p>
                    May throw an exception derived from <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">runtime_error</span></code>
                    if file io fails.
                  </p>
                </td>
</tr>
<tr