r</span></code></a> that will enumerate
        one string for each regular expression match of the expression <span class="emphasis"><em>re</em></span>
        found within the sequence [a,b), using match flags <span class="emphasis"><em>m</em></span>
        (see <a class="link" href="match_flag_type.html" title="match_flag_type"><code class="computeroutput"><span class="identifier">match_flag_type</span></code></a>).
        The string enumerated is the sub-expression <span class="emphasis"><em>submatch<