tput"><span class="identifier">multi_pass</span></code>,
        it will call <code class="computeroutput"><span class="identifier">multi_pass</span><span class="special">::</span><span class="identifier">clear_queue</span><span class="special">()</span></code>.
        This will cause any buffered data to be erased. This also will invalidate
        all other copies of multi_pass and they should not be used. If they are,
        an <code class="computeroutput"><span class="identifier">boost</span><span cla