ier">s</span><span class="special">)</span>
        <span class="special">:</span> <span class="identifier">m_str</span><span class="special">(&amp;</span><span class="identifier">s</span><span class="special">)</span>
    <span class="special">{}</span>

    <span class="keyword">void</span> <span class="keyword">operator</span><span class="special">()(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span clas