n class="identifier">attr</span><span class="special">&lt;</span> <span class="identifier">severity_level</span> <span class="special">&gt;(</span><span class="string">"Severity"</span><span class="special">)</span>
            <span class="special">&lt;&lt;</span> <span class="string">" Message: "</span> <span class="special">&lt;&lt;</span> <span class="identifier">expr</span><span class="special">::</span><span class="identifier">smessage</span>
    <span class="special">);</span>

    <span class="comme