pan> <span class="identifier">SeverityT</span><span class="special">,</span> <span class="identifier">SeverityFallbackT</span><span class="special">,</span> <span class="identifier">SeverityTagT</span><span class="special">,</span> <span class="identifier">ActorT</span> <span class="special">&gt;</span> <span class="keyword">const</span> <span class="special">&amp;</span> severity_placeholder<span class="special">,</span> 
                          <span class="identifier">SeverityCompareT</span> <span clas