the category
for a specific <a class="reference external" href="reference-Alerts.html#alert">alert</a> is enabled or not, without instantiating the <a class="reference external" href="reference-Alerts.html#alert">alert</a>.
The <tt class="docutils literal">category</tt> virtual function is the run-time equivalence.</p>
<p>The <tt class="docutils literal">what()</tt> virtual function may simply be a string literal of the class
name of your <a class="reference external" href="reference-Alerts.html#alert">aler