a></em></span>

<span class="keyword">explicit</span>
<a class="link" href="handler/overload3.html" title="test::handler::handler (3 of 4 overloads)">handler</a><span class="special">(</span>
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">none_t</span><span class="special">);</span>
  <span class="emphasis"><em>» <a class="link" href="handler/overload3.html" title="test::handler::handler (3 of 4 overloads)"><code class="computeroutput"><span class="identifi