al">&gt;</span> 
  <span class="keyword">struct</span> <a class="link" href="map/on_definedness_idp41603648.html" title="Struct template on_definedness&lt;Type, false&gt;">on_definedness</a><span class="special">&lt;</span><span class="identifier">Type</span><span class="special">,</span> <span class="keyword">false</span><span class="special">&gt;</span> <span class="special">{</span>

    <span class="comment">// <a class="link" href="map/on_definedness_idp41603648.html#idp41605600-bb">public static funct