 class="special">,</span> <span class="keyword">typename</span> Checker<span class="special">&gt;</span> 
<span class="keyword">class</span> <a class="link" href="checked_observer.html" title="Class template checked_observer">checked_observer</a> <span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
  <span class="comment">// types</span>
  <span class="keyword">typedef</span> <span class="identifier">Observer</span> <a name="boost.numeric.odeint.checked_observer.o