ecked_stepper</a><span class="special">&lt;</span><span class="identifier">Stepper</span><span class="special">,</span> <span class="identifier">Checker</span><span class="special">,</span> <span class="identifier">stepper_tag</span><span class="special">&gt;</span><span class="special">;</span>
      <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> ControlledStepper<span class="special">,</span> <span class="keyword">typename</span> Checker<span cl