</span> f<span class="special">,</span> <span class="identifier">I</span> l<span class="special">,</span> <span class="identifier">F</span> r<span class="special">,</span> <span class="emphasis"><em><span class="identifier">unspecified</span></em></span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span><span class="special">;</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> I<span class="special">,</