::</span><span class="identifier">pair</span><span class="special">&lt;</span> <span class="identifier">corpusIter</span><span class="special">,</span> <span class="identifier">corpusIter</span> <span class="special">&gt;</span> 
  <a name="idp50504400-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">corpusIter</span> corpus_first<span class="special">,</span> <span class="identifier">corpusIter</s