title: STL priority Queue constructor
body: <p>Why priority queue have that signature ? </p>
  
  <pre><code>std::priority_queue&lt;int, std::vector&lt;int&gt;, std::greater&lt;int&gt; &gt; third;
  </code></pre>
  
  <p>For what need <code>std::vector&lt;int&gt;</code>? If I, for example, need to store in queue only ints ?</p>