title: total template specialization
body: <p>I'm reading the book of Meyers about effective c++ programming, in item 25 I found <code>total template specialization</code>, but I can't understand it, what does that it mean? he also gives example:</p>
  
  <pre><code>namespace std {
  
      template&lt;&gt;
      void swap&lt;Widget&gt;(Widget&amp; a, Widget&amp; b)
        {
            swap(a.pimpl, b.pimpl);
        }
  
      }
  </code></pre>
  
  <p>what does this statement mean : <code>template&lt;&gt;</code>(why without typename?)</p>
  
  <p>thanks in advance</p>