title: Strange declaration with using in C++
body: <p>On a piece of code in a previous question in <em>stackoverflow</em> I saw this, strange to me, declaration with <code>using</code>:</p>
  
  <pre><code>template &lt;std::size_t SIZE&gt; 
  class A
  {
  public:
    ...
    using const_buffer_t = const char(&amp;)[SIZE];
    ...
  };
  </code></pre>
  
  <p>Could someone please address the following questions:</p>
  
  <ol>
  <li>What type it represents?</li>
  <li>Where do we need such kind of declarations?</li>
  </ol>