title: How to get array size stored in unique_ptr?
body: <p>if I do:</p>
  
  <pre><code>std::unique_ptr&lt;int[]&gt; uparr(new int[1984]);
  </code></pre>
  
  <p>and I pass <code>uparr</code> to somebody without passing the <code>1984</code> to them can they see how many elements it has?<br>
  aka is there equivalent of vector's .size() for  unique_ptr of array ? </p>