Reference to NULL
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/2165078/a-reference-can-not-be-null-or-it-can-be-null">A reference can not be NULL or it can be NULL?</a>  </p>
</blockquote>



<p>How does the below program compile successfully?</p>

<pre><code>int main()
{
   int *ptr = NULL;
   int &amp;ref = *ptr;
   return 0;
}
</code></pre>

<p>See it on <a href="http://ideone.com/a5jG7" rel="nofollow">ideone</a>.</p>

<p>Can we define reference to NULL?</p>
