What's the benefit of function refrence?
<p>When I reading the code of CodeIgniter,I found some functions written as follows:</p>

<pre><code>function &amp;get_instance()
{
   global $CI, $OBJ;

   if (is_object($CI))
   {
       return $CI;
   }

   return $OBJ-&gt;load;
}
</code></pre>

<p>I can understand variable refrence,but I can hardly get this through.Is it necessary to use this function style?And any benefit?</p>

<p>Thanks.</p>
