PHP awkward function declaration
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/1676897/what-does-it-mean-to-start-a-php-function-with-an-ampersand">What does it mean to start a PHP function with an ampersand?</a>  </p>
</blockquote>



<p>Recently I stumbled upon this piece of code:</p>

<pre><code>public static function &amp;get_instance()
{
return self::$instance;
}
</code></pre>

<p>What does this kind of function declaration <code>&amp;get_instance()</code> mean? Can the function name be a variable?</p>
