<?php
class C
{
    function __call($name, $values)
    {
        $values[0][0] = 'changed';
    }
}
function main() {
    $a = array('original');
    $b = array('original');

     $hack =& $b[0];

    $c = new C;
    $c->f($a);
    $c->f($b);

    var_dump($a, $b);
}