Overloading Limitation- Can Someone Confirm?

While playing with an unnamed framework, I think I discovered an overloading limitation (PHP 5.1.2). Can someone please confirm this limitation? Example class: class testClass {

    public $vars = array();

    public function __get($key)
    {
        return array_key_exists($key, $this->vars) ? $this->vars[$key] : null;
    }

    public function __set($key, $value)
    {
        $this->vars[$key] = $value;
    }

    public function __isset($key)
    {
        return array_key_exists($key, $this->vars);
    }

    public function __unset($key)
    {
        unset($this->vars[$key]);
    }

} Given the above class, the following code will not work: $tc = new testClass(); $tc->arr = array(); $tc->arr['a'] = 'A'; $tc->arr['b'] = 'B'; if (isset($tc->arr['b'])) {

    unset($tc->arr['b']);

} //var_dump is only to see results of above var_dump($tc); Am I a moron or, in fact, does this not work and is a language limitation? Chris chris@dented-planet.net