Description:
------------
If I use an Object, with an ArrayAccess interface, I can't modify element arrays the same way like 2-dimensional arrays

Test script:
---------------
<?php
// Just a simple class, for testing.
class ArrayTest implements ArrayAccess
{
	private $array;
	
	public function offsetGet($offset) {
		return $this->array[$offset];
	}
	
	public function offsetSet($offset,$value) {
		$this->array[$offset] = $value;
	}
	
	public function offsetUnset($offset) {
		unset($this->array[$offset]);
	}
	
	public function offsetExists($offset) {
		return isset($this->array[$offset]);
	}
}

$a = new ArrayTest();
$b = new ArrayTest();

$a['numbers'] = array('one'=>1);
var_dump($a['numbers']);

$b['numbers']['one'] = 1;
var_dump($b['numbers']);
?>



Expected result:
----------------
I want to get:

array ( 'one' => 1, )
array ( 'one' => 1, )

But I got instead:

array ( 'one' => 1, )
Notice: Indirect modification of overloaded element of ArrayTest has no effect in /home/zsolt94/www/oopy/arraytest.php on line 30
null

I think that:
$a['foo']['bar'] = $anything;

Should do the same effect as that:

$foo = $a['foo'];
$foo['bar'] = $anything;
$a['foo'] = $foo;
unset($foo);