<?php
class foo {
	public $a1;
	public $a2 = array();
	public $a3;
	public $o1;
	public $o2;
	
	public function f1() {
		return $this->a1;
	}

	public function f2() {
		return $this->a2;
	}

	public function f3() {
		$this->a3 = array();
		return $this->a3;
	}

	public function f4() {
		return $this->o1;
	}

	public function f5() {
		$this->o2 = new stdClass;
		return $this->o2;
	}

	public function &f6() {
		return $this->a1;
	}

	public function f7(&$x) {
		$x = 2;
	}

}

$foo = new foo;

$foo->f1()[0] = 1;
var_dump($foo->a1);

$foo->f2()[0] = 1;
var_dump($foo->a2);

$foo->f3()[0] = 1;
var_dump($foo->a3);

$foo->f4()->a = 1;
var_dump($foo->o1);

$foo->f5()->a = 1;
var_dump($foo->o2);

$foo->a1[0] = 1;
$foo->f7($foo->f6()[0]);
var_dump($foo->a1[0]);
$foo->f1()[0]++;
var_dump($foo->a1[0]);
$foo->f6()[0]++;
var_dump($foo->a1[0]);
