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<?php class A implements Serializable { function __construct($o) { $this->o = $o; } function serialize() { return serialize([$this->o]); } function unserialize($s) { $this->o = unserialize($s)[0]; } } $o = new stdClass; $r = unserialize(serialize([new A($o), new A($o)])); var_dump($r[0]->o === $r[1]->o);

preferences:
54.02 ms | 2554 KiB | 5 Q