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<?php $a = 1; $array = array(&$a, &$a); var_dump(serialize($array)); var_dump(unserialize(serialize($array)));
Output for 4.3.0 - 7.2.0
string(22) "a:2:{i:0;i:1;i:1;R:2;}" array(2) { [0]=> &int(1) [1]=> &int(1) }