I want to make a function, modify for instance, for clients where user can modify passed object BUT not override it with another one.

I mean… if any user wants to override the passed object for instance:
$originObject = new StdClass();
after the function execution
I’ll be able to restore the SAME object passed to the function.

function modify(object &$obj): void {
    $obj = new StdClass();
}

function back(object &$obj, int $previousObjectId, string $serializedOriginObject): void {
    if (spl_object_id($obj) !== $previousObjectId) {
        $obj = unserialize($serializedOriginObject);
    }
}

$originObject = new StdClass; // ORIGIN OBJECT
$serializedOriginObject = serialize($originObject);

$objectIdBeforeModify = spl_object_id($originObject);
var_dump($objectIdBeforeModify); // in my case object id: "1"

modify($originObject); // PASSES BY REFERENCE AND OVERRIDES IT
$objectIdAfterModify = spl_object_id($originObject);
var_dump($objectIdAfterModify); // in my case object id: "2"

back($originObject, $objectIdBeforeModify, $serializedOriginObject);
$returnedObjectId = spl_object_id($originObject);
var_dump($returnedObjectId);    // in my case object id: "1"

My question is: are there any ways to make it without serialization?
To restore an object that was overriden, cuz it was passed by reference in the function.