"Attempting to set reference to non referenceable value" upon array destructuring by reference

Description

The following code:

<?php

$someglobal = 1;

function foo() {
    global $someglobal;
    return [&$someglobal];
}

list(&$ref) = foo();
++$ref;
var_dump($someglobal);

Resulted in this output:

Notice: Attempting to set reference to non referenceable value in /tmp/preview on line 10

int(1)

But I expected this output instead:

int(2)

Making foo return by reference silences this warning, i.e. this is a valid workaround:

function &foo() {
    global $someglobal;
    $ref = [&$someglobal];
    return $ref;
}

But actually, the array itself should not need to return by reference, if we only desire to access a by-reference value within the array.

On top of this, this simple code:

<?php

[&$a] = [&$b];

emits Fatal error: Cannot assign reference to non referenceable value.

PHP Version

PHP 7.3-8.3

Operating System

No response

Commencez par reproduire les deux exemples de déstructuration avec PHP 7.3–8.3 et comparez leurs avertissements, leur erreur fatale et leur sortie avec les attentes signalées. C’est terminé lorsque le premier exemple incrémente la valeur globale à int(2) sans émettre la notice et que le second n’émet plus l’erreur fatale d’affectation par référence.