"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

Empieza reproduciendo los dos ejemplos de desestructuración en PHP 7.3–8.3 y compara sus advertencias, el error fatal y la salida con las expectativas indicadas. Se considera terminado cuando el primer ejemplo incrementa el valor global a int(2) sin emitir el aviso, y el segundo ya no emite el error fatal de asignación por referencia.