Bug #80066 [Opn->Ver]: List Reference Assignment: Cannot reference an array value by return

Edit report at https://bugs.php.net/bug.php?id=80066&edit=1 ID: 80066 Updated by: requinix@php.net Reported by: php-0919 at jan-runte dot de Summary: List Reference Assignment: Cannot reference an array value by return -Status: Open +Status: Verified Type: Bug Package: Variables related Operating System: macOS 10.15.6 PHP Version: 7.3.22 Block user comment: N Private report: N New Comment: PHP is complaining because the function doesn't return by-reference. If it does then there's no error and everything works. I don't think that requirement is necessary: the whole return value is not what is being referenced, only the items inside, and array items can certainly be references without their parent arrays being references too. Previous Comments: ------------------------------------------------------------------------ [2020-09-06 19:40:24] php-0919 at jan-runte dot de Description: ------------ Feature 7.3 - List Reference Assignment: - https://wiki.php.net/rfc/list_reference_assignment When attempting to transfer an array return value via the list reference assignment to certain keys with by-reference, the error "Attempting to set reference to non referenceable value" occurs. But the belonging value of that key is a referenceable value - it is an array. 7.3.13: failed 7.3.22: failed 7.4.3: failed 7.4.10: failed 8.0.0beta2: failed 8.0.0beta3: failed Test script: --------------- function returnsArrayWithReferencedValue(array &$subject) : array { return [ 'a' => &$subject, 'b' => 123, ]; } $source = [ 'c' => [], ]; /***************** /* PREFERRED WAY * *****************/ ['a' => &$referencedArray] = returnsArrayWithReferencedValue($source); // Throws an error: "Attempting to set reference to non referenceable value in ..." /************** /* WORKAROUND * **************/ // First set returned array to a variable $returnedArray = returnsArrayWithReferencedValue($source); $source['d'] = 456; // manipulate source array var_dump($returnedArray['a']); /********** /* MOCKUP * **********/ // Fake returned array as a prepared variable $fakeReturnedArray = [ 'a' => &$source, 'b' => 123, ]; ['a' => &$referencedArray] = $fakeReturnedArray; $source['d'] = 456; // manipulate source array var_dump($referencedArray); Expected result: ---------------- array(2) { ["c"]=> array(0) { } ["d"]=> int(456) } Actual result: -------------- Throws an error: Attempting to set reference to non referenceable value ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=80066&edit=1