Cannot use positional argument after argument unpacking

Description

It is not possible to put simple arguments after an unpacked argument. Said another way, the unpacked arguments must be the last one in the list.

This happens when using a mix of array unpacking and arguments. It also happens when spreading an array with a mix of numeric and string keys.

Example

<?php

// Valid, the unpacked argument is the last
foo($a, $b, ...$c);

// Also valid, the unpacked arguments are the last
foo($a, $b, ...$c, ...$d);

// Not valid
foo(...$a, $b, ...$c);

// This is invalid, as the numeric arguments are after the 'x'
$a = ['x' => [1], 13, 14];
foo(...$a);

// This is valid, as long as x is not argument 0 or 1. Then, it yields another error.
$a = [13, 14, 'x' => [1]];
foo(...$a);

?>

Solutions

• Move the positional arguments to be beginning of the signature call.

• Sort the unpacked array with krsort() or ksort(), before or after PHP 8.2.

• Remove the positional arguments.