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Broken parameter type evaluation inside a closure for a by-ref variable #13614
Description
Bug report
Broken parameter type evaluation inside a closure for a by-ref variable.
Code:
<?php declare(strict_types = 1);
use function PHPStan\dumpType;
use function PHPStan\Testing\assertType;
enum FooEnum: string
{
case BAR = 'bar';
case BAZ = 'baz';
}
$var = [FooEnum::BAR];
$closure = function () use (&$var): array {
$var = array_map(fn (FooEnum $item): string => $item->value, $var);
return [
'var' => array_flip($var),
];
};It reports the following error:
Parameter #1 $callback of function array_map expects (callable('bar'|FooEnum::BAR): mixed)|null, Closure(FooEnum): 'bar' given.
Type #1 from the union: Type FooEnum of parameter #1 $item of passed callable needs to be same or wider than parameter type FooEnum::BAR|string of accepting callable.
argument.type
At the same time, if I remove the closuer, this code doesn't trigger anything:
<?php declare(strict_types = 1);
use function PHPStan\dumpType;
use function PHPStan\Testing\assertType;
enum FooEnum: string
{
case BAR = 'bar';
case BAZ = 'baz';
}
$var = [FooEnum::BAR];
$var = array_map(fn (FooEnum $item): string => $item->value, $var);
return [
'var' => array_flip($var),
];No errors snippet: https://phpstan.org/r/3ca9bc47-a5e9-4d6f-86e3-164180021ab9
Code snippet that reproduces the problem
https://phpstan.org/r/5482060c-ec17-4566-b36f-e965cfc02a21
Expected output
No errors.
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Activity
ondrejmirtes commentedon Feb 5, 2026
This is expected. If you call the closure twice, it fails: https://3v4l.org/MtVgo
github-actions commentedon Mar 9, 2026
This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.