Nested array return value false positive when using template T of array

[ArtemGoutsoul]

Bug report

Consider the following example. The function is filtering a 2d array based on a value in the inner array. The input array can contain multiple keys, but we only care about an int element with the key 'value'. The returned array should contain the elements with the same keys, but possibly fewer.

/**
 * @template T of array{value: int, ...}
 * @param array<int, T> $array
 * @return array<int, T>
 */
function filter(array $array, int $min_value): array
{
	foreach ($array as $key => $row) {
		if ($row['value'] < $min_value) unset($array[$key]);
	}
	return array_values($array);
}

I get an error:

Function filter() should return array<int, T of array{value: int}> but returns array<int, array{value: int}>.
Type array{value: int} is not always the same as T. It breaks the contract for some argument types, typically subtypes.

The returned array structure is clearly the same and should match the template, but phpstan disagrees :) Iäm not sure how to modify the code or annotations to make it work.

Playground has one more similar example (tried to rebuild the array).

Code snippet that reproduces the problem

https://phpstan.org/r/d9abcd5f-d336-406d-9e25-b2750bcc789e

Expected output

No error

Did PHPStan help you today? Did it make you happy in any way?

PHPStan always makes me happy, @ondrejmirtes and the team are awesome! :)

I don't know how other dynamic language ecosystems survive without tools like phpstan and psalm! (python I'm looking at you! mypy just doesn't cut it)

[phpstan-bot]

@ArtemGoutsoul After the latest push in 2.0.x, PHPStan now reports different result with your code snippet:

@@ @@
-13: Function filter() should return array<int, T of array{value: int}> but returns array<int, array{value: int}>.
-27: Function filter2() should return array<int<0, max>, T of array{value: int}> but returns array<int<0, max>, array{value: int}>.
+13: Function filter() should return array<int, T of array{value: int}> but returns list<array{value: int}>.
+27: Function filter2() should return array<int<0, max>, T of array{value: int}> but returns list<array{value: int}>.

Full report

Line	Error
13	Function filter() should return array<int, T of array{value: int}> but returns list<array{value: int}>.
27	Function filter2() should return array<int<0, max>, T of array{value: int}> but returns list<array{value: int}>.

[ondrejmirtes]

Unfortunately the issue-bot was too optimistic and this isn't true :( Deleting the comment now.

[phpstan-bot]

@ArtemGoutsoul After the latest push in 2.2.x, PHPStan now reports different result with your code snippet:

@@ @@
-13: Function filter() should return array<int, T of array{value: int}> but returns array<int, array{value: int}>.
-27: Function filter2() should return array<int<0, max>, T of array{value: int}> but returns array<int<0, max>, array{value: int}>.
+No errors

[github-actions]

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