Bug report

Code snippet that reproduces the problem

<?php declare(strict_types = 1);

enum Foo {
	case Bar;
	case Baz;
	case Gar;
	case Gaz;
	
	public function startsWithB(): bool
	{
		return inArray($this, [static::Baz, static::Bar]);
	}
}

/**
* @template    T
* @psalm-param T $needle
* @psalm-param array<array-key, T> $haystack
*/
function inArray(mixed $needle, array $haystack): bool
{
	return \in_array($needle, $haystack, true);
}

Phpstan gives an error in the Foo::startsWithB function:

Parameter #2 $haystack of function inArray expects array<$this(Foo)>, array<int, Foo::Bar|Foo::Baz> given.

It seems to that $this(Foo) does not match Foo::Bar|Foo::Baz, whereas I think that it should.

https://phpstan.org/r/102df9d0-30af-4810-a9de-d3e4ba87fe5f

Expected output

I don't think that it should be an error at all.

As a side note, Psalm doesn't get an error: https://psalm.dev/r/87ee1f1051

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

I love generics provided by both phpstan and psalm. It allows me to write much more clean and succinct code.