Cannot define a param of a class template, with a function template hydrated by the param?

[devnix]

Yup, I don't know how to phrase the title better 😰

I'll let this snippet describe it better: https://psalm.dev/r/ffdbd898f0

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/ffdbd898f0

<?php declare(strict_types=1);

/**
 * @template T
 */
interface Query
{
}

/**
 * @template TQuery of Query
 */
interface QueryHandler
{
    /**
     * @template TReturn
     *
     * @param TQuery<TReturn> $query
     *
     * @return TReturn
     */
    public function __invoke($query);
}

/**
 * @implements Query<int>
 */
final readonly class Get implements Query
{
    public function __construct(public string $id)
    {
    }
}

/**
 * @implements QueryHandler<Get>
 */
final class GetHandler implements QueryHandler
{
    public function __invoke($get)
    {
        return 42;
    }
}

Psalm output (using commit 03ee02c):

ERROR: UndefinedDocblockClass - 18:15 - Docblock-defined class, interface or enum named TQuery does not exist

ERROR: InvalidReturnType - 40:21 - The declared return type 'TReturn:fn-queryhandler::__invoke as mixed' for GetHandler::__invoke is incorrect, got 'int'

[devnix]

I posted a different report with the same example in PHPStan: phpstan/phpstan#11839

Maybe I'm missing an already existing solution around "inner templates"? If not, would my example be an agreeable common syntax for this problem in both projects?