Function isRock

examples/demo.php:5024–5027

@phpstan-assert-if-true Rock $value */

(mixed $value)

/** @phpstan-assert-if-true Rock $value */
function isRock(mixed $value): bool
{
    return $value instanceof Rock;
}

/** @phpstan-assert-if-false Rock $value */
function isNotRock(mixed $value): bool