generics.notCompatible

Code example

<?php declare(strict_types = 1);

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

/**
 * @implements class-string<int>
 */
class NumberList implements Collection
{
}

Why is it reported?

The @implements, @extends, or @use PHPDoc tag specifies a type that is not a valid generic type for the referenced class or interface. The type in the tag must be a generic object type like Collection<int>, not a scalar type, class-string, or other non-generic type. PHPStan expects the tag to match the generic signature of the parent class or interface.

In the example above, @implements class-string<int> is not a generic object type -- it is a class-string type and cannot be used as an @implements value.

How to fix it

Use the correct generic type syntax in the PHPDoc tag:

 /**
- * @implements class-string<int>
+ * @implements Collection<int>
  */
 class NumberList implements Collection
 {
 }

If the parent class or interface has multiple template parameters, specify all of them:

 /**
- * @implements Map<string>
+ * @implements Map<string, int>
  */
 class StringIntMap implements Map
 {
 }