generics.templateDefaultOutOfBounds - Phpstan

Code example

php

<?php declare(strict_types = 1);

/**
 * @template T of int
 * @template U of string = int
 */
class Container
{
}

Why is it reported?

The default type specified for a @template tag is not a subtype of the template's bound. In the example above, U is bounded by string (via of string), but the default is int, which is not a subtype of string.

How to fix it

Change the default type so that it satisfies the bound constraint:

diff-php

 <?php declare(strict_types = 1);

 /**
  * @template T of int
- * @template U of string = int
+ * @template U of string = string
  */
 class Container
 {
 }

Alternatively, change the bound to accommodate the desired default:

diff-php

 <?php declare(strict_types = 1);

 /**
  * @template T of int
- * @template U of string = int
+ * @template U of string|int = int
  */
 class Container
 {
 }