generics.deprecatedTraitDefault

Code example

<?php declare(strict_types = 1);

/** @deprecated Use NewTrait instead */
trait OldTrait
{
}

/**
 * @template T = OldTrait
 */
class Collection
{
}

Why is it reported?

The @template tag default value references a trait that is marked as @deprecated. Using deprecated types in generic type defaults propagates the dependency on outdated code to all consumers that rely on the default. This rule is provided by phpstan-deprecation-rules.

How to fix it

Replace the deprecated trait with its non-deprecated replacement in the template default:

 /**
- * @template T = OldTrait
+ * @template T = NewTrait
  */
 class Collection
 {
 }