feature #19515 [Cache] Drop TaggedCacheItemInterface (nicolas-grekas)

This PR was merged into the 3.2-dev branch.

Discussion
----------

[Cache] Drop TaggedCacheItemInterface

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Introducing this interface was a mistake, we should drop it: the CacheItem class is final, and it can be instantiated only through a cache adapter. Which means there is no way to reuse this interface in any meaningful way as far as extensibility/interoperability is concerned.

Commits
-------

624890b [Cache] Drop TaggedCacheItemInterface

src/Symfony/Component/Cache/CacheItem.php

@@ -11,13 +11,14 @@
 
 namespace Symfony\Component\Cache;
 
+use Psr\Cache\CacheItemInterface;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\Cache\Exception\InvalidArgumentException;
 
 /**
  * @author Nicolas Grekas <p@tchwork.com>
  */
-final class CacheItem implements TaggedCacheItemInterface
+final class CacheItem implements CacheItemInterface
 {
     protected $key;
     protected $value;
@@ -97,7 +98,13 @@ final class CacheItem implements TaggedCacheItemInterface
     }
 
     /**
-     * {@inheritdoc}
+     * Adds a tag to a cache item.
+     *
+     * @param string|string[] $tags A tag or array of tags
+     *
+     * @return static
+     *
+     * @throws InvalidArgumentException When $tag is not valid.
      */
     public function tag($tags)
     {

src/Symfony/Component/Cache/TaggedCacheItemInterface.php

@@ -1,34 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\Cache;
-
-use Psr\Cache\CacheItemInterface;
-use Psr\Cache\InvalidArgumentException;
-
-/**
- * Interface for adding tags to cache items.
- *
- * @author Nicolas Grekas <p@tchwork.com>
- */
-interface TaggedCacheItemInterface extends CacheItemInterface
-{
-    /**
-     * Adds a tag to a cache item.
-     *
-     * @param string|string[] $tags A tag or array of tags
-     *
-     * @return static
-     *
-     * @throws InvalidArgumentException When $tag is not valid.
-     */
-    public function tag($tags);
-}