document enum casting

Author: taylorotwell

eloquent-mutators.md

@@ -7,6 +7,7 @@
 - [Attribute Casting](#attribute-casting)
     - [Array & JSON Casting](#array-and-json-casting)
     - [Date Casting](#date-casting)
+    - [Enum Casting](#enum-casting)
     - [Encrypted Casting](#encrypted-casting)
     - [Query Time Casting](#query-time-casting)
 - [Custom Casts](#custom-casts)
@@ -326,6 +327,32 @@ By default, the `date` and `datetime` casts will serialize dates to a UTC ISO-86
 
 If a custom format is applied to the `date` or `datetime` cast, such as `datetime:Y-m-d H:i:s`, the inner timezone of the Carbon instance will be used during date serialization. Typically, this will be the timezone specified in your application's `timezone` configuration option.
 
+<a name="enum-casting"></a>
+### Enum Casting
+
+> {note} Enum casting is only available for PHP 8.1+.
+
+Eloquent also allows you to cast your attribute values to PHP enums. To accomplish this, you may specify the attribute and enum you wish to cast in your model's `$casts` property array:
+
+    use App\Enums\ServerStatus;
+
+    /**
+     * The attributes that should be cast.
+     *
+     * @var array
+     */
+    protected $casts = [
+        'status' => ServerStatus::class,
+    ];
+
+Once you have defined the cast on your model, the specified attribute will be automatically cast to and from an enum when you interact with the attribute:
+
+    if ($server->status == ServerStatus::provisioned) {
+        $server->status = ServerStatus::ready;
+
+        $server->save();
+    }
+
 <a name="encrypted-casting"></a>
 ### Encrypted Casting