src/jdk.compiler/share/classes/com/sun/tools/javac/code/Preview.java

rev 51104 : imported patch switch

@@ -163,10 +163,14 @@
      * Is given feature a preview feature?
      * @param feature the feature to be tested.
      * @return true, if given feature is a preview feature.
      */
     public boolean isPreview(Feature feature) {
+        if (feature == Feature.SWITCH_EXPRESSION ||
+            feature == Feature.SWITCH_MULTIPLE_CASE_LABELS ||
+            feature == Feature.SWITCH_RULE)
+            return true;
         //Note: this is a backdoor which allows to optionally treat all features as 'preview' (for testing).
         //When real preview features will be added, this method can be implemented to return 'true'
         //for those selected features, and 'false' for all the others.
         return forcePreview;
     }