Merge pull request #12293 from dotty-staging/enum/remove-unchecked

remove unchecked annotation from enum $values array

Author: smarter

compiler/src/dotty/tools/dotc/ast/DesugarEnums.scala

@@ -104,7 +104,7 @@ object DesugarEnums {
 
   /**  The following lists of definitions for an enum type E and known value cases e_0, ..., e_n:
    *
-   *   private val $values = Array[E](this.e_0,...,this.e_n)(ClassTag[E](classOf[E])): @unchecked
+   *   private val $values = Array[E](this.e_0,...,this.e_n)(ClassTag[E](classOf[E]))
    *   def values = $values.clone
    *   def valueOf($name: String) = $name match {
    *     case "e_0" => this.e_0
@@ -118,15 +118,7 @@ object DesugarEnums {
     extension (tpe: NamedType) def ofRawEnum = AppliedTypeTree(ref(tpe), rawEnumClassRef)
 
     val privateValuesDef =
-      val uncheckedValues =
-        // Here we use an unchecked annotation to silence warnings from the init checker. Without it, we get a warning
-        // that simple enum cases are promoting this from warm to initialised. This is because we are populating the
-        // array by selecting enum values from `this`, a value under construction.
-        // Singleton enum values always construct a new anonymous class, which will not be checked by the init-checker,
-        // so this warning will always persist even if the implementation of the anonymous class is safe.
-        // TODO: remove @unchecked after https://github.com/lampepfl/dotty-feature-requests/issues/135 is resolved.
-        Annotated(ArrayLiteral(enumValues, rawEnumClassRef), New(ref(defn.UncheckedAnnot.typeRef), Nil))
-      ValDef(nme.DOLLAR_VALUES, TypeTree(), uncheckedValues)
+      ValDef(nme.DOLLAR_VALUES, TypeTree(), ArrayLiteral(enumValues, rawEnumClassRef))
         .withFlags(Private | Synthetic)
 
     val valuesDef =