| // Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| /// @assertion It’s currently a compile-time error for a class to implement, |
| /// extend or mix-in the Enum class. |
| /// |
| /// Because we want to allow interfaces and mixins that are intended to be |
| /// applied to enum declarations, and therefore to assume Enum to be a |
| /// superclass, we loosen that restriction to: |
| /// ... |
| /// It's a compile-time error if a class or mixin declaration has Enum as a |
| /// superinterface, and that class or mixin declares or inherits a concrete |
| /// instance member named `index`, `hashCode` or `==` (an `operator ==` |
| /// declaration). That `index` member could override the `index` getter |
| /// inherited from `Enum`, and we currently do not allow that. The `hashCode` |
| /// and `operator ==` declarations would prevent the enum class from having |
| /// "primitive equality", and we want to ensure that enums can be used in |
| /// switches. |
| /// |
| /// @description Check that it's a compile-time error if an enum declaration has |
| /// Enum as a superinterface, and it declares a non-abstract instance member |
| /// named `index`. |
| /// @author sgrekhov@unipro.ru |
| /// @issue 48353 |
| |
| // SharedOptions=--enable-experiment=enhanced-enums |
| |
| enum E1 { |
| e1, |
| e2; |
| |
| final int index = 42; |
| // ^^^^^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| } |
| |
| enum E2 { |
| e1(42), |
| e2(0); |
| |
| const E2(int i); |
| final List<E2> index = const []; |
| // ^^^^^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| } |
| |
| main() { |
| print(E1); |
| print(E2); |
| } |