LanguageFeatures/Super-mixins/implementation_t01.dart

// Copyright (c) 2018, 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 In a mixin declaration like
/// mixin A<X extends S, Y extends T> on B, C implements D, E { body }
/// the on clause declares the interfaces B and C as super-class constraints of
/// the mixin. Having a super-class constaint allows the mixin declaration
/// instance members to perform super-invocations (like super.foo()) if they are
/// allowed by a class implementing both B and C. The mixin introduced by A can
/// then only be applied to classes that implement both B and C.
///
/// @description Checks that mixin declaration can only be applied to classes
/// that implement both B and C.
/// @author ngl@unipro.ru
/// @author sgrekhov@unipro.ru

import "../../Utils/expect.dart";

abstract class B {
  int get gb1;
}
abstract class C {
  int get gc1;
}

class A implements B, C {
  int get gb1 => 1;
  int get gc1 => 2;
}

mixin M on B, C {}

class MA extends A with M {
}

main() {
  MA ma = new MA();
  Expect.equals(1, ma.gb1);
  Expect.equals(2, ma.gc1);
}