| // Copyright (c) 2020, 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. |
| |
| abstract class Interface { |
| String method(num i); |
| } |
| |
| abstract class Interface2 { |
| String method(covariant int i); |
| } |
| |
| mixin A implements Interface { |
| String method(num i, {String s = "hello"}) => s; |
| } |
| |
| abstract class B implements Interface { |
| String method(num i); |
| } |
| |
| class C with A, B {} // error |
| |
| abstract class D implements Interface, Interface2 {} |
| |
| class E with A, D {} // ok |
| |
| main() { |
| print(C().method(0)); |
| } |
