|  | // Copyright (c) 2012, 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. | 
|  |  | 
|  | import "package:expect/expect.dart"; | 
|  |  | 
|  | class AlwaysTrue { | 
|  | operator ==(a) => true; | 
|  | } | 
|  |  | 
|  | class AlwaysFalse { | 
|  | operator ==(b) => false; | 
|  | } | 
|  |  | 
|  | main() { | 
|  | dynamic a = new AlwaysTrue(); | 
|  | Expect.isTrue(a == 2); | 
|  | Expect.isFalse(a == null); | 
|  | Expect.isFalse(a != 2); | 
|  | Expect.isTrue(a != null); | 
|  |  | 
|  | a = new AlwaysFalse(); | 
|  | Expect.isFalse(a == 2); | 
|  | Expect.isFalse(a == null); | 
|  | Expect.isTrue(a != 2); | 
|  | Expect.isTrue(a != null); | 
|  | } |