Operators.

frog/tests/leg_only/src/OperatorEqualsTest.dart

+// 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.
+
+class AlwaysTrue {
+  operator ==(a) => true;
+}
+
+class AlwaysFalse {
+  operator ==(b) => false;
+}
+
+main() {
+  var a = new AlwaysTrue();
+  Expect.isTrue(a == 2);
+  Expect.isTrue(a == null);
+  Expect.isFalse(a != 2);
+  Expect.isFalse(a != null);
+
+  a = new AlwaysFalse();
+  Expect.isFalse(a == 2);
+  Expect.isFalse(a == null);
+  Expect.isTrue(a != 2);
+  Expect.isTrue(a != null);
+}