// Copyright (c) 2015, 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.

// @dart = 2.9

import "package:expect/expect.dart";

class A {}

class $B extends A {}

class C implements $B {
  // Try to clash with dart2js's isCLASS field.
  var isB = false;
  var $isB = false;
  var is$B = false;
  var is$$B = false;
  var $is$B = false;

  var isA = false;
  var $isA = false;
  var is$A = false;
  var is$$A = false;
  var $is$A = false;
}

int inscrutable(int x) => x == 0 ? 0 : x | inscrutable(x & (x - 1));

main() {
  var things = [new A(), new $B(), new C()];

  var a = things[inscrutable(0)];
  Expect.isTrue(a is A);
  Expect.isFalse(a is $B);
  Expect.isFalse(a is C);

  var b = things[inscrutable(1)];
  Expect.isTrue(b is A);
  Expect.isTrue(b is $B);
  Expect.isFalse(b is C);

  var c = things[inscrutable(2)];
  Expect.isTrue(c is A);
  Expect.isTrue(c is $B);
  Expect.isTrue(c is C);
}