Language/Expressions/Object_Identity/double_t02.dart

// Copyright (c) 2011, 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 The predefined Dart function identical() is defined such that
 * identical(c1, c2) iff:
 * . . .
 *  • c1 and c2 are instances of double and one of the following holds:
 *      – c1 and c2 are non-zero and c1 == c2.
 *      – Both c1 and c2 are +0.0.
 *      – Both c1 and c2 are −0.0.
 *      – Both c1 and c2 represent a NaN value with the same underlying bit
 *        pattern.
 * @description Checks that two NaNs are identical.
 * @author kaigorodov
 * @issue 42224
 */
import "../../../Utils/expect.dart";

div(var a, var b) {
  return a / b;
}

var nol = 0.0;

main() {
  double nan1 = div(nol, nol);
  double nan2 = div(nol, nol);
  Expect.isTrue(identical(nan1, nan2));
  Expect.isTrue(identical(nan1, double.nan));
  Expect.isTrue(identical(double.nan, double.nan));
}