Language/Expressions/Constants/logical_expression_t01.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 A constant expression is an expression whose value can never
 * change, and that can be evaluated entirely at compile time.
 * A constant expression is one of the following:
 * . . .
 * • An expression of one of the forms !e, e1 && e2 or e1 || e2, where e, e1
 *   and e2 are constant expressions that evaluate to a boolean value.
 * @description Checks that various expressions of the specified forms can be
 * used within the initializer list of a constant constructor and are,
 * therefore, constant expressions.
 * @author iefremov
 */

class C {
  final a, b, c, d, e;
  const C() :
    a = !true,
    b = !false,
    c = true && false,
    d = false || true,
    e = (!true || true) && !(false == true);
}

main() {
  try {
    const C();
  } catch (ok) {} // NPEs and whatnot
}