LanguageFeatures/nnbd/Constant-update-2018/TypeTestOperator_A03_t06.dart

/*
 * Copyright (c) 2019, 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 An expression of the form [e is T] or [e is! T] is accepted as a
 * potentially and compile-time constant expression if [e] is potentially
 * constant or compile-time constant, respectively, and [T] is a compile-time
 * constant type.
 * @description Checks that an expression of the form [e is! T] is not accepted
 * if [e] is not a constant
 * @compile-error
 * @author iarkh@unipro.ru
 */

String anObject = "";

class MyClass {
  final String obj;
  const MyClass(Object o) : obj = o is! String ? "OK" : "incorrect";
}

main() {
  const MyClass c = MyClass(anObject);
}