// 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.

// @dart = 2.9

/// @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 accepted if
/// [e] is not a constant
/// @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);
//                          ^
// [analyzer] unspecified
// [cfe] unspecified
}