| // Copyright (c) 2020, 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. | 
 |  | 
 | const int? a = 42; | 
 | const int b = a!; | 
 |  | 
 | const int? c = null; | 
 | const int? d = c!; | 
 |  | 
 | class Class { | 
 |   final int y; | 
 |   const Class(int? x) : y = x!; | 
 | } | 
 |  | 
 | const Class e = const Class(a); | 
 | const Class f = const Class(c); | 
 |  | 
 | test() { | 
 |   expect(42, a); | 
 |   expect(42, b); | 
 |   expect(42, e.y); | 
 | } | 
 |  | 
 | main() {} | 
 |  | 
 | expect(expected, actual) { | 
 |   if (expected != actual) throw 'Expected $expected, actual $actual'; | 
 | } |