| // Copyright (c) 2022, 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 = 2.15 |
| |
| /// Marks its argument as live and prevents tree-shaking. |
| /// |
| /// This is more hermetic than using `package:expect` or `print`. This function |
| /// may need to be updated as optimizations improve. |
| @pragma('dart2js:noInline') |
| void makeLive(dynamic x) => x; |
| |
| @pragma('dart2js:noInline') |
| void _subtypeAtRuntime<Sub, Super>() => makeLive(<Sub>[] is List<Super>); |
| |
| void subtype<Sub extends Super, Super>() => _subtypeAtRuntime<Sub, Super>(); |
| void notSubtype<Sub, Super>() => _subtypeAtRuntime<Sub, Super>(); |