pkg/front_end/testcases/patterns/language_issue2770.dart

// Copyright (c) 2023, 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.

class Class<T extends Object> {
  T field;
  Class(this.field);
}

method1(Object object) {
  if (object case Class(:var field)) {
    print(field);
  }
}

main() {
  method1(new Class(42));
  method1(new Class('foo'));
}