Language/Generics/Superbounded_types/class_A03_t03.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 AIt is a compile-time error if a parameterized type [T] is
 * super-bounded when it is used in any of the following ways:
 *   ...
 *   [T] is an immediate subterm of a redirecting factory constructor signature
 * @description Checks that compile error is not thrown when non-super-bounded
 * type [T] is used in the redirecting factory constructor signature
 * @Issue 37048
 * @author iarkh@unipro.ru
 */

class A<X> {
  A() {}
  factory A.foo1() = C<Never>;
  factory A.foo2() = C<A<Never>>;
  //                 ^^^^^^^^^^^
  // [analyzer] COMPILE_TIME_ERROR.REDIRECT_TO_INVALID_RETURN_TYPE
  // [cfe] The constructor function type 'C<A<Never>> Function()' isn't a subtype of 'A<X> Function()'.
  factory A.foo3() = C<A<A<Never>>>;
  //                 ^^^^^^^^^^^^^^
  // [analyzer] COMPILE_TIME_ERROR.REDIRECT_TO_INVALID_RETURN_TYPE
  // [cfe] The constructor function type 'C<A<A<Never>>> Function()' isn't a subtype of 'A<X> Function()'.
  factory A.foo4() = C<A<A<A<Never>>>>;
  //                 ^^^^^^^^^^^^^^^^^
  // [analyzer] COMPILE_TIME_ERROR.REDIRECT_TO_INVALID_RETURN_TYPE
  // [cfe] The constructor function type 'C<A<A<A<Never>>>> Function()' isn't a subtype of 'A<X> Function()'.

}

class C<X extends A<X>> extends A<X> {
  C() {}
}

main() {}