Language/Interfaces/Superinterfaces/Inheritance_and_Overriding/same_name_getters_type_t12.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 We define inherited(J, K) to be
/// the set of members m such that all of the following hold:
/// • m is accessible to K and
/// • A is a direct superinterface of J and either
/// – A declares a member m or
/// – m is a member of inherited(A, K).
/// • m is not overridden by J.
/// ...
/// If some but not all of the mi, 1 ≤ i ≤ k are getters none of the mi are
/// inherited, and a static warning is issued.
/// Otherwise, if the static types T1,...,Tk of the members m1,...,mk are not
/// identical, then there must be a member mx such that Tx <: Ti, 1 ≤ x ≤ k for
/// all i ∈ 1..k, or a static type warning occurs.
/// @description Checks that if all inherited members with the same name are
/// methods and their static types are not identical, but there is no method
/// such that its type is subtype of types of all other methods, then a compile
/// error occurs. Test type aliases
/// @author sgrekhov@unipro.ru

abstract class SI1 {
  int m();
}

abstract class SI2 {
  bool m();
}

abstract class SI3 {
  String m();
}

typedef SIAlias1 = SI1;
typedef SIAlias2 = SI2;
typedef SIAlias3 = SI3;

abstract class I implements SIAlias1, SIAlias2, SIAlias3 {
//             ^
// [analyzer] unspecified
// [cfe] unspecified
}

main() {
  I? i = null;
}