LanguageFeatures/nnbd/nullability_definitions_A02_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 We say that a type T is non-nullable if T <: Object. This is
/// equivalent to the syntactic criterion that T is any of:
///  Never
///  Any function type (including Function)
///  Any interface type except Null.
///  S* for some S where S is non-nullable
///  FutureOr<S> where S is non-nullable
///  X extends S where S is non-nullable
///  X & S where S is non-nullable
///
/// @description Check that type which is not subtype of Object cannot be
/// assigned to non-nullable type. Test interface type
/// @author sgrekhov@unipro.ru


abstract class A {
  void foo(int i);
}

class C {
  int bar(int i) => i;
}

main() {
  A a1 = null;
//       ^^^^
// [analyzer] unspecified
// [cfe] unspecified

  C c1 = null;
//      ^^^^
// [analyzer] unspecified
// [cfe] unspecified

  A? a = null;
  A a2 = a;
//       ^
// [analyzer] unspecified
// [cfe] unspecified

  var c = new C() as C?;
  C c2 = c;
//       ^
// [analyzer] unspecified
// [cfe] unspecified
}