LanguageFeatures/Control-flow-collections/type_promotion_A01_t02.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 As with the if statement, the condition expression of an if
/// element induces type promotion in the "then" element of the if when the
/// condition expression shows that a variable has some type and promotion isn't
/// otherwise aborted.
///
/// @description Checks that it is a compile error if type promotion occurs in
/// the "else" element
/// @compile-error
/// @author sgrekhov@unipro.ru


class A {
  int get a => 0;
}
class C extends A {
  int get c => 1;
}


main() {
  A c = new C();
  [
    if (c is C)
      1
    else
      c.c
  ];
}