LanguageFeatures/Extension-methods/explicit_extension_member_invocation_A19_t13.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 It is a compile-time error if an extension application occurs in a
 * place where it is not the target expression of a simple or composite member
 * invocation. That is, the only valid use of an extension application is to
 * invoke members on it.
 *
 * @description Check that it is a compile-time error if an extension
 * application occurs in a place where it is not the target expression of a
 * simple or composite member invocation. Test ++ operator
 * @author sgrekhov@unipro.ru
 */


class C {
  int value;
  C() : value = 0 {}
}

extension Ext on C {
  C operator +(int val) {
    this.value += val;
    return this;
  }
}

main() {
  C c = C();
  Ext(c)++;
//^^^^^^^^
// [analyzer] unspecified
// [cfe] unspecified

  ++Ext(c);
//^^^^^^^^
// [analyzer] unspecified
// [cfe] unspecified
}