// 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 If e1 translates to F then e1[e2] translates to:
///  PASSTHRU[F, fn[x] => x[EXP(e2)]]
///
/// @description If e1 translates to F then e1[e2] translates to:
///  PASSTHRU[F, fn[x] => x[EXP(e2)]]. Test type aliases
/// @author sgrekhov@unipro.ru

// Requirements=nnbd-strong
import '../../Utils/expect.dart';

class C {
  int operator[](int index) => index;
}

typedef CAlias1 = C;
typedef CAlias2 = C?;

main() {
  CAlias1 c1 = new C();
  Expect.equals(42, c1[42]);

  CAlias1? c2 = new C();
  if (c2 != null) {
    Expect.equals(42, c2[42]);
  }

  CAlias2 c3 = new C();
  if (c3 != null) {
    Expect.equals(42, c3[42]);
  }

  CAlias2? c4 = new C();
  if (c4 != null) {
    Expect.equals(42, c4[42]);
  }
}