chromium/base/functional/callback_tags.h

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This defines helpful tags for dealing with Callbacks. Those tags can be used
// to construct special callbacks. This lives in its own file to avoid circular
// dependencies.

#ifndef BASE_FUNCTIONAL_CALLBACK_TAGS_H_
#define BASE_FUNCTIONAL_CALLBACK_TAGS_H_

namespace base::internal {

struct NullCallbackTag { … };

struct DoNothingCallbackTag { … };

}  // namespace base::internal

#endif  // BASE_FUNCTIONAL_CALLBACK_TAGS_H_