chromium/components/sync/base/client_tag_hash.h

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_SYNC_BASE_CLIENT_TAG_HASH_H_
#define COMPONENTS_SYNC_BASE_CLIENT_TAG_HASH_H_

#include <compare>
#include <iosfwd>
#include <string>
#include <string_view>

#include "base/hash/hash.h"
#include "components/sync/base/data_type.h"

namespace syncer {

// Represents a client defined unique hash for sync entities. Hash is derived
// from client tag, and should be used as |client_tag_hash| for
// SyncEntity at least for CommitMessages. For convenience it supports storing
// in ordered stl containers, logging and equality comparisons. It also supports
// unordered stl containers using ClientTagHash::Hash.
class ClientTagHash { … };

std::ostream& operator<<(std::ostream& os,
                         const ClientTagHash& client_tag_hash);

}  // namespace syncer

#endif  // COMPONENTS_SYNC_BASE_CLIENT_TAG_HASH_H_