// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_BIGTABLE_ROW_KEY_H
#define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_BIGTABLE_ROW_KEY_H

#include "google/cloud/bigtable/internal/google_bytes_traits.h"
#include "google/cloud/bigtable/version.h"
#include <google/bigtable/v2/data.pb.h>
#include <type_traits>
#include <utility>

namespace google {
namespace cloud {
namespace bigtable {
inline namespace BIGTABLE_CLIENT_NS {
/**
 * Defines the type for row keys.
 *
 * Inside Google some protobuf fields of type `bytes` are mapped to a different
 * type than `std::string`. This is the case for row keys. We use this type to
 * automatically detect what is the representation for this field and use the
 * correct mapping.
 *
 * External users of the Cloud Bigtable C++ client library should treat this as
 * a complicated `typedef` for `std::string`. We have no plans to change the
 * type in the external version of the C++ client library for the foreseeable
 * future. In the eventuality that we do decide to change the type, this would
 * be a reason update the library major version number, and we would give users
 * time to migrate.
 *
 * In other words, external users of the Cloud Bigtable C++ client should simply
 * write `std::string` where this type appears. For Google projects that must
 * compile both inside and outside Google, this alias may be convenient.
 */
using RowKeyType =
    std::decay<decltype(std::declval<google::bigtable::v2::Row>().key())>::type;

}  // namespace BIGTABLE_CLIENT_NS
}  // namespace bigtable
}  // namespace cloud
}  // namespace google

#endif  // GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_BIGTABLE_ROW_KEY_H