mirror of
https://github.com/kidfromjupiter/nearby.git
synced 2026-09-14 22:56:12 -04:00
120 lines
3.6 KiB
C++
120 lines
3.6 KiB
C++
// Copyright 2024 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
|
|
//
|
|
// https://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 PLATFORM_BASE_EXPECTED_H_
|
|
#define PLATFORM_BASE_EXPECTED_H_
|
|
|
|
#include <optional>
|
|
#include <string>
|
|
#include <utility>
|
|
#include <variant>
|
|
|
|
#include "proto/connections_enums.pb.h"
|
|
|
|
namespace nearby {
|
|
|
|
class Error {
|
|
public:
|
|
Error() = default;
|
|
|
|
explicit Error(location::nearby::proto::connections::OperationResultCode
|
|
operation_result_code)
|
|
: operation_result_code_(operation_result_code) {}
|
|
|
|
bool success() const {
|
|
return operation_result_code_ == location::nearby::proto::connections::
|
|
OperationResultCode::DETAIL_SUCCESS;
|
|
}
|
|
bool failure() const { return !success(); }
|
|
|
|
std::optional<location::nearby::proto::connections::OperationResultCode>
|
|
operation_result_code() const {
|
|
return operation_result_code_;
|
|
}
|
|
|
|
static Error Success() { return Error(); }
|
|
|
|
private:
|
|
location::nearby::proto::connections::OperationResultCode
|
|
operation_result_code_ = location::nearby::proto::connections::
|
|
OperationResultCode::DETAIL_UNKNOWN;
|
|
};
|
|
|
|
// Forward declare.
|
|
template <typename E>
|
|
class Unexpected;
|
|
|
|
template <typename T, typename E>
|
|
class Expected {
|
|
public:
|
|
constexpr Expected(T value) : data_(std::move(value)) {} // NOLINT
|
|
constexpr Expected(Unexpected<E> u); // NOLINT
|
|
|
|
constexpr operator bool() const { // NOLINT
|
|
return has_value();
|
|
}
|
|
|
|
constexpr T& operator*() & { return value(); }
|
|
constexpr const T& operator*() const& { return value(); }
|
|
constexpr T&& operator*() && { return std::move(value()); }
|
|
constexpr const T& operator*() const&& { return std::move(value()); }
|
|
|
|
constexpr T* operator->() { return &value(); }
|
|
constexpr const T* operator->() const { return &value(); }
|
|
|
|
constexpr bool has_value() const { return std::holds_alternative<T>(data_); }
|
|
constexpr bool has_error() const { return std::holds_alternative<E>(data_); }
|
|
|
|
constexpr T& value() & { return std::get<T>(data_); }
|
|
constexpr const T& value() const& { return std::get<T>(data_); }
|
|
constexpr T&& value() && { return std::get<T>(std::move(data_)); }
|
|
constexpr const T& value() const&& { return std::get<T>(std::move(data_)); }
|
|
|
|
constexpr E& error() & { return std::get<E>(data_); }
|
|
constexpr const E& error() const& { return std::get<E>(data_); }
|
|
constexpr E&& error() && { return std::get<E>(std::move(data_)); }
|
|
constexpr const E&& error() const&& { return std::get<E>(std::move(data_)); }
|
|
|
|
private:
|
|
std::variant<T, E> data_;
|
|
};
|
|
|
|
template <typename E>
|
|
class Unexpected {
|
|
public:
|
|
constexpr Unexpected(E error) : error_(std::move(error)) {} // NOLINT
|
|
|
|
private:
|
|
template <typename, typename>
|
|
friend class Expected;
|
|
|
|
E error_;
|
|
};
|
|
|
|
Unexpected(const char*) -> Unexpected<std::string>;
|
|
|
|
template <typename T, typename E>
|
|
constexpr Expected<T, E>::Expected(Unexpected<E> u)
|
|
: data_(std::move(u.error_)) {}
|
|
|
|
template <typename T>
|
|
class ErrorOr : public Expected<T, Error> {
|
|
public:
|
|
using Expected<T, Error>::Expected;
|
|
};
|
|
|
|
} // namespace nearby
|
|
|
|
#endif // PLATFORM_BASE_EXPECTED_H_
|