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/*
* Copyright (C) 2018 The Android Open Source Project
*
* 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.
*/
#pragma once
#include <variant>
#include <log/log.h>
namespace android::uirenderer {
template <typename E>
struct Error {
E error;
};
template <typename R, typename E>
class Result {
public:
Result(const R& r) : result(std::forward<R>(r)) {}
Result(R&& r) : result(std::forward<R>(r)) {}
Result(Error<E>&& error) : result(std::forward<Error<E>>(error)) {}
operator bool() const {
return result.index() == 0;
}
R unwrap() const {
LOG_ALWAYS_FATAL_IF(result.index() == 1, "unwrap called on error value!");
return std::get<R>(result);
}
E error() const {
LOG_ALWAYS_FATAL_IF(result.index() == 0, "No error to get from Result");
return std::get<Error<E>>(result).error;
}
private:
std::variant<R, Error<E>> result;
};
} // namespace android::uirenderer
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