55 lines
1.4 KiB
C
55 lines
1.4 KiB
C
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/*
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* Copyright (C) 2018 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#pragma once
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#include <variant>
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#include <log/log.h>
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namespace android::uirenderer {
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template <typename E>
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struct Error {
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E error;
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};
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template <typename R, typename E>
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class Result {
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public:
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Result(const R& r) : result(std::forward<R>(r)) {}
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Result(R&& r) : result(std::forward<R>(r)) {}
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Result(Error<E>&& error) : result(std::forward<Error<E>>(error)) {}
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operator bool() const {
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return result.index() == 0;
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}
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R unwrap() const {
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LOG_ALWAYS_FATAL_IF(result.index() == 1, "unwrap called on error value!");
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return std::get<R>(result);
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}
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E error() const {
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LOG_ALWAYS_FATAL_IF(result.index() == 0, "No error to get from Result");
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return std::get<Error<E>>(result).error;
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}
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private:
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std::variant<R, Error<E>> result;
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};
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} // namespace android::uirenderer
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