70 lines
1.7 KiB
C++
70 lines
1.7 KiB
C++
/*
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* Copyright 2017 The Cartographer Authors
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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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#ifndef CARTOGRAPHER_COMMON_OPTIONAL_H_
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#define CARTOGRAPHER_COMMON_OPTIONAL_H_
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#include <memory>
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#include "absl/memory/memory.h"
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#include "glog/logging.h"
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namespace cartographer {
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namespace common {
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template <class T>
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class optional {
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public:
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optional() {}
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optional(const optional& other) {
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if (other.has_value()) {
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value_ = absl::make_unique<T>(other.value());
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}
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}
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explicit optional(const T& value) { value_ = absl::make_unique<T>(value); }
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bool has_value() const { return value_ != nullptr; }
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const T& value() const {
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CHECK(value_ != nullptr);
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return *value_;
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}
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optional<T>& operator=(const T& other_value) {
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this->value_ = absl::make_unique<T>(other_value);
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return *this;
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}
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optional<T>& operator=(const optional<T>& other) {
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if (!other.has_value()) {
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this->value_ = nullptr;
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} else {
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this->value_ = absl::make_unique<T>(other.value());
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}
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return *this;
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}
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private:
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std::unique_ptr<T> value_;
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};
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} // namespace common
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} // namespace cartographer
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#endif // CARTOGRAPHER_COMMON_OPTIONAL_H_
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