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extern/gltf-draco/draco/src/draco/core/statusor.h
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| // Copyright 2017 The Draco Authors. | |||||
| // | |||||
| // 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 DRACO_CORE_STATUSOR_H_ | |||||
| #define DRACO_CORE_STATUSOR_H_ | |||||
| #include "draco/core/macros.h" | |||||
| #include "draco/core/status.h" | |||||
| namespace draco { | |||||
| // Class StatusOr is used to wrap a Status along with a value of a specified | |||||
| // type |T|. StatusOr is intended to be returned from functions in situations | |||||
| // where it is desirable to carry over more information about the potential | |||||
| // errors encountered during the function execution. If there are not errors, | |||||
| // the caller can simply use the return value, otherwise the Status object | |||||
| // provides more info about the encountered problem. | |||||
| template <class T> | |||||
| class StatusOr { | |||||
| public: | |||||
| StatusOr() {} | |||||
| // Note: Constructors are intentionally not explicit to allow returning | |||||
| // Status or the return value directly from functions. | |||||
| StatusOr(const StatusOr &) = default; | |||||
| StatusOr(StatusOr &&) = default; | |||||
| StatusOr(const Status &status) : status_(status) {} | |||||
| StatusOr(const T &value) : status_(OkStatus()), value_(value) {} | |||||
| StatusOr(T &&value) : status_(OkStatus()), value_(std::move(value)) {} | |||||
| StatusOr(const Status &status, const T &value) | |||||
| : status_(status), value_(value) {} | |||||
| const Status &status() const { return status_; } | |||||
| const T &value() const & { return value_; } | |||||
| const T &&value() const && { return std::move(value_); } | |||||
| T &&value() && { return std::move(value_); } | |||||
| // For consistency with existing Google StatusOr API we also include | |||||
| // ValueOrDie() that currently returns the value(). | |||||
| const T &ValueOrDie() const & { return value(); } | |||||
| T &&ValueOrDie() && { return std::move(value()); } | |||||
| bool ok() const { return status_.ok(); } | |||||
| private: | |||||
| Status status_; | |||||
| T value_; | |||||
| }; | |||||
| // In case StatusOr<T> is ok(), this macro assigns value stored in StatusOr<T> | |||||
| // to |lhs|, otherwise it returns the error Status. | |||||
| // | |||||
| // DRACO_ASSIGN_OR_RETURN(lhs, expression) | |||||
| // | |||||
| #define DRACO_ASSIGN_OR_RETURN(lhs, expression) \ | |||||
| DRACO_ASSIGN_OR_RETURN_IMPL_(DRACO_MACROS_IMPL_CONCAT_(_statusor, __LINE__), \ | |||||
| lhs, expression, _status) | |||||
| // The actual implementation of the above macro. | |||||
| #define DRACO_ASSIGN_OR_RETURN_IMPL_(statusor, lhs, expression, error_expr) \ | |||||
| auto statusor = (expression); \ | |||||
| if (!statusor.ok()) { \ | |||||
| auto _status = std::move(statusor.status()); \ | |||||
| (void)_status; /* error_expression may not use it */ \ | |||||
| return error_expr; \ | |||||
| } \ | |||||
| lhs = std::move(statusor).value(); | |||||
| } // namespace draco | |||||
| #endif // DRACO_CORE_STATUSOR_H_ | |||||