| // Copyright 2013 Google Inc. All Rights Reserved. |
| // |
| // 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 TINK_UTIL_STATUSOR_H_ |
| #define TINK_UTIL_STATUSOR_H_ |
| |
| #include <cstdlib> |
| #include <iostream> |
| #include <utility> |
| |
| #include "absl/status/statusor.h" |
| #include "tink/util/status.h" |
| |
| namespace crypto { |
| namespace tink { |
| namespace util { |
| |
| #ifndef TINK_USE_ABSL_STATUSOR |
| |
| #ifndef CPP_TINK_TEMPORARY_STATUS_MUST_NOT_USE_RESULT |
| template <typename T> |
| class ABSL_MUST_USE_RESULT StatusOr; |
| #endif |
| |
| // TODO(b/122292096): Migrate this to absl::StatusOr |
| // A StatusOr holds a Status (in the case of an error), or a value T. |
| template <typename T> |
| class StatusOr { |
| public: |
| // StatusOr<T>::value_type |
| // |
| // This instance data provides a generic `value_type` member for use within |
| // generic programming. This usage is analogous to that of |
| // `optional::value_type` in the case of `std::optional`. |
| using value_type = T; |
| |
| using type = T; |
| // Has status UNKNOWN. |
| inline StatusOr(); |
| |
| // Builds from a non-OK status. Crashes if an OK status is specified. |
| inline StatusOr(const ::crypto::tink::util::Status& status); // NOLINT |
| |
| // Builds from the specified value. |
| inline StatusOr(const T& value); // NOLINT |
| inline StatusOr(T&& value); // NOLINT |
| |
| // Copy constructor. |
| inline StatusOr(const StatusOr& other); |
| |
| // Move constructor. |
| inline StatusOr(StatusOr&& other); |
| |
| // Conversion copy constructor, T must be copy constructible from U. |
| template <typename U> |
| inline StatusOr(const StatusOr<U>& other); |
| |
| // Assignment operator. |
| inline const StatusOr& operator=(const StatusOr& other); |
| |
| // Conversion assignment operator, T must be assignable from U |
| template <typename U> |
| inline const StatusOr& operator=(const StatusOr<U>& other); |
| |
| // Accessors. |
| inline const ::crypto::tink::util::Status& status() const { |
| return status_; |
| } |
| |
| // Shorthand for status().ok(). |
| inline bool ok() const { |
| return status_.ok(); |
| } |
| |
| // Returns value or crashes if ok() is false. |
| inline const T& ValueOrDie() const& { |
| EnsureOk(); |
| return *value_; |
| } |
| inline T& ValueOrDie() & { |
| EnsureOk(); |
| return *value_; |
| } |
| inline const T&& ValueOrDie() const&& { |
| EnsureOk(); |
| return *std::move(value_); |
| } |
| inline T&& ValueOrDie() && { |
| EnsureOk(); |
| return *std::move(value_); |
| } |
| |
| // Returns value if ok(), otherwise crashes if exceptions are disabled OR |
| // throws if exceptions are enabled. |
| inline const T& value() const& { |
| if (!ok()) AbortWithMessageFrom(status_); |
| return *value_; |
| } |
| inline T& value() & { |
| if (!ok()) AbortWithMessageFrom(status_); |
| return *value_; |
| } |
| inline const T&& value() const&& { |
| if (!ok()) AbortWithMessageFrom(std::move(status_)); |
| return *std::move(value_); |
| } |
| inline T&& value() && { |
| if (!ok()) AbortWithMessageFrom(std::move(status_)); |
| return *std::move(value_); |
| } |
| |
| // Implicitly convertible to absl::StatusOr. Implicit conversions explicitly |
| // allowed by style arbiter waiver in cl/351594378. |
| operator ::absl::StatusOr<T>() const&; // NOLINT |
| operator ::absl::StatusOr<T>() &&; // NOLINT |
| |
| // Returns value or crashes if ok() is false. |
| inline const T& operator*() const& { |
| EnsureOk(); |
| return *value_; |
| } |
| |
| inline T& operator*() & { |
| EnsureOk(); |
| return *value_; |
| } |
| |
| inline T&& operator*() && { |
| EnsureOk(); |
| return *std::move(value_); |
| } |
| |
| inline const T&& operator*() const&& { |
| EnsureOk(); |
| return *std::move(value_); |
| } |
| |
| // Returns reference to value or crashes if ok() is false. |
| T* operator->() { |
| EnsureOk(); |
| return &(value_.value()); |
| } |
| |
| const T* operator->() const { |
| EnsureOk(); |
| return &(value_.value()); |
| } |
| |
| template <typename U> |
| friend class StatusOr; |
| |
| private: |
| void EnsureOk() const { |
| if (ABSL_PREDICT_FALSE(!ok())) { |
| std::cerr << "Attempting to fetch value of non-OK StatusOr\n"; |
| std::cerr << status() << std::endl; |
| std::_Exit(1); |
| } |
| } |
| |
| void AbortWithMessageFrom(crypto::tink::util::Status status) const { |
| std::cerr << "Attempting to fetch value instead of handling error\n"; |
| std::cerr << status.ToString(); |
| std::abort(); |
| } |
| |
| |
| Status status_; |
| absl::optional<T> value_; |
| }; |
| |
| // Implementation. |
| |
| template <typename T> |
| inline StatusOr<T>::StatusOr() |
| : status_(absl::StatusCode::kUnknown, "") { |
| } |
| |
| template <typename T> |
| inline StatusOr<T>::StatusOr( |
| const ::crypto::tink::util::Status& status) : status_(status) { |
| if (status.ok()) { |
| std::cerr << "::crypto::tink::util::OkStatus() " |
| << "is not a valid argument to StatusOr\n"; |
| std::_Exit(1); |
| } |
| } |
| |
| template <typename T> |
| inline StatusOr<T>::StatusOr(const T& value) : value_(value) { |
| } |
| |
| template <typename T> |
| inline StatusOr<T>::StatusOr(T&& value) : value_(std::move(value)) { |
| } |
| |
| template <typename T> |
| inline StatusOr<T>::StatusOr(const StatusOr& other) |
| : status_(other.status_), value_(other.value_) { |
| } |
| |
| template <typename T> |
| inline StatusOr<T>::StatusOr(StatusOr&& other) |
| : status_(other.status_), value_(std::move(other.value_)) { |
| } |
| |
| template <typename T> |
| template <typename U> |
| inline StatusOr<T>::StatusOr(const StatusOr<U>& other) |
| : status_(other.status_), value_(other.value_) { |
| } |
| |
| template <typename T> |
| inline const StatusOr<T>& StatusOr<T>::operator=(const StatusOr& other) { |
| status_ = other.status_; |
| if (status_.ok()) { |
| value_ = *other.value_; |
| } else { |
| value_ = absl::nullopt; |
| } |
| return *this; |
| } |
| |
| template <typename T> |
| template <typename U> |
| inline const StatusOr<T>& StatusOr<T>::operator=(const StatusOr<U>& other) { |
| status_ = other.status_; |
| if (status_.ok()) { |
| value_ = *other.value_; |
| } else { |
| value_ = absl::nullopt; |
| } |
| return *this; |
| } |
| |
| template <typename T> |
| StatusOr<T>::operator ::absl::StatusOr<T>() const& { |
| if (!ok()) return ::absl::Status(status_); |
| return *value_; |
| } |
| |
| template <typename T> |
| StatusOr<T>::operator ::absl::StatusOr<T>() && { |
| if (!ok()) return ::absl::Status(std::move(status_)); |
| return std::move(*value_); |
| } |
| |
| #else |
| |
| template <typename T> |
| using StatusOr = absl::StatusOr<T>; |
| |
| #endif // TINK_USE_ABSL_STATUSOR |
| |
| } // namespace util |
| } // namespace tink |
| } // namespace crypto |
| |
| #endif // TINK_UTIL_STATUSOR_H_ |