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Diffstat (limited to 'NorthstarDedicatedTest/include/protobuf/stubs/statusor.h')
-rw-r--r-- | NorthstarDedicatedTest/include/protobuf/stubs/statusor.h | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/NorthstarDedicatedTest/include/protobuf/stubs/statusor.h b/NorthstarDedicatedTest/include/protobuf/stubs/statusor.h new file mode 100644 index 00000000..55aa4f73 --- /dev/null +++ b/NorthstarDedicatedTest/include/protobuf/stubs/statusor.h @@ -0,0 +1,253 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2008 Google Inc. All rights reserved. +// https://developers.google.com/protocol-buffers/ +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// StatusOr<T> is the union of a Status object and a T +// object. StatusOr models the concept of an object that is either a +// usable value, or an error Status explaining why such a value is +// not present. To this end, StatusOr<T> does not allow its Status +// value to be OkStatus(). Further, StatusOr<T*> does not allow the +// contained pointer to be nullptr. +// +// The primary use-case for StatusOr<T> is as the return value of a +// function which may fail. +// +// Example client usage for a StatusOr<T>, where T is not a pointer: +// +// StatusOr<float> result = DoBigCalculationThatCouldFail(); +// if (result.ok()) { +// float answer = result.value(); +// printf("Big calculation yielded: %f", answer); +// } else { +// LOG(ERROR) << result.status(); +// } +// +// Example client usage for a StatusOr<T*>: +// +// StatusOr<Foo*> result = FooFactory::MakeNewFoo(arg); +// if (result.ok()) { +// std::unique_ptr<Foo> foo(result.value()); +// foo->DoSomethingCool(); +// } else { +// LOG(ERROR) << result.status(); +// } +// +// Example factory implementation returning StatusOr<T*>: +// +// StatusOr<Foo*> FooFactory::MakeNewFoo(int arg) { +// if (arg <= 0) { +// return InvalidArgumentError("Arg must be positive"); +// } else { +// return new Foo(arg); +// } +// } +// + +#ifndef GOOGLE_PROTOBUF_STUBS_STATUSOR_H_ +#define GOOGLE_PROTOBUF_STUBS_STATUSOR_H_ + +#include <new> +#include <string> +#include <utility> + +#include <stubs/status.h> + +#include <port_def.inc> + +namespace google { +namespace protobuf { +namespace util { +namespace statusor_internal { + +template<typename T> +class StatusOr { + template<typename U> friend class StatusOr; + + public: + using value_type = T; + + // Construct a new StatusOr with Status::UNKNOWN status. + // Construct a new StatusOr with UnknownError() status. + explicit StatusOr(); + + // Construct a new StatusOr with the given non-ok status. After calling + // this constructor, calls to value() will CHECK-fail. + // + // NOTE: Not explicit - we want to use StatusOr<T> as a return + // value, so it is convenient and sensible to be able to do 'return + // Status()' when the return type is StatusOr<T>. + // + // REQUIRES: status != OkStatus(). This requirement is DCHECKed. + // In optimized builds, passing OkStatus() here will have the effect + // of passing PosixErrorSpace::EINVAL as a fallback. + StatusOr(const Status& status); // NOLINT + + // Construct a new StatusOr with the given value. If T is a plain pointer, + // value must not be nullptr. After calling this constructor, calls to + // value() will succeed, and calls to status() will return OK. + // + // NOTE: Not explicit - we want to use StatusOr<T> as a return type + // so it is convenient and sensible to be able to do 'return T()' + // when when the return type is StatusOr<T>. + // + // REQUIRES: if T is a plain pointer, value != nullptr. This requirement is + // DCHECKed. In optimized builds, passing a null pointer here will have + // the effect of passing PosixErrorSpace::EINVAL as a fallback. + StatusOr(const T& value); // NOLINT + + // Copy constructor. + StatusOr(const StatusOr& other); + + // Conversion copy constructor, T must be copy constructible from U + template<typename U> + StatusOr(const StatusOr<U>& other); + + // Assignment operator. + StatusOr& operator=(const StatusOr& other); + + // Conversion assignment operator, T must be assignable from U + template<typename U> + StatusOr& operator=(const StatusOr<U>& other); + + // Returns a reference to our status. If this contains a T, then + // returns OkStatus(). + const Status& status() const; + + // Returns this->status().ok() + bool ok() const; + + // Returns a reference to our current value, or CHECK-fails if !this->ok(). + const T& value () const; + + private: + Status status_; + T value_; +}; + +//////////////////////////////////////////////////////////////////////////////// +// Implementation details for StatusOr<T> + +class PROTOBUF_EXPORT StatusOrHelper { + public: + // Move type-agnostic error handling to the .cc. + static void Crash(const util::Status& status); + + // Customized behavior for StatusOr<T> vs. StatusOr<T*> + template<typename T> + struct Specialize; +}; + +template<typename T> +struct StatusOrHelper::Specialize { + // For non-pointer T, a reference can never be nullptr. + static inline bool IsValueNull(const T& /*t*/) { return false; } +}; + +template<typename T> +struct StatusOrHelper::Specialize<T*> { + static inline bool IsValueNull(const T* t) { return t == nullptr; } +}; + +template <typename T> +inline StatusOr<T>::StatusOr() : status_(util::UnknownError("")) {} + +template<typename T> +inline StatusOr<T>::StatusOr(const Status& status) { + if (status.ok()) { + status_ = util::InternalError("OkStatus() is not a valid argument."); + } else { + status_ = status; + } +} + +template<typename T> +inline StatusOr<T>::StatusOr(const T& value) { + if (StatusOrHelper::Specialize<T>::IsValueNull(value)) { + status_ = util::InternalError("nullptr is not a valid argument."); + } else { + status_ = util::OkStatus(); + value_ = value; + } +} + +template<typename T> +inline StatusOr<T>::StatusOr(const StatusOr<T>& other) + : status_(other.status_), value_(other.value_) { +} + +template<typename T> +inline StatusOr<T>& StatusOr<T>::operator=(const StatusOr<T>& other) { + status_ = other.status_; + value_ = other.value_; + return *this; +} + +template<typename T> +template<typename U> +inline StatusOr<T>::StatusOr(const StatusOr<U>& other) + : status_(other.status_), value_(other.status_.ok() ? other.value_ : T()) { +} + +template<typename T> +template<typename U> +inline StatusOr<T>& StatusOr<T>::operator=(const StatusOr<U>& other) { + status_ = other.status_; + if (status_.ok()) value_ = other.value_; + return *this; +} + +template<typename T> +inline const Status& StatusOr<T>::status() const { + return status_; +} + +template<typename T> +inline bool StatusOr<T>::ok() const { + return status().ok(); +} + +template<typename T> +inline const T& StatusOr<T>::value() const { + if (!status_.ok()) { + StatusOrHelper::Crash(status_); + } + return value_; +} + +} // namespace statusor_internal + +using ::google::protobuf::util::statusor_internal::StatusOr; + +} // namespace util +} // namespace protobuf +} // namespace google + +#include <port_undef.inc> + +#endif // GOOGLE_PROTOBUF_STUBS_STATUSOR_H_ |