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Diffstat (limited to 'src/google/protobuf/stubs/statusor.h')
| -rw-r--r-- | src/google/protobuf/stubs/statusor.h | 259 |
1 files changed, 0 insertions, 259 deletions
diff --git a/src/google/protobuf/stubs/statusor.h b/src/google/protobuf/stubs/statusor.h deleted file mode 100644 index 29f869ad..00000000 --- a/src/google/protobuf/stubs/statusor.h +++ /dev/null @@ -1,259 +0,0 @@ -// 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 Status::OK. Further, StatusOr<T*> does not allow the -// contained pointer to be NULL. -// -// 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.ValueOrDie(); -// 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.ValueOrDie()); -// foo->DoSomethingCool(); -// } else { -// LOG(ERROR) << result.status(); -// } -// -// Example client usage for a StatusOr<std::unique_ptr<T>>: -// -// StatusOr<std::unique_ptr<Foo>> result = FooFactory::MakeNewFoo(arg); -// if (result.ok()) { -// std::unique_ptr<Foo> foo = result.ConsumeValueOrDie(); -// foo->DoSomethingCool(); -// } else { -// LOG(ERROR) << result.status(); -// } -// -// Example factory implementation returning StatusOr<T*>: -// -// StatusOr<Foo*> FooFactory::MakeNewFoo(int arg) { -// if (arg <= 0) { -// return ::util::Status(::util::error::INVALID_ARGUMENT, -// "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 <google/protobuf/stubs/status.h> - -namespace google { -namespace protobuf { -namespace util { - -template<typename T> -class StatusOr { - template<typename U> friend class StatusOr; - - public: - // Construct a new StatusOr with Status::UNKNOWN status - StatusOr(); - - // Construct a new StatusOr with the given non-ok status. After calling - // this constructor, calls to ValueOrDie() 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 != Status::OK. This requirement is DCHECKed. - // In optimized builds, passing Status::OK 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 NULL. After calling this constructor, calls to - // ValueOrDie() 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 != NULL. 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 Status::OK. - const Status& status() const; - - // Returns this->status().ok() - bool ok() const; - - // Returns a reference to our current value, or CHECK-fails if !this->ok(). - // If you need to initialize a T object from the stored value, - // ConsumeValueOrDie() may be more efficient. - const T& ValueOrDie() const; - - private: - Status status_; - T value_; -}; - -//////////////////////////////////////////////////////////////////////////////// -// Implementation details for StatusOr<T> - -namespace internal { - -class LIBPROTOBUF_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 NULL. - 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 == NULL; } -}; - -} // namespace internal - -template<typename T> -inline StatusOr<T>::StatusOr() - : status_(util::Status::UNKNOWN) { -} - -template<typename T> -inline StatusOr<T>::StatusOr(const Status& status) { - if (status.ok()) { - status_ = Status(error::INTERNAL, "Status::OK is not a valid argument."); - } else { - status_ = status; - } -} - -template<typename T> -inline StatusOr<T>::StatusOr(const T& value) { - if (internal::StatusOrHelper::Specialize<T>::IsValueNull(value)) { - status_ = Status(error::INTERNAL, "NULL is not a vaild argument."); - } else { - status_ = Status::OK; - 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>::ValueOrDie() const { - if (!status_.ok()) { - internal::StatusOrHelper::Crash(status_); - } - return value_; -} -} // namespace util -} // namespace protobuf -} // namespace google - -#endif // GOOGLE_PROTOBUF_STUBS_STATUSOR_H_ |