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Diffstat (limited to 'third_party/abseil_cpp/absl/status/internal/statusor_internal.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/status/internal/statusor_internal.h | 396 |
1 files changed, 0 insertions, 396 deletions
diff --git a/third_party/abseil_cpp/absl/status/internal/statusor_internal.h b/third_party/abseil_cpp/absl/status/internal/statusor_internal.h deleted file mode 100644 index eaac2c0b14..0000000000 --- a/third_party/abseil_cpp/absl/status/internal/statusor_internal.h +++ /dev/null @@ -1,396 +0,0 @@ -// Copyright 2020 The Abseil 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 -// -// https://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 ABSL_STATUS_INTERNAL_STATUSOR_INTERNAL_H_ -#define ABSL_STATUS_INTERNAL_STATUSOR_INTERNAL_H_ - -#include <type_traits> -#include <utility> - -#include "absl/base/attributes.h" -#include "absl/meta/type_traits.h" -#include "absl/status/status.h" -#include "absl/utility/utility.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN - -template <typename T> -class ABSL_MUST_USE_RESULT StatusOr; - -namespace internal_statusor { - -// Detects whether `U` has conversion operator to `StatusOr<T>`, i.e. `operator -// StatusOr<T>()`. -template <typename T, typename U, typename = void> -struct HasConversionOperatorToStatusOr : std::false_type {}; - -template <typename T, typename U> -void test(char (*)[sizeof(std::declval<U>().operator absl::StatusOr<T>())]); - -template <typename T, typename U> -struct HasConversionOperatorToStatusOr<T, U, decltype(test<T, U>(0))> - : std::true_type {}; - -// Detects whether `T` is constructible or convertible from `StatusOr<U>`. -template <typename T, typename U> -using IsConstructibleOrConvertibleFromStatusOr = - absl::disjunction<std::is_constructible<T, StatusOr<U>&>, - std::is_constructible<T, const StatusOr<U>&>, - std::is_constructible<T, StatusOr<U>&&>, - std::is_constructible<T, const StatusOr<U>&&>, - std::is_convertible<StatusOr<U>&, T>, - std::is_convertible<const StatusOr<U>&, T>, - std::is_convertible<StatusOr<U>&&, T>, - std::is_convertible<const StatusOr<U>&&, T>>; - -// Detects whether `T` is constructible or convertible or assignable from -// `StatusOr<U>`. -template <typename T, typename U> -using IsConstructibleOrConvertibleOrAssignableFromStatusOr = - absl::disjunction<IsConstructibleOrConvertibleFromStatusOr<T, U>, - std::is_assignable<T&, StatusOr<U>&>, - std::is_assignable<T&, const StatusOr<U>&>, - std::is_assignable<T&, StatusOr<U>&&>, - std::is_assignable<T&, const StatusOr<U>&&>>; - -// Detects whether direct initializing `StatusOr<T>` from `U` is ambiguous, i.e. -// when `U` is `StatusOr<V>` and `T` is constructible or convertible from `V`. -template <typename T, typename U> -struct IsDirectInitializationAmbiguous - : public absl::conditional_t< - std::is_same<absl::remove_cv_t<absl::remove_reference_t<U>>, - U>::value, - std::false_type, - IsDirectInitializationAmbiguous< - T, absl::remove_cv_t<absl::remove_reference_t<U>>>> {}; - -template <typename T, typename V> -struct IsDirectInitializationAmbiguous<T, absl::StatusOr<V>> - : public IsConstructibleOrConvertibleFromStatusOr<T, V> {}; - -// Checks against the constraints of the direction initialization, i.e. when -// `StatusOr<T>::StatusOr(U&&)` should participate in overload resolution. -template <typename T, typename U> -using IsDirectInitializationValid = absl::disjunction< - // Short circuits if T is basically U. - std::is_same<T, absl::remove_cv_t<absl::remove_reference_t<U>>>, - absl::negation<absl::disjunction< - std::is_same<absl::StatusOr<T>, - absl::remove_cv_t<absl::remove_reference_t<U>>>, - std::is_same<absl::Status, - absl::remove_cv_t<absl::remove_reference_t<U>>>, - std::is_same<absl::in_place_t, - absl::remove_cv_t<absl::remove_reference_t<U>>>, - IsDirectInitializationAmbiguous<T, U>>>>; - -// This trait detects whether `StatusOr<T>::operator=(U&&)` is ambiguous, which -// is equivalent to whether all the following conditions are met: -// 1. `U` is `StatusOr<V>`. -// 2. `T` is constructible and assignable from `V`. -// 3. `T` is constructible and assignable from `U` (i.e. `StatusOr<V>`). -// For example, the following code is considered ambiguous: -// (`T` is `bool`, `U` is `StatusOr<bool>`, `V` is `bool`) -// StatusOr<bool> s1 = true; // s1.ok() && s1.ValueOrDie() == true -// StatusOr<bool> s2 = false; // s2.ok() && s2.ValueOrDie() == false -// s1 = s2; // ambiguous, `s1 = s2.ValueOrDie()` or `s1 = bool(s2)`? -template <typename T, typename U> -struct IsForwardingAssignmentAmbiguous - : public absl::conditional_t< - std::is_same<absl::remove_cv_t<absl::remove_reference_t<U>>, - U>::value, - std::false_type, - IsForwardingAssignmentAmbiguous< - T, absl::remove_cv_t<absl::remove_reference_t<U>>>> {}; - -template <typename T, typename U> -struct IsForwardingAssignmentAmbiguous<T, absl::StatusOr<U>> - : public IsConstructibleOrConvertibleOrAssignableFromStatusOr<T, U> {}; - -// Checks against the constraints of the forwarding assignment, i.e. whether -// `StatusOr<T>::operator(U&&)` should participate in overload resolution. -template <typename T, typename U> -using IsForwardingAssignmentValid = absl::disjunction< - // Short circuits if T is basically U. - std::is_same<T, absl::remove_cv_t<absl::remove_reference_t<U>>>, - absl::negation<absl::disjunction< - std::is_same<absl::StatusOr<T>, - absl::remove_cv_t<absl::remove_reference_t<U>>>, - std::is_same<absl::Status, - absl::remove_cv_t<absl::remove_reference_t<U>>>, - std::is_same<absl::in_place_t, - absl::remove_cv_t<absl::remove_reference_t<U>>>, - IsForwardingAssignmentAmbiguous<T, U>>>>; - -class Helper { - public: - // Move type-agnostic error handling to the .cc. - static void HandleInvalidStatusCtorArg(Status*); - ABSL_ATTRIBUTE_NORETURN static void Crash(const absl::Status& status); -}; - -// Construct an instance of T in `p` through placement new, passing Args... to -// the constructor. -// This abstraction is here mostly for the gcc performance fix. -template <typename T, typename... Args> -ABSL_ATTRIBUTE_NONNULL(1) void PlacementNew(void* p, Args&&... args) { - new (p) T(std::forward<Args>(args)...); -} - -// Helper base class to hold the data and all operations. -// We move all this to a base class to allow mixing with the appropriate -// TraitsBase specialization. -template <typename T> -class StatusOrData { - template <typename U> - friend class StatusOrData; - - public: - StatusOrData() = delete; - - StatusOrData(const StatusOrData& other) { - if (other.ok()) { - MakeValue(other.data_); - MakeStatus(); - } else { - MakeStatus(other.status_); - } - } - - StatusOrData(StatusOrData&& other) noexcept { - if (other.ok()) { - MakeValue(std::move(other.data_)); - MakeStatus(); - } else { - MakeStatus(std::move(other.status_)); - } - } - - template <typename U> - explicit StatusOrData(const StatusOrData<U>& other) { - if (other.ok()) { - MakeValue(other.data_); - MakeStatus(); - } else { - MakeStatus(other.status_); - } - } - - template <typename U> - explicit StatusOrData(StatusOrData<U>&& other) { - if (other.ok()) { - MakeValue(std::move(other.data_)); - MakeStatus(); - } else { - MakeStatus(std::move(other.status_)); - } - } - - template <typename... Args> - explicit StatusOrData(absl::in_place_t, Args&&... args) - : data_(std::forward<Args>(args)...) { - MakeStatus(); - } - - explicit StatusOrData(const T& value) : data_(value) { - MakeStatus(); - } - explicit StatusOrData(T&& value) : data_(std::move(value)) { - MakeStatus(); - } - - template <typename U, - absl::enable_if_t<std::is_constructible<absl::Status, U&&>::value, - int> = 0> - explicit StatusOrData(U&& v) : status_(std::forward<U>(v)) { - EnsureNotOk(); - } - - StatusOrData& operator=(const StatusOrData& other) { - if (this == &other) return *this; - if (other.ok()) - Assign(other.data_); - else - AssignStatus(other.status_); - return *this; - } - - StatusOrData& operator=(StatusOrData&& other) { - if (this == &other) return *this; - if (other.ok()) - Assign(std::move(other.data_)); - else - AssignStatus(std::move(other.status_)); - return *this; - } - - ~StatusOrData() { - if (ok()) { - status_.~Status(); - data_.~T(); - } else { - status_.~Status(); - } - } - - template <typename U> - void Assign(U&& value) { - if (ok()) { - data_ = std::forward<U>(value); - } else { - MakeValue(std::forward<U>(value)); - status_ = OkStatus(); - } - } - - template <typename U> - void AssignStatus(U&& v) { - Clear(); - status_ = static_cast<absl::Status>(std::forward<U>(v)); - EnsureNotOk(); - } - - bool ok() const { return status_.ok(); } - - protected: - // status_ will always be active after the constructor. - // We make it a union to be able to initialize exactly how we need without - // waste. - // Eg. in the copy constructor we use the default constructor of Status in - // the ok() path to avoid an extra Ref call. - union { - Status status_; - }; - - // data_ is active iff status_.ok()==true - struct Dummy {}; - union { - // When T is const, we need some non-const object we can cast to void* for - // the placement new. dummy_ is that object. - Dummy dummy_; - T data_; - }; - - void Clear() { - if (ok()) data_.~T(); - } - - void EnsureOk() const { - if (ABSL_PREDICT_FALSE(!ok())) Helper::Crash(status_); - } - - void EnsureNotOk() { - if (ABSL_PREDICT_FALSE(ok())) Helper::HandleInvalidStatusCtorArg(&status_); - } - - // Construct the value (ie. data_) through placement new with the passed - // argument. - template <typename... Arg> - void MakeValue(Arg&&... arg) { - internal_statusor::PlacementNew<T>(&dummy_, std::forward<Arg>(arg)...); - } - - // Construct the status (ie. status_) through placement new with the passed - // argument. - template <typename... Args> - void MakeStatus(Args&&... args) { - internal_statusor::PlacementNew<Status>(&status_, - std::forward<Args>(args)...); - } -}; - -// Helper base classes to allow implicitly deleted constructors and assignment -// operators in `StatusOr`. For example, `CopyCtorBase` will explicitly delete -// the copy constructor when T is not copy constructible and `StatusOr` will -// inherit that behavior implicitly. -template <typename T, bool = std::is_copy_constructible<T>::value> -struct CopyCtorBase { - CopyCtorBase() = default; - CopyCtorBase(const CopyCtorBase&) = default; - CopyCtorBase(CopyCtorBase&&) = default; - CopyCtorBase& operator=(const CopyCtorBase&) = default; - CopyCtorBase& operator=(CopyCtorBase&&) = default; -}; - -template <typename T> -struct CopyCtorBase<T, false> { - CopyCtorBase() = default; - CopyCtorBase(const CopyCtorBase&) = delete; - CopyCtorBase(CopyCtorBase&&) = default; - CopyCtorBase& operator=(const CopyCtorBase&) = default; - CopyCtorBase& operator=(CopyCtorBase&&) = default; -}; - -template <typename T, bool = std::is_move_constructible<T>::value> -struct MoveCtorBase { - MoveCtorBase() = default; - MoveCtorBase(const MoveCtorBase&) = default; - MoveCtorBase(MoveCtorBase&&) = default; - MoveCtorBase& operator=(const MoveCtorBase&) = default; - MoveCtorBase& operator=(MoveCtorBase&&) = default; -}; - -template <typename T> -struct MoveCtorBase<T, false> { - MoveCtorBase() = default; - MoveCtorBase(const MoveCtorBase&) = default; - MoveCtorBase(MoveCtorBase&&) = delete; - MoveCtorBase& operator=(const MoveCtorBase&) = default; - MoveCtorBase& operator=(MoveCtorBase&&) = default; -}; - -template <typename T, bool = std::is_copy_constructible<T>::value&& - std::is_copy_assignable<T>::value> -struct CopyAssignBase { - CopyAssignBase() = default; - CopyAssignBase(const CopyAssignBase&) = default; - CopyAssignBase(CopyAssignBase&&) = default; - CopyAssignBase& operator=(const CopyAssignBase&) = default; - CopyAssignBase& operator=(CopyAssignBase&&) = default; -}; - -template <typename T> -struct CopyAssignBase<T, false> { - CopyAssignBase() = default; - CopyAssignBase(const CopyAssignBase&) = default; - CopyAssignBase(CopyAssignBase&&) = default; - CopyAssignBase& operator=(const CopyAssignBase&) = delete; - CopyAssignBase& operator=(CopyAssignBase&&) = default; -}; - -template <typename T, bool = std::is_move_constructible<T>::value&& - std::is_move_assignable<T>::value> -struct MoveAssignBase { - MoveAssignBase() = default; - MoveAssignBase(const MoveAssignBase&) = default; - MoveAssignBase(MoveAssignBase&&) = default; - MoveAssignBase& operator=(const MoveAssignBase&) = default; - MoveAssignBase& operator=(MoveAssignBase&&) = default; -}; - -template <typename T> -struct MoveAssignBase<T, false> { - MoveAssignBase() = default; - MoveAssignBase(const MoveAssignBase&) = default; - MoveAssignBase(MoveAssignBase&&) = default; - MoveAssignBase& operator=(const MoveAssignBase&) = default; - MoveAssignBase& operator=(MoveAssignBase&&) = delete; -}; - -ABSL_ATTRIBUTE_NORETURN void ThrowBadStatusOrAccess(absl::Status status); - -} // namespace internal_statusor -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_STATUS_INTERNAL_STATUSOR_INTERNAL_H_ |