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Diffstat (limited to 'third_party/abseil_cpp/absl/types/any.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/types/any.h | 528 |
1 files changed, 0 insertions, 528 deletions
diff --git a/third_party/abseil_cpp/absl/types/any.h b/third_party/abseil_cpp/absl/types/any.h deleted file mode 100644 index 7eed519791..0000000000 --- a/third_party/abseil_cpp/absl/types/any.h +++ /dev/null @@ -1,528 +0,0 @@ -// -// Copyright 2017 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. -// -// ----------------------------------------------------------------------------- -// any.h -// ----------------------------------------------------------------------------- -// -// This header file define the `absl::any` type for holding a type-safe value -// of any type. The 'absl::any` type is useful for providing a way to hold -// something that is, as yet, unspecified. Such unspecified types -// traditionally are passed between API boundaries until they are later cast to -// their "destination" types. To cast to such a destination type, use -// `absl::any_cast()`. Note that when casting an `absl::any`, you must cast it -// to an explicit type; implicit conversions will throw. -// -// Example: -// -// auto a = absl::any(65); -// absl::any_cast<int>(a); // 65 -// absl::any_cast<char>(a); // throws absl::bad_any_cast -// absl::any_cast<std::string>(a); // throws absl::bad_any_cast -// -// `absl::any` is a C++11 compatible version of the C++17 `std::any` abstraction -// and is designed to be a drop-in replacement for code compliant with C++17. -// -// Traditionally, the behavior of casting to a temporary unspecified type has -// been accomplished with the `void *` paradigm, where the pointer was to some -// other unspecified type. `absl::any` provides an "owning" version of `void *` -// that avoids issues of pointer management. -// -// Note: just as in the case of `void *`, use of `absl::any` (and its C++17 -// version `std::any`) is a code smell indicating that your API might not be -// constructed correctly. We have seen that most uses of `any` are unwarranted, -// and `absl::any`, like `std::any`, is difficult to use properly. Before using -// this abstraction, make sure that you should not instead be rewriting your -// code to be more specific. -// -// Abseil expects to release an `absl::variant` type shortly (a C++11 compatible -// version of the C++17 `std::variant), which is generally preferred for use -// over `absl::any`. -#ifndef ABSL_TYPES_ANY_H_ -#define ABSL_TYPES_ANY_H_ - -#include "absl/base/config.h" -#include "absl/utility/utility.h" - -#ifdef ABSL_USES_STD_ANY - -#include <any> // IWYU pragma: export - -namespace absl { -ABSL_NAMESPACE_BEGIN -using std::any; -using std::any_cast; -using std::bad_any_cast; -using std::make_any; -ABSL_NAMESPACE_END -} // namespace absl - -#else // ABSL_USES_STD_ANY - -#include <algorithm> -#include <cstddef> -#include <initializer_list> -#include <memory> -#include <stdexcept> -#include <type_traits> -#include <typeinfo> -#include <utility> - -#include "absl/base/internal/fast_type_id.h" -#include "absl/base/macros.h" -#include "absl/meta/type_traits.h" -#include "absl/types/bad_any_cast.h" - -// NOTE: This macro is an implementation detail that is undefined at the bottom -// of the file. It is not intended for expansion directly from user code. -#ifdef ABSL_ANY_DETAIL_HAS_RTTI -#error ABSL_ANY_DETAIL_HAS_RTTI cannot be directly set -#elif !defined(__GNUC__) || defined(__GXX_RTTI) -#define ABSL_ANY_DETAIL_HAS_RTTI 1 -#endif // !defined(__GNUC__) || defined(__GXX_RTTI) - -namespace absl { -ABSL_NAMESPACE_BEGIN - -class any; - -// swap() -// -// Swaps two `absl::any` values. Equivalent to `x.swap(y) where `x` and `y` are -// `absl::any` types. -void swap(any& x, any& y) noexcept; - -// make_any() -// -// Constructs an `absl::any` of type `T` with the given arguments. -template <typename T, typename... Args> -any make_any(Args&&... args); - -// Overload of `absl::make_any()` for constructing an `absl::any` type from an -// initializer list. -template <typename T, typename U, typename... Args> -any make_any(std::initializer_list<U> il, Args&&... args); - -// any_cast() -// -// Statically casts the value of a `const absl::any` type to the given type. -// This function will throw `absl::bad_any_cast` if the stored value type of the -// `absl::any` does not match the cast. -// -// `any_cast()` can also be used to get a reference to the internal storage iff -// a reference type is passed as its `ValueType`: -// -// Example: -// -// absl::any my_any = std::vector<int>(); -// absl::any_cast<std::vector<int>&>(my_any).push_back(42); -template <typename ValueType> -ValueType any_cast(const any& operand); - -// Overload of `any_cast()` to statically cast the value of a non-const -// `absl::any` type to the given type. This function will throw -// `absl::bad_any_cast` if the stored value type of the `absl::any` does not -// match the cast. -template <typename ValueType> -ValueType any_cast(any& operand); // NOLINT(runtime/references) - -// Overload of `any_cast()` to statically cast the rvalue of an `absl::any` -// type. This function will throw `absl::bad_any_cast` if the stored value type -// of the `absl::any` does not match the cast. -template <typename ValueType> -ValueType any_cast(any&& operand); - -// Overload of `any_cast()` to statically cast the value of a const pointer -// `absl::any` type to the given pointer type, or `nullptr` if the stored value -// type of the `absl::any` does not match the cast. -template <typename ValueType> -const ValueType* any_cast(const any* operand) noexcept; - -// Overload of `any_cast()` to statically cast the value of a pointer -// `absl::any` type to the given pointer type, or `nullptr` if the stored value -// type of the `absl::any` does not match the cast. -template <typename ValueType> -ValueType* any_cast(any* operand) noexcept; - -// ----------------------------------------------------------------------------- -// absl::any -// ----------------------------------------------------------------------------- -// -// An `absl::any` object provides the facility to either store an instance of a -// type, known as the "contained object", or no value. An `absl::any` is used to -// store values of types that are unknown at compile time. The `absl::any` -// object, when containing a value, must contain a value type; storing a -// reference type is neither desired nor supported. -// -// An `absl::any` can only store a type that is copy-constructible; move-only -// types are not allowed within an `any` object. -// -// Example: -// -// auto a = absl::any(65); // Literal, copyable -// auto b = absl::any(std::vector<int>()); // Default-initialized, copyable -// std::unique_ptr<Foo> my_foo; -// auto c = absl::any(std::move(my_foo)); // Error, not copy-constructible -// -// Note that `absl::any` makes use of decayed types (`absl::decay_t` in this -// context) to remove const-volatile qualifiers (known as "cv qualifiers"), -// decay functions to function pointers, etc. We essentially "decay" a given -// type into its essential type. -// -// `absl::any` makes use of decayed types when determining the basic type `T` of -// the value to store in the any's contained object. In the documentation below, -// we explicitly denote this by using the phrase "a decayed type of `T`". -// -// Example: -// -// const int a = 4; -// absl::any foo(a); // Decay ensures we store an "int", not a "const int&". -// -// void my_function() {} -// absl::any bar(my_function); // Decay ensures we store a function pointer. -// -// `absl::any` is a C++11 compatible version of the C++17 `std::any` abstraction -// and is designed to be a drop-in replacement for code compliant with C++17. -class any { - private: - template <typename T> - struct IsInPlaceType; - - public: - // Constructors - - // Constructs an empty `absl::any` object (`any::has_value()` will return - // `false`). - constexpr any() noexcept; - - // Copy constructs an `absl::any` object with a "contained object" of the - // passed type of `other` (or an empty `absl::any` if `other.has_value()` is - // `false`. - any(const any& other) - : obj_(other.has_value() ? other.obj_->Clone() - : std::unique_ptr<ObjInterface>()) {} - - // Move constructs an `absl::any` object with a "contained object" of the - // passed type of `other` (or an empty `absl::any` if `other.has_value()` is - // `false`). - any(any&& other) noexcept = default; - - // Constructs an `absl::any` object with a "contained object" of the decayed - // type of `T`, which is initialized via `std::forward<T>(value)`. - // - // This constructor will not participate in overload resolution if the - // decayed type of `T` is not copy-constructible. - template < - typename T, typename VT = absl::decay_t<T>, - absl::enable_if_t<!absl::disjunction< - std::is_same<any, VT>, IsInPlaceType<VT>, - absl::negation<std::is_copy_constructible<VT> > >::value>* = nullptr> - any(T&& value) : obj_(new Obj<VT>(in_place, std::forward<T>(value))) {} - - // Constructs an `absl::any` object with a "contained object" of the decayed - // type of `T`, which is initialized via `std::forward<T>(value)`. - template <typename T, typename... Args, typename VT = absl::decay_t<T>, - absl::enable_if_t<absl::conjunction< - std::is_copy_constructible<VT>, - std::is_constructible<VT, Args...>>::value>* = nullptr> - explicit any(in_place_type_t<T> /*tag*/, Args&&... args) - : obj_(new Obj<VT>(in_place, std::forward<Args>(args)...)) {} - - // Constructs an `absl::any` object with a "contained object" of the passed - // type `VT` as a decayed type of `T`. `VT` is initialized as if - // direct-non-list-initializing an object of type `VT` with the arguments - // `initializer_list, std::forward<Args>(args)...`. - template < - typename T, typename U, typename... Args, typename VT = absl::decay_t<T>, - absl::enable_if_t< - absl::conjunction<std::is_copy_constructible<VT>, - std::is_constructible<VT, std::initializer_list<U>&, - Args...>>::value>* = nullptr> - explicit any(in_place_type_t<T> /*tag*/, std::initializer_list<U> ilist, - Args&&... args) - : obj_(new Obj<VT>(in_place, ilist, std::forward<Args>(args)...)) {} - - // Assignment operators - - // Copy assigns an `absl::any` object with a "contained object" of the - // passed type. - any& operator=(const any& rhs) { - any(rhs).swap(*this); - return *this; - } - - // Move assigns an `absl::any` object with a "contained object" of the - // passed type. `rhs` is left in a valid but otherwise unspecified state. - any& operator=(any&& rhs) noexcept { - any(std::move(rhs)).swap(*this); - return *this; - } - - // Assigns an `absl::any` object with a "contained object" of the passed type. - template <typename T, typename VT = absl::decay_t<T>, - absl::enable_if_t<absl::conjunction< - absl::negation<std::is_same<VT, any>>, - std::is_copy_constructible<VT>>::value>* = nullptr> - any& operator=(T&& rhs) { - any tmp(in_place_type_t<VT>(), std::forward<T>(rhs)); - tmp.swap(*this); - return *this; - } - - // Modifiers - - // any::emplace() - // - // Emplaces a value within an `absl::any` object by calling `any::reset()`, - // initializing the contained value as if direct-non-list-initializing an - // object of type `VT` with the arguments `std::forward<Args>(args)...`, and - // returning a reference to the new contained value. - // - // Note: If an exception is thrown during the call to `VT`'s constructor, - // `*this` does not contain a value, and any previously contained value has - // been destroyed. - template < - typename T, typename... Args, typename VT = absl::decay_t<T>, - absl::enable_if_t<std::is_copy_constructible<VT>::value && - std::is_constructible<VT, Args...>::value>* = nullptr> - VT& emplace(Args&&... args) { - reset(); // NOTE: reset() is required here even in the world of exceptions. - Obj<VT>* const object_ptr = - new Obj<VT>(in_place, std::forward<Args>(args)...); - obj_ = std::unique_ptr<ObjInterface>(object_ptr); - return object_ptr->value; - } - - // Overload of `any::emplace()` to emplace a value within an `absl::any` - // object by calling `any::reset()`, initializing the contained value as if - // direct-non-list-initializing an object of type `VT` with the arguments - // `initializer_list, std::forward<Args>(args)...`, and returning a reference - // to the new contained value. - // - // Note: If an exception is thrown during the call to `VT`'s constructor, - // `*this` does not contain a value, and any previously contained value has - // been destroyed. The function shall not participate in overload resolution - // unless `is_copy_constructible_v<VT>` is `true` and - // `is_constructible_v<VT, initializer_list<U>&, Args...>` is `true`. - template < - typename T, typename U, typename... Args, typename VT = absl::decay_t<T>, - absl::enable_if_t<std::is_copy_constructible<VT>::value && - std::is_constructible<VT, std::initializer_list<U>&, - Args...>::value>* = nullptr> - VT& emplace(std::initializer_list<U> ilist, Args&&... args) { - reset(); // NOTE: reset() is required here even in the world of exceptions. - Obj<VT>* const object_ptr = - new Obj<VT>(in_place, ilist, std::forward<Args>(args)...); - obj_ = std::unique_ptr<ObjInterface>(object_ptr); - return object_ptr->value; - } - - // any::reset() - // - // Resets the state of the `absl::any` object, destroying the contained object - // if present. - void reset() noexcept { obj_ = nullptr; } - - // any::swap() - // - // Swaps the passed value and the value of this `absl::any` object. - void swap(any& other) noexcept { obj_.swap(other.obj_); } - - // Observers - - // any::has_value() - // - // Returns `true` if the `any` object has a contained value, otherwise - // returns `false`. - bool has_value() const noexcept { return obj_ != nullptr; } - -#if ABSL_ANY_DETAIL_HAS_RTTI - // Returns: typeid(T) if *this has a contained object of type T, otherwise - // typeid(void). - const std::type_info& type() const noexcept { - if (has_value()) { - return obj_->Type(); - } - - return typeid(void); - } -#endif // ABSL_ANY_DETAIL_HAS_RTTI - - private: - // Tagged type-erased abstraction for holding a cloneable object. - class ObjInterface { - public: - virtual ~ObjInterface() = default; - virtual std::unique_ptr<ObjInterface> Clone() const = 0; - virtual const void* ObjTypeId() const noexcept = 0; -#if ABSL_ANY_DETAIL_HAS_RTTI - virtual const std::type_info& Type() const noexcept = 0; -#endif // ABSL_ANY_DETAIL_HAS_RTTI - }; - - // Hold a value of some queryable type, with an ability to Clone it. - template <typename T> - class Obj : public ObjInterface { - public: - template <typename... Args> - explicit Obj(in_place_t /*tag*/, Args&&... args) - : value(std::forward<Args>(args)...) {} - - std::unique_ptr<ObjInterface> Clone() const final { - return std::unique_ptr<ObjInterface>(new Obj(in_place, value)); - } - - const void* ObjTypeId() const noexcept final { return IdForType<T>(); } - -#if ABSL_ANY_DETAIL_HAS_RTTI - const std::type_info& Type() const noexcept final { return typeid(T); } -#endif // ABSL_ANY_DETAIL_HAS_RTTI - - T value; - }; - - std::unique_ptr<ObjInterface> CloneObj() const { - if (!obj_) return nullptr; - return obj_->Clone(); - } - - template <typename T> - constexpr static const void* IdForType() { - // Note: This type dance is to make the behavior consistent with typeid. - using NormalizedType = - typename std::remove_cv<typename std::remove_reference<T>::type>::type; - - return base_internal::FastTypeId<NormalizedType>(); - } - - const void* GetObjTypeId() const { - return obj_ ? obj_->ObjTypeId() : base_internal::FastTypeId<void>(); - } - - // `absl::any` nonmember functions // - - // Description at the declaration site (top of file). - template <typename ValueType> - friend ValueType any_cast(const any& operand); - - // Description at the declaration site (top of file). - template <typename ValueType> - friend ValueType any_cast(any& operand); // NOLINT(runtime/references) - - // Description at the declaration site (top of file). - template <typename T> - friend const T* any_cast(const any* operand) noexcept; - - // Description at the declaration site (top of file). - template <typename T> - friend T* any_cast(any* operand) noexcept; - - std::unique_ptr<ObjInterface> obj_; -}; - -// ----------------------------------------------------------------------------- -// Implementation Details -// ----------------------------------------------------------------------------- - -constexpr any::any() noexcept = default; - -template <typename T> -struct any::IsInPlaceType : std::false_type {}; - -template <typename T> -struct any::IsInPlaceType<in_place_type_t<T>> : std::true_type {}; - -inline void swap(any& x, any& y) noexcept { x.swap(y); } - -// Description at the declaration site (top of file). -template <typename T, typename... Args> -any make_any(Args&&... args) { - return any(in_place_type_t<T>(), std::forward<Args>(args)...); -} - -// Description at the declaration site (top of file). -template <typename T, typename U, typename... Args> -any make_any(std::initializer_list<U> il, Args&&... args) { - return any(in_place_type_t<T>(), il, std::forward<Args>(args)...); -} - -// Description at the declaration site (top of file). -template <typename ValueType> -ValueType any_cast(const any& operand) { - using U = typename std::remove_cv< - typename std::remove_reference<ValueType>::type>::type; - static_assert(std::is_constructible<ValueType, const U&>::value, - "Invalid ValueType"); - auto* const result = (any_cast<U>)(&operand); - if (result == nullptr) { - any_internal::ThrowBadAnyCast(); - } - return static_cast<ValueType>(*result); -} - -// Description at the declaration site (top of file). -template <typename ValueType> -ValueType any_cast(any& operand) { // NOLINT(runtime/references) - using U = typename std::remove_cv< - typename std::remove_reference<ValueType>::type>::type; - static_assert(std::is_constructible<ValueType, U&>::value, - "Invalid ValueType"); - auto* result = (any_cast<U>)(&operand); - if (result == nullptr) { - any_internal::ThrowBadAnyCast(); - } - return static_cast<ValueType>(*result); -} - -// Description at the declaration site (top of file). -template <typename ValueType> -ValueType any_cast(any&& operand) { - using U = typename std::remove_cv< - typename std::remove_reference<ValueType>::type>::type; - static_assert(std::is_constructible<ValueType, U>::value, - "Invalid ValueType"); - return static_cast<ValueType>(std::move((any_cast<U&>)(operand))); -} - -// Description at the declaration site (top of file). -template <typename T> -const T* any_cast(const any* operand) noexcept { - using U = - typename std::remove_cv<typename std::remove_reference<T>::type>::type; - return operand && operand->GetObjTypeId() == any::IdForType<U>() - ? std::addressof( - static_cast<const any::Obj<U>*>(operand->obj_.get())->value) - : nullptr; -} - -// Description at the declaration site (top of file). -template <typename T> -T* any_cast(any* operand) noexcept { - using U = - typename std::remove_cv<typename std::remove_reference<T>::type>::type; - return operand && operand->GetObjTypeId() == any::IdForType<U>() - ? std::addressof( - static_cast<any::Obj<U>*>(operand->obj_.get())->value) - : nullptr; -} - -ABSL_NAMESPACE_END -} // namespace absl - -#undef ABSL_ANY_DETAIL_HAS_RTTI - -#endif // ABSL_USES_STD_ANY - -#endif // ABSL_TYPES_ANY_H_ |