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Diffstat (limited to 'third_party/abseil_cpp/absl/types/optional.h')
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diff --git a/third_party/abseil_cpp/absl/types/optional.h b/third_party/abseil_cpp/absl/types/optional.h deleted file mode 100644 index 61540cfdb2..0000000000 --- a/third_party/abseil_cpp/absl/types/optional.h +++ /dev/null @@ -1,776 +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. -// -// ----------------------------------------------------------------------------- -// optional.h -// ----------------------------------------------------------------------------- -// -// This header file defines the `absl::optional` type for holding a value which -// may or may not be present. This type is useful for providing value semantics -// for operations that may either wish to return or hold "something-or-nothing". -// -// Example: -// -// // A common way to signal operation failure is to provide an output -// // parameter and a bool return type: -// bool AcquireResource(const Input&, Resource * out); -// -// // Providing an absl::optional return type provides a cleaner API: -// absl::optional<Resource> AcquireResource(const Input&); -// -// `absl::optional` is a C++11 compatible version of the C++17 `std::optional` -// abstraction and is designed to be a drop-in replacement for code compliant -// with C++17. -#ifndef ABSL_TYPES_OPTIONAL_H_ -#define ABSL_TYPES_OPTIONAL_H_ - -#include "absl/base/config.h" // TODO(calabrese) IWYU removal? -#include "absl/utility/utility.h" - -#ifdef ABSL_USES_STD_OPTIONAL - -#include <optional> // IWYU pragma: export - -namespace absl { -ABSL_NAMESPACE_BEGIN -using std::bad_optional_access; -using std::optional; -using std::make_optional; -using std::nullopt_t; -using std::nullopt; -ABSL_NAMESPACE_END -} // namespace absl - -#else // ABSL_USES_STD_OPTIONAL - -#include <cassert> -#include <functional> -#include <initializer_list> -#include <type_traits> -#include <utility> - -#include "absl/base/attributes.h" -#include "absl/base/internal/inline_variable.h" -#include "absl/meta/type_traits.h" -#include "absl/types/bad_optional_access.h" -#include "absl/types/internal/optional.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN - -// nullopt_t -// -// Class type for `absl::nullopt` used to indicate an `absl::optional<T>` type -// that does not contain a value. -struct nullopt_t { - // It must not be default-constructible to avoid ambiguity for opt = {}. - explicit constexpr nullopt_t(optional_internal::init_t) noexcept {} -}; - -// nullopt -// -// A tag constant of type `absl::nullopt_t` used to indicate an empty -// `absl::optional` in certain functions, such as construction or assignment. -ABSL_INTERNAL_INLINE_CONSTEXPR(nullopt_t, nullopt, - nullopt_t(optional_internal::init_t())); - -// ----------------------------------------------------------------------------- -// absl::optional -// ----------------------------------------------------------------------------- -// -// A value of type `absl::optional<T>` holds either a value of `T` or an -// "empty" value. When it holds a value of `T`, it stores it as a direct -// sub-object, so `sizeof(optional<T>)` is approximately -// `sizeof(T) + sizeof(bool)`. -// -// This implementation is based on the specification in the latest draft of the -// C++17 `std::optional` specification as of May 2017, section 20.6. -// -// Differences between `absl::optional<T>` and `std::optional<T>` include: -// -// * `constexpr` is not used for non-const member functions. -// (dependency on some differences between C++11 and C++14.) -// * `absl::nullopt` and `absl::in_place` are not declared `constexpr`. We -// need the inline variable support in C++17 for external linkage. -// * Throws `absl::bad_optional_access` instead of -// `std::bad_optional_access`. -// * `make_optional()` cannot be declared `constexpr` due to the absence of -// guaranteed copy elision. -// * The move constructor's `noexcept` specification is stronger, i.e. if the -// default allocator is non-throwing (via setting -// `ABSL_ALLOCATOR_NOTHROW`), it evaluates to `noexcept(true)`, because -// we assume -// a) move constructors should only throw due to allocation failure and -// b) if T's move constructor allocates, it uses the same allocation -// function as the default allocator. -// -template <typename T> -class optional : private optional_internal::optional_data<T>, - private optional_internal::optional_ctor_base< - optional_internal::ctor_copy_traits<T>::traits>, - private optional_internal::optional_assign_base< - optional_internal::assign_copy_traits<T>::traits> { - using data_base = optional_internal::optional_data<T>; - - public: - typedef T value_type; - - // Constructors - - // Constructs an `optional` holding an empty value, NOT a default constructed - // `T`. - constexpr optional() noexcept {} - - // Constructs an `optional` initialized with `nullopt` to hold an empty value. - constexpr optional(nullopt_t) noexcept {} // NOLINT(runtime/explicit) - - // Copy constructor, standard semantics - optional(const optional&) = default; - - // Move constructor, standard semantics - optional(optional&&) = default; - - // Constructs a non-empty `optional` direct-initialized value of type `T` from - // the arguments `std::forward<Args>(args)...` within the `optional`. - // (The `in_place_t` is a tag used to indicate that the contained object - // should be constructed in-place.) - template <typename InPlaceT, typename... Args, - absl::enable_if_t<absl::conjunction< - std::is_same<InPlaceT, in_place_t>, - std::is_constructible<T, Args&&...> >::value>* = nullptr> - constexpr explicit optional(InPlaceT, Args&&... args) - : data_base(in_place_t(), absl::forward<Args>(args)...) {} - - // Constructs a non-empty `optional` direct-initialized value of type `T` from - // the arguments of an initializer_list and `std::forward<Args>(args)...`. - // (The `in_place_t` is a tag used to indicate that the contained object - // should be constructed in-place.) - template <typename U, typename... Args, - typename = typename std::enable_if<std::is_constructible< - T, std::initializer_list<U>&, Args&&...>::value>::type> - constexpr explicit optional(in_place_t, std::initializer_list<U> il, - Args&&... args) - : data_base(in_place_t(), il, absl::forward<Args>(args)...) { - } - - // Value constructor (implicit) - template < - typename U = T, - typename std::enable_if< - absl::conjunction<absl::negation<std::is_same< - in_place_t, typename std::decay<U>::type> >, - absl::negation<std::is_same< - optional<T>, typename std::decay<U>::type> >, - std::is_convertible<U&&, T>, - std::is_constructible<T, U&&> >::value, - bool>::type = false> - constexpr optional(U&& v) : data_base(in_place_t(), absl::forward<U>(v)) {} - - // Value constructor (explicit) - template < - typename U = T, - typename std::enable_if< - absl::conjunction<absl::negation<std::is_same< - in_place_t, typename std::decay<U>::type>>, - absl::negation<std::is_same< - optional<T>, typename std::decay<U>::type>>, - absl::negation<std::is_convertible<U&&, T>>, - std::is_constructible<T, U&&>>::value, - bool>::type = false> - explicit constexpr optional(U&& v) - : data_base(in_place_t(), absl::forward<U>(v)) {} - - // Converting copy constructor (implicit) - template <typename U, - typename std::enable_if< - absl::conjunction< - absl::negation<std::is_same<T, U> >, - std::is_constructible<T, const U&>, - absl::negation< - optional_internal:: - is_constructible_convertible_from_optional<T, U> >, - std::is_convertible<const U&, T> >::value, - bool>::type = false> - optional(const optional<U>& rhs) { - if (rhs) { - this->construct(*rhs); - } - } - - // Converting copy constructor (explicit) - template <typename U, - typename std::enable_if< - absl::conjunction< - absl::negation<std::is_same<T, U>>, - std::is_constructible<T, const U&>, - absl::negation< - optional_internal:: - is_constructible_convertible_from_optional<T, U>>, - absl::negation<std::is_convertible<const U&, T>>>::value, - bool>::type = false> - explicit optional(const optional<U>& rhs) { - if (rhs) { - this->construct(*rhs); - } - } - - // Converting move constructor (implicit) - template <typename U, - typename std::enable_if< - absl::conjunction< - absl::negation<std::is_same<T, U> >, - std::is_constructible<T, U&&>, - absl::negation< - optional_internal:: - is_constructible_convertible_from_optional<T, U> >, - std::is_convertible<U&&, T> >::value, - bool>::type = false> - optional(optional<U>&& rhs) { - if (rhs) { - this->construct(std::move(*rhs)); - } - } - - // Converting move constructor (explicit) - template < - typename U, - typename std::enable_if< - absl::conjunction< - absl::negation<std::is_same<T, U>>, std::is_constructible<T, U&&>, - absl::negation< - optional_internal::is_constructible_convertible_from_optional< - T, U>>, - absl::negation<std::is_convertible<U&&, T>>>::value, - bool>::type = false> - explicit optional(optional<U>&& rhs) { - if (rhs) { - this->construct(std::move(*rhs)); - } - } - - // Destructor. Trivial if `T` is trivially destructible. - ~optional() = default; - - // Assignment Operators - - // Assignment from `nullopt` - // - // Example: - // - // struct S { int value; }; - // optional<S> opt = absl::nullopt; // Could also use opt = { }; - optional& operator=(nullopt_t) noexcept { - this->destruct(); - return *this; - } - - // Copy assignment operator, standard semantics - optional& operator=(const optional& src) = default; - - // Move assignment operator, standard semantics - optional& operator=(optional&& src) = default; - - // Value assignment operators - template < - typename U = T, - typename = typename std::enable_if<absl::conjunction< - absl::negation< - std::is_same<optional<T>, typename std::decay<U>::type>>, - absl::negation< - absl::conjunction<std::is_scalar<T>, - std::is_same<T, typename std::decay<U>::type>>>, - std::is_constructible<T, U>, std::is_assignable<T&, U>>::value>::type> - optional& operator=(U&& v) { - this->assign(std::forward<U>(v)); - return *this; - } - - template < - typename U, - typename = typename std::enable_if<absl::conjunction< - absl::negation<std::is_same<T, U>>, - std::is_constructible<T, const U&>, std::is_assignable<T&, const U&>, - absl::negation< - optional_internal:: - is_constructible_convertible_assignable_from_optional< - T, U>>>::value>::type> - optional& operator=(const optional<U>& rhs) { - if (rhs) { - this->assign(*rhs); - } else { - this->destruct(); - } - return *this; - } - - template <typename U, - typename = typename std::enable_if<absl::conjunction< - absl::negation<std::is_same<T, U>>, std::is_constructible<T, U>, - std::is_assignable<T&, U>, - absl::negation< - optional_internal:: - is_constructible_convertible_assignable_from_optional< - T, U>>>::value>::type> - optional& operator=(optional<U>&& rhs) { - if (rhs) { - this->assign(std::move(*rhs)); - } else { - this->destruct(); - } - return *this; - } - - // Modifiers - - // optional::reset() - // - // Destroys the inner `T` value of an `absl::optional` if one is present. - ABSL_ATTRIBUTE_REINITIALIZES void reset() noexcept { this->destruct(); } - - // optional::emplace() - // - // (Re)constructs the underlying `T` in-place with the given forwarded - // arguments. - // - // Example: - // - // optional<Foo> opt; - // opt.emplace(arg1,arg2,arg3); // Constructs Foo(arg1,arg2,arg3) - // - // If the optional is non-empty, and the `args` refer to subobjects of the - // current object, then behaviour is undefined, because the current object - // will be destructed before the new object is constructed with `args`. - template <typename... Args, - typename = typename std::enable_if< - std::is_constructible<T, Args&&...>::value>::type> - T& emplace(Args&&... args) { - this->destruct(); - this->construct(std::forward<Args>(args)...); - return reference(); - } - - // Emplace reconstruction overload for an initializer list and the given - // forwarded arguments. - // - // Example: - // - // struct Foo { - // Foo(std::initializer_list<int>); - // }; - // - // optional<Foo> opt; - // opt.emplace({1,2,3}); // Constructs Foo({1,2,3}) - template <typename U, typename... Args, - typename = typename std::enable_if<std::is_constructible< - T, std::initializer_list<U>&, Args&&...>::value>::type> - T& emplace(std::initializer_list<U> il, Args&&... args) { - this->destruct(); - this->construct(il, std::forward<Args>(args)...); - return reference(); - } - - // Swaps - - // Swap, standard semantics - void swap(optional& rhs) noexcept( - std::is_nothrow_move_constructible<T>::value&& - type_traits_internal::IsNothrowSwappable<T>::value) { - if (*this) { - if (rhs) { - type_traits_internal::Swap(**this, *rhs); - } else { - rhs.construct(std::move(**this)); - this->destruct(); - } - } else { - if (rhs) { - this->construct(std::move(*rhs)); - rhs.destruct(); - } else { - // No effect (swap(disengaged, disengaged)). - } - } - } - - // Observers - - // optional::operator->() - // - // Accesses the underlying `T` value's member `m` of an `optional`. If the - // `optional` is empty, behavior is undefined. - // - // If you need myOpt->foo in constexpr, use (*myOpt).foo instead. - const T* operator->() const { - ABSL_HARDENING_ASSERT(this->engaged_); - return std::addressof(this->data_); - } - T* operator->() { - ABSL_HARDENING_ASSERT(this->engaged_); - return std::addressof(this->data_); - } - - // optional::operator*() - // - // Accesses the underlying `T` value of an `optional`. If the `optional` is - // empty, behavior is undefined. - constexpr const T& operator*() const& { - return ABSL_HARDENING_ASSERT(this->engaged_), reference(); - } - T& operator*() & { - ABSL_HARDENING_ASSERT(this->engaged_); - return reference(); - } - constexpr const T&& operator*() const && { - return ABSL_HARDENING_ASSERT(this->engaged_), absl::move(reference()); - } - T&& operator*() && { - ABSL_HARDENING_ASSERT(this->engaged_); - return std::move(reference()); - } - - // optional::operator bool() - // - // Returns false if and only if the `optional` is empty. - // - // if (opt) { - // // do something with *opt or opt->; - // } else { - // // opt is empty. - // } - // - constexpr explicit operator bool() const noexcept { return this->engaged_; } - - // optional::has_value() - // - // Determines whether the `optional` contains a value. Returns `false` if and - // only if `*this` is empty. - constexpr bool has_value() const noexcept { return this->engaged_; } - -// Suppress bogus warning on MSVC: MSVC complains call to reference() after -// throw_bad_optional_access() is unreachable. -#ifdef _MSC_VER -#pragma warning(push) -#pragma warning(disable : 4702) -#endif // _MSC_VER - // optional::value() - // - // Returns a reference to an `optional`s underlying value. The constness - // and lvalue/rvalue-ness of the `optional` is preserved to the view of - // the `T` sub-object. Throws `absl::bad_optional_access` when the `optional` - // is empty. - constexpr const T& value() const & { - return static_cast<bool>(*this) - ? reference() - : (optional_internal::throw_bad_optional_access(), reference()); - } - T& value() & { - return static_cast<bool>(*this) - ? reference() - : (optional_internal::throw_bad_optional_access(), reference()); - } - T&& value() && { // NOLINT(build/c++11) - return std::move( - static_cast<bool>(*this) - ? reference() - : (optional_internal::throw_bad_optional_access(), reference())); - } - constexpr const T&& value() const && { // NOLINT(build/c++11) - return absl::move( - static_cast<bool>(*this) - ? reference() - : (optional_internal::throw_bad_optional_access(), reference())); - } -#ifdef _MSC_VER -#pragma warning(pop) -#endif // _MSC_VER - - // optional::value_or() - // - // Returns either the value of `T` or a passed default `v` if the `optional` - // is empty. - template <typename U> - constexpr T value_or(U&& v) const& { - static_assert(std::is_copy_constructible<value_type>::value, - "optional<T>::value_or: T must be copy constructible"); - static_assert(std::is_convertible<U&&, value_type>::value, - "optional<T>::value_or: U must be convertible to T"); - return static_cast<bool>(*this) - ? **this - : static_cast<T>(absl::forward<U>(v)); - } - template <typename U> - T value_or(U&& v) && { // NOLINT(build/c++11) - static_assert(std::is_move_constructible<value_type>::value, - "optional<T>::value_or: T must be move constructible"); - static_assert(std::is_convertible<U&&, value_type>::value, - "optional<T>::value_or: U must be convertible to T"); - return static_cast<bool>(*this) ? std::move(**this) - : static_cast<T>(std::forward<U>(v)); - } - - private: - // Private accessors for internal storage viewed as reference to T. - constexpr const T& reference() const { return this->data_; } - T& reference() { return this->data_; } - - // T constraint checks. You can't have an optional of nullopt_t, in_place_t - // or a reference. - static_assert( - !std::is_same<nullopt_t, typename std::remove_cv<T>::type>::value, - "optional<nullopt_t> is not allowed."); - static_assert( - !std::is_same<in_place_t, typename std::remove_cv<T>::type>::value, - "optional<in_place_t> is not allowed."); - static_assert(!std::is_reference<T>::value, - "optional<reference> is not allowed."); -}; - -// Non-member functions - -// swap() -// -// Performs a swap between two `absl::optional` objects, using standard -// semantics. -template <typename T, typename std::enable_if< - std::is_move_constructible<T>::value && - type_traits_internal::IsSwappable<T>::value, - bool>::type = false> -void swap(optional<T>& a, optional<T>& b) noexcept(noexcept(a.swap(b))) { - a.swap(b); -} - -// make_optional() -// -// Creates a non-empty `optional<T>` where the type of `T` is deduced. An -// `absl::optional` can also be explicitly instantiated with -// `make_optional<T>(v)`. -// -// Note: `make_optional()` constructions may be declared `constexpr` for -// trivially copyable types `T`. Non-trivial types require copy elision -// support in C++17 for `make_optional` to support `constexpr` on such -// non-trivial types. -// -// Example: -// -// constexpr absl::optional<int> opt = absl::make_optional(1); -// static_assert(opt.value() == 1, ""); -template <typename T> -constexpr optional<typename std::decay<T>::type> make_optional(T&& v) { - return optional<typename std::decay<T>::type>(absl::forward<T>(v)); -} - -template <typename T, typename... Args> -constexpr optional<T> make_optional(Args&&... args) { - return optional<T>(in_place_t(), absl::forward<Args>(args)...); -} - -template <typename T, typename U, typename... Args> -constexpr optional<T> make_optional(std::initializer_list<U> il, - Args&&... args) { - return optional<T>(in_place_t(), il, - absl::forward<Args>(args)...); -} - -// Relational operators [optional.relops] - -// Empty optionals are considered equal to each other and less than non-empty -// optionals. Supports relations between optional<T> and optional<U>, between -// optional<T> and U, and between optional<T> and nullopt. -// -// Note: We're careful to support T having non-bool relationals. - -// Requires: The expression, e.g. "*x == *y" shall be well-formed and its result -// shall be convertible to bool. -// The C++17 (N4606) "Returns:" statements are translated into -// code in an obvious way here, and the original text retained as function docs. -// Returns: If bool(x) != bool(y), false; otherwise if bool(x) == false, true; -// otherwise *x == *y. -template <typename T, typename U> -constexpr auto operator==(const optional<T>& x, const optional<U>& y) - -> decltype(optional_internal::convertible_to_bool(*x == *y)) { - return static_cast<bool>(x) != static_cast<bool>(y) - ? false - : static_cast<bool>(x) == false ? true - : static_cast<bool>(*x == *y); -} - -// Returns: If bool(x) != bool(y), true; otherwise, if bool(x) == false, false; -// otherwise *x != *y. -template <typename T, typename U> -constexpr auto operator!=(const optional<T>& x, const optional<U>& y) - -> decltype(optional_internal::convertible_to_bool(*x != *y)) { - return static_cast<bool>(x) != static_cast<bool>(y) - ? true - : static_cast<bool>(x) == false ? false - : static_cast<bool>(*x != *y); -} -// Returns: If !y, false; otherwise, if !x, true; otherwise *x < *y. -template <typename T, typename U> -constexpr auto operator<(const optional<T>& x, const optional<U>& y) - -> decltype(optional_internal::convertible_to_bool(*x < *y)) { - return !y ? false : !x ? true : static_cast<bool>(*x < *y); -} -// Returns: If !x, false; otherwise, if !y, true; otherwise *x > *y. -template <typename T, typename U> -constexpr auto operator>(const optional<T>& x, const optional<U>& y) - -> decltype(optional_internal::convertible_to_bool(*x > *y)) { - return !x ? false : !y ? true : static_cast<bool>(*x > *y); -} -// Returns: If !x, true; otherwise, if !y, false; otherwise *x <= *y. -template <typename T, typename U> -constexpr auto operator<=(const optional<T>& x, const optional<U>& y) - -> decltype(optional_internal::convertible_to_bool(*x <= *y)) { - return !x ? true : !y ? false : static_cast<bool>(*x <= *y); -} -// Returns: If !y, true; otherwise, if !x, false; otherwise *x >= *y. -template <typename T, typename U> -constexpr auto operator>=(const optional<T>& x, const optional<U>& y) - -> decltype(optional_internal::convertible_to_bool(*x >= *y)) { - return !y ? true : !x ? false : static_cast<bool>(*x >= *y); -} - -// Comparison with nullopt [optional.nullops] -// The C++17 (N4606) "Returns:" statements are used directly here. -template <typename T> -constexpr bool operator==(const optional<T>& x, nullopt_t) noexcept { - return !x; -} -template <typename T> -constexpr bool operator==(nullopt_t, const optional<T>& x) noexcept { - return !x; -} -template <typename T> -constexpr bool operator!=(const optional<T>& x, nullopt_t) noexcept { - return static_cast<bool>(x); -} -template <typename T> -constexpr bool operator!=(nullopt_t, const optional<T>& x) noexcept { - return static_cast<bool>(x); -} -template <typename T> -constexpr bool operator<(const optional<T>&, nullopt_t) noexcept { - return false; -} -template <typename T> -constexpr bool operator<(nullopt_t, const optional<T>& x) noexcept { - return static_cast<bool>(x); -} -template <typename T> -constexpr bool operator<=(const optional<T>& x, nullopt_t) noexcept { - return !x; -} -template <typename T> -constexpr bool operator<=(nullopt_t, const optional<T>&) noexcept { - return true; -} -template <typename T> -constexpr bool operator>(const optional<T>& x, nullopt_t) noexcept { - return static_cast<bool>(x); -} -template <typename T> -constexpr bool operator>(nullopt_t, const optional<T>&) noexcept { - return false; -} -template <typename T> -constexpr bool operator>=(const optional<T>&, nullopt_t) noexcept { - return true; -} -template <typename T> -constexpr bool operator>=(nullopt_t, const optional<T>& x) noexcept { - return !x; -} - -// Comparison with T [optional.comp_with_t] - -// Requires: The expression, e.g. "*x == v" shall be well-formed and its result -// shall be convertible to bool. -// The C++17 (N4606) "Equivalent to:" statements are used directly here. -template <typename T, typename U> -constexpr auto operator==(const optional<T>& x, const U& v) - -> decltype(optional_internal::convertible_to_bool(*x == v)) { - return static_cast<bool>(x) ? static_cast<bool>(*x == v) : false; -} -template <typename T, typename U> -constexpr auto operator==(const U& v, const optional<T>& x) - -> decltype(optional_internal::convertible_to_bool(v == *x)) { - return static_cast<bool>(x) ? static_cast<bool>(v == *x) : false; -} -template <typename T, typename U> -constexpr auto operator!=(const optional<T>& x, const U& v) - -> decltype(optional_internal::convertible_to_bool(*x != v)) { - return static_cast<bool>(x) ? static_cast<bool>(*x != v) : true; -} -template <typename T, typename U> -constexpr auto operator!=(const U& v, const optional<T>& x) - -> decltype(optional_internal::convertible_to_bool(v != *x)) { - return static_cast<bool>(x) ? static_cast<bool>(v != *x) : true; -} -template <typename T, typename U> -constexpr auto operator<(const optional<T>& x, const U& v) - -> decltype(optional_internal::convertible_to_bool(*x < v)) { - return static_cast<bool>(x) ? static_cast<bool>(*x < v) : true; -} -template <typename T, typename U> -constexpr auto operator<(const U& v, const optional<T>& x) - -> decltype(optional_internal::convertible_to_bool(v < *x)) { - return static_cast<bool>(x) ? static_cast<bool>(v < *x) : false; -} -template <typename T, typename U> -constexpr auto operator<=(const optional<T>& x, const U& v) - -> decltype(optional_internal::convertible_to_bool(*x <= v)) { - return static_cast<bool>(x) ? static_cast<bool>(*x <= v) : true; -} -template <typename T, typename U> -constexpr auto operator<=(const U& v, const optional<T>& x) - -> decltype(optional_internal::convertible_to_bool(v <= *x)) { - return static_cast<bool>(x) ? static_cast<bool>(v <= *x) : false; -} -template <typename T, typename U> -constexpr auto operator>(const optional<T>& x, const U& v) - -> decltype(optional_internal::convertible_to_bool(*x > v)) { - return static_cast<bool>(x) ? static_cast<bool>(*x > v) : false; -} -template <typename T, typename U> -constexpr auto operator>(const U& v, const optional<T>& x) - -> decltype(optional_internal::convertible_to_bool(v > *x)) { - return static_cast<bool>(x) ? static_cast<bool>(v > *x) : true; -} -template <typename T, typename U> -constexpr auto operator>=(const optional<T>& x, const U& v) - -> decltype(optional_internal::convertible_to_bool(*x >= v)) { - return static_cast<bool>(x) ? static_cast<bool>(*x >= v) : false; -} -template <typename T, typename U> -constexpr auto operator>=(const U& v, const optional<T>& x) - -> decltype(optional_internal::convertible_to_bool(v >= *x)) { - return static_cast<bool>(x) ? static_cast<bool>(v >= *x) : true; -} - -ABSL_NAMESPACE_END -} // namespace absl - -namespace std { - -// std::hash specialization for absl::optional. -template <typename T> -struct hash<absl::optional<T> > - : absl::optional_internal::optional_hash_base<T> {}; - -} // namespace std - -#undef ABSL_MSVC_CONSTEXPR_BUG_IN_UNION_LIKE_CLASS - -#endif // ABSL_USES_STD_OPTIONAL - -#endif // ABSL_TYPES_OPTIONAL_H_ |