|  | // -*- C++ -*- | 
|  | //===-------------------------- optional ----------------------------------===// | 
|  | // | 
|  | //                     The LLVM Compiler Infrastructure | 
|  | // | 
|  | // This file is dual licensed under the MIT and the University of Illinois Open | 
|  | // Source Licenses. See LICENSE.TXT for details. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #ifndef _LIBCPP_EXPERIMENTAL_OPTIONAL | 
|  | #define _LIBCPP_EXPERIMENTAL_OPTIONAL | 
|  |  | 
|  | /* | 
|  | optional synopsis | 
|  |  | 
|  | // C++1y | 
|  |  | 
|  | namespace std { namespace experimental { inline namespace fundamentals_v1 { | 
|  |  | 
|  | // 5.3, optional for object types | 
|  | template <class T> class optional; | 
|  |  | 
|  | // 5.4, In-place construction | 
|  | struct in_place_t{}; | 
|  | constexpr in_place_t in_place{}; | 
|  |  | 
|  | // 5.5, No-value state indicator | 
|  | struct nullopt_t{see below}; | 
|  | constexpr nullopt_t nullopt(unspecified); | 
|  |  | 
|  | // 5.6, Class bad_optional_access | 
|  | class bad_optional_access; | 
|  |  | 
|  | // 5.7, Relational operators | 
|  | template <class T> | 
|  | constexpr bool operator==(const optional<T>&, const optional<T>&); | 
|  | template <class T> | 
|  | constexpr bool operator!=(const optional<T>&, const optional<T>&); | 
|  | template <class T> | 
|  | constexpr bool operator<(const optional<T>&, const optional<T>&); | 
|  | template <class T> | 
|  | constexpr bool operator>(const optional<T>&, const optional<T>&); | 
|  | template <class T> | 
|  | constexpr bool operator<=(const optional<T>&, const optional<T>&); | 
|  | template <class T> | 
|  | constexpr bool operator>=(const optional<T>&, const optional<T>&); | 
|  |  | 
|  | // 5.8, Comparison with nullopt | 
|  | template <class T> constexpr bool operator==(const optional<T>&, nullopt_t) noexcept; | 
|  | template <class T> constexpr bool operator==(nullopt_t, const optional<T>&) noexcept; | 
|  | template <class T> constexpr bool operator!=(const optional<T>&, nullopt_t) noexcept; | 
|  | template <class T> constexpr bool operator!=(nullopt_t, const optional<T>&) noexcept; | 
|  | template <class T> constexpr bool operator<(const optional<T>&, nullopt_t) noexcept; | 
|  | template <class T> constexpr bool operator<(nullopt_t, const optional<T>&) noexcept; | 
|  | template <class T> constexpr bool operator<=(const optional<T>&, nullopt_t) noexcept; | 
|  | template <class T> constexpr bool operator<=(nullopt_t, const optional<T>&) noexcept; | 
|  | template <class T> constexpr bool operator>(const optional<T>&, nullopt_t) noexcept; | 
|  | template <class T> constexpr bool operator>(nullopt_t, const optional<T>&) noexcept; | 
|  | template <class T> constexpr bool operator>=(const optional<T>&, nullopt_t) noexcept; | 
|  | template <class T> constexpr bool operator>=(nullopt_t, const optional<T>&) noexcept; | 
|  |  | 
|  | // 5.9, Comparison with T | 
|  | template <class T> constexpr bool operator==(const optional<T>&, const T&); | 
|  | template <class T> constexpr bool operator==(const T&, const optional<T>&); | 
|  | template <class T> constexpr bool operator!=(const optional<T>&, const T&); | 
|  | template <class T> constexpr bool operator!=(const T&, const optional<T>&); | 
|  | template <class T> constexpr bool operator<(const optional<T>&, const T&); | 
|  | template <class T> constexpr bool operator<(const T&, const optional<T>&); | 
|  | template <class T> constexpr bool operator<=(const optional<T>&, const T&); | 
|  | template <class T> constexpr bool operator<=(const T&, const optional<T>&); | 
|  | template <class T> constexpr bool operator>(const optional<T>&, const T&); | 
|  | template <class T> constexpr bool operator>(const T&, const optional<T>&); | 
|  | template <class T> constexpr bool operator>=(const optional<T>&, const T&); | 
|  | template <class T> constexpr bool operator>=(const T&, const optional<T>&); | 
|  |  | 
|  | // 5.10, Specialized algorithms | 
|  | template <class T> void swap(optional<T>&, optional<T>&) noexcept(see below); | 
|  | template <class T> constexpr optional<see below> make_optional(T&&); | 
|  |  | 
|  | template <class T> | 
|  | class optional | 
|  | { | 
|  | public: | 
|  | typedef T value_type; | 
|  |  | 
|  | // 5.3.1, Constructors | 
|  | constexpr optional() noexcept; | 
|  | constexpr optional(nullopt_t) noexcept; | 
|  | optional(const optional&); | 
|  | optional(optional&&) noexcept(see below); | 
|  | constexpr optional(const T&); | 
|  | constexpr optional(T&&); | 
|  | template <class... Args> constexpr explicit optional(in_place_t, Args&&...); | 
|  | template <class U, class... Args> | 
|  | constexpr explicit optional(in_place_t, initializer_list<U>, Args&&...); | 
|  |  | 
|  | // 5.3.2, Destructor | 
|  | ~optional(); | 
|  |  | 
|  | // 5.3.3, Assignment | 
|  | optional& operator=(nullopt_t) noexcept; | 
|  | optional& operator=(const optional&); | 
|  | optional& operator=(optional&&) noexcept(see below); | 
|  | template <class U> optional& operator=(U&&); | 
|  | template <class... Args> void emplace(Args&&...); | 
|  | template <class U, class... Args> | 
|  | void emplace(initializer_list<U>, Args&&...); | 
|  |  | 
|  | // 5.3.4, Swap | 
|  | void swap(optional&) noexcept(see below); | 
|  |  | 
|  | // 5.3.5, Observers | 
|  | constexpr T const* operator ->() const; | 
|  | constexpr T* operator ->(); | 
|  | constexpr T const& operator *() const &; | 
|  | constexpr T& operator *() &; | 
|  | constexpr T&& operator *() &&; | 
|  | constexpr const T&& operator *() const &&; | 
|  | constexpr explicit operator bool() const noexcept; | 
|  | constexpr T const& value() const &; | 
|  | constexpr T& value() &; | 
|  | constexpr T&& value() &&; | 
|  | constexpr const T&& value() const &&; | 
|  | template <class U> constexpr T value_or(U&&) const &; | 
|  | template <class U> constexpr T value_or(U&&) &&; | 
|  |  | 
|  | private: | 
|  | T*   val;  // exposition only | 
|  | }; | 
|  |  | 
|  | } // namespace fundamentals_v1 | 
|  | } // namespace experimental | 
|  |  | 
|  | // 5.11, Hash support | 
|  | template <class T> struct hash; | 
|  | template <class T> struct hash<experimental::optional<T>>; | 
|  |  | 
|  | } // namespace std | 
|  |  | 
|  | */ | 
|  |  | 
|  | #include <experimental/__config> | 
|  | #include <functional> | 
|  | #include <stdexcept> | 
|  |  | 
|  | _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL | 
|  | class _LIBCPP_EXCEPTION_ABI bad_optional_access | 
|  | : public std::logic_error | 
|  | { | 
|  | public: | 
|  | bad_optional_access() : std::logic_error("Bad optional Access") {} | 
|  |  | 
|  | //	Get the key function ~bad_optional_access() into the dylib | 
|  | virtual ~bad_optional_access() _NOEXCEPT; | 
|  | }; | 
|  |  | 
|  | _LIBCPP_END_NAMESPACE_EXPERIMENTAL | 
|  |  | 
|  |  | 
|  | #if _LIBCPP_STD_VER > 11 | 
|  |  | 
|  | #include <initializer_list> | 
|  | #include <type_traits> | 
|  | #include <new> | 
|  | #include <__functional_base> | 
|  | #include <__undef_min_max> | 
|  | #include <__debug> | 
|  |  | 
|  | #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) | 
|  | #pragma GCC system_header | 
|  | #endif | 
|  |  | 
|  | _LIBCPP_BEGIN_NAMESPACE_LFTS | 
|  |  | 
|  | struct in_place_t {}; | 
|  | constexpr in_place_t in_place{}; | 
|  |  | 
|  | struct nullopt_t | 
|  | { | 
|  | explicit constexpr nullopt_t(int) noexcept {} | 
|  | }; | 
|  |  | 
|  | constexpr nullopt_t nullopt{0}; | 
|  |  | 
|  | template <class _Tp, bool = is_trivially_destructible<_Tp>::value> | 
|  | class __optional_storage | 
|  | { | 
|  | protected: | 
|  | typedef _Tp value_type; | 
|  | union | 
|  | { | 
|  | char __null_state_; | 
|  | value_type __val_; | 
|  | }; | 
|  | bool __engaged_ = false; | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | ~__optional_storage() | 
|  | { | 
|  | if (__engaged_) | 
|  | __val_.~value_type(); | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr __optional_storage() noexcept | 
|  | :  __null_state_('\0') {} | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | __optional_storage(const __optional_storage& __x) | 
|  | :  __engaged_(__x.__engaged_) | 
|  | { | 
|  | if (__engaged_) | 
|  | ::new((void*)_VSTD::addressof(__val_)) value_type(__x.__val_); | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | __optional_storage(__optional_storage&& __x) | 
|  | noexcept(is_nothrow_move_constructible<value_type>::value) | 
|  | :  __engaged_(__x.__engaged_) | 
|  | { | 
|  | if (__engaged_) | 
|  | ::new((void*)_VSTD::addressof(__val_)) value_type(_VSTD::move(__x.__val_)); | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr __optional_storage(const value_type& __v) | 
|  | :  __val_(__v), | 
|  | __engaged_(true) {} | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr __optional_storage(value_type&& __v) | 
|  | :  __val_(_VSTD::move(__v)), | 
|  | __engaged_(true) {} | 
|  |  | 
|  | template <class... _Args> | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | explicit __optional_storage(in_place_t, _Args&&... __args) | 
|  | :  __val_(_VSTD::forward<_Args>(__args)...), | 
|  | __engaged_(true) {} | 
|  | }; | 
|  |  | 
|  | template <class _Tp> | 
|  | class __optional_storage<_Tp, true> | 
|  | { | 
|  | protected: | 
|  | typedef _Tp value_type; | 
|  | union | 
|  | { | 
|  | char __null_state_; | 
|  | value_type __val_; | 
|  | }; | 
|  | bool __engaged_ = false; | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr __optional_storage() noexcept | 
|  | :  __null_state_('\0') {} | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | __optional_storage(const __optional_storage& __x) | 
|  | :  __engaged_(__x.__engaged_) | 
|  | { | 
|  | if (__engaged_) | 
|  | ::new((void*)_VSTD::addressof(__val_)) value_type(__x.__val_); | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | __optional_storage(__optional_storage&& __x) | 
|  | noexcept(is_nothrow_move_constructible<value_type>::value) | 
|  | :  __engaged_(__x.__engaged_) | 
|  | { | 
|  | if (__engaged_) | 
|  | ::new((void*)_VSTD::addressof(__val_)) value_type(_VSTD::move(__x.__val_)); | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr __optional_storage(const value_type& __v) | 
|  | :  __val_(__v), | 
|  | __engaged_(true) {} | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr __optional_storage(value_type&& __v) | 
|  | :  __val_(_VSTD::move(__v)), | 
|  | __engaged_(true) {} | 
|  |  | 
|  | template <class... _Args> | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | explicit __optional_storage(in_place_t, _Args&&... __args) | 
|  | :  __val_(_VSTD::forward<_Args>(__args)...), | 
|  | __engaged_(true) {} | 
|  | }; | 
|  |  | 
|  | template <class _Tp> | 
|  | class optional | 
|  | : private __optional_storage<_Tp> | 
|  | { | 
|  | typedef __optional_storage<_Tp> __base; | 
|  | public: | 
|  | typedef _Tp value_type; | 
|  |  | 
|  | static_assert(!is_reference<value_type>::value, | 
|  | "Instantiation of optional with a reference type is ill-formed."); | 
|  | static_assert(!is_same<typename remove_cv<value_type>::type, in_place_t>::value, | 
|  | "Instantiation of optional with a in_place_t type is ill-formed."); | 
|  | static_assert(!is_same<typename remove_cv<value_type>::type, nullopt_t>::value, | 
|  | "Instantiation of optional with a nullopt_t type is ill-formed."); | 
|  | static_assert(is_object<value_type>::value, | 
|  | "Instantiation of optional with a non-object type is undefined behavior."); | 
|  | static_assert(is_nothrow_destructible<value_type>::value, | 
|  | "Instantiation of optional with an object type that is not noexcept destructible is undefined behavior."); | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY constexpr optional() noexcept {} | 
|  | _LIBCPP_INLINE_VISIBILITY optional(const optional&) = default; | 
|  | _LIBCPP_INLINE_VISIBILITY optional(optional&&) = default; | 
|  | _LIBCPP_INLINE_VISIBILITY ~optional() = default; | 
|  | _LIBCPP_INLINE_VISIBILITY constexpr optional(nullopt_t) noexcept {} | 
|  | _LIBCPP_INLINE_VISIBILITY constexpr optional(const value_type& __v) | 
|  | : __base(__v) {} | 
|  | _LIBCPP_INLINE_VISIBILITY constexpr optional(value_type&& __v) | 
|  | : __base(_VSTD::move(__v)) {} | 
|  |  | 
|  | template <class... _Args, | 
|  | class = typename enable_if | 
|  | < | 
|  | is_constructible<value_type, _Args...>::value | 
|  | >::type | 
|  | > | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | explicit optional(in_place_t, _Args&&... __args) | 
|  | : __base(in_place, _VSTD::forward<_Args>(__args)...) {} | 
|  |  | 
|  | template <class _Up, class... _Args, | 
|  | class = typename enable_if | 
|  | < | 
|  | is_constructible<value_type, initializer_list<_Up>&, _Args...>::value | 
|  | >::type | 
|  | > | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | explicit optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args) | 
|  | : __base(in_place, __il, _VSTD::forward<_Args>(__args)...) {} | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | optional& operator=(nullopt_t) noexcept | 
|  | { | 
|  | if (this->__engaged_) | 
|  | { | 
|  | this->__val_.~value_type(); | 
|  | this->__engaged_ = false; | 
|  | } | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | optional& | 
|  | operator=(const optional& __opt) | 
|  | { | 
|  | if (this->__engaged_ == __opt.__engaged_) | 
|  | { | 
|  | if (this->__engaged_) | 
|  | this->__val_ = __opt.__val_; | 
|  | } | 
|  | else | 
|  | { | 
|  | if (this->__engaged_) | 
|  | this->__val_.~value_type(); | 
|  | else | 
|  | ::new((void*)_VSTD::addressof(this->__val_)) value_type(__opt.__val_); | 
|  | this->__engaged_ = __opt.__engaged_; | 
|  | } | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | optional& | 
|  | operator=(optional&& __opt) | 
|  | noexcept(is_nothrow_move_assignable<value_type>::value && | 
|  | is_nothrow_move_constructible<value_type>::value) | 
|  | { | 
|  | if (this->__engaged_ == __opt.__engaged_) | 
|  | { | 
|  | if (this->__engaged_) | 
|  | this->__val_ = _VSTD::move(__opt.__val_); | 
|  | } | 
|  | else | 
|  | { | 
|  | if (this->__engaged_) | 
|  | this->__val_.~value_type(); | 
|  | else | 
|  | ::new((void*)_VSTD::addressof(this->__val_)) | 
|  | value_type(_VSTD::move(__opt.__val_)); | 
|  | this->__engaged_ = __opt.__engaged_; | 
|  | } | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | template <class _Up, | 
|  | class = typename enable_if | 
|  | < | 
|  | is_same<typename remove_reference<_Up>::type, value_type>::value && | 
|  | is_constructible<value_type, _Up>::value && | 
|  | is_assignable<value_type&, _Up>::value | 
|  | >::type | 
|  | > | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | optional& | 
|  | operator=(_Up&& __v) | 
|  | { | 
|  | if (this->__engaged_) | 
|  | this->__val_ = _VSTD::forward<_Up>(__v); | 
|  | else | 
|  | { | 
|  | ::new((void*)_VSTD::addressof(this->__val_)) value_type(_VSTD::forward<_Up>(__v)); | 
|  | this->__engaged_ = true; | 
|  | } | 
|  | return *this; | 
|  | } | 
|  |  | 
|  | template <class... _Args, | 
|  | class = typename enable_if | 
|  | < | 
|  | is_constructible<value_type, _Args...>::value | 
|  | >::type | 
|  | > | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | void | 
|  | emplace(_Args&&... __args) | 
|  | { | 
|  | *this = nullopt; | 
|  | ::new((void*)_VSTD::addressof(this->__val_)) | 
|  | value_type(_VSTD::forward<_Args>(__args)...); | 
|  | this->__engaged_ = true; | 
|  | } | 
|  |  | 
|  | template <class _Up, class... _Args, | 
|  | class = typename enable_if | 
|  | < | 
|  | is_constructible<value_type, initializer_list<_Up>&, _Args...>::value | 
|  | >::type | 
|  | > | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | void | 
|  | emplace(initializer_list<_Up> __il, _Args&&... __args) | 
|  | { | 
|  | *this = nullopt; | 
|  | ::new((void*)_VSTD::addressof(this->__val_)) | 
|  | value_type(__il, _VSTD::forward<_Args>(__args)...); | 
|  | this->__engaged_ = true; | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | void | 
|  | swap(optional& __opt) | 
|  | noexcept(is_nothrow_move_constructible<value_type>::value && | 
|  | __is_nothrow_swappable<value_type>::value) | 
|  | { | 
|  | using _VSTD::swap; | 
|  | if (this->__engaged_ == __opt.__engaged_) | 
|  | { | 
|  | if (this->__engaged_) | 
|  | swap(this->__val_, __opt.__val_); | 
|  | } | 
|  | else | 
|  | { | 
|  | if (this->__engaged_) | 
|  | { | 
|  | ::new((void*)_VSTD::addressof(__opt.__val_)) | 
|  | value_type(_VSTD::move(this->__val_)); | 
|  | this->__val_.~value_type(); | 
|  | } | 
|  | else | 
|  | { | 
|  | ::new((void*)_VSTD::addressof(this->__val_)) | 
|  | value_type(_VSTD::move(__opt.__val_)); | 
|  | __opt.__val_.~value_type(); | 
|  | } | 
|  | swap(this->__engaged_, __opt.__engaged_); | 
|  | } | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | value_type const* | 
|  | operator->() const | 
|  | { | 
|  | _LIBCPP_ASSERT(this->__engaged_, "optional operator-> called for disengaged value"); | 
|  | return __operator_arrow(__has_operator_addressof<value_type>{}); | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | value_type* | 
|  | operator->() | 
|  | { | 
|  | _LIBCPP_ASSERT(this->__engaged_, "optional operator-> called for disengaged value"); | 
|  | return _VSTD::addressof(this->__val_); | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | const value_type& | 
|  | operator*() const | 
|  | { | 
|  | _LIBCPP_ASSERT(this->__engaged_, "optional operator* called for disengaged value"); | 
|  | return this->__val_; | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | value_type& | 
|  | operator*() | 
|  | { | 
|  | _LIBCPP_ASSERT(this->__engaged_, "optional operator* called for disengaged value"); | 
|  | return this->__val_; | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr explicit operator bool() const noexcept {return this->__engaged_;} | 
|  |  | 
|  | _LIBCPP_NORETURN _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr void __throw_bad_optional_access() const | 
|  | { | 
|  | #ifndef _LIBCPP_NO_EXCEPTIONS | 
|  | throw bad_optional_access(); | 
|  | #else | 
|  | _VSTD::abort(); | 
|  | #endif | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr value_type const& value() const | 
|  | { | 
|  | if (!this->__engaged_) | 
|  | __throw_bad_optional_access(); | 
|  | return this->__val_; | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | value_type& value() | 
|  | { | 
|  | if (!this->__engaged_) | 
|  | __throw_bad_optional_access(); | 
|  | return this->__val_; | 
|  | } | 
|  |  | 
|  | template <class _Up> | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr value_type value_or(_Up&& __v) const& | 
|  | { | 
|  | static_assert(is_copy_constructible<value_type>::value, | 
|  | "optional<T>::value_or: T must be copy constructible"); | 
|  | static_assert(is_convertible<_Up, value_type>::value, | 
|  | "optional<T>::value_or: U must be convertible to T"); | 
|  | return this->__engaged_ ? this->__val_ : | 
|  | static_cast<value_type>(_VSTD::forward<_Up>(__v)); | 
|  | } | 
|  |  | 
|  | template <class _Up> | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | value_type value_or(_Up&& __v) && | 
|  | { | 
|  | static_assert(is_move_constructible<value_type>::value, | 
|  | "optional<T>::value_or: T must be move constructible"); | 
|  | static_assert(is_convertible<_Up, value_type>::value, | 
|  | "optional<T>::value_or: U must be convertible to T"); | 
|  | return this->__engaged_ ? _VSTD::move(this->__val_) : | 
|  | static_cast<value_type>(_VSTD::forward<_Up>(__v)); | 
|  | } | 
|  |  | 
|  | private: | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | value_type const* | 
|  | __operator_arrow(true_type) const | 
|  | { | 
|  | return _VSTD::addressof(this->__val_); | 
|  | } | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | value_type const* | 
|  | __operator_arrow(false_type) const | 
|  | { | 
|  | return &this->__val_; | 
|  | } | 
|  | }; | 
|  |  | 
|  | // Comparisons between optionals | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator==(const optional<_Tp>& __x, const optional<_Tp>& __y) | 
|  | { | 
|  | if (static_cast<bool>(__x) != static_cast<bool>(__y)) | 
|  | return false; | 
|  | if (!static_cast<bool>(__x)) | 
|  | return true; | 
|  | return *__x == *__y; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator!=(const optional<_Tp>& __x, const optional<_Tp>& __y) | 
|  | { | 
|  | return !(__x == __y); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator<(const optional<_Tp>& __x, const optional<_Tp>& __y) | 
|  | { | 
|  | if (!static_cast<bool>(__y)) | 
|  | return false; | 
|  | if (!static_cast<bool>(__x)) | 
|  | return true; | 
|  | return *__x < *__y; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator>(const optional<_Tp>& __x, const optional<_Tp>& __y) | 
|  | { | 
|  | return __y < __x; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator<=(const optional<_Tp>& __x, const optional<_Tp>& __y) | 
|  | { | 
|  | return !(__y < __x); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator>=(const optional<_Tp>& __x, const optional<_Tp>& __y) | 
|  | { | 
|  | return !(__x < __y); | 
|  | } | 
|  |  | 
|  |  | 
|  | // Comparisons with nullopt | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator==(const optional<_Tp>& __x, nullopt_t) noexcept | 
|  | { | 
|  | return !static_cast<bool>(__x); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator==(nullopt_t, const optional<_Tp>& __x) noexcept | 
|  | { | 
|  | return !static_cast<bool>(__x); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator!=(const optional<_Tp>& __x, nullopt_t) noexcept | 
|  | { | 
|  | return static_cast<bool>(__x); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator!=(nullopt_t, const optional<_Tp>& __x) noexcept | 
|  | { | 
|  | return static_cast<bool>(__x); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator<(const optional<_Tp>&, nullopt_t) noexcept | 
|  | { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator<(nullopt_t, const optional<_Tp>& __x) noexcept | 
|  | { | 
|  | return static_cast<bool>(__x); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator<=(const optional<_Tp>& __x, nullopt_t) noexcept | 
|  | { | 
|  | return !static_cast<bool>(__x); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator<=(nullopt_t, const optional<_Tp>& __x) noexcept | 
|  | { | 
|  | return true; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator>(const optional<_Tp>& __x, nullopt_t) noexcept | 
|  | { | 
|  | return static_cast<bool>(__x); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator>(nullopt_t, const optional<_Tp>& __x) noexcept | 
|  | { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator>=(const optional<_Tp>&, nullopt_t) noexcept | 
|  | { | 
|  | return true; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator>=(nullopt_t, const optional<_Tp>& __x) noexcept | 
|  | { | 
|  | return !static_cast<bool>(__x); | 
|  | } | 
|  |  | 
|  | // Comparisons with T | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator==(const optional<_Tp>& __x, const _Tp& __v) | 
|  | { | 
|  | return static_cast<bool>(__x) ? *__x == __v : false; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator==(const _Tp& __v, const optional<_Tp>& __x) | 
|  | { | 
|  | return static_cast<bool>(__x) ? *__x == __v : false; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator!=(const optional<_Tp>& __x, const _Tp& __v) | 
|  | { | 
|  | return static_cast<bool>(__x) ? !(*__x == __v) : true; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator!=(const _Tp& __v, const optional<_Tp>& __x) | 
|  | { | 
|  | return static_cast<bool>(__x) ? !(*__x == __v) : true; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator<(const optional<_Tp>& __x, const _Tp& __v) | 
|  | { | 
|  | return static_cast<bool>(__x) ? less<_Tp>{}(*__x, __v) : true; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator<(const _Tp& __v, const optional<_Tp>& __x) | 
|  | { | 
|  | return static_cast<bool>(__x) ? less<_Tp>{}(__v, *__x) : false; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator<=(const optional<_Tp>& __x, const _Tp& __v) | 
|  | { | 
|  | return !(__x > __v); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator<=(const _Tp& __v, const optional<_Tp>& __x) | 
|  | { | 
|  | return !(__v > __x); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator>(const optional<_Tp>& __x, const _Tp& __v) | 
|  | { | 
|  | return static_cast<bool>(__x) ? __v < __x : false; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator>(const _Tp& __v, const optional<_Tp>& __x) | 
|  | { | 
|  | return static_cast<bool>(__x) ? __x < __v : true; | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator>=(const optional<_Tp>& __x, const _Tp& __v) | 
|  | { | 
|  | return !(__x < __v); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | bool | 
|  | operator>=(const _Tp& __v, const optional<_Tp>& __x) | 
|  | { | 
|  | return !(__v < __x); | 
|  | } | 
|  |  | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | void | 
|  | swap(optional<_Tp>& __x, optional<_Tp>& __y) noexcept(noexcept(__x.swap(__y))) | 
|  | { | 
|  | __x.swap(__y); | 
|  | } | 
|  |  | 
|  | template <class _Tp> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | constexpr | 
|  | optional<typename decay<_Tp>::type> | 
|  | make_optional(_Tp&& __v) | 
|  | { | 
|  | return optional<typename decay<_Tp>::type>(_VSTD::forward<_Tp>(__v)); | 
|  | } | 
|  |  | 
|  | _LIBCPP_END_NAMESPACE_LFTS | 
|  |  | 
|  | _LIBCPP_BEGIN_NAMESPACE_STD | 
|  |  | 
|  | template <class _Tp> | 
|  | struct _LIBCPP_TYPE_VIS_ONLY hash<std::experimental::optional<_Tp> > | 
|  | { | 
|  | typedef std::experimental::optional<_Tp> argument_type; | 
|  | typedef size_t        result_type; | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | result_type operator()(const argument_type& __opt) const _NOEXCEPT | 
|  | { | 
|  | return static_cast<bool>(__opt) ? hash<_Tp>()(*__opt) : 0; | 
|  | } | 
|  | }; | 
|  |  | 
|  | _LIBCPP_END_NAMESPACE_STD | 
|  |  | 
|  | #endif  // _LIBCPP_STD_VER > 11 | 
|  |  | 
|  | #endif  // _LIBCPP_EXPERIMENTAL_OPTIONAL |