| // -*- C++ -*- | |
| //===------------------------------ variant -------------------------------===// | |
| // | |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |
| // See https://llvm.org/LICENSE.txt for license information. | |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |
| // | |
| //===----------------------------------------------------------------------===// | |
| #ifndef _LIBCPP_VARIANT | |
| #define _LIBCPP_VARIANT | |
| /* | |
| variant synopsis | |
| namespace std { | |
| // 20.7.2, class template variant | |
| template <class... Types> | |
| class variant { | |
| public: | |
| // 20.7.2.1, constructors | |
| constexpr variant() noexcept(see below); | |
| variant(const variant&); // constexpr in C++20 | |
| variant(variant&&) noexcept(see below); // constexpr in C++20 | |
| template <class T> constexpr variant(T&&) noexcept(see below); | |
| template <class T, class... Args> | |
| constexpr explicit variant(in_place_type_t<T>, Args&&...); | |
| template <class T, class U, class... Args> | |
| constexpr explicit variant( | |
| in_place_type_t<T>, initializer_list<U>, Args&&...); | |
| template <size_t I, class... Args> | |
| constexpr explicit variant(in_place_index_t<I>, Args&&...); | |
| template <size_t I, class U, class... Args> | |
| constexpr explicit variant( | |
| in_place_index_t<I>, initializer_list<U>, Args&&...); | |
| // 20.7.2.2, destructor | |
| ~variant(); | |
| // 20.7.2.3, assignment | |
| variant& operator=(const variant&); // constexpr in C++20 | |
| variant& operator=(variant&&) noexcept(see below); // constexpr in C++20 | |
| template <class T> variant& operator=(T&&) noexcept(see below); | |
| // 20.7.2.4, modifiers | |
| template <class T, class... Args> | |
| T& emplace(Args&&...); | |
| template <class T, class U, class... Args> | |
| T& emplace(initializer_list<U>, Args&&...); | |
| template <size_t I, class... Args> | |
| variant_alternative_t<I, variant>& emplace(Args&&...); | |
| template <size_t I, class U, class... Args> | |
| variant_alternative_t<I, variant>& emplace(initializer_list<U>, Args&&...); | |
| // 20.7.2.5, value status | |
| constexpr bool valueless_by_exception() const noexcept; | |
| constexpr size_t index() const noexcept; | |
| // 20.7.2.6, swap | |
| void swap(variant&) noexcept(see below); | |
| }; | |
| // 20.7.3, variant helper classes | |
| template <class T> struct variant_size; // undefined | |
| template <class T> | |
| inline constexpr size_t variant_size_v = variant_size<T>::value; | |
| template <class T> struct variant_size<const T>; | |
| template <class T> struct variant_size<volatile T>; | |
| template <class T> struct variant_size<const volatile T>; | |
| template <class... Types> | |
| struct variant_size<variant<Types...>>; | |
| template <size_t I, class T> struct variant_alternative; // undefined | |
| template <size_t I, class T> | |
| using variant_alternative_t = typename variant_alternative<I, T>::type; | |
| template <size_t I, class T> struct variant_alternative<I, const T>; | |
| template <size_t I, class T> struct variant_alternative<I, volatile T>; | |
| template <size_t I, class T> struct variant_alternative<I, const volatile T>; | |
| template <size_t I, class... Types> | |
| struct variant_alternative<I, variant<Types...>>; | |
| inline constexpr size_t variant_npos = -1; | |
| // 20.7.4, value access | |
| template <class T, class... Types> | |
| constexpr bool holds_alternative(const variant<Types...>&) noexcept; | |
| template <size_t I, class... Types> | |
| constexpr variant_alternative_t<I, variant<Types...>>& | |
| get(variant<Types...>&); | |
| template <size_t I, class... Types> | |
| constexpr variant_alternative_t<I, variant<Types...>>&& | |
| get(variant<Types...>&&); | |
| template <size_t I, class... Types> | |
| constexpr variant_alternative_t<I, variant<Types...>> const& | |
| get(const variant<Types...>&); | |
| template <size_t I, class... Types> | |
| constexpr variant_alternative_t<I, variant<Types...>> const&& | |
| get(const variant<Types...>&&); | |
| template <class T, class... Types> | |
| constexpr T& get(variant<Types...>&); | |
| template <class T, class... Types> | |
| constexpr T&& get(variant<Types...>&&); | |
| template <class T, class... Types> | |
| constexpr const T& get(const variant<Types...>&); | |
| template <class T, class... Types> | |
| constexpr const T&& get(const variant<Types...>&&); | |
| template <size_t I, class... Types> | |
| constexpr add_pointer_t<variant_alternative_t<I, variant<Types...>>> | |
| get_if(variant<Types...>*) noexcept; | |
| template <size_t I, class... Types> | |
| constexpr add_pointer_t<const variant_alternative_t<I, variant<Types...>>> | |
| get_if(const variant<Types...>*) noexcept; | |
| template <class T, class... Types> | |
| constexpr add_pointer_t<T> | |
| get_if(variant<Types...>*) noexcept; | |
| template <class T, class... Types> | |
| constexpr add_pointer_t<const T> | |
| get_if(const variant<Types...>*) noexcept; | |
| // 20.7.5, relational operators | |
| template <class... Types> | |
| constexpr bool operator==(const variant<Types...>&, const variant<Types...>&); | |
| template <class... Types> | |
| constexpr bool operator!=(const variant<Types...>&, const variant<Types...>&); | |
| template <class... Types> | |
| constexpr bool operator<(const variant<Types...>&, const variant<Types...>&); | |
| template <class... Types> | |
| constexpr bool operator>(const variant<Types...>&, const variant<Types...>&); | |
| template <class... Types> | |
| constexpr bool operator<=(const variant<Types...>&, const variant<Types...>&); | |
| template <class... Types> | |
| constexpr bool operator>=(const variant<Types...>&, const variant<Types...>&); | |
| // 20.7.6, visitation | |
| template <class Visitor, class... Variants> | |
| constexpr see below visit(Visitor&&, Variants&&...); | |
| template <class R, class Visitor, class... Variants> | |
| constexpr R visit(Visitor&&, Variants&&...); // since C++20 | |
| // 20.7.7, class monostate | |
| struct monostate; | |
| // 20.7.8, monostate relational operators | |
| constexpr bool operator<(monostate, monostate) noexcept; | |
| constexpr bool operator>(monostate, monostate) noexcept; | |
| constexpr bool operator<=(monostate, monostate) noexcept; | |
| constexpr bool operator>=(monostate, monostate) noexcept; | |
| constexpr bool operator==(monostate, monostate) noexcept; | |
| constexpr bool operator!=(monostate, monostate) noexcept; | |
| // 20.7.9, specialized algorithms | |
| template <class... Types> | |
| void swap(variant<Types...>&, variant<Types...>&) noexcept(see below); | |
| // 20.7.10, class bad_variant_access | |
| class bad_variant_access; | |
| // 20.7.11, hash support | |
| template <class T> struct hash; | |
| template <class... Types> struct hash<variant<Types...>>; | |
| template <> struct hash<monostate>; | |
| } // namespace std | |
| */ | |
| #include <__availability> | |
| #include <__config> | |
| #include <__functional/hash.h> | |
| #include <__tuple> | |
| #include <__utility/forward.h> | |
| #include <__variant/monostate.h> | |
| #include <compare> | |
| #include <exception> | |
| #include <initializer_list> | |
| #include <limits> | |
| #include <new> | |
| #include <tuple> | |
| #include <type_traits> | |
| #include <utility> | |
| #include <version> | |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) | |
| #pragma GCC system_header | |
| #endif | |
| _LIBCPP_PUSH_MACROS | |
| #include <__undef_macros> | |
| namespace std { // explicitly not using versioning namespace | |
| class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS bad_variant_access : public exception { | |
| public: | |
| virtual const char* what() const _NOEXCEPT; | |
| }; | |
| } // namespace std | |
| _LIBCPP_BEGIN_NAMESPACE_STD | |
| // TODO: GCC 5 lies about its support for C++17 (it says it supports it but it | |
| // really doesn't). That breaks variant, which uses some C++17 features. | |
| // Remove this once we drop support for GCC 5. | |
| #if _LIBCPP_STD_VER > 14 && !(defined(_LIBCPP_COMPILER_GCC) && _GNUC_VER_NEW < 6000) | |
| // Light N-dimensional array of function pointers. Used in place of std::array to avoid | |
| // adding a dependency. | |
| template<class _Tp, size_t _Size> | |
| struct __farray { | |
| static_assert(_Size > 0, "N-dimensional array should never be empty in std::visit"); | |
| _Tp __buf_[_Size] = {}; | |
| _LIBCPP_INLINE_VISIBILITY constexpr | |
| const _Tp &operator[](size_t __n) const noexcept { | |
| return __buf_[__n]; | |
| } | |
| }; | |
| _LIBCPP_NORETURN | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS | |
| void __throw_bad_variant_access() { | |
| #ifndef _LIBCPP_NO_EXCEPTIONS | |
| throw bad_variant_access(); | |
| #else | |
| _VSTD::abort(); | |
| #endif | |
| } | |
| template <class... _Types> | |
| class _LIBCPP_TEMPLATE_VIS variant; | |
| template <class _Tp> | |
| struct _LIBCPP_TEMPLATE_VIS variant_size; | |
| template <class _Tp> | |
| _LIBCPP_INLINE_VAR constexpr size_t variant_size_v = variant_size<_Tp>::value; | |
| template <class _Tp> | |
| struct _LIBCPP_TEMPLATE_VIS variant_size<const _Tp> : variant_size<_Tp> {}; | |
| template <class _Tp> | |
| struct _LIBCPP_TEMPLATE_VIS variant_size<volatile _Tp> : variant_size<_Tp> {}; | |
| template <class _Tp> | |
| struct _LIBCPP_TEMPLATE_VIS variant_size<const volatile _Tp> | |
| : variant_size<_Tp> {}; | |
| template <class... _Types> | |
| struct _LIBCPP_TEMPLATE_VIS variant_size<variant<_Types...>> | |
| : integral_constant<size_t, sizeof...(_Types)> {}; | |
| template <size_t _Ip, class _Tp> | |
| struct _LIBCPP_TEMPLATE_VIS variant_alternative; | |
| template <size_t _Ip, class _Tp> | |
| using variant_alternative_t = typename variant_alternative<_Ip, _Tp>::type; | |
| template <size_t _Ip, class _Tp> | |
| struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, const _Tp> | |
| : add_const<variant_alternative_t<_Ip, _Tp>> {}; | |
| template <size_t _Ip, class _Tp> | |
| struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, volatile _Tp> | |
| : add_volatile<variant_alternative_t<_Ip, _Tp>> {}; | |
| template <size_t _Ip, class _Tp> | |
| struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, const volatile _Tp> | |
| : add_cv<variant_alternative_t<_Ip, _Tp>> {}; | |
| template <size_t _Ip, class... _Types> | |
| struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, variant<_Types...>> { | |
| static_assert(_Ip < sizeof...(_Types), "Index out of bounds in std::variant_alternative<>"); | |
| using type = __type_pack_element<_Ip, _Types...>; | |
| }; | |
| _LIBCPP_INLINE_VAR constexpr size_t variant_npos = static_cast<size_t>(-1); | |
| constexpr int __choose_index_type(unsigned int __num_elem) { | |
| if (__num_elem < numeric_limits<unsigned char>::max()) | |
| return 0; | |
| if (__num_elem < numeric_limits<unsigned short>::max()) | |
| return 1; | |
| return 2; | |
| } | |
| template <size_t _NumAlts> | |
| using __variant_index_t = | |
| #ifndef _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION | |
| unsigned int; | |
| #else | |
| std::tuple_element_t< | |
| __choose_index_type(_NumAlts), | |
| std::tuple<unsigned char, unsigned short, unsigned int> | |
| >; | |
| #endif | |
| template <class _IndexType> | |
| constexpr _IndexType __variant_npos = static_cast<_IndexType>(-1); | |
| template <class... _Types> | |
| class _LIBCPP_TEMPLATE_VIS variant; | |
| template <class... _Types> | |
| _LIBCPP_INLINE_VISIBILITY constexpr variant<_Types...>& | |
| __as_variant(variant<_Types...>& __vs) noexcept { | |
| return __vs; | |
| } | |
| template <class... _Types> | |
| _LIBCPP_INLINE_VISIBILITY constexpr const variant<_Types...>& | |
| __as_variant(const variant<_Types...>& __vs) noexcept { | |
| return __vs; | |
| } | |
| template <class... _Types> | |
| _LIBCPP_INLINE_VISIBILITY constexpr variant<_Types...>&& | |
| __as_variant(variant<_Types...>&& __vs) noexcept { | |
| return _VSTD::move(__vs); | |
| } | |
| template <class... _Types> | |
| _LIBCPP_INLINE_VISIBILITY constexpr const variant<_Types...>&& | |
| __as_variant(const variant<_Types...>&& __vs) noexcept { | |
| return _VSTD::move(__vs); | |
| } | |
| namespace __find_detail { | |
| template <class _Tp, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr size_t __find_index() { | |
| constexpr bool __matches[] = {is_same_v<_Tp, _Types>...}; | |
| size_t __result = __not_found; | |
| for (size_t __i = 0; __i < sizeof...(_Types); ++__i) { | |
| if (__matches[__i]) { | |
| if (__result != __not_found) { | |
| return __ambiguous; | |
| } | |
| __result = __i; | |
| } | |
| } | |
| return __result; | |
| } | |
| template <size_t _Index> | |
| struct __find_unambiguous_index_sfinae_impl | |
| : integral_constant<size_t, _Index> {}; | |
| template <> | |
| struct __find_unambiguous_index_sfinae_impl<__not_found> {}; | |
| template <> | |
| struct __find_unambiguous_index_sfinae_impl<__ambiguous> {}; | |
| template <class _Tp, class... _Types> | |
| struct __find_unambiguous_index_sfinae | |
| : __find_unambiguous_index_sfinae_impl<__find_index<_Tp, _Types...>()> {}; | |
| } // namespace __find_detail | |
| namespace __variant_detail { | |
| struct __valueless_t {}; | |
| enum class _Trait { _TriviallyAvailable, _Available, _Unavailable }; | |
| template <typename _Tp, | |
| template <typename> class _IsTriviallyAvailable, | |
| template <typename> class _IsAvailable> | |
| constexpr _Trait __trait = | |
| _IsTriviallyAvailable<_Tp>::value | |
| ? _Trait::_TriviallyAvailable | |
| : _IsAvailable<_Tp>::value ? _Trait::_Available : _Trait::_Unavailable; | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr _Trait __common_trait(initializer_list<_Trait> __traits) { | |
| _Trait __result = _Trait::_TriviallyAvailable; | |
| for (_Trait __t : __traits) { | |
| if (static_cast<int>(__t) > static_cast<int>(__result)) { | |
| __result = __t; | |
| } | |
| } | |
| return __result; | |
| } | |
| template <typename... _Types> | |
| struct __traits { | |
| static constexpr _Trait __copy_constructible_trait = | |
| __common_trait({__trait<_Types, | |
| is_trivially_copy_constructible, | |
| is_copy_constructible>...}); | |
| static constexpr _Trait __move_constructible_trait = | |
| __common_trait({__trait<_Types, | |
| is_trivially_move_constructible, | |
| is_move_constructible>...}); | |
| static constexpr _Trait __copy_assignable_trait = __common_trait( | |
| {__copy_constructible_trait, | |
| __trait<_Types, is_trivially_copy_assignable, is_copy_assignable>...}); | |
| static constexpr _Trait __move_assignable_trait = __common_trait( | |
| {__move_constructible_trait, | |
| __trait<_Types, is_trivially_move_assignable, is_move_assignable>...}); | |
| static constexpr _Trait __destructible_trait = __common_trait( | |
| {__trait<_Types, is_trivially_destructible, is_destructible>...}); | |
| }; | |
| namespace __access { | |
| struct __union { | |
| template <class _Vp> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto&& __get_alt(_Vp&& __v, in_place_index_t<0>) { | |
| return _VSTD::forward<_Vp>(__v).__head; | |
| } | |
| template <class _Vp, size_t _Ip> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto&& __get_alt(_Vp&& __v, in_place_index_t<_Ip>) { | |
| return __get_alt(_VSTD::forward<_Vp>(__v).__tail, in_place_index<_Ip - 1>); | |
| } | |
| }; | |
| struct __base { | |
| template <size_t _Ip, class _Vp> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto&& __get_alt(_Vp&& __v) { | |
| return __union::__get_alt(_VSTD::forward<_Vp>(__v).__data, | |
| in_place_index<_Ip>); | |
| } | |
| }; | |
| struct __variant { | |
| template <size_t _Ip, class _Vp> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto&& __get_alt(_Vp&& __v) { | |
| return __base::__get_alt<_Ip>(_VSTD::forward<_Vp>(__v).__impl); | |
| } | |
| }; | |
| } // namespace __access | |
| namespace __visitation { | |
| struct __base { | |
| template <class _Visitor, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr decltype(auto) | |
| __visit_alt_at(size_t __index, _Visitor&& __visitor, _Vs&&... __vs) { | |
| constexpr auto __fdiagonal = | |
| __make_fdiagonal<_Visitor&&, | |
| decltype(_VSTD::forward<_Vs>(__vs).__as_base())...>(); | |
| return __fdiagonal[__index](_VSTD::forward<_Visitor>(__visitor), | |
| _VSTD::forward<_Vs>(__vs).__as_base()...); | |
| } | |
| template <class _Visitor, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr decltype(auto) __visit_alt(_Visitor&& __visitor, | |
| _Vs&&... __vs) { | |
| constexpr auto __fmatrix = | |
| __make_fmatrix<_Visitor&&, | |
| decltype(_VSTD::forward<_Vs>(__vs).__as_base())...>(); | |
| return __at(__fmatrix, __vs.index()...)( | |
| _VSTD::forward<_Visitor>(__visitor), | |
| _VSTD::forward<_Vs>(__vs).__as_base()...); | |
| } | |
| private: | |
| template <class _Tp> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr const _Tp& __at(const _Tp& __elem) { return __elem; } | |
| template <class _Tp, size_t _Np, typename... _Indices> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto&& __at(const __farray<_Tp, _Np>& __elems, | |
| size_t __index, _Indices... __indices) { | |
| return __at(__elems[__index], __indices...); | |
| } | |
| template <class _Fp, class... _Fs> | |
| static constexpr void __std_visit_visitor_return_type_check() { | |
| static_assert( | |
| __all<is_same_v<_Fp, _Fs>...>::value, | |
| "`std::visit` requires the visitor to have a single return type."); | |
| } | |
| template <class... _Fs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto __make_farray(_Fs&&... __fs) { | |
| __std_visit_visitor_return_type_check<__uncvref_t<_Fs>...>(); | |
| using __result = __farray<common_type_t<__uncvref_t<_Fs>...>, sizeof...(_Fs)>; | |
| return __result{{_VSTD::forward<_Fs>(__fs)...}}; | |
| } | |
| template <size_t... _Is> | |
| struct __dispatcher { | |
| template <class _Fp, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr decltype(auto) __dispatch(_Fp __f, _Vs... __vs) { | |
| return _VSTD::__invoke_constexpr( | |
| static_cast<_Fp>(__f), | |
| __access::__base::__get_alt<_Is>(static_cast<_Vs>(__vs))...); | |
| } | |
| }; | |
| template <class _Fp, class... _Vs, size_t... _Is> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto __make_dispatch(index_sequence<_Is...>) { | |
| return __dispatcher<_Is...>::template __dispatch<_Fp, _Vs...>; | |
| } | |
| template <size_t _Ip, class _Fp, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto __make_fdiagonal_impl() { | |
| return __make_dispatch<_Fp, _Vs...>( | |
| index_sequence<(__identity<_Vs>{}, _Ip)...>{}); | |
| } | |
| template <class _Fp, class... _Vs, size_t... _Is> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto __make_fdiagonal_impl(index_sequence<_Is...>) { | |
| return __base::__make_farray(__make_fdiagonal_impl<_Is, _Fp, _Vs...>()...); | |
| } | |
| template <class _Fp, class _Vp, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto __make_fdiagonal() { | |
| constexpr size_t _Np = __uncvref_t<_Vp>::__size(); | |
| static_assert(__all<(_Np == __uncvref_t<_Vs>::__size())...>::value); | |
| return __make_fdiagonal_impl<_Fp, _Vp, _Vs...>(make_index_sequence<_Np>{}); | |
| } | |
| template <class _Fp, class... _Vs, size_t... _Is> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto __make_fmatrix_impl(index_sequence<_Is...> __is) { | |
| return __make_dispatch<_Fp, _Vs...>(__is); | |
| } | |
| template <class _Fp, class... _Vs, size_t... _Is, size_t... _Js, class... _Ls> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto __make_fmatrix_impl(index_sequence<_Is...>, | |
| index_sequence<_Js...>, | |
| _Ls... __ls) { | |
| return __base::__make_farray(__make_fmatrix_impl<_Fp, _Vs...>( | |
| index_sequence<_Is..., _Js>{}, __ls...)...); | |
| } | |
| template <class _Fp, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto __make_fmatrix() { | |
| return __make_fmatrix_impl<_Fp, _Vs...>( | |
| index_sequence<>{}, make_index_sequence<__uncvref_t<_Vs>::__size()>{}...); | |
| } | |
| }; | |
| struct __variant { | |
| template <class _Visitor, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr decltype(auto) | |
| __visit_alt_at(size_t __index, _Visitor&& __visitor, _Vs&&... __vs) { | |
| return __base::__visit_alt_at(__index, | |
| _VSTD::forward<_Visitor>(__visitor), | |
| _VSTD::forward<_Vs>(__vs).__impl...); | |
| } | |
| template <class _Visitor, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr decltype(auto) __visit_alt(_Visitor&& __visitor, | |
| _Vs&&... __vs) { | |
| return __base::__visit_alt( | |
| _VSTD::forward<_Visitor>(__visitor), | |
| _VSTD::__as_variant(_VSTD::forward<_Vs>(__vs)).__impl...); | |
| } | |
| template <class _Visitor, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr decltype(auto) | |
| __visit_value_at(size_t __index, _Visitor&& __visitor, _Vs&&... __vs) { | |
| return __visit_alt_at( | |
| __index, | |
| __make_value_visitor(_VSTD::forward<_Visitor>(__visitor)), | |
| _VSTD::forward<_Vs>(__vs)...); | |
| } | |
| template <class _Visitor, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr decltype(auto) __visit_value(_Visitor&& __visitor, | |
| _Vs&&... __vs) { | |
| return __visit_alt( | |
| __make_value_visitor(_VSTD::forward<_Visitor>(__visitor)), | |
| _VSTD::forward<_Vs>(__vs)...); | |
| } | |
| #if _LIBCPP_STD_VER > 17 | |
| template <class _Rp, class _Visitor, class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr _Rp __visit_value(_Visitor&& __visitor, | |
| _Vs&&... __vs) { | |
| return __visit_alt( | |
| __make_value_visitor<_Rp>(_VSTD::forward<_Visitor>(__visitor)), | |
| _VSTD::forward<_Vs>(__vs)...); | |
| } | |
| #endif | |
| private: | |
| template <class _Visitor, class... _Values> | |
| static constexpr void __std_visit_exhaustive_visitor_check() { | |
| static_assert(is_invocable_v<_Visitor, _Values...>, | |
| "`std::visit` requires the visitor to be exhaustive."); | |
| } | |
| template <class _Visitor> | |
| struct __value_visitor { | |
| template <class... _Alts> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr decltype(auto) operator()(_Alts&&... __alts) const { | |
| __std_visit_exhaustive_visitor_check< | |
| _Visitor, | |
| decltype((_VSTD::forward<_Alts>(__alts).__value))...>(); | |
| return _VSTD::__invoke_constexpr(_VSTD::forward<_Visitor>(__visitor), | |
| _VSTD::forward<_Alts>(__alts).__value...); | |
| } | |
| _Visitor&& __visitor; | |
| }; | |
| #if _LIBCPP_STD_VER > 17 | |
| template <class _Rp, class _Visitor> | |
| struct __value_visitor_return_type { | |
| template <class... _Alts> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr _Rp operator()(_Alts&&... __alts) const { | |
| __std_visit_exhaustive_visitor_check< | |
| _Visitor, | |
| decltype((_VSTD::forward<_Alts>(__alts).__value))...>(); | |
| if constexpr (is_void_v<_Rp>) { | |
| _VSTD::__invoke_constexpr(_VSTD::forward<_Visitor>(__visitor), | |
| _VSTD::forward<_Alts>(__alts).__value...); | |
| } | |
| else { | |
| return _VSTD::__invoke_constexpr(_VSTD::forward<_Visitor>(__visitor), | |
| _VSTD::forward<_Alts>(__alts).__value...); | |
| } | |
| } | |
| _Visitor&& __visitor; | |
| }; | |
| #endif | |
| template <class _Visitor> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto __make_value_visitor(_Visitor&& __visitor) { | |
| return __value_visitor<_Visitor>{_VSTD::forward<_Visitor>(__visitor)}; | |
| } | |
| #if _LIBCPP_STD_VER > 17 | |
| template <class _Rp, class _Visitor> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr auto __make_value_visitor(_Visitor&& __visitor) { | |
| return __value_visitor_return_type<_Rp, _Visitor>{_VSTD::forward<_Visitor>(__visitor)}; | |
| } | |
| #endif | |
| }; | |
| } // namespace __visitation | |
| template <size_t _Index, class _Tp> | |
| struct _LIBCPP_TEMPLATE_VIS __alt { | |
| using __value_type = _Tp; | |
| template <class... _Args> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| explicit constexpr __alt(in_place_t, _Args&&... __args) | |
| : __value(_VSTD::forward<_Args>(__args)...) {} | |
| __value_type __value; | |
| }; | |
| template <_Trait _DestructibleTrait, size_t _Index, class... _Types> | |
| union _LIBCPP_TEMPLATE_VIS __union; | |
| template <_Trait _DestructibleTrait, size_t _Index> | |
| union _LIBCPP_TEMPLATE_VIS __union<_DestructibleTrait, _Index> {}; | |
| #define _LIBCPP_VARIANT_UNION(destructible_trait, destructor) \ | |
| template <size_t _Index, class _Tp, class... _Types> \ | |
| union _LIBCPP_TEMPLATE_VIS __union<destructible_trait, \ | |
| _Index, \ | |
| _Tp, \ | |
| _Types...> { \ | |
| public: \ | |
| inline _LIBCPP_INLINE_VISIBILITY \ | |
| explicit constexpr __union(__valueless_t) noexcept : __dummy{} {} \ | |
| \ | |
| template <class... _Args> \ | |
| inline _LIBCPP_INLINE_VISIBILITY \ | |
| explicit constexpr __union(in_place_index_t<0>, _Args&&... __args) \ | |
| : __head(in_place, _VSTD::forward<_Args>(__args)...) {} \ | |
| \ | |
| template <size_t _Ip, class... _Args> \ | |
| inline _LIBCPP_INLINE_VISIBILITY \ | |
| explicit constexpr __union(in_place_index_t<_Ip>, _Args&&... __args) \ | |
| : __tail(in_place_index<_Ip - 1>, _VSTD::forward<_Args>(__args)...) {} \ | |
| \ | |
| __union(const __union&) = default; \ | |
| __union(__union&&) = default; \ | |
| \ | |
| destructor \ | |
| \ | |
| __union& operator=(const __union&) = default; \ | |
| __union& operator=(__union&&) = default; \ | |
| \ | |
| private: \ | |
| char __dummy; \ | |
| __alt<_Index, _Tp> __head; \ | |
| __union<destructible_trait, _Index + 1, _Types...> __tail; \ | |
| \ | |
| friend struct __access::__union; \ | |
| } | |
| _LIBCPP_VARIANT_UNION(_Trait::_TriviallyAvailable, ~__union() = default;); | |
| _LIBCPP_VARIANT_UNION(_Trait::_Available, ~__union() {}); | |
| _LIBCPP_VARIANT_UNION(_Trait::_Unavailable, ~__union() = delete;); | |
| #undef _LIBCPP_VARIANT_UNION | |
| template <_Trait _DestructibleTrait, class... _Types> | |
| class _LIBCPP_TEMPLATE_VIS __base { | |
| public: | |
| using __index_t = __variant_index_t<sizeof...(_Types)>; | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| explicit constexpr __base(__valueless_t tag) noexcept | |
| : __data(tag), __index(__variant_npos<__index_t>) {} | |
| template <size_t _Ip, class... _Args> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| explicit constexpr __base(in_place_index_t<_Ip>, _Args&&... __args) | |
| : | |
| __data(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...), | |
| __index(_Ip) {} | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr bool valueless_by_exception() const noexcept { | |
| return index() == variant_npos; | |
| } | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr size_t index() const noexcept { | |
| return __index == __variant_npos<__index_t> ? variant_npos : __index; | |
| } | |
| protected: | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr auto&& __as_base() & { return *this; } | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr auto&& __as_base() && { return _VSTD::move(*this); } | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr auto&& __as_base() const & { return *this; } | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr auto&& __as_base() const && { return _VSTD::move(*this); } | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static constexpr size_t __size() { return sizeof...(_Types); } | |
| __union<_DestructibleTrait, 0, _Types...> __data; | |
| __index_t __index; | |
| friend struct __access::__base; | |
| friend struct __visitation::__base; | |
| }; | |
| template <class _Traits, _Trait = _Traits::__destructible_trait> | |
| class _LIBCPP_TEMPLATE_VIS __dtor; | |
| #define _LIBCPP_VARIANT_DESTRUCTOR(destructible_trait, destructor, destroy) \ | |
| template <class... _Types> \ | |
| class _LIBCPP_TEMPLATE_VIS __dtor<__traits<_Types...>, \ | |
| destructible_trait> \ | |
| : public __base<destructible_trait, _Types...> { \ | |
| using __base_type = __base<destructible_trait, _Types...>; \ | |
| using __index_t = typename __base_type::__index_t; \ | |
| \ | |
| public: \ | |
| using __base_type::__base_type; \ | |
| using __base_type::operator=; \ | |
| \ | |
| __dtor(const __dtor&) = default; \ | |
| __dtor(__dtor&&) = default; \ | |
| destructor \ | |
| __dtor& operator=(const __dtor&) = default; \ | |
| __dtor& operator=(__dtor&&) = default; \ | |
| \ | |
| protected: \ | |
| inline _LIBCPP_INLINE_VISIBILITY \ | |
| destroy \ | |
| } | |
| _LIBCPP_VARIANT_DESTRUCTOR( | |
| _Trait::_TriviallyAvailable, | |
| ~__dtor() = default;, | |
| void __destroy() noexcept { this->__index = __variant_npos<__index_t>; }); | |
| _LIBCPP_VARIANT_DESTRUCTOR( | |
| _Trait::_Available, | |
| ~__dtor() { __destroy(); }, | |
| void __destroy() noexcept { | |
| if (!this->valueless_by_exception()) { | |
| __visitation::__base::__visit_alt( | |
| [](auto& __alt) noexcept { | |
| using __alt_type = __uncvref_t<decltype(__alt)>; | |
| __alt.~__alt_type(); | |
| }, | |
| *this); | |
| } | |
| this->__index = __variant_npos<__index_t>; | |
| }); | |
| _LIBCPP_VARIANT_DESTRUCTOR( | |
| _Trait::_Unavailable, | |
| ~__dtor() = delete;, | |
| void __destroy() noexcept = delete;); | |
| #undef _LIBCPP_VARIANT_DESTRUCTOR | |
| template <class _Traits> | |
| class _LIBCPP_TEMPLATE_VIS __ctor : public __dtor<_Traits> { | |
| using __base_type = __dtor<_Traits>; | |
| public: | |
| using __base_type::__base_type; | |
| using __base_type::operator=; | |
| protected: | |
| template <size_t _Ip, class _Tp, class... _Args> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static _Tp& __construct_alt(__alt<_Ip, _Tp>& __a, _Args&&... __args) { | |
| ::new ((void*)_VSTD::addressof(__a)) | |
| __alt<_Ip, _Tp>(in_place, _VSTD::forward<_Args>(__args)...); | |
| return __a.__value; | |
| } | |
| template <class _Rhs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| static void __generic_construct(__ctor& __lhs, _Rhs&& __rhs) { | |
| __lhs.__destroy(); | |
| if (!__rhs.valueless_by_exception()) { | |
| __visitation::__base::__visit_alt_at( | |
| __rhs.index(), | |
| [](auto& __lhs_alt, auto&& __rhs_alt) { | |
| __construct_alt( | |
| __lhs_alt, | |
| _VSTD::forward<decltype(__rhs_alt)>(__rhs_alt).__value); | |
| }, | |
| __lhs, _VSTD::forward<_Rhs>(__rhs)); | |
| __lhs.__index = __rhs.index(); | |
| } | |
| } | |
| }; | |
| template <class _Traits, _Trait = _Traits::__move_constructible_trait> | |
| class _LIBCPP_TEMPLATE_VIS __move_constructor; | |
| #define _LIBCPP_VARIANT_MOVE_CONSTRUCTOR(move_constructible_trait, \ | |
| move_constructor) \ | |
| template <class... _Types> \ | |
| class _LIBCPP_TEMPLATE_VIS __move_constructor<__traits<_Types...>, \ | |
| move_constructible_trait> \ | |
| : public __ctor<__traits<_Types...>> { \ | |
| using __base_type = __ctor<__traits<_Types...>>; \ | |
| \ | |
| public: \ | |
| using __base_type::__base_type; \ | |
| using __base_type::operator=; \ | |
| \ | |
| __move_constructor(const __move_constructor&) = default; \ | |
| move_constructor \ | |
| ~__move_constructor() = default; \ | |
| __move_constructor& operator=(const __move_constructor&) = default; \ | |
| __move_constructor& operator=(__move_constructor&&) = default; \ | |
| } | |
| _LIBCPP_VARIANT_MOVE_CONSTRUCTOR( | |
| _Trait::_TriviallyAvailable, | |
| __move_constructor(__move_constructor&& __that) = default;); | |
| _LIBCPP_VARIANT_MOVE_CONSTRUCTOR( | |
| _Trait::_Available, | |
| __move_constructor(__move_constructor&& __that) noexcept( | |
| __all<is_nothrow_move_constructible_v<_Types>...>::value) | |
| : __move_constructor(__valueless_t{}) { | |
| this->__generic_construct(*this, _VSTD::move(__that)); | |
| }); | |
| _LIBCPP_VARIANT_MOVE_CONSTRUCTOR( | |
| _Trait::_Unavailable, | |
| __move_constructor(__move_constructor&&) = delete;); | |
| #undef _LIBCPP_VARIANT_MOVE_CONSTRUCTOR | |
| template <class _Traits, _Trait = _Traits::__copy_constructible_trait> | |
| class _LIBCPP_TEMPLATE_VIS __copy_constructor; | |
| #define _LIBCPP_VARIANT_COPY_CONSTRUCTOR(copy_constructible_trait, \ | |
| copy_constructor) \ | |
| template <class... _Types> \ | |
| class _LIBCPP_TEMPLATE_VIS __copy_constructor<__traits<_Types...>, \ | |
| copy_constructible_trait> \ | |
| : public __move_constructor<__traits<_Types...>> { \ | |
| using __base_type = __move_constructor<__traits<_Types...>>; \ | |
| \ | |
| public: \ | |
| using __base_type::__base_type; \ | |
| using __base_type::operator=; \ | |
| \ | |
| copy_constructor \ | |
| __copy_constructor(__copy_constructor&&) = default; \ | |
| ~__copy_constructor() = default; \ | |
| __copy_constructor& operator=(const __copy_constructor&) = default; \ | |
| __copy_constructor& operator=(__copy_constructor&&) = default; \ | |
| } | |
| _LIBCPP_VARIANT_COPY_CONSTRUCTOR( | |
| _Trait::_TriviallyAvailable, | |
| __copy_constructor(const __copy_constructor& __that) = default;); | |
| _LIBCPP_VARIANT_COPY_CONSTRUCTOR( | |
| _Trait::_Available, | |
| __copy_constructor(const __copy_constructor& __that) | |
| : __copy_constructor(__valueless_t{}) { | |
| this->__generic_construct(*this, __that); | |
| }); | |
| _LIBCPP_VARIANT_COPY_CONSTRUCTOR( | |
| _Trait::_Unavailable, | |
| __copy_constructor(const __copy_constructor&) = delete;); | |
| #undef _LIBCPP_VARIANT_COPY_CONSTRUCTOR | |
| template <class _Traits> | |
| class _LIBCPP_TEMPLATE_VIS __assignment : public __copy_constructor<_Traits> { | |
| using __base_type = __copy_constructor<_Traits>; | |
| public: | |
| using __base_type::__base_type; | |
| using __base_type::operator=; | |
| template <size_t _Ip, class... _Args> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| auto& __emplace(_Args&&... __args) { | |
| this->__destroy(); | |
| auto& __res = this->__construct_alt(__access::__base::__get_alt<_Ip>(*this), | |
| _VSTD::forward<_Args>(__args)...); | |
| this->__index = _Ip; | |
| return __res; | |
| } | |
| protected: | |
| template <size_t _Ip, class _Tp, class _Arg> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| void __assign_alt(__alt<_Ip, _Tp>& __a, _Arg&& __arg) { | |
| if (this->index() == _Ip) { | |
| __a.__value = _VSTD::forward<_Arg>(__arg); | |
| } else { | |
| struct { | |
| void operator()(true_type) const { | |
| __this->__emplace<_Ip>(_VSTD::forward<_Arg>(__arg)); | |
| } | |
| void operator()(false_type) const { | |
| __this->__emplace<_Ip>(_Tp(_VSTD::forward<_Arg>(__arg))); | |
| } | |
| __assignment* __this; | |
| _Arg&& __arg; | |
| } __impl{this, _VSTD::forward<_Arg>(__arg)}; | |
| __impl(bool_constant<is_nothrow_constructible_v<_Tp, _Arg> || | |
| !is_nothrow_move_constructible_v<_Tp>>{}); | |
| } | |
| } | |
| template <class _That> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| void __generic_assign(_That&& __that) { | |
| if (this->valueless_by_exception() && __that.valueless_by_exception()) { | |
| // do nothing. | |
| } else if (__that.valueless_by_exception()) { | |
| this->__destroy(); | |
| } else { | |
| __visitation::__base::__visit_alt_at( | |
| __that.index(), | |
| [this](auto& __this_alt, auto&& __that_alt) { | |
| this->__assign_alt( | |
| __this_alt, | |
| _VSTD::forward<decltype(__that_alt)>(__that_alt).__value); | |
| }, | |
| *this, _VSTD::forward<_That>(__that)); | |
| } | |
| } | |
| }; | |
| template <class _Traits, _Trait = _Traits::__move_assignable_trait> | |
| class _LIBCPP_TEMPLATE_VIS __move_assignment; | |
| #define _LIBCPP_VARIANT_MOVE_ASSIGNMENT(move_assignable_trait, \ | |
| move_assignment) \ | |
| template <class... _Types> \ | |
| class _LIBCPP_TEMPLATE_VIS __move_assignment<__traits<_Types...>, \ | |
| move_assignable_trait> \ | |
| : public __assignment<__traits<_Types...>> { \ | |
| using __base_type = __assignment<__traits<_Types...>>; \ | |
| \ | |
| public: \ | |
| using __base_type::__base_type; \ | |
| using __base_type::operator=; \ | |
| \ | |
| __move_assignment(const __move_assignment&) = default; \ | |
| __move_assignment(__move_assignment&&) = default; \ | |
| ~__move_assignment() = default; \ | |
| __move_assignment& operator=(const __move_assignment&) = default; \ | |
| move_assignment \ | |
| } | |
| _LIBCPP_VARIANT_MOVE_ASSIGNMENT( | |
| _Trait::_TriviallyAvailable, | |
| __move_assignment& operator=(__move_assignment&& __that) = default;); | |
| _LIBCPP_VARIANT_MOVE_ASSIGNMENT( | |
| _Trait::_Available, | |
| __move_assignment& operator=(__move_assignment&& __that) noexcept( | |
| __all<(is_nothrow_move_constructible_v<_Types> && | |
| is_nothrow_move_assignable_v<_Types>)...>::value) { | |
| this->__generic_assign(_VSTD::move(__that)); | |
| return *this; | |
| }); | |
| _LIBCPP_VARIANT_MOVE_ASSIGNMENT( | |
| _Trait::_Unavailable, | |
| __move_assignment& operator=(__move_assignment&&) = delete;); | |
| #undef _LIBCPP_VARIANT_MOVE_ASSIGNMENT | |
| template <class _Traits, _Trait = _Traits::__copy_assignable_trait> | |
| class _LIBCPP_TEMPLATE_VIS __copy_assignment; | |
| #define _LIBCPP_VARIANT_COPY_ASSIGNMENT(copy_assignable_trait, \ | |
| copy_assignment) \ | |
| template <class... _Types> \ | |
| class _LIBCPP_TEMPLATE_VIS __copy_assignment<__traits<_Types...>, \ | |
| copy_assignable_trait> \ | |
| : public __move_assignment<__traits<_Types...>> { \ | |
| using __base_type = __move_assignment<__traits<_Types...>>; \ | |
| \ | |
| public: \ | |
| using __base_type::__base_type; \ | |
| using __base_type::operator=; \ | |
| \ | |
| __copy_assignment(const __copy_assignment&) = default; \ | |
| __copy_assignment(__copy_assignment&&) = default; \ | |
| ~__copy_assignment() = default; \ | |
| copy_assignment \ | |
| __copy_assignment& operator=(__copy_assignment&&) = default; \ | |
| } | |
| _LIBCPP_VARIANT_COPY_ASSIGNMENT( | |
| _Trait::_TriviallyAvailable, | |
| __copy_assignment& operator=(const __copy_assignment& __that) = default;); | |
| _LIBCPP_VARIANT_COPY_ASSIGNMENT( | |
| _Trait::_Available, | |
| __copy_assignment& operator=(const __copy_assignment& __that) { | |
| this->__generic_assign(__that); | |
| return *this; | |
| }); | |
| _LIBCPP_VARIANT_COPY_ASSIGNMENT( | |
| _Trait::_Unavailable, | |
| __copy_assignment& operator=(const __copy_assignment&) = delete;); | |
| #undef _LIBCPP_VARIANT_COPY_ASSIGNMENT | |
| template <class... _Types> | |
| class _LIBCPP_TEMPLATE_VIS __impl | |
| : public __copy_assignment<__traits<_Types...>> { | |
| using __base_type = __copy_assignment<__traits<_Types...>>; | |
| public: | |
| using __base_type::__base_type; | |
| using __base_type::operator=; | |
| template <size_t _Ip, class _Arg> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| void __assign(_Arg&& __arg) { | |
| this->__assign_alt(__access::__base::__get_alt<_Ip>(*this), | |
| _VSTD::forward<_Arg>(__arg)); | |
| } | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| void __swap(__impl& __that) { | |
| if (this->valueless_by_exception() && __that.valueless_by_exception()) { | |
| // do nothing. | |
| } else if (this->index() == __that.index()) { | |
| __visitation::__base::__visit_alt_at( | |
| this->index(), | |
| [](auto& __this_alt, auto& __that_alt) { | |
| using _VSTD::swap; | |
| swap(__this_alt.__value, __that_alt.__value); | |
| }, | |
| *this, | |
| __that); | |
| } else { | |
| __impl* __lhs = this; | |
| __impl* __rhs = _VSTD::addressof(__that); | |
| if (__lhs->__move_nothrow() && !__rhs->__move_nothrow()) { | |
| _VSTD::swap(__lhs, __rhs); | |
| } | |
| __impl __tmp(_VSTD::move(*__rhs)); | |
| #ifndef _LIBCPP_NO_EXCEPTIONS | |
| if constexpr (__all<is_nothrow_move_constructible_v<_Types>...>::value) { | |
| this->__generic_construct(*__rhs, _VSTD::move(*__lhs)); | |
| } else { | |
| // EXTENSION: When the move construction of `__lhs` into `__rhs` throws | |
| // and `__tmp` is nothrow move constructible then we move `__tmp` back | |
| // into `__rhs` and provide the strong exception safety guarantee. | |
| try { | |
| this->__generic_construct(*__rhs, _VSTD::move(*__lhs)); | |
| } catch (...) { | |
| if (__tmp.__move_nothrow()) { | |
| this->__generic_construct(*__rhs, _VSTD::move(__tmp)); | |
| } | |
| throw; | |
| } | |
| } | |
| #else | |
| // this isn't consolidated with the `if constexpr` branch above due to | |
| // `throw` being ill-formed with exceptions disabled even when discarded. | |
| this->__generic_construct(*__rhs, _VSTD::move(*__lhs)); | |
| #endif | |
| this->__generic_construct(*__lhs, _VSTD::move(__tmp)); | |
| } | |
| } | |
| private: | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| bool __move_nothrow() const { | |
| constexpr bool __results[] = {is_nothrow_move_constructible_v<_Types>...}; | |
| return this->valueless_by_exception() || __results[this->index()]; | |
| } | |
| }; | |
| struct __no_narrowing_check { | |
| template <class _Dest, class _Source> | |
| using _Apply = __identity<_Dest>; | |
| }; | |
| struct __narrowing_check { | |
| template <class _Dest> | |
| static auto __test_impl(_Dest (&&)[1]) -> __identity<_Dest>; | |
| template <class _Dest, class _Source> | |
| using _Apply _LIBCPP_NODEBUG_TYPE = decltype(__test_impl<_Dest>({declval<_Source>()})); | |
| }; | |
| template <class _Dest, class _Source> | |
| using __check_for_narrowing _LIBCPP_NODEBUG_TYPE = | |
| typename _If< | |
| #ifdef _LIBCPP_ENABLE_NARROWING_CONVERSIONS_IN_VARIANT | |
| false && | |
| #endif | |
| is_arithmetic<_Dest>::value, | |
| __narrowing_check, | |
| __no_narrowing_check | |
| >::template _Apply<_Dest, _Source>; | |
| template <class _Tp, size_t _Idx> | |
| struct __overload { | |
| template <class _Up> | |
| auto operator()(_Tp, _Up&&) const -> __check_for_narrowing<_Tp, _Up>; | |
| }; | |
| template <class _Tp, size_t> | |
| struct __overload_bool { | |
| template <class _Up, class _Ap = __uncvref_t<_Up>> | |
| auto operator()(bool, _Up&&) const | |
| -> enable_if_t<is_same_v<_Ap, bool>, __identity<_Tp>>; | |
| }; | |
| template <size_t _Idx> | |
| struct __overload<bool, _Idx> : __overload_bool<bool, _Idx> {}; | |
| template <size_t _Idx> | |
| struct __overload<bool const, _Idx> : __overload_bool<bool const, _Idx> {}; | |
| template <size_t _Idx> | |
| struct __overload<bool volatile, _Idx> : __overload_bool<bool volatile, _Idx> {}; | |
| template <size_t _Idx> | |
| struct __overload<bool const volatile, _Idx> : __overload_bool<bool const volatile, _Idx> {}; | |
| template <class ..._Bases> | |
| struct __all_overloads : _Bases... { | |
| void operator()() const; | |
| using _Bases::operator()...; | |
| }; | |
| template <class IdxSeq> | |
| struct __make_overloads_imp; | |
| template <size_t ..._Idx> | |
| struct __make_overloads_imp<__tuple_indices<_Idx...> > { | |
| template <class ..._Types> | |
| using _Apply _LIBCPP_NODEBUG_TYPE = __all_overloads<__overload<_Types, _Idx>...>; | |
| }; | |
| template <class ..._Types> | |
| using _MakeOverloads _LIBCPP_NODEBUG_TYPE = typename __make_overloads_imp< | |
| __make_indices_imp<sizeof...(_Types), 0> >::template _Apply<_Types...>; | |
| template <class _Tp, class... _Types> | |
| using __best_match_t = | |
| typename invoke_result_t<_MakeOverloads<_Types...>, _Tp, _Tp>::type; | |
| } // __variant_detail | |
| template <class... _Types> | |
| class _LIBCPP_TEMPLATE_VIS variant | |
| : private __sfinae_ctor_base< | |
| __all<is_copy_constructible_v<_Types>...>::value, | |
| __all<is_move_constructible_v<_Types>...>::value>, | |
| private __sfinae_assign_base< | |
| __all<(is_copy_constructible_v<_Types> && | |
| is_copy_assignable_v<_Types>)...>::value, | |
| __all<(is_move_constructible_v<_Types> && | |
| is_move_assignable_v<_Types>)...>::value> { | |
| static_assert(0 < sizeof...(_Types), | |
| "variant must consist of at least one alternative."); | |
| static_assert(__all<!is_array_v<_Types>...>::value, | |
| "variant can not have an array type as an alternative."); | |
| static_assert(__all<!is_reference_v<_Types>...>::value, | |
| "variant can not have a reference type as an alternative."); | |
| static_assert(__all<!is_void_v<_Types>...>::value, | |
| "variant can not have a void type as an alternative."); | |
| using __first_type = variant_alternative_t<0, variant>; | |
| public: | |
| template <bool _Dummy = true, | |
| enable_if_t<__dependent_type<is_default_constructible<__first_type>, | |
| _Dummy>::value, | |
| int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr variant() noexcept(is_nothrow_default_constructible_v<__first_type>) | |
| : __impl(in_place_index<0>) {} | |
| variant(const variant&) = default; | |
| variant(variant&&) = default; | |
| template < | |
| class _Arg, | |
| enable_if_t<!is_same_v<__uncvref_t<_Arg>, variant>, int> = 0, | |
| enable_if_t<!__is_inplace_type<__uncvref_t<_Arg>>::value, int> = 0, | |
| enable_if_t<!__is_inplace_index<__uncvref_t<_Arg>>::value, int> = 0, | |
| class _Tp = __variant_detail::__best_match_t<_Arg, _Types...>, | |
| size_t _Ip = | |
| __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value, | |
| enable_if_t<is_constructible_v<_Tp, _Arg>, int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr variant(_Arg&& __arg) noexcept( | |
| is_nothrow_constructible_v<_Tp, _Arg>) | |
| : __impl(in_place_index<_Ip>, _VSTD::forward<_Arg>(__arg)) {} | |
| template <size_t _Ip, class... _Args, | |
| class = enable_if_t<(_Ip < sizeof...(_Types)), int>, | |
| class _Tp = variant_alternative_t<_Ip, variant<_Types...>>, | |
| enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| explicit constexpr variant( | |
| in_place_index_t<_Ip>, | |
| _Args&&... __args) noexcept(is_nothrow_constructible_v<_Tp, _Args...>) | |
| : __impl(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...) {} | |
| template < | |
| size_t _Ip, | |
| class _Up, | |
| class... _Args, | |
| enable_if_t<(_Ip < sizeof...(_Types)), int> = 0, | |
| class _Tp = variant_alternative_t<_Ip, variant<_Types...>>, | |
| enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>, | |
| int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| explicit constexpr variant( | |
| in_place_index_t<_Ip>, | |
| initializer_list<_Up> __il, | |
| _Args&&... __args) noexcept( | |
| is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>) | |
| : __impl(in_place_index<_Ip>, __il, _VSTD::forward<_Args>(__args)...) {} | |
| template < | |
| class _Tp, | |
| class... _Args, | |
| size_t _Ip = | |
| __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value, | |
| enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| explicit constexpr variant(in_place_type_t<_Tp>, _Args&&... __args) noexcept( | |
| is_nothrow_constructible_v<_Tp, _Args...>) | |
| : __impl(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...) {} | |
| template < | |
| class _Tp, | |
| class _Up, | |
| class... _Args, | |
| size_t _Ip = | |
| __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value, | |
| enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>, | |
| int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| explicit constexpr variant( | |
| in_place_type_t<_Tp>, | |
| initializer_list<_Up> __il, | |
| _Args&&... __args) noexcept( | |
| is_nothrow_constructible_v<_Tp, initializer_list< _Up>&, _Args...>) | |
| : __impl(in_place_index<_Ip>, __il, _VSTD::forward<_Args>(__args)...) {} | |
| ~variant() = default; | |
| variant& operator=(const variant&) = default; | |
| variant& operator=(variant&&) = default; | |
| template < | |
| class _Arg, | |
| enable_if_t<!is_same_v<__uncvref_t<_Arg>, variant>, int> = 0, | |
| class _Tp = __variant_detail::__best_match_t<_Arg, _Types...>, | |
| size_t _Ip = | |
| __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value, | |
| enable_if_t<is_assignable_v<_Tp&, _Arg> && is_constructible_v<_Tp, _Arg>, | |
| int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| variant& operator=(_Arg&& __arg) noexcept( | |
| is_nothrow_assignable_v<_Tp&, _Arg> && | |
| is_nothrow_constructible_v<_Tp, _Arg>) { | |
| __impl.template __assign<_Ip>(_VSTD::forward<_Arg>(__arg)); | |
| return *this; | |
| } | |
| template < | |
| size_t _Ip, | |
| class... _Args, | |
| enable_if_t<(_Ip < sizeof...(_Types)), int> = 0, | |
| class _Tp = variant_alternative_t<_Ip, variant<_Types...>>, | |
| enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _Tp& emplace(_Args&&... __args) { | |
| return __impl.template __emplace<_Ip>(_VSTD::forward<_Args>(__args)...); | |
| } | |
| template < | |
| size_t _Ip, | |
| class _Up, | |
| class... _Args, | |
| enable_if_t<(_Ip < sizeof...(_Types)), int> = 0, | |
| class _Tp = variant_alternative_t<_Ip, variant<_Types...>>, | |
| enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>, | |
| int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) { | |
| return __impl.template __emplace<_Ip>(__il, _VSTD::forward<_Args>(__args)...); | |
| } | |
| template < | |
| class _Tp, | |
| class... _Args, | |
| size_t _Ip = | |
| __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value, | |
| enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _Tp& emplace(_Args&&... __args) { | |
| return __impl.template __emplace<_Ip>(_VSTD::forward<_Args>(__args)...); | |
| } | |
| template < | |
| class _Tp, | |
| class _Up, | |
| class... _Args, | |
| size_t _Ip = | |
| __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value, | |
| enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>, | |
| int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) { | |
| return __impl.template __emplace<_Ip>(__il, _VSTD::forward<_Args>(__args)...); | |
| } | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr bool valueless_by_exception() const noexcept { | |
| return __impl.valueless_by_exception(); | |
| } | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr size_t index() const noexcept { return __impl.index(); } | |
| template < | |
| bool _Dummy = true, | |
| enable_if_t< | |
| __all<( | |
| __dependent_type<is_move_constructible<_Types>, _Dummy>::value && | |
| __dependent_type<is_swappable<_Types>, _Dummy>::value)...>::value, | |
| int> = 0> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| void swap(variant& __that) noexcept( | |
| __all<(is_nothrow_move_constructible_v<_Types> && | |
| is_nothrow_swappable_v<_Types>)...>::value) { | |
| __impl.__swap(__that.__impl); | |
| } | |
| private: | |
| __variant_detail::__impl<_Types...> __impl; | |
| friend struct __variant_detail::__access::__variant; | |
| friend struct __variant_detail::__visitation::__variant; | |
| }; | |
| template <size_t _Ip, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr bool __holds_alternative(const variant<_Types...>& __v) noexcept { | |
| return __v.index() == _Ip; | |
| } | |
| template <class _Tp, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr bool holds_alternative(const variant<_Types...>& __v) noexcept { | |
| return __holds_alternative<__find_exactly_one_t<_Tp, _Types...>::value>(__v); | |
| } | |
| template <size_t _Ip, class _Vp> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS | |
| constexpr auto&& __generic_get(_Vp&& __v) { | |
| using __variant_detail::__access::__variant; | |
| if (!__holds_alternative<_Ip>(__v)) { | |
| __throw_bad_variant_access(); | |
| } | |
| return __variant::__get_alt<_Ip>(_VSTD::forward<_Vp>(__v)).__value; | |
| } | |
| template <size_t _Ip, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS | |
| constexpr variant_alternative_t<_Ip, variant<_Types...>>& get( | |
| variant<_Types...>& __v) { | |
| static_assert(_Ip < sizeof...(_Types)); | |
| static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>); | |
| return __generic_get<_Ip>(__v); | |
| } | |
| template <size_t _Ip, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS | |
| constexpr variant_alternative_t<_Ip, variant<_Types...>>&& get( | |
| variant<_Types...>&& __v) { | |
| static_assert(_Ip < sizeof...(_Types)); | |
| static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>); | |
| return __generic_get<_Ip>(_VSTD::move(__v)); | |
| } | |
| template <size_t _Ip, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS | |
| constexpr const variant_alternative_t<_Ip, variant<_Types...>>& get( | |
| const variant<_Types...>& __v) { | |
| static_assert(_Ip < sizeof...(_Types)); | |
| static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>); | |
| return __generic_get<_Ip>(__v); | |
| } | |
| template <size_t _Ip, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS | |
| constexpr const variant_alternative_t<_Ip, variant<_Types...>>&& get( | |
| const variant<_Types...>&& __v) { | |
| static_assert(_Ip < sizeof...(_Types)); | |
| static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>); | |
| return __generic_get<_Ip>(_VSTD::move(__v)); | |
| } | |
| template <class _Tp, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS | |
| constexpr _Tp& get(variant<_Types...>& __v) { | |
| static_assert(!is_void_v<_Tp>); | |
| return _VSTD::get<__find_exactly_one_t<_Tp, _Types...>::value>(__v); | |
| } | |
| template <class _Tp, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS | |
| constexpr _Tp&& get(variant<_Types...>&& __v) { | |
| static_assert(!is_void_v<_Tp>); | |
| return _VSTD::get<__find_exactly_one_t<_Tp, _Types...>::value>( | |
| _VSTD::move(__v)); | |
| } | |
| template <class _Tp, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS | |
| constexpr const _Tp& get(const variant<_Types...>& __v) { | |
| static_assert(!is_void_v<_Tp>); | |
| return _VSTD::get<__find_exactly_one_t<_Tp, _Types...>::value>(__v); | |
| } | |
| template <class _Tp, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS | |
| constexpr const _Tp&& get(const variant<_Types...>&& __v) { | |
| static_assert(!is_void_v<_Tp>); | |
| return _VSTD::get<__find_exactly_one_t<_Tp, _Types...>::value>( | |
| _VSTD::move(__v)); | |
| } | |
| template <size_t _Ip, class _Vp> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr auto* __generic_get_if(_Vp* __v) noexcept { | |
| using __variant_detail::__access::__variant; | |
| return __v && __holds_alternative<_Ip>(*__v) | |
| ? _VSTD::addressof(__variant::__get_alt<_Ip>(*__v).__value) | |
| : nullptr; | |
| } | |
| template <size_t _Ip, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr add_pointer_t<variant_alternative_t<_Ip, variant<_Types...>>> | |
| get_if(variant<_Types...>* __v) noexcept { | |
| static_assert(_Ip < sizeof...(_Types)); | |
| static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>); | |
| return __generic_get_if<_Ip>(__v); | |
| } | |
| template <size_t _Ip, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr add_pointer_t<const variant_alternative_t<_Ip, variant<_Types...>>> | |
| get_if(const variant<_Types...>* __v) noexcept { | |
| static_assert(_Ip < sizeof...(_Types)); | |
| static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>); | |
| return __generic_get_if<_Ip>(__v); | |
| } | |
| template <class _Tp, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr add_pointer_t<_Tp> | |
| get_if(variant<_Types...>* __v) noexcept { | |
| static_assert(!is_void_v<_Tp>); | |
| return _VSTD::get_if<__find_exactly_one_t<_Tp, _Types...>::value>(__v); | |
| } | |
| template <class _Tp, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr add_pointer_t<const _Tp> | |
| get_if(const variant<_Types...>* __v) noexcept { | |
| static_assert(!is_void_v<_Tp>); | |
| return _VSTD::get_if<__find_exactly_one_t<_Tp, _Types...>::value>(__v); | |
| } | |
| template <class _Operator> | |
| struct __convert_to_bool { | |
| template <class _T1, class _T2> | |
| _LIBCPP_INLINE_VISIBILITY constexpr bool operator()(_T1 && __t1, _T2&& __t2) const { | |
| static_assert(is_convertible<decltype(_Operator{}(_VSTD::forward<_T1>(__t1), _VSTD::forward<_T2>(__t2))), bool>::value, | |
| "the relational operator does not return a type which is implicitly convertible to bool"); | |
| return _Operator{}(_VSTD::forward<_T1>(__t1), _VSTD::forward<_T2>(__t2)); | |
| } | |
| }; | |
| template <class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr bool operator==(const variant<_Types...>& __lhs, | |
| const variant<_Types...>& __rhs) { | |
| using __variant_detail::__visitation::__variant; | |
| if (__lhs.index() != __rhs.index()) return false; | |
| if (__lhs.valueless_by_exception()) return true; | |
| return __variant::__visit_value_at(__lhs.index(), __convert_to_bool<equal_to<>>{}, __lhs, __rhs); | |
| } | |
| template <class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr bool operator!=(const variant<_Types...>& __lhs, | |
| const variant<_Types...>& __rhs) { | |
| using __variant_detail::__visitation::__variant; | |
| if (__lhs.index() != __rhs.index()) return true; | |
| if (__lhs.valueless_by_exception()) return false; | |
| return __variant::__visit_value_at( | |
| __lhs.index(), __convert_to_bool<not_equal_to<>>{}, __lhs, __rhs); | |
| } | |
| template <class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr bool operator<(const variant<_Types...>& __lhs, | |
| const variant<_Types...>& __rhs) { | |
| using __variant_detail::__visitation::__variant; | |
| if (__rhs.valueless_by_exception()) return false; | |
| if (__lhs.valueless_by_exception()) return true; | |
| if (__lhs.index() < __rhs.index()) return true; | |
| if (__lhs.index() > __rhs.index()) return false; | |
| return __variant::__visit_value_at(__lhs.index(), __convert_to_bool<less<>>{}, __lhs, __rhs); | |
| } | |
| template <class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr bool operator>(const variant<_Types...>& __lhs, | |
| const variant<_Types...>& __rhs) { | |
| using __variant_detail::__visitation::__variant; | |
| if (__lhs.valueless_by_exception()) return false; | |
| if (__rhs.valueless_by_exception()) return true; | |
| if (__lhs.index() > __rhs.index()) return true; | |
| if (__lhs.index() < __rhs.index()) return false; | |
| return __variant::__visit_value_at(__lhs.index(), __convert_to_bool<greater<>>{}, __lhs, __rhs); | |
| } | |
| template <class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr bool operator<=(const variant<_Types...>& __lhs, | |
| const variant<_Types...>& __rhs) { | |
| using __variant_detail::__visitation::__variant; | |
| if (__lhs.valueless_by_exception()) return true; | |
| if (__rhs.valueless_by_exception()) return false; | |
| if (__lhs.index() < __rhs.index()) return true; | |
| if (__lhs.index() > __rhs.index()) return false; | |
| return __variant::__visit_value_at( | |
| __lhs.index(), __convert_to_bool<less_equal<>>{}, __lhs, __rhs); | |
| } | |
| template <class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr bool operator>=(const variant<_Types...>& __lhs, | |
| const variant<_Types...>& __rhs) { | |
| using __variant_detail::__visitation::__variant; | |
| if (__rhs.valueless_by_exception()) return true; | |
| if (__lhs.valueless_by_exception()) return false; | |
| if (__lhs.index() > __rhs.index()) return true; | |
| if (__lhs.index() < __rhs.index()) return false; | |
| return __variant::__visit_value_at( | |
| __lhs.index(), __convert_to_bool<greater_equal<>>{}, __lhs, __rhs); | |
| } | |
| template <class... _Vs> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr void | |
| __throw_if_valueless(_Vs&&... __vs) { | |
| const bool __valueless = | |
| (... || _VSTD::__as_variant(__vs).valueless_by_exception()); | |
| if (__valueless) { | |
| __throw_bad_variant_access(); | |
| } | |
| } | |
| template < | |
| class _Visitor, class... _Vs, | |
| typename = void_t<decltype(_VSTD::__as_variant(declval<_Vs>()))...> > | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr | |
| decltype(auto) visit(_Visitor&& __visitor, _Vs&&... __vs) { | |
| using __variant_detail::__visitation::__variant; | |
| _VSTD::__throw_if_valueless(_VSTD::forward<_Vs>(__vs)...); | |
| return __variant::__visit_value(_VSTD::forward<_Visitor>(__visitor), | |
| _VSTD::forward<_Vs>(__vs)...); | |
| } | |
| #if _LIBCPP_STD_VER > 17 | |
| template < | |
| class _Rp, class _Visitor, class... _Vs, | |
| typename = void_t<decltype(_VSTD::__as_variant(declval<_Vs>()))...> > | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr _Rp | |
| visit(_Visitor&& __visitor, _Vs&&... __vs) { | |
| using __variant_detail::__visitation::__variant; | |
| _VSTD::__throw_if_valueless(_VSTD::forward<_Vs>(__vs)...); | |
| return __variant::__visit_value<_Rp>(_VSTD::forward<_Visitor>(__visitor), | |
| _VSTD::forward<_Vs>(__vs)...); | |
| } | |
| #endif | |
| template <class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| auto swap(variant<_Types...>& __lhs, | |
| variant<_Types...>& __rhs) noexcept(noexcept(__lhs.swap(__rhs))) | |
| -> decltype(__lhs.swap(__rhs)) { | |
| __lhs.swap(__rhs); | |
| } | |
| template <class... _Types> | |
| struct _LIBCPP_TEMPLATE_VIS hash< | |
| __enable_hash_helper<variant<_Types...>, remove_const_t<_Types>...>> { | |
| using argument_type = variant<_Types...>; | |
| using result_type = size_t; | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| result_type operator()(const argument_type& __v) const { | |
| using __variant_detail::__visitation::__variant; | |
| size_t __res = | |
| __v.valueless_by_exception() | |
| ? 299792458 // Random value chosen by the universe upon creation | |
| : __variant::__visit_alt( | |
| [](const auto& __alt) { | |
| using __alt_type = __uncvref_t<decltype(__alt)>; | |
| using __value_type = remove_const_t< | |
| typename __alt_type::__value_type>; | |
| return hash<__value_type>{}(__alt.__value); | |
| }, | |
| __v); | |
| return __hash_combine(__res, hash<size_t>{}(__v.index())); | |
| } | |
| }; | |
| // __unchecked_get is the same as std::get, except, it is UB to use it with the wrong | |
| // type whereas std::get will throw or returning nullptr. This makes it faster than | |
| // std::get. | |
| template <size_t _Ip, class _Vp> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr auto&& __unchecked_get(_Vp&& __v) noexcept { | |
| using __variant_detail::__access::__variant; | |
| return __variant::__get_alt<_Ip>(_VSTD::forward<_Vp>(__v)).__value; | |
| } | |
| template <class _Tp, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr auto&& __unchecked_get(const variant<_Types...>& __v) noexcept { | |
| return __unchecked_get<__find_exactly_one_t<_Tp, _Types...>::value>(__v); | |
| } | |
| template <class _Tp, class... _Types> | |
| inline _LIBCPP_INLINE_VISIBILITY | |
| constexpr auto&& __unchecked_get(variant<_Types...>& __v) noexcept { | |
| return __unchecked_get<__find_exactly_one_t<_Tp, _Types...>::value>(__v); | |
| } | |
| #endif // _LIBCPP_STD_VER > 14 | |
| _LIBCPP_END_NAMESPACE_STD | |
| _LIBCPP_POP_MACROS | |
| #endif // _LIBCPP_VARIANT |