// -*- C++ -*- //===----------------------------------------------------------------------===// // // 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 variant { public: // 20.7.2.1, constructors constexpr variant() noexcept(see below); constexpr variant(const variant&); constexpr variant(variant&&) noexcept(see below); template constexpr variant(T&&) noexcept(see below); template constexpr explicit variant(in_place_type_t, Args&&...); template constexpr explicit variant( in_place_type_t, initializer_list, Args&&...); template constexpr explicit variant(in_place_index_t, Args&&...); template constexpr explicit variant( in_place_index_t, initializer_list, Args&&...); // 20.7.2.2, destructor ~variant(); // 20.7.2.3, assignment constexpr variant& operator=(const variant&); constexpr variant& operator=(variant&&) noexcept(see below); template variant& operator=(T&&) noexcept(see below); // 20.7.2.4, modifiers template T& emplace(Args&&...); template T& emplace(initializer_list, Args&&...); template variant_alternative_t& emplace(Args&&...); template variant_alternative_t& emplace(initializer_list, 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 struct variant_size; // undefined template inline constexpr size_t variant_size_v = variant_size::value; template struct variant_size; template struct variant_size; template struct variant_size; template struct variant_size>; template struct variant_alternative; // undefined template using variant_alternative_t = typename variant_alternative::type; template struct variant_alternative; template struct variant_alternative; template struct variant_alternative; template struct variant_alternative>; inline constexpr size_t variant_npos = -1; // 20.7.4, value access template constexpr bool holds_alternative(const variant&) noexcept; template constexpr variant_alternative_t>& get(variant&); template constexpr variant_alternative_t>&& get(variant&&); template constexpr variant_alternative_t> const& get(const variant&); template constexpr variant_alternative_t> const&& get(const variant&&); template constexpr T& get(variant&); template constexpr T&& get(variant&&); template constexpr const T& get(const variant&); template constexpr const T&& get(const variant&&); template constexpr add_pointer_t>> get_if(variant*) noexcept; template constexpr add_pointer_t>> get_if(const variant*) noexcept; template constexpr add_pointer_t get_if(variant*) noexcept; template constexpr add_pointer_t get_if(const variant*) noexcept; // 20.7.5, relational operators template constexpr bool operator==(const variant&, const variant&); template constexpr bool operator!=(const variant&, const variant&); template constexpr bool operator<(const variant&, const variant&); template constexpr bool operator>(const variant&, const variant&); template constexpr bool operator<=(const variant&, const variant&); template constexpr bool operator>=(const variant&, const variant&); template requires (three_way_comparable && ...) constexpr common_comparison_category_t...> operator<=>(const variant&, const variant&); // since C++20 // 20.7.6, visitation template constexpr see below visit(Visitor&&, Variants&&...); template 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; // until C++20 constexpr bool operator<(monostate, monostate) noexcept; // until C++20 constexpr bool operator>(monostate, monostate) noexcept; // until C++20 constexpr bool operator<=(monostate, monostate) noexcept; // until C++20 constexpr bool operator>=(monostate, monostate) noexcept; // until C++20 constexpr strong_ordering operator<=>(monostate, monostate) noexcept; // since C++20 // 20.7.9, specialized algorithms template void swap(variant&, variant&) noexcept(see below); // 20.7.10, class bad_variant_access class bad_variant_access; // 20.7.11, hash support template struct hash; template struct hash>; template <> struct hash; } // namespace std */ #include <__assert> // all public C++ headers provide the assertion handler #include <__availability> #include <__compare/common_comparison_category.h> #include <__compare/compare_three_way_result.h> #include <__compare/three_way_comparable.h> #include <__config> #include <__exception/exception.h> #include <__functional/hash.h> #include <__functional/invoke.h> #include <__functional/operations.h> #include <__functional/unary_function.h> #include <__memory/addressof.h> #include <__type_traits/add_const.h> #include <__type_traits/add_cv.h> #include <__type_traits/add_pointer.h> #include <__type_traits/add_volatile.h> #include <__type_traits/dependent_type.h> #include <__type_traits/is_array.h> #include <__type_traits/is_destructible.h> #include <__type_traits/is_nothrow_move_constructible.h> #include <__type_traits/is_trivially_copy_assignable.h> #include <__type_traits/is_trivially_copy_constructible.h> #include <__type_traits/is_trivially_destructible.h> #include <__type_traits/is_trivially_move_assignable.h> #include <__type_traits/is_trivially_move_constructible.h> #include <__type_traits/is_void.h> #include <__type_traits/remove_const.h> #include <__type_traits/type_identity.h> #include <__type_traits/void_t.h> #include <__utility/declval.h> #include <__utility/forward.h> #include <__utility/in_place.h> #include <__utility/move.h> #include <__utility/swap.h> #include <__variant/monostate.h> #include <__verbose_abort> #include #include #include #include #include // standard-mandated includes // [variant.syn] #include #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_EXPORTED_FROM_ABI _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS bad_variant_access : public exception { public: const char* what() const _NOEXCEPT override; }; } // namespace std _LIBCPP_BEGIN_NAMESPACE_STD #if _LIBCPP_STD_VER >= 17 // Light N-dimensional array of function pointers. Used in place of std::array to avoid // adding a dependency. template 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_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS void __throw_bad_variant_access() { #ifndef _LIBCPP_HAS_NO_EXCEPTIONS throw bad_variant_access(); #else _LIBCPP_VERBOSE_ABORT("bad_variant_access was thrown in -fno-exceptions mode"); #endif } template class _LIBCPP_TEMPLATE_VIS variant; template struct _LIBCPP_TEMPLATE_VIS variant_size; template inline constexpr size_t variant_size_v = variant_size<_Tp>::value; template struct _LIBCPP_TEMPLATE_VIS variant_size : variant_size<_Tp> {}; template struct _LIBCPP_TEMPLATE_VIS variant_size : variant_size<_Tp> {}; template struct _LIBCPP_TEMPLATE_VIS variant_size : variant_size<_Tp> {}; template struct _LIBCPP_TEMPLATE_VIS variant_size> : integral_constant {}; template struct _LIBCPP_TEMPLATE_VIS variant_alternative; template using variant_alternative_t = typename variant_alternative<_Ip, _Tp>::type; template struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, const _Tp> : add_const> {}; template struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, volatile _Tp> : add_volatile> {}; template struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, const volatile _Tp> : add_cv> {}; template 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...>; }; inline constexpr size_t variant_npos = static_cast(-1); _LIBCPP_HIDE_FROM_ABI constexpr int __choose_index_type(unsigned int __num_elem) { if (__num_elem < numeric_limits::max()) return 0; if (__num_elem < numeric_limits::max()) return 1; return 2; } template using __variant_index_t = #ifndef _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION unsigned int; #else std::tuple_element_t< __choose_index_type(_NumAlts), std::tuple >; #endif template constexpr _IndexType __variant_npos = static_cast<_IndexType>(-1); template class _LIBCPP_TEMPLATE_VIS variant; template _LIBCPP_INLINE_VISIBILITY constexpr variant<_Types...>& __as_variant(variant<_Types...>& __vs) noexcept { return __vs; } template _LIBCPP_INLINE_VISIBILITY constexpr const variant<_Types...>& __as_variant(const variant<_Types...>& __vs) noexcept { return __vs; } template _LIBCPP_INLINE_VISIBILITY constexpr variant<_Types...>&& __as_variant(variant<_Types...>&& __vs) noexcept { return _VSTD::move(__vs); } template _LIBCPP_INLINE_VISIBILITY constexpr const variant<_Types...>&& __as_variant(const variant<_Types...>&& __vs) noexcept { return _VSTD::move(__vs); } namespace __find_detail { template _LIBCPP_HIDE_FROM_ABI 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 struct __find_unambiguous_index_sfinae_impl : integral_constant {}; template <> struct __find_unambiguous_index_sfinae_impl<__not_found> {}; template <> struct __find_unambiguous_index_sfinae_impl<__ambiguous> {}; template 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 class _IsTriviallyAvailable, template class _IsAvailable> constexpr _Trait __trait = _IsTriviallyAvailable<_Tp>::value ? _Trait::_TriviallyAvailable : _IsAvailable<_Tp>::value ? _Trait::_Available : _Trait::_Unavailable; _LIBCPP_HIDE_FROM_ABI constexpr _Trait __common_trait(initializer_list<_Trait> __traits) { _Trait __result = _Trait::_TriviallyAvailable; for (_Trait __t : __traits) { if (static_cast(__t) > static_cast(__result)) { __result = __t; } } return __result; } template struct __traits { static constexpr _Trait __copy_constructible_trait = __variant_detail::__common_trait({__trait<_Types, is_trivially_copy_constructible, is_copy_constructible>...}); static constexpr _Trait __move_constructible_trait = __variant_detail::__common_trait({__trait<_Types, is_trivially_move_constructible, is_move_constructible>...}); static constexpr _Trait __copy_assignable_trait = __variant_detail::__common_trait( {__copy_constructible_trait, __trait<_Types, is_trivially_copy_assignable, is_copy_assignable>...}); static constexpr _Trait __move_assignable_trait = __variant_detail::__common_trait( {__move_constructible_trait, __trait<_Types, is_trivially_move_assignable, is_move_assignable>...}); static constexpr _Trait __destructible_trait = __variant_detail::__common_trait( {__trait<_Types, is_trivially_destructible, is_destructible>...}); }; namespace __access { struct __union { template _LIBCPP_HIDE_FROM_ABI static constexpr auto&& __get_alt(_Vp&& __v, in_place_index_t<0>) { return _VSTD::forward<_Vp>(__v).__head; } template _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI static constexpr auto&& __get_alt(_Vp&& __v) { return __union::__get_alt(_VSTD::forward<_Vp>(__v).__data, in_place_index<_Ip>); } }; struct __variant { template _LIBCPP_HIDE_FROM_ABI static constexpr auto&& __get_alt(_Vp&& __v) { return __base::__get_alt<_Ip>(_VSTD::forward<_Vp>(__v).__impl_); } }; } // namespace __access namespace __visitation { struct __base { template _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI static constexpr const _Tp& __at(const _Tp& __elem) { return __elem; } template _LIBCPP_HIDE_FROM_ABI static constexpr auto&& __at(const __farray<_Tp, _Np>& __elems, size_t __index, _Indices... __indices) { return __at(__elems[__index], __indices...); } template static _LIBCPP_HIDE_FROM_ABI constexpr void __std_visit_visitor_return_type_check() { static_assert( __all...>::value, "`std::visit` requires the visitor to have a single return type."); } template _LIBCPP_HIDE_FROM_ABI static constexpr auto __make_farray(_Fs&&... __fs) { __std_visit_visitor_return_type_check<__remove_cvref_t<_Fs>...>(); using __result = __farray...>, sizeof...(_Fs)>; return __result{{_VSTD::forward<_Fs>(__fs)...}}; } template struct __dispatcher { template _LIBCPP_HIDE_FROM_ABI static constexpr decltype(auto) __dispatch(_Fp __f, _Vs... __vs) { return _VSTD::__invoke( static_cast<_Fp>(__f), __access::__base::__get_alt<_Is>(static_cast<_Vs>(__vs))...); } }; template _LIBCPP_HIDE_FROM_ABI static constexpr auto __make_dispatch(index_sequence<_Is...>) { return __dispatcher<_Is...>::template __dispatch<_Fp, _Vs...>; } template _LIBCPP_HIDE_FROM_ABI static constexpr auto __make_fdiagonal_impl() { return __make_dispatch<_Fp, _Vs...>( index_sequence<((void)__type_identity<_Vs>{}, _Ip)...>{}); } template _LIBCPP_HIDE_FROM_ABI static constexpr auto __make_fdiagonal_impl(index_sequence<_Is...>) { return __base::__make_farray(__make_fdiagonal_impl<_Is, _Fp, _Vs...>()...); } template _LIBCPP_HIDE_FROM_ABI static constexpr auto __make_fdiagonal() { constexpr size_t __np = __remove_cvref_t<_Vp>::__size(); static_assert(__all<(__np == __remove_cvref_t<_Vs>::__size())...>::value); return __make_fdiagonal_impl<_Fp, _Vp, _Vs...>(make_index_sequence<__np>{}); } template _LIBCPP_HIDE_FROM_ABI static constexpr auto __make_fmatrix_impl(index_sequence<_Is...> __is) { return __make_dispatch<_Fp, _Vs...>(__is); } template _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI static constexpr auto __make_fmatrix() { return __make_fmatrix_impl<_Fp, _Vs...>( index_sequence<>{}, make_index_sequence<__remove_cvref_t<_Vs>::__size()>{}...); } }; struct __variant { template _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI 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 >= 20 template _LIBCPP_HIDE_FROM_ABI 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 static _LIBCPP_HIDE_FROM_ABI constexpr void __std_visit_exhaustive_visitor_check() { static_assert(is_invocable_v<_Visitor, _Values...>, "`std::visit` requires the visitor to be exhaustive."); } template struct __value_visitor { template _LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) operator()(_Alts&&... __alts) const { __std_visit_exhaustive_visitor_check< _Visitor, decltype((_VSTD::forward<_Alts>(__alts).__value))...>(); return _VSTD::__invoke(_VSTD::forward<_Visitor>(__visitor), _VSTD::forward<_Alts>(__alts).__value...); } _Visitor&& __visitor; }; #if _LIBCPP_STD_VER >= 20 template struct __value_visitor_return_type { template _LIBCPP_HIDE_FROM_ABI 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(_VSTD::forward<_Visitor>(__visitor), _VSTD::forward<_Alts>(__alts).__value...); } else { return _VSTD::__invoke(_VSTD::forward<_Visitor>(__visitor), _VSTD::forward<_Alts>(__alts).__value...); } } _Visitor&& __visitor; }; #endif template _LIBCPP_HIDE_FROM_ABI static constexpr auto __make_value_visitor(_Visitor&& __visitor) { return __value_visitor<_Visitor>{_VSTD::forward<_Visitor>(__visitor)}; } #if _LIBCPP_STD_VER >= 20 template _LIBCPP_HIDE_FROM_ABI static constexpr auto __make_value_visitor(_Visitor&& __visitor) { return __value_visitor_return_type<_Rp, _Visitor>{_VSTD::forward<_Visitor>(__visitor)}; } #endif }; } // namespace __visitation template struct _LIBCPP_TEMPLATE_VIS __alt { using __value_type = _Tp; template _LIBCPP_HIDE_FROM_ABI 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 \ union _LIBCPP_TEMPLATE_VIS __union { \ public: \ _LIBCPP_HIDE_FROM_ABI \ explicit constexpr __union(__valueless_t) noexcept : __dummy{} {} \ \ template \ _LIBCPP_HIDE_FROM_ABI \ explicit constexpr __union(in_place_index_t<0>, _Args&&... __args) \ : __head(in_place, _VSTD::forward<_Args>(__args)...) {} \ \ template \ _LIBCPP_HIDE_FROM_ABI \ 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 __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; _LIBCPP_HIDE_FROM_ABI explicit constexpr __base(__valueless_t __tag) noexcept : __data(__tag), __index(__variant_npos<__index_t>) {} template _LIBCPP_HIDE_FROM_ABI explicit constexpr __base(in_place_index_t<_Ip>, _Args&&... __args) : __data(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...), __index(_Ip) {} _LIBCPP_HIDE_FROM_ABI constexpr bool valueless_by_exception() const noexcept { return index() == variant_npos; } _LIBCPP_HIDE_FROM_ABI constexpr size_t index() const noexcept { return __index == __variant_npos<__index_t> ? variant_npos : __index; } protected: _LIBCPP_HIDE_FROM_ABI constexpr auto&& __as_base() & { return *this; } _LIBCPP_HIDE_FROM_ABI constexpr auto&& __as_base() && { return _VSTD::move(*this); } _LIBCPP_HIDE_FROM_ABI constexpr auto&& __as_base() const & { return *this; } _LIBCPP_HIDE_FROM_ABI constexpr auto&& __as_base() const && { return _VSTD::move(*this); } _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_TEMPLATE_VIS __dtor; #define _LIBCPP_VARIANT_DESTRUCTOR(destructible_trait, destructor, destroy) \ template \ class _LIBCPP_TEMPLATE_VIS __dtor<__traits<_Types...>, \ destructible_trait> \ : public __base { \ using __base_type = __base; \ 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_HIDE_FROM_ABI \ 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 = __remove_cvref_t; __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 _LIBCPP_TEMPLATE_VIS __ctor : public __dtor<_Traits> { using __base_type = __dtor<_Traits>; public: using __base_type::__base_type; using __base_type::operator=; protected: template _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI 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(__rhs_alt).__value); }, __lhs, _VSTD::forward<_Rhs>(__rhs)); __lhs.__index = __rhs.index(); } } }; template class _LIBCPP_TEMPLATE_VIS __move_constructor; #define _LIBCPP_VARIANT_MOVE_CONSTRUCTOR(move_constructible_trait, \ move_constructor) \ template \ 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...>::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 _LIBCPP_TEMPLATE_VIS __copy_constructor; #define _LIBCPP_VARIANT_COPY_CONSTRUCTOR(copy_constructible_trait, \ copy_constructor) \ template \ 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 _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 _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI void __assign_alt(__alt<_Ip, _Tp>& __a, _Arg&& __arg) { if (this->index() == _Ip) { __a.__value = _VSTD::forward<_Arg>(__arg); } else { struct { _LIBCPP_HIDE_FROM_ABI void operator()(true_type) const { __this->__emplace<_Ip>(_VSTD::forward<_Arg>(__arg)); } _LIBCPP_HIDE_FROM_ABI 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_move_constructible_v<_Tp>>{}); } } template _LIBCPP_HIDE_FROM_ABI 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(__that_alt).__value); }, *this, _VSTD::forward<_That>(__that)); } } }; template class _LIBCPP_TEMPLATE_VIS __move_assignment; #define _LIBCPP_VARIANT_MOVE_ASSIGNMENT(move_assignable_trait, \ move_assignment) \ template \ 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 _LIBCPP_TEMPLATE_VIS __copy_assignment; #define _LIBCPP_VARIANT_COPY_ASSIGNMENT(copy_assignable_trait, \ copy_assignment) \ template \ 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 _LIBCPP_TEMPLATE_VIS __impl : public __copy_assignment<__traits<_Types...>> { using __base_type = __copy_assignment<__traits<_Types...>>; public: using __base_type::__base_type; // get in_place_index_t constructor & friends _LIBCPP_HIDE_FROM_ABI __impl(__impl const&) = default; _LIBCPP_HIDE_FROM_ABI __impl(__impl&&) = default; _LIBCPP_HIDE_FROM_ABI __impl& operator=(__impl const&) = default; _LIBCPP_HIDE_FROM_ABI __impl& operator=(__impl&&) = default; template _LIBCPP_HIDE_FROM_ABI void __assign(_Arg&& __arg) { this->__assign_alt(__access::__base::__get_alt<_Ip>(*this), _VSTD::forward<_Arg>(__arg)); } inline _LIBCPP_HIDE_FROM_ABI 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_HAS_NO_EXCEPTIONS if constexpr (__all...>::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_HIDE_FROM_ABI 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 using _Apply = __type_identity<_Dest>; }; struct __narrowing_check { template static auto __test_impl(_Dest (&&)[1]) -> __type_identity<_Dest>; template using _Apply _LIBCPP_NODEBUG = decltype(__test_impl<_Dest>({std::declval<_Source>()})); }; template using __check_for_narrowing _LIBCPP_NODEBUG = 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 struct __overload { template auto operator()(_Tp, _Up&&) const -> __check_for_narrowing<_Tp, _Up>; }; template struct __overload_bool { template > auto operator()(bool, _Up&&) const -> enable_if_t, __type_identity<_Tp>>; }; template struct __overload : __overload_bool {}; template struct __overload : __overload_bool {}; template struct __overload : __overload_bool {}; template struct __overload : __overload_bool {}; template struct __all_overloads : _Bases... { void operator()() const; using _Bases::operator()...; }; template struct __make_overloads_imp; template struct __make_overloads_imp<__tuple_indices<_Idx...> > { template using _Apply _LIBCPP_NODEBUG = __all_overloads<__overload<_Types, _Idx>...>; }; template using _MakeOverloads _LIBCPP_NODEBUG = typename __make_overloads_imp< __make_indices_imp >::template _Apply<_Types...>; template using __best_match_t = typename invoke_result_t<_MakeOverloads<_Types...>, _Tp, _Tp>::type; } // namespace __variant_detail template class _LIBCPP_TEMPLATE_VIS _LIBCPP_DECLSPEC_EMPTY_BASES variant : private __sfinae_ctor_base< __all...>::value, __all...>::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...>::value, "variant can not have an array type as an alternative."); static_assert(__all...>::value, "variant can not have a reference type as an alternative."); static_assert(__all...>::value, "variant can not have a void type as an alternative."); using __first_type = variant_alternative_t<0, variant>; public: template , _Dummy>::value, int> = 0> _LIBCPP_HIDE_FROM_ABI constexpr variant() noexcept(is_nothrow_default_constructible_v<__first_type>) : __impl_(in_place_index<0>) {} _LIBCPP_HIDE_FROM_ABI constexpr variant(const variant&) = default; _LIBCPP_HIDE_FROM_ABI constexpr variant(variant&&) = default; template < class _Arg, enable_if_t, variant>, int> = 0, enable_if_t>::value, int> = 0, enable_if_t>::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, int> = 0> _LIBCPP_HIDE_FROM_ABI constexpr variant(_Arg&& __arg) noexcept( is_nothrow_constructible_v<_Tp, _Arg>) : __impl_(in_place_index<_Ip>, _VSTD::forward<_Arg>(__arg)) {} template , class _Tp = variant_alternative_t<_Ip, variant<_Types...>>, enable_if_t, int> = 0> _LIBCPP_HIDE_FROM_ABI 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&, _Args...>, int> = 0> _LIBCPP_HIDE_FROM_ABI 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, int> = 0> _LIBCPP_HIDE_FROM_ABI 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&, _Args...>, int> = 0> _LIBCPP_HIDE_FROM_ABI 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)...) {} _LIBCPP_HIDE_FROM_ABI ~variant() = default; _LIBCPP_HIDE_FROM_ABI constexpr variant& operator=(const variant&) = default; _LIBCPP_HIDE_FROM_ABI constexpr variant& operator=(variant&&) = default; template < class _Arg, enable_if_t, 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_constructible_v<_Tp, _Arg>, int> = 0> _LIBCPP_HIDE_FROM_ABI 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, int> = 0> _LIBCPP_HIDE_FROM_ABI _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&, _Args...>, int> = 0> _LIBCPP_HIDE_FROM_ABI _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, int> = 0> _LIBCPP_HIDE_FROM_ABI _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&, _Args...>, int> = 0> _LIBCPP_HIDE_FROM_ABI _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) { return __impl_.template __emplace<_Ip>(__il, _VSTD::forward<_Args>(__args)...); } _LIBCPP_HIDE_FROM_ABI constexpr bool valueless_by_exception() const noexcept { return __impl_.valueless_by_exception(); } _LIBCPP_HIDE_FROM_ABI constexpr size_t index() const noexcept { return __impl_.index(); } template < bool _Dummy = true, enable_if_t< __all<( __dependent_type, _Dummy>::value && __dependent_type, _Dummy>::value)...>::value, int> = 0> _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI constexpr bool __holds_alternative(const variant<_Types...>& __v) noexcept { return __v.index() == _Ip; } template _LIBCPP_HIDE_FROM_ABI constexpr bool holds_alternative(const variant<_Types...>& __v) noexcept { return std::__holds_alternative<__find_exactly_one_t<_Tp, _Types...>::value>(__v); } template _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr auto&& __generic_get(_Vp&& __v) { using __variant_detail::__access::__variant; if (!std::__holds_alternative<_Ip>(__v)) { __throw_bad_variant_access(); } return __variant::__get_alt<_Ip>(_VSTD::forward<_Vp>(__v)).__value; } template _LIBCPP_HIDE_FROM_ABI _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>>); return std::__generic_get<_Ip>(__v); } template _LIBCPP_HIDE_FROM_ABI _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>>); return std::__generic_get<_Ip>(_VSTD::move(__v)); } template _LIBCPP_HIDE_FROM_ABI _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>>); return std::__generic_get<_Ip>(__v); } template _LIBCPP_HIDE_FROM_ABI _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>>); return std::__generic_get<_Ip>(_VSTD::move(__v)); } template _LIBCPP_HIDE_FROM_ABI _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 _LIBCPP_HIDE_FROM_ABI _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 _LIBCPP_HIDE_FROM_ABI _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 _LIBCPP_HIDE_FROM_ABI _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 _LIBCPP_HIDE_FROM_ABI constexpr auto* __generic_get_if(_Vp* __v) noexcept { using __variant_detail::__access::__variant; return __v && std::__holds_alternative<_Ip>(*__v) ? _VSTD::addressof(__variant::__get_alt<_Ip>(*__v).__value) : nullptr; } template _LIBCPP_HIDE_FROM_ABI constexpr add_pointer_t>> get_if(variant<_Types...>* __v) noexcept { static_assert(_Ip < sizeof...(_Types)); static_assert(!is_void_v>>); return std::__generic_get_if<_Ip>(__v); } template _LIBCPP_HIDE_FROM_ABI constexpr add_pointer_t>> get_if(const variant<_Types...>* __v) noexcept { static_assert(_Ip < sizeof...(_Types)); static_assert(!is_void_v>>); return std::__generic_get_if<_Ip>(__v); } template _LIBCPP_HIDE_FROM_ABI 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 _LIBCPP_HIDE_FROM_ABI constexpr add_pointer_t 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 struct __convert_to_bool { template _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(_T1 && __t1, _T2&& __t2) const { static_assert(is_convertible(__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 _LIBCPP_HIDE_FROM_ABI 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>{}, __lhs, __rhs); } # if _LIBCPP_STD_VER >= 20 template requires (three_way_comparable<_Types> && ...) _LIBCPP_HIDE_FROM_ABI constexpr common_comparison_category_t...> operator<=>(const variant<_Types...>& __lhs, const variant<_Types...>& __rhs) { using __variant_detail::__visitation::__variant; using __result_t = common_comparison_category_t...>; if (__lhs.valueless_by_exception() && __rhs.valueless_by_exception()) return strong_ordering::equal; if (__lhs.valueless_by_exception()) return strong_ordering::less; if (__rhs.valueless_by_exception()) return strong_ordering::greater; if (auto __c = __lhs.index() <=> __rhs.index(); __c != 0) return __c; auto __three_way = [](const _Type& __v, const _Type& __w) -> __result_t { return __v <=> __w; }; return __variant::__visit_value_at(__lhs.index(), __three_way, __lhs, __rhs); } # endif // _LIBCPP_STD_VER >= 20 template _LIBCPP_HIDE_FROM_ABI 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>{}, __lhs, __rhs); } template _LIBCPP_HIDE_FROM_ABI 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>{}, __lhs, __rhs); } template _LIBCPP_HIDE_FROM_ABI 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>{}, __lhs, __rhs); } template _LIBCPP_HIDE_FROM_ABI 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>{}, __lhs, __rhs); } template _LIBCPP_HIDE_FROM_ABI 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>{}, __lhs, __rhs); } template _LIBCPP_HIDE_FROM_ABI _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()))...> > _LIBCPP_HIDE_FROM_ABI _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 >= 20 template < class _Rp, class _Visitor, class... _Vs, typename = void_t()))...> > _LIBCPP_HIDE_FROM_ABI _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 _LIBCPP_HIDE_FROM_ABI auto swap(variant<_Types...>& __lhs, variant<_Types...>& __rhs) noexcept(noexcept(__lhs.swap(__rhs))) -> decltype( __lhs.swap(__rhs)) { return __lhs.swap(__rhs); } template struct _LIBCPP_TEMPLATE_VIS hash< __enable_hash_helper, remove_const_t<_Types>...>> { using argument_type = variant<_Types...>; using result_type = size_t; _LIBCPP_HIDE_FROM_ABI 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 = __remove_cvref_t; using __value_type = remove_const_t< typename __alt_type::__value_type>; return hash<__value_type>{}(__alt.__value); }, __v); return std::__hash_combine(__res, hash{}(__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 _LIBCPP_HIDE_FROM_ABI constexpr auto&& __unchecked_get(_Vp&& __v) noexcept { using __variant_detail::__access::__variant; return __variant::__get_alt<_Ip>(_VSTD::forward<_Vp>(__v)).__value; } template _LIBCPP_HIDE_FROM_ABI constexpr auto&& __unchecked_get(const variant<_Types...>& __v) noexcept { return std::__unchecked_get<__find_exactly_one_t<_Tp, _Types...>::value>(__v); } template _LIBCPP_HIDE_FROM_ABI constexpr auto&& __unchecked_get(variant<_Types...>& __v) noexcept { return std::__unchecked_get<__find_exactly_one_t<_Tp, _Types...>::value>(__v); } #endif // _LIBCPP_STD_VER >= 17 _LIBCPP_END_NAMESPACE_STD _LIBCPP_POP_MACROS #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20 # include # include # include # include #endif #endif // _LIBCPP_VARIANT