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Diffstat (limited to 'include/mapbox/variant.hpp')
| -rw-r--r-- | include/mapbox/variant.hpp | 1013 |
1 files changed, 0 insertions, 1013 deletions
diff --git a/include/mapbox/variant.hpp b/include/mapbox/variant.hpp deleted file mode 100644 index fb0f77e..0000000 --- a/include/mapbox/variant.hpp +++ /dev/null @@ -1,1013 +0,0 @@ -#ifndef MAPBOX_UTIL_VARIANT_HPP -#define MAPBOX_UTIL_VARIANT_HPP - -#include <cassert> -#include <cstddef> // size_t -#include <new> // operator new -#include <stdexcept> // runtime_error -#include <string> -#include <tuple> -#include <type_traits> -#include <typeinfo> -#include <utility> -#include <functional> - -#include <mapbox/recursive_wrapper.hpp> -#include <mapbox/variant_visitor.hpp> - -// clang-format off -// [[deprecated]] is only available in C++14, use this for the time being -#if __cplusplus <= 201103L -# ifdef __GNUC__ -# define MAPBOX_VARIANT_DEPRECATED __attribute__((deprecated)) -# elif defined(_MSC_VER) -# define MAPBOX_VARIANT_DEPRECATED __declspec(deprecated) -# else -# define MAPBOX_VARIANT_DEPRECATED -# endif -#else -# define MAPBOX_VARIANT_DEPRECATED [[deprecated]] -#endif - - -#ifdef _MSC_VER -// https://msdn.microsoft.com/en-us/library/bw1hbe6y.aspx -# ifdef NDEBUG -# define VARIANT_INLINE __forceinline -# else -# define VARIANT_INLINE //__declspec(noinline) -# endif -#else -# ifdef NDEBUG -# define VARIANT_INLINE //inline __attribute__((always_inline)) -# else -# define VARIANT_INLINE __attribute__((noinline)) -# endif -#endif -// clang-format on - -// Exceptions -#if defined( __EXCEPTIONS) || defined( _MSC_VER) -#define HAS_EXCEPTIONS -#endif - -#define VARIANT_MAJOR_VERSION 1 -#define VARIANT_MINOR_VERSION 1 -#define VARIANT_PATCH_VERSION 0 - -#define VARIANT_VERSION (VARIANT_MAJOR_VERSION * 100000) + (VARIANT_MINOR_VERSION * 100) + (VARIANT_PATCH_VERSION) - -namespace mapbox { -namespace util { - -// XXX This should derive from std::logic_error instead of std::runtime_error. -// See https://github.com/mapbox/variant/issues/48 for details. -class bad_variant_access : public std::runtime_error -{ - -public: - explicit bad_variant_access(const std::string& what_arg) - : runtime_error(what_arg) {} - - explicit bad_variant_access(const char* what_arg) - : runtime_error(what_arg) {} - -}; // class bad_variant_access - -template <typename R = void> -struct MAPBOX_VARIANT_DEPRECATED static_visitor -{ - using result_type = R; - -protected: - static_visitor() {} - ~static_visitor() {} -}; - -namespace detail { - -static constexpr std::size_t invalid_value = std::size_t(-1); - -template <typename T, typename... Types> -struct direct_type; - -template <typename T, typename First, typename... Types> -struct direct_type<T, First, Types...> -{ - static constexpr std::size_t index = std::is_same<T, First>::value - ? sizeof...(Types) - : direct_type<T, Types...>::index; -}; - -template <typename T> -struct direct_type<T> -{ - static constexpr std::size_t index = invalid_value; -}; - -#if __cpp_lib_logical_traits >= 201510L - -using std::disjunction; - -#else - -template <typename...> -struct disjunction : std::false_type {}; - -template <typename B1> -struct disjunction<B1> : B1 {}; - -template <typename B1, typename B2> -struct disjunction<B1, B2> : std::conditional<B1::value, B1, B2>::type {}; - -template <typename B1, typename... Bs> -struct disjunction<B1, Bs...> : std::conditional<B1::value, B1, disjunction<Bs...>>::type {}; - -#endif - -template <typename T, typename... Types> -struct convertible_type; - -template <typename T, typename First, typename... Types> -struct convertible_type<T, First, Types...> -{ - static constexpr std::size_t index = std::is_convertible<T, First>::value - ? disjunction<std::is_convertible<T, Types>...>::value ? invalid_value : sizeof...(Types) - : convertible_type<T, Types...>::index; -}; - -template <typename T> -struct convertible_type<T> -{ - static constexpr std::size_t index = invalid_value; -}; - -template <typename T, typename... Types> -struct value_traits -{ - using value_type = typename std::remove_const<typename std::remove_reference<T>::type>::type; - static constexpr std::size_t direct_index = direct_type<value_type, Types...>::index; - static constexpr bool is_direct = direct_index != invalid_value; - static constexpr std::size_t index = is_direct ? direct_index : convertible_type<value_type, Types...>::index; - static constexpr bool is_valid = index != invalid_value; - static constexpr std::size_t tindex = is_valid ? sizeof...(Types)-index : 0; - using target_type = typename std::tuple_element<tindex, std::tuple<void, Types...>>::type; -}; - -template <typename T, typename R = void> -struct enable_if_type -{ - using type = R; -}; - -template <typename F, typename V, typename Enable = void> -struct result_of_unary_visit -{ - using type = typename std::result_of<F(V&)>::type; -}; - -template <typename F, typename V> -struct result_of_unary_visit<F, V, typename enable_if_type<typename F::result_type>::type> -{ - using type = typename F::result_type; -}; - -template <typename F, typename V, typename Enable = void> -struct result_of_binary_visit -{ - using type = typename std::result_of<F(V&, V&)>::type; -}; - -template <typename F, typename V> -struct result_of_binary_visit<F, V, typename enable_if_type<typename F::result_type>::type> -{ - using type = typename F::result_type; -}; - -template <std::size_t arg1, std::size_t... others> -struct static_max; - -template <std::size_t arg> -struct static_max<arg> -{ - static const std::size_t value = arg; -}; - -template <std::size_t arg1, std::size_t arg2, std::size_t... others> -struct static_max<arg1, arg2, others...> -{ - static const std::size_t value = arg1 >= arg2 ? static_max<arg1, others...>::value : static_max<arg2, others...>::value; -}; - -template <typename... Types> -struct variant_helper; - -template <typename T, typename... Types> -struct variant_helper<T, Types...> -{ - VARIANT_INLINE static void destroy(const std::size_t type_index, void* data) - { - if (type_index == sizeof...(Types)) - { - reinterpret_cast<T*>(data)->~T(); - } - else - { - variant_helper<Types...>::destroy(type_index, data); - } - } - - VARIANT_INLINE static void move(const std::size_t old_type_index, void* old_value, void* new_value) - { - if (old_type_index == sizeof...(Types)) - { - new (new_value) T(std::move(*reinterpret_cast<T*>(old_value))); - } - else - { - variant_helper<Types...>::move(old_type_index, old_value, new_value); - } - } - - VARIANT_INLINE static void copy(const std::size_t old_type_index, const void* old_value, void* new_value) - { - if (old_type_index == sizeof...(Types)) - { - new (new_value) T(*reinterpret_cast<const T*>(old_value)); - } - else - { - variant_helper<Types...>::copy(old_type_index, old_value, new_value); - } - } -}; - -template <> -struct variant_helper<> -{ - VARIANT_INLINE static void destroy(const std::size_t, void*) {} - VARIANT_INLINE static void move(const std::size_t, void*, void*) {} - VARIANT_INLINE static void copy(const std::size_t, const void*, void*) {} -}; - -template <typename T> -struct unwrapper -{ - static T const& apply_const(T const& obj) { return obj; } - static T& apply(T& obj) { return obj; } -}; - -template <typename T> -struct unwrapper<recursive_wrapper<T>> -{ - static auto apply_const(recursive_wrapper<T> const& obj) - -> typename recursive_wrapper<T>::type const& - { - return obj.get(); - } - static auto apply(recursive_wrapper<T>& obj) - -> typename recursive_wrapper<T>::type& - { - return obj.get(); - } -}; - -template <typename T> -struct unwrapper<std::reference_wrapper<T>> -{ - static auto apply_const(std::reference_wrapper<T> const& obj) - -> typename std::reference_wrapper<T>::type const& - { - return obj.get(); - } - static auto apply(std::reference_wrapper<T>& obj) - -> typename std::reference_wrapper<T>::type& - { - return obj.get(); - } -}; - -template <typename F, typename V, typename R, typename... Types> -struct dispatcher; - -template <typename F, typename V, typename R, typename T, typename... Types> -struct dispatcher<F, V, R, T, Types...> -{ - VARIANT_INLINE static R apply_const(V const& v, F&& f) - { - if (v.template is<T>()) - { - return f(unwrapper<T>::apply_const(v.template get_unchecked<T>())); - } - else - { - return dispatcher<F, V, R, Types...>::apply_const(v, std::forward<F>(f)); - } - } - - VARIANT_INLINE static R apply(V& v, F&& f) - { - if (v.template is<T>()) - { - return f(unwrapper<T>::apply(v.template get_unchecked<T>())); - } - else - { - return dispatcher<F, V, R, Types...>::apply(v, std::forward<F>(f)); - } - } -}; - -template <typename F, typename V, typename R, typename T> -struct dispatcher<F, V, R, T> -{ - VARIANT_INLINE static R apply_const(V const& v, F&& f) - { - return f(unwrapper<T>::apply_const(v.template get_unchecked<T>())); - } - - VARIANT_INLINE static R apply(V& v, F&& f) - { - return f(unwrapper<T>::apply(v.template get_unchecked<T>())); - } -}; - -template <typename F, typename V, typename R, typename T, typename... Types> -struct binary_dispatcher_rhs; - -template <typename F, typename V, typename R, typename T0, typename T1, typename... Types> -struct binary_dispatcher_rhs<F, V, R, T0, T1, Types...> -{ - VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f) - { - if (rhs.template is<T1>()) // call binary functor - { - return f(unwrapper<T0>::apply_const(lhs.template get_unchecked<T0>()), - unwrapper<T1>::apply_const(rhs.template get_unchecked<T1>())); - } - else - { - return binary_dispatcher_rhs<F, V, R, T0, Types...>::apply_const(lhs, rhs, std::forward<F>(f)); - } - } - - VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f) - { - if (rhs.template is<T1>()) // call binary functor - { - return f(unwrapper<T0>::apply(lhs.template get_unchecked<T0>()), - unwrapper<T1>::apply(rhs.template get_unchecked<T1>())); - } - else - { - return binary_dispatcher_rhs<F, V, R, T0, Types...>::apply(lhs, rhs, std::forward<F>(f)); - } - } -}; - -template <typename F, typename V, typename R, typename T0, typename T1> -struct binary_dispatcher_rhs<F, V, R, T0, T1> -{ - VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f) - { - return f(unwrapper<T0>::apply_const(lhs.template get_unchecked<T0>()), - unwrapper<T1>::apply_const(rhs.template get_unchecked<T1>())); - } - - VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f) - { - return f(unwrapper<T0>::apply(lhs.template get_unchecked<T0>()), - unwrapper<T1>::apply(rhs.template get_unchecked<T1>())); - } -}; - -template <typename F, typename V, typename R, typename T, typename... Types> -struct binary_dispatcher_lhs; - -template <typename F, typename V, typename R, typename T0, typename T1, typename... Types> -struct binary_dispatcher_lhs<F, V, R, T0, T1, Types...> -{ - VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f) - { - if (lhs.template is<T1>()) // call binary functor - { - return f(unwrapper<T1>::apply_const(lhs.template get_unchecked<T1>()), - unwrapper<T0>::apply_const(rhs.template get_unchecked<T0>())); - } - else - { - return binary_dispatcher_lhs<F, V, R, T0, Types...>::apply_const(lhs, rhs, std::forward<F>(f)); - } - } - - VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f) - { - if (lhs.template is<T1>()) // call binary functor - { - return f(unwrapper<T1>::apply(lhs.template get_unchecked<T1>()), - unwrapper<T0>::apply(rhs.template get_unchecked<T0>())); - } - else - { - return binary_dispatcher_lhs<F, V, R, T0, Types...>::apply(lhs, rhs, std::forward<F>(f)); - } - } -}; - -template <typename F, typename V, typename R, typename T0, typename T1> -struct binary_dispatcher_lhs<F, V, R, T0, T1> -{ - VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f) - { - return f(unwrapper<T1>::apply_const(lhs.template get_unchecked<T1>()), - unwrapper<T0>::apply_const(rhs.template get_unchecked<T0>())); - } - - VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f) - { - return f(unwrapper<T1>::apply(lhs.template get_unchecked<T1>()), - unwrapper<T0>::apply(rhs.template get_unchecked<T0>())); - } -}; - -template <typename F, typename V, typename R, typename... Types> -struct binary_dispatcher; - -template <typename F, typename V, typename R, typename T, typename... Types> -struct binary_dispatcher<F, V, R, T, Types...> -{ - VARIANT_INLINE static R apply_const(V const& v0, V const& v1, F&& f) - { - if (v0.template is<T>()) - { - if (v1.template is<T>()) - { - return f(unwrapper<T>::apply_const(v0.template get_unchecked<T>()), - unwrapper<T>::apply_const(v1.template get_unchecked<T>())); // call binary functor - } - else - { - return binary_dispatcher_rhs<F, V, R, T, Types...>::apply_const(v0, v1, std::forward<F>(f)); - } - } - else if (v1.template is<T>()) - { - return binary_dispatcher_lhs<F, V, R, T, Types...>::apply_const(v0, v1, std::forward<F>(f)); - } - return binary_dispatcher<F, V, R, Types...>::apply_const(v0, v1, std::forward<F>(f)); - } - - VARIANT_INLINE static R apply(V& v0, V& v1, F&& f) - { - if (v0.template is<T>()) - { - if (v1.template is<T>()) - { - return f(unwrapper<T>::apply(v0.template get_unchecked<T>()), - unwrapper<T>::apply(v1.template get_unchecked<T>())); // call binary functor - } - else - { - return binary_dispatcher_rhs<F, V, R, T, Types...>::apply(v0, v1, std::forward<F>(f)); - } - } - else if (v1.template is<T>()) - { - return binary_dispatcher_lhs<F, V, R, T, Types...>::apply(v0, v1, std::forward<F>(f)); - } - return binary_dispatcher<F, V, R, Types...>::apply(v0, v1, std::forward<F>(f)); - } -}; - -template <typename F, typename V, typename R, typename T> -struct binary_dispatcher<F, V, R, T> -{ - VARIANT_INLINE static R apply_const(V const& v0, V const& v1, F&& f) - { - return f(unwrapper<T>::apply_const(v0.template get_unchecked<T>()), - unwrapper<T>::apply_const(v1.template get_unchecked<T>())); // call binary functor - } - - VARIANT_INLINE static R apply(V& v0, V& v1, F&& f) - { - return f(unwrapper<T>::apply(v0.template get_unchecked<T>()), - unwrapper<T>::apply(v1.template get_unchecked<T>())); // call binary functor - } -}; - -// comparator functors -struct equal_comp -{ - template <typename T> - bool operator()(T const& lhs, T const& rhs) const - { - return lhs == rhs; - } -}; - -struct less_comp -{ - template <typename T> - bool operator()(T const& lhs, T const& rhs) const - { - return lhs < rhs; - } -}; - -template <typename Variant, typename Comp> -class comparer -{ -public: - explicit comparer(Variant const& lhs) noexcept - : lhs_(lhs) {} - comparer& operator=(comparer const&) = delete; - // visitor - template <typename T> - bool operator()(T const& rhs_content) const - { - T const& lhs_content = lhs_.template get_unchecked<T>(); - return Comp()(lhs_content, rhs_content); - } - -private: - Variant const& lhs_; -}; - -// hashing visitor -struct hasher -{ - template <typename T> - std::size_t operator()(const T& hashable) const - { - return std::hash<T>{}(hashable); - } -}; - -} // namespace detail - -struct no_init -{ -}; - -template <typename... Types> -class variant -{ - static_assert(sizeof...(Types) > 0, "Template parameter type list of variant can not be empty"); - static_assert(!detail::disjunction<std::is_reference<Types>...>::value, "Variant can not hold reference types. Maybe use std::reference_wrapper?"); - -private: - static const std::size_t data_size = detail::static_max<sizeof(Types)...>::value; - static const std::size_t data_align = detail::static_max<alignof(Types)...>::value; -public: - struct adapted_variant_tag; - using types = std::tuple<Types...>; -private: - using first_type = typename std::tuple_element<0, types>::type; - using data_type = typename std::aligned_storage<data_size, data_align>::type; - using helper_type = detail::variant_helper<Types...>; - - std::size_t type_index; - data_type data; - -public: - VARIANT_INLINE variant() noexcept(std::is_nothrow_default_constructible<first_type>::value) - : type_index(sizeof...(Types)-1) - { - static_assert(std::is_default_constructible<first_type>::value, "First type in variant must be default constructible to allow default construction of variant"); - new (&data) first_type(); - } - - VARIANT_INLINE variant(no_init) noexcept - : type_index(detail::invalid_value) {} - - // http://isocpp.org/blog/2012/11/universal-references-in-c11-scott-meyers - template <typename T, typename Traits = detail::value_traits<T, Types...>, - typename Enable = typename std::enable_if<Traits::is_valid && !std::is_same<variant<Types...>, typename Traits::value_type>::value>::type > - VARIANT_INLINE variant(T&& val) noexcept(std::is_nothrow_constructible<typename Traits::target_type, T&&>::value) - : type_index(Traits::index) - { - new (&data) typename Traits::target_type(std::forward<T>(val)); - } - - VARIANT_INLINE variant(variant<Types...> const& old) - : type_index(old.type_index) - { - helper_type::copy(old.type_index, &old.data, &data); - } - - VARIANT_INLINE variant(variant<Types...>&& old) noexcept(std::is_nothrow_move_constructible<types>::value) - : type_index(old.type_index) - { - helper_type::move(old.type_index, &old.data, &data); - } - -private: - VARIANT_INLINE void copy_assign(variant<Types...> const& rhs) - { - helper_type::destroy(type_index, &data); - type_index = detail::invalid_value; - helper_type::copy(rhs.type_index, &rhs.data, &data); - type_index = rhs.type_index; - } - - VARIANT_INLINE void move_assign(variant<Types...>&& rhs) - { - helper_type::destroy(type_index, &data); - type_index = detail::invalid_value; - helper_type::move(rhs.type_index, &rhs.data, &data); - type_index = rhs.type_index; - } - -public: - VARIANT_INLINE variant<Types...>& operator=(variant<Types...>&& other) - { - move_assign(std::move(other)); - return *this; - } - - VARIANT_INLINE variant<Types...>& operator=(variant<Types...> const& other) - { - copy_assign(other); - return *this; - } - - // conversions - // move-assign - template <typename T> - VARIANT_INLINE variant<Types...>& operator=(T&& rhs) noexcept - { - variant<Types...> temp(std::forward<T>(rhs)); - move_assign(std::move(temp)); - return *this; - } - - // copy-assign - template <typename T> - VARIANT_INLINE variant<Types...>& operator=(T const& rhs) - { - variant<Types...> temp(rhs); - copy_assign(temp); - return *this; - } - - template <typename T, typename std::enable_if< - (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE bool is() const - { - return type_index == detail::direct_type<T, Types...>::index; - } - - template <typename T,typename std::enable_if< - (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE bool is() const - { - return type_index == detail::direct_type<recursive_wrapper<T>, Types...>::index; - } - - VARIANT_INLINE bool valid() const - { - return type_index != detail::invalid_value; - } - - template <typename T, typename... Args> - VARIANT_INLINE void set(Args&&... args) - { - helper_type::destroy(type_index, &data); - type_index = detail::invalid_value; - new (&data) T(std::forward<Args>(args)...); - type_index = detail::direct_type<T, Types...>::index; - } - - // get_unchecked<T>() - template <typename T, typename std::enable_if< - (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T& get_unchecked() - { - return *reinterpret_cast<T*>(&data); - } - -#ifdef HAS_EXCEPTIONS - // get<T>() - template <typename T, typename std::enable_if< - (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T& get() - { - if (type_index == detail::direct_type<T, Types...>::index) - { - return *reinterpret_cast<T*>(&data); - } - else - { - throw bad_variant_access("in get<T>()"); - } - } -#endif - - template <typename T, typename std::enable_if< - (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T const& get_unchecked() const - { - return *reinterpret_cast<T const*>(&data); - } - -#ifdef HAS_EXCEPTIONS - template <typename T, typename std::enable_if< - (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T const& get() const - { - if (type_index == detail::direct_type<T, Types...>::index) - { - return *reinterpret_cast<T const*>(&data); - } - else - { - throw bad_variant_access("in get<T>()"); - } - } -#endif - - // get_unchecked<T>() - T stored as recursive_wrapper<T> - template <typename T, typename std::enable_if< - (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T& get_unchecked() - { - return (*reinterpret_cast<recursive_wrapper<T>*>(&data)).get(); - } - -#ifdef HAS_EXCEPTIONS - // get<T>() - T stored as recursive_wrapper<T> - template <typename T, typename std::enable_if< - (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T& get() - { - if (type_index == detail::direct_type<recursive_wrapper<T>, Types...>::index) - { - return (*reinterpret_cast<recursive_wrapper<T>*>(&data)).get(); - } - else - { - throw bad_variant_access("in get<T>()"); - } - } -#endif - - template <typename T, typename std::enable_if< - (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T const& get_unchecked() const - { - return (*reinterpret_cast<recursive_wrapper<T> const*>(&data)).get(); - } - -#ifdef HAS_EXCEPTIONS - template <typename T, typename std::enable_if< - (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T const& get() const - { - if (type_index == detail::direct_type<recursive_wrapper<T>, Types...>::index) - { - return (*reinterpret_cast<recursive_wrapper<T> const*>(&data)).get(); - } - else - { - throw bad_variant_access("in get<T>()"); - } - } -#endif - - // get_unchecked<T>() - T stored as std::reference_wrapper<T> - template <typename T, typename std::enable_if< - (detail::direct_type<std::reference_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T& get_unchecked() - { - return (*reinterpret_cast<std::reference_wrapper<T>*>(&data)).get(); - } - -#ifdef HAS_EXCEPTIONS - // get<T>() - T stored as std::reference_wrapper<T> - template <typename T, typename std::enable_if< - (detail::direct_type<std::reference_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T& get() - { - if (type_index == detail::direct_type<std::reference_wrapper<T>, Types...>::index) - { - return (*reinterpret_cast<std::reference_wrapper<T>*>(&data)).get(); - } - else - { - throw bad_variant_access("in get<T>()"); - } - } -#endif - - template <typename T, typename std::enable_if< - (detail::direct_type<std::reference_wrapper<T const>, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T const& get_unchecked() const - { - return (*reinterpret_cast<std::reference_wrapper<T const> const*>(&data)).get(); - } - -#ifdef HAS_EXCEPTIONS - template <typename T, typename std::enable_if< - (detail::direct_type<std::reference_wrapper<T const>, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE T const& get() const - { - if (type_index == detail::direct_type<std::reference_wrapper<T const>, Types...>::index) - { - return (*reinterpret_cast<std::reference_wrapper<T const> const*>(&data)).get(); - } - else - { - throw bad_variant_access("in get<T>()"); - } - } -#endif - - // This function is deprecated because it returns an internal index field. - // Use which() instead. - MAPBOX_VARIANT_DEPRECATED VARIANT_INLINE std::size_t get_type_index() const - { - return type_index; - } - - VARIANT_INLINE int which() const noexcept - { - return static_cast<int>(sizeof...(Types)-type_index - 1); - } - - template <typename T, typename std::enable_if< - (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr> - VARIANT_INLINE static constexpr int which() noexcept - { - return static_cast<int>(sizeof...(Types)-detail::direct_type<T, Types...>::index - 1); - } - - // visitor - // unary - template <typename F, typename V, typename R = typename detail::result_of_unary_visit<F, first_type>::type> - auto VARIANT_INLINE static visit(V const& v, F&& f) - -> decltype(detail::dispatcher<F, V, R, Types...>::apply_const(v, std::forward<F>(f))) - { - return detail::dispatcher<F, V, R, Types...>::apply_const(v, std::forward<F>(f)); - } - // non-const - template <typename F, typename V, typename R = typename detail::result_of_unary_visit<F, first_type>::type> - auto VARIANT_INLINE static visit(V& v, F&& f) - -> decltype(detail::dispatcher<F, V, R, Types...>::apply(v, std::forward<F>(f))) - { - return detail::dispatcher<F, V, R, Types...>::apply(v, std::forward<F>(f)); - } - - // binary - // const - template <typename F, typename V, typename R = typename detail::result_of_binary_visit<F, first_type>::type> - auto VARIANT_INLINE static binary_visit(V const& v0, V const& v1, F&& f) - -> decltype(detail::binary_dispatcher<F, V, R, Types...>::apply_const(v0, v1, std::forward<F>(f))) - { - return detail::binary_dispatcher<F, V, R, Types...>::apply_const(v0, v1, std::forward<F>(f)); - } - // non-const - template <typename F, typename V, typename R = typename detail::result_of_binary_visit<F, first_type>::type> - auto VARIANT_INLINE static binary_visit(V& v0, V& v1, F&& f) - -> decltype(detail::binary_dispatcher<F, V, R, Types...>::apply(v0, v1, std::forward<F>(f))) - { - return detail::binary_dispatcher<F, V, R, Types...>::apply(v0, v1, std::forward<F>(f)); - } - - // match - // unary - template <typename... Fs> - auto VARIANT_INLINE match(Fs&&... fs) const - -> decltype(variant::visit(*this, ::mapbox::util::make_visitor(std::forward<Fs>(fs)...))) - { - return variant::visit(*this, ::mapbox::util::make_visitor(std::forward<Fs>(fs)...)); - } - // non-const - template <typename... Fs> - auto VARIANT_INLINE match(Fs&&... fs) - -> decltype(variant::visit(*this, ::mapbox::util::make_visitor(std::forward<Fs>(fs)...))) - { - return variant::visit(*this, ::mapbox::util::make_visitor(std::forward<Fs>(fs)...)); - } - - ~variant() noexcept // no-throw destructor - { - helper_type::destroy(type_index, &data); - } - - // comparison operators - // equality - VARIANT_INLINE bool operator==(variant const& rhs) const - { - assert(valid() && rhs.valid()); - if (this->which() != rhs.which()) - { - return false; - } - detail::comparer<variant, detail::equal_comp> visitor(*this); - return visit(rhs, visitor); - } - - VARIANT_INLINE bool operator!=(variant const& rhs) const - { - return !(*this == rhs); - } - - // less than - VARIANT_INLINE bool operator<(variant const& rhs) const - { - assert(valid() && rhs.valid()); - if (this->which() != rhs.which()) - { - return this->which() < rhs.which(); - } - detail::comparer<variant, detail::less_comp> visitor(*this); - return visit(rhs, visitor); - } - VARIANT_INLINE bool operator>(variant const& rhs) const - { - return rhs < *this; - } - VARIANT_INLINE bool operator<=(variant const& rhs) const - { - return !(*this > rhs); - } - VARIANT_INLINE bool operator>=(variant const& rhs) const - { - return !(*this < rhs); - } -}; - -// unary visitor interface -// const -template <typename F, typename V> -auto VARIANT_INLINE apply_visitor(F&& f, V const& v) -> decltype(V::visit(v, std::forward<F>(f))) -{ - return V::visit(v, std::forward<F>(f)); -} - -// non-const -template <typename F, typename V> -auto VARIANT_INLINE apply_visitor(F&& f, V& v) -> decltype(V::visit(v, std::forward<F>(f))) -{ - return V::visit(v, std::forward<F>(f)); -} - -// binary visitor interface -// const -template <typename F, typename V> -auto VARIANT_INLINE apply_visitor(F&& f, V const& v0, V const& v1) -> decltype(V::binary_visit(v0, v1, std::forward<F>(f))) -{ - return V::binary_visit(v0, v1, std::forward<F>(f)); -} - -// non-const -template <typename F, typename V> -auto VARIANT_INLINE apply_visitor(F&& f, V& v0, V& v1) -> decltype(V::binary_visit(v0, v1, std::forward<F>(f))) -{ - return V::binary_visit(v0, v1, std::forward<F>(f)); -} - -// getter interface - -#ifdef HAS_EXCEPTIONS -template <typename ResultType, typename T> -auto get(T& var)->decltype(var.template get<ResultType>()) -{ - return var.template get<ResultType>(); -} -#endif - -template <typename ResultType, typename T> -ResultType& get_unchecked(T& var) -{ - return var.template get_unchecked<ResultType>(); -} - -#ifdef HAS_EXCEPTIONS -template <typename ResultType, typename T> -auto get(T const& var)->decltype(var.template get<ResultType>()) -{ - return var.template get<ResultType>(); -} -#endif - -template <typename ResultType, typename T> -ResultType const& get_unchecked(T const& var) -{ - return var.template get_unchecked<ResultType>(); -} -} // namespace util -} // namespace mapbox - -// hashable iff underlying types are hashable -namespace std { -template <typename... Types> -struct hash< ::mapbox::util::variant<Types...>> { - std::size_t operator()(const ::mapbox::util::variant<Types...>& v) const noexcept - { - return ::mapbox::util::apply_visitor(::mapbox::util::detail::hasher{}, v); - } -}; -} - -#endif // MAPBOX_UTIL_VARIANT_HPP |