Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 1 | #ifndef MAPBOX_UTIL_VARIANT_HPP |
| 2 | #define MAPBOX_UTIL_VARIANT_HPP |
| 3 | |
| 4 | #include <cassert> |
Patrick Venture | 95269db | 2018-08-31 09:19:17 -0700 | [diff] [blame^] | 5 | #include <cstddef> // size_t |
| 6 | #include <mapbox/recursive_wrapper.hpp> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 7 | #include <new> // operator new |
| 8 | #include <stdexcept> // runtime_error |
| 9 | #include <string> |
| 10 | #include <tuple> |
| 11 | #include <type_traits> |
| 12 | #include <typeinfo> |
| 13 | #include <utility> |
| 14 | |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 15 | // clang-format off |
| 16 | // [[deprecated]] is only available in C++14, use this for the time being |
| 17 | #if __cplusplus <= 201103L |
| 18 | # ifdef __GNUC__ |
| 19 | # define MAPBOX_VARIANT_DEPRECATED __attribute__((deprecated)) |
| 20 | # elif defined(_MSC_VER) |
| 21 | # define MAPBOX_VARIANT_DEPRECATED __declspec(deprecated) |
| 22 | # else |
| 23 | # define MAPBOX_VARIANT_DEPRECATED |
| 24 | # endif |
| 25 | #else |
| 26 | # define MAPBOX_VARIANT_DEPRECATED [[deprecated]] |
| 27 | #endif |
| 28 | |
| 29 | |
| 30 | #ifdef _MSC_VER |
| 31 | // https://msdn.microsoft.com/en-us/library/bw1hbe6y.aspx |
| 32 | # ifdef NDEBUG |
| 33 | # define VARIANT_INLINE __forceinline |
| 34 | # else |
| 35 | # define VARIANT_INLINE //__declspec(noinline) |
| 36 | # endif |
| 37 | #else |
| 38 | # ifdef NDEBUG |
| 39 | # define VARIANT_INLINE //inline __attribute__((always_inline)) |
| 40 | # else |
| 41 | # define VARIANT_INLINE __attribute__((noinline)) |
| 42 | # endif |
| 43 | #endif |
| 44 | // clang-format on |
| 45 | |
| 46 | // Exceptions |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 47 | #if defined(__EXCEPTIONS) || defined(_MSC_VER) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 48 | #define HAS_EXCEPTIONS |
| 49 | #endif |
| 50 | |
| 51 | #define VARIANT_MAJOR_VERSION 1 |
| 52 | #define VARIANT_MINOR_VERSION 1 |
| 53 | #define VARIANT_PATCH_VERSION 0 |
| 54 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 55 | #define VARIANT_VERSION \ |
| 56 | (VARIANT_MAJOR_VERSION * 100000) + (VARIANT_MINOR_VERSION * 100) + \ |
| 57 | (VARIANT_PATCH_VERSION) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 58 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 59 | namespace mapbox |
| 60 | { |
| 61 | namespace util |
| 62 | { |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 63 | |
| 64 | // XXX This should derive from std::logic_error instead of std::runtime_error. |
| 65 | // See https://github.com/mapbox/variant/issues/48 for details. |
| 66 | class bad_variant_access : public std::runtime_error |
| 67 | { |
| 68 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 69 | public: |
| 70 | explicit bad_variant_access(const std::string& what_arg) : |
| 71 | runtime_error(what_arg) |
| 72 | { |
| 73 | } |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 74 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 75 | explicit bad_variant_access(const char* what_arg) : runtime_error(what_arg) |
| 76 | { |
| 77 | } |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 78 | |
| 79 | }; // class bad_variant_access |
| 80 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 81 | template <typename R = void> struct MAPBOX_VARIANT_DEPRECATED static_visitor |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 82 | { |
| 83 | using result_type = R; |
| 84 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 85 | protected: |
| 86 | static_visitor() |
| 87 | { |
| 88 | } |
| 89 | ~static_visitor() |
| 90 | { |
| 91 | } |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 92 | }; |
| 93 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 94 | namespace detail |
| 95 | { |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 96 | |
| 97 | static constexpr std::size_t invalid_value = std::size_t(-1); |
| 98 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 99 | template <typename T, typename... Types> struct direct_type; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 100 | |
| 101 | template <typename T, typename First, typename... Types> |
| 102 | struct direct_type<T, First, Types...> |
| 103 | { |
| 104 | static constexpr std::size_t index = std::is_same<T, First>::value |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 105 | ? sizeof...(Types) |
| 106 | : direct_type<T, Types...>::index; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 107 | }; |
| 108 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 109 | template <typename T> struct direct_type<T> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 110 | { |
| 111 | static constexpr std::size_t index = invalid_value; |
| 112 | }; |
| 113 | |
| 114 | #if __cpp_lib_logical_traits >= 201510L |
| 115 | |
| 116 | using std::disjunction; |
| 117 | |
| 118 | #else |
| 119 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 120 | template <typename...> struct disjunction : std::false_type |
| 121 | { |
| 122 | }; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 123 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 124 | template <typename B1> struct disjunction<B1> : B1 |
| 125 | { |
| 126 | }; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 127 | |
| 128 | template <typename B1, typename B2> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 129 | struct disjunction<B1, B2> : std::conditional<B1::value, B1, B2>::type |
| 130 | { |
| 131 | }; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 132 | |
| 133 | template <typename B1, typename... Bs> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 134 | struct disjunction<B1, Bs...> |
| 135 | : std::conditional<B1::value, B1, disjunction<Bs...>>::type |
| 136 | { |
| 137 | }; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 138 | |
| 139 | #endif |
| 140 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 141 | template <typename T, typename... Types> struct convertible_type; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 142 | |
| 143 | template <typename T, typename First, typename... Types> |
| 144 | struct convertible_type<T, First, Types...> |
| 145 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 146 | static constexpr std::size_t index = |
| 147 | std::is_convertible<T, First>::value |
| 148 | ? disjunction<std::is_convertible<T, Types>...>::value |
| 149 | ? invalid_value |
| 150 | : sizeof...(Types) |
| 151 | : convertible_type<T, Types...>::index; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 152 | }; |
| 153 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 154 | template <typename T> struct convertible_type<T> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 155 | { |
| 156 | static constexpr std::size_t index = invalid_value; |
| 157 | }; |
| 158 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 159 | template <typename T, typename... Types> struct value_traits |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 160 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 161 | using value_type = typename std::remove_const< |
| 162 | typename std::remove_reference<T>::type>::type; |
| 163 | static constexpr std::size_t direct_index = |
| 164 | direct_type<value_type, Types...>::index; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 165 | static constexpr bool is_direct = direct_index != invalid_value; |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 166 | static constexpr std::size_t index = |
| 167 | is_direct ? direct_index |
| 168 | : convertible_type<value_type, Types...>::index; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 169 | static constexpr bool is_valid = index != invalid_value; |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 170 | static constexpr std::size_t tindex = |
| 171 | is_valid ? sizeof...(Types) - index : 0; |
| 172 | using target_type = |
| 173 | typename std::tuple_element<tindex, std::tuple<void, Types...>>::type; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 174 | }; |
| 175 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 176 | template <typename T, typename R = void> struct enable_if_type |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 177 | { |
| 178 | using type = R; |
| 179 | }; |
| 180 | |
| 181 | template <typename F, typename V, typename Enable = void> |
| 182 | struct result_of_unary_visit |
| 183 | { |
| 184 | using type = typename std::result_of<F(V&)>::type; |
| 185 | }; |
| 186 | |
| 187 | template <typename F, typename V> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 188 | struct result_of_unary_visit< |
| 189 | F, V, typename enable_if_type<typename F::result_type>::type> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 190 | { |
| 191 | using type = typename F::result_type; |
| 192 | }; |
| 193 | |
| 194 | template <typename F, typename V, typename Enable = void> |
| 195 | struct result_of_binary_visit |
| 196 | { |
| 197 | using type = typename std::result_of<F(V&, V&)>::type; |
| 198 | }; |
| 199 | |
| 200 | template <typename F, typename V> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 201 | struct result_of_binary_visit< |
| 202 | F, V, typename enable_if_type<typename F::result_type>::type> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 203 | { |
| 204 | using type = typename F::result_type; |
| 205 | }; |
| 206 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 207 | template <std::size_t arg1, std::size_t... others> struct static_max; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 208 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 209 | template <std::size_t arg> struct static_max<arg> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 210 | { |
| 211 | static const std::size_t value = arg; |
| 212 | }; |
| 213 | |
| 214 | template <std::size_t arg1, std::size_t arg2, std::size_t... others> |
| 215 | struct static_max<arg1, arg2, others...> |
| 216 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 217 | static const std::size_t value = arg1 >= arg2 |
| 218 | ? static_max<arg1, others...>::value |
| 219 | : static_max<arg2, others...>::value; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 220 | }; |
| 221 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 222 | template <typename... Types> struct variant_helper; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 223 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 224 | template <typename T, typename... Types> struct variant_helper<T, Types...> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 225 | { |
| 226 | VARIANT_INLINE static void destroy(const std::size_t type_index, void* data) |
| 227 | { |
| 228 | if (type_index == sizeof...(Types)) |
| 229 | { |
| 230 | reinterpret_cast<T*>(data)->~T(); |
| 231 | } |
| 232 | else |
| 233 | { |
| 234 | variant_helper<Types...>::destroy(type_index, data); |
| 235 | } |
| 236 | } |
| 237 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 238 | VARIANT_INLINE static void move(const std::size_t old_type_index, |
| 239 | void* old_value, void* new_value) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 240 | { |
| 241 | if (old_type_index == sizeof...(Types)) |
| 242 | { |
| 243 | new (new_value) T(std::move(*reinterpret_cast<T*>(old_value))); |
| 244 | } |
| 245 | else |
| 246 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 247 | variant_helper<Types...>::move(old_type_index, old_value, |
| 248 | new_value); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 249 | } |
| 250 | } |
| 251 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 252 | VARIANT_INLINE static void copy(const std::size_t old_type_index, |
| 253 | const void* old_value, void* new_value) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 254 | { |
| 255 | if (old_type_index == sizeof...(Types)) |
| 256 | { |
| 257 | new (new_value) T(*reinterpret_cast<const T*>(old_value)); |
| 258 | } |
| 259 | else |
| 260 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 261 | variant_helper<Types...>::copy(old_type_index, old_value, |
| 262 | new_value); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 263 | } |
| 264 | } |
| 265 | }; |
| 266 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 267 | template <> struct variant_helper<> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 268 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 269 | VARIANT_INLINE static void destroy(const std::size_t, void*) |
| 270 | { |
| 271 | } |
| 272 | VARIANT_INLINE static void move(const std::size_t, void*, void*) |
| 273 | { |
| 274 | } |
| 275 | VARIANT_INLINE static void copy(const std::size_t, const void*, void*) |
| 276 | { |
| 277 | } |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 278 | }; |
| 279 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 280 | template <typename T> struct unwrapper |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 281 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 282 | static T const& apply_const(T const& obj) |
| 283 | { |
| 284 | return obj; |
| 285 | } |
| 286 | static T& apply(T& obj) |
| 287 | { |
| 288 | return obj; |
| 289 | } |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 290 | }; |
| 291 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 292 | template <typename T> struct unwrapper<recursive_wrapper<T>> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 293 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 294 | static auto apply_const(recursive_wrapper<T> const& obj) -> |
| 295 | typename recursive_wrapper<T>::type const& |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 296 | { |
| 297 | return obj.get(); |
| 298 | } |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 299 | static auto apply(recursive_wrapper<T>& obj) -> |
| 300 | typename recursive_wrapper<T>::type& |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 301 | { |
| 302 | return obj.get(); |
| 303 | } |
| 304 | }; |
| 305 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 306 | template <typename T> struct unwrapper<std::reference_wrapper<T>> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 307 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 308 | static auto apply_const(std::reference_wrapper<T> const& obj) -> |
| 309 | typename std::reference_wrapper<T>::type const& |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 310 | { |
| 311 | return obj.get(); |
| 312 | } |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 313 | static auto apply(std::reference_wrapper<T>& obj) -> |
| 314 | typename std::reference_wrapper<T>::type& |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 315 | { |
| 316 | return obj.get(); |
| 317 | } |
| 318 | }; |
| 319 | |
| 320 | template <typename F, typename V, typename R, typename... Types> |
| 321 | struct dispatcher; |
| 322 | |
| 323 | template <typename F, typename V, typename R, typename T, typename... Types> |
| 324 | struct dispatcher<F, V, R, T, Types...> |
| 325 | { |
| 326 | VARIANT_INLINE static R apply_const(V const& v, F&& f) |
| 327 | { |
| 328 | if (v.template is<T>()) |
| 329 | { |
| 330 | return f(unwrapper<T>::apply_const(v.template get_unchecked<T>())); |
| 331 | } |
| 332 | else |
| 333 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 334 | return dispatcher<F, V, R, Types...>::apply_const( |
| 335 | v, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 336 | } |
| 337 | } |
| 338 | |
| 339 | VARIANT_INLINE static R apply(V& v, F&& f) |
| 340 | { |
| 341 | if (v.template is<T>()) |
| 342 | { |
| 343 | return f(unwrapper<T>::apply(v.template get_unchecked<T>())); |
| 344 | } |
| 345 | else |
| 346 | { |
| 347 | return dispatcher<F, V, R, Types...>::apply(v, std::forward<F>(f)); |
| 348 | } |
| 349 | } |
| 350 | }; |
| 351 | |
| 352 | template <typename F, typename V, typename R, typename T> |
| 353 | struct dispatcher<F, V, R, T> |
| 354 | { |
| 355 | VARIANT_INLINE static R apply_const(V const& v, F&& f) |
| 356 | { |
| 357 | return f(unwrapper<T>::apply_const(v.template get_unchecked<T>())); |
| 358 | } |
| 359 | |
| 360 | VARIANT_INLINE static R apply(V& v, F&& f) |
| 361 | { |
| 362 | return f(unwrapper<T>::apply(v.template get_unchecked<T>())); |
| 363 | } |
| 364 | }; |
| 365 | |
| 366 | template <typename F, typename V, typename R, typename T, typename... Types> |
| 367 | struct binary_dispatcher_rhs; |
| 368 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 369 | template <typename F, typename V, typename R, typename T0, typename T1, |
| 370 | typename... Types> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 371 | struct binary_dispatcher_rhs<F, V, R, T0, T1, Types...> |
| 372 | { |
| 373 | VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f) |
| 374 | { |
| 375 | if (rhs.template is<T1>()) // call binary functor |
| 376 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 377 | return f( |
| 378 | unwrapper<T0>::apply_const(lhs.template get_unchecked<T0>()), |
| 379 | unwrapper<T1>::apply_const(rhs.template get_unchecked<T1>())); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 380 | } |
| 381 | else |
| 382 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 383 | return binary_dispatcher_rhs<F, V, R, T0, Types...>::apply_const( |
| 384 | lhs, rhs, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 385 | } |
| 386 | } |
| 387 | |
| 388 | VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f) |
| 389 | { |
| 390 | if (rhs.template is<T1>()) // call binary functor |
| 391 | { |
| 392 | return f(unwrapper<T0>::apply(lhs.template get_unchecked<T0>()), |
| 393 | unwrapper<T1>::apply(rhs.template get_unchecked<T1>())); |
| 394 | } |
| 395 | else |
| 396 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 397 | return binary_dispatcher_rhs<F, V, R, T0, Types...>::apply( |
| 398 | lhs, rhs, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 399 | } |
| 400 | } |
| 401 | }; |
| 402 | |
| 403 | template <typename F, typename V, typename R, typename T0, typename T1> |
| 404 | struct binary_dispatcher_rhs<F, V, R, T0, T1> |
| 405 | { |
| 406 | VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f) |
| 407 | { |
| 408 | return f(unwrapper<T0>::apply_const(lhs.template get_unchecked<T0>()), |
| 409 | unwrapper<T1>::apply_const(rhs.template get_unchecked<T1>())); |
| 410 | } |
| 411 | |
| 412 | VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f) |
| 413 | { |
| 414 | return f(unwrapper<T0>::apply(lhs.template get_unchecked<T0>()), |
| 415 | unwrapper<T1>::apply(rhs.template get_unchecked<T1>())); |
| 416 | } |
| 417 | }; |
| 418 | |
| 419 | template <typename F, typename V, typename R, typename T, typename... Types> |
| 420 | struct binary_dispatcher_lhs; |
| 421 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 422 | template <typename F, typename V, typename R, typename T0, typename T1, |
| 423 | typename... Types> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 424 | struct binary_dispatcher_lhs<F, V, R, T0, T1, Types...> |
| 425 | { |
| 426 | VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f) |
| 427 | { |
| 428 | if (lhs.template is<T1>()) // call binary functor |
| 429 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 430 | return f( |
| 431 | unwrapper<T1>::apply_const(lhs.template get_unchecked<T1>()), |
| 432 | unwrapper<T0>::apply_const(rhs.template get_unchecked<T0>())); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 433 | } |
| 434 | else |
| 435 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 436 | return binary_dispatcher_lhs<F, V, R, T0, Types...>::apply_const( |
| 437 | lhs, rhs, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 438 | } |
| 439 | } |
| 440 | |
| 441 | VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f) |
| 442 | { |
| 443 | if (lhs.template is<T1>()) // call binary functor |
| 444 | { |
| 445 | return f(unwrapper<T1>::apply(lhs.template get_unchecked<T1>()), |
| 446 | unwrapper<T0>::apply(rhs.template get_unchecked<T0>())); |
| 447 | } |
| 448 | else |
| 449 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 450 | return binary_dispatcher_lhs<F, V, R, T0, Types...>::apply( |
| 451 | lhs, rhs, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 452 | } |
| 453 | } |
| 454 | }; |
| 455 | |
| 456 | template <typename F, typename V, typename R, typename T0, typename T1> |
| 457 | struct binary_dispatcher_lhs<F, V, R, T0, T1> |
| 458 | { |
| 459 | VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f) |
| 460 | { |
| 461 | return f(unwrapper<T1>::apply_const(lhs.template get_unchecked<T1>()), |
| 462 | unwrapper<T0>::apply_const(rhs.template get_unchecked<T0>())); |
| 463 | } |
| 464 | |
| 465 | VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f) |
| 466 | { |
| 467 | return f(unwrapper<T1>::apply(lhs.template get_unchecked<T1>()), |
| 468 | unwrapper<T0>::apply(rhs.template get_unchecked<T0>())); |
| 469 | } |
| 470 | }; |
| 471 | |
| 472 | template <typename F, typename V, typename R, typename... Types> |
| 473 | struct binary_dispatcher; |
| 474 | |
| 475 | template <typename F, typename V, typename R, typename T, typename... Types> |
| 476 | struct binary_dispatcher<F, V, R, T, Types...> |
| 477 | { |
| 478 | VARIANT_INLINE static R apply_const(V const& v0, V const& v1, F&& f) |
| 479 | { |
| 480 | if (v0.template is<T>()) |
| 481 | { |
| 482 | if (v1.template is<T>()) |
| 483 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 484 | return f( |
| 485 | unwrapper<T>::apply_const(v0.template get_unchecked<T>()), |
| 486 | unwrapper<T>::apply_const( |
| 487 | v1.template get_unchecked<T>())); // call binary functor |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 488 | } |
| 489 | else |
| 490 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 491 | return binary_dispatcher_rhs<F, V, R, T, Types...>::apply_const( |
| 492 | v0, v1, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 493 | } |
| 494 | } |
| 495 | else if (v1.template is<T>()) |
| 496 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 497 | return binary_dispatcher_lhs<F, V, R, T, Types...>::apply_const( |
| 498 | v0, v1, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 499 | } |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 500 | return binary_dispatcher<F, V, R, Types...>::apply_const( |
| 501 | v0, v1, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 502 | } |
| 503 | |
| 504 | VARIANT_INLINE static R apply(V& v0, V& v1, F&& f) |
| 505 | { |
| 506 | if (v0.template is<T>()) |
| 507 | { |
| 508 | if (v1.template is<T>()) |
| 509 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 510 | return f( |
| 511 | unwrapper<T>::apply(v0.template get_unchecked<T>()), |
| 512 | unwrapper<T>::apply( |
| 513 | v1.template get_unchecked<T>())); // call binary functor |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 514 | } |
| 515 | else |
| 516 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 517 | return binary_dispatcher_rhs<F, V, R, T, Types...>::apply( |
| 518 | v0, v1, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 519 | } |
| 520 | } |
| 521 | else if (v1.template is<T>()) |
| 522 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 523 | return binary_dispatcher_lhs<F, V, R, T, Types...>::apply( |
| 524 | v0, v1, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 525 | } |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 526 | return binary_dispatcher<F, V, R, Types...>::apply(v0, v1, |
| 527 | std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 528 | } |
| 529 | }; |
| 530 | |
| 531 | template <typename F, typename V, typename R, typename T> |
| 532 | struct binary_dispatcher<F, V, R, T> |
| 533 | { |
| 534 | VARIANT_INLINE static R apply_const(V const& v0, V const& v1, F&& f) |
| 535 | { |
| 536 | return f(unwrapper<T>::apply_const(v0.template get_unchecked<T>()), |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 537 | unwrapper<T>::apply_const( |
| 538 | v1.template get_unchecked<T>())); // call binary functor |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 539 | } |
| 540 | |
| 541 | VARIANT_INLINE static R apply(V& v0, V& v1, F&& f) |
| 542 | { |
| 543 | return f(unwrapper<T>::apply(v0.template get_unchecked<T>()), |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 544 | unwrapper<T>::apply( |
| 545 | v1.template get_unchecked<T>())); // call binary functor |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 546 | } |
| 547 | }; |
| 548 | |
| 549 | // comparator functors |
| 550 | struct equal_comp |
| 551 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 552 | template <typename T> bool operator()(T const& lhs, T const& rhs) const |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 553 | { |
| 554 | return lhs == rhs; |
| 555 | } |
| 556 | }; |
| 557 | |
| 558 | struct less_comp |
| 559 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 560 | template <typename T> bool operator()(T const& lhs, T const& rhs) const |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 561 | { |
| 562 | return lhs < rhs; |
| 563 | } |
| 564 | }; |
| 565 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 566 | template <typename Variant, typename Comp> class comparer |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 567 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 568 | public: |
| 569 | explicit comparer(Variant const& lhs) noexcept : lhs_(lhs) |
| 570 | { |
| 571 | } |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 572 | comparer& operator=(comparer const&) = delete; |
| 573 | // visitor |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 574 | template <typename T> bool operator()(T const& rhs_content) const |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 575 | { |
| 576 | T const& lhs_content = lhs_.template get_unchecked<T>(); |
| 577 | return Comp()(lhs_content, rhs_content); |
| 578 | } |
| 579 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 580 | private: |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 581 | Variant const& lhs_; |
| 582 | }; |
| 583 | |
| 584 | } // namespace detail |
| 585 | |
| 586 | struct no_init |
| 587 | { |
| 588 | }; |
| 589 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 590 | template <typename... Types> class variant |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 591 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 592 | static_assert(sizeof...(Types) > 0, |
| 593 | "Template parameter type list of variant can not be empty"); |
| 594 | static_assert(!detail::disjunction<std::is_reference<Types>...>::value, |
| 595 | "Variant can not hold reference types. Maybe use " |
| 596 | "std::reference_wrapper?"); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 597 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 598 | private: |
| 599 | static const std::size_t data_size = |
| 600 | detail::static_max<sizeof(Types)...>::value; |
| 601 | static const std::size_t data_align = |
| 602 | detail::static_max<alignof(Types)...>::value; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 603 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 604 | using first_type = |
| 605 | typename std::tuple_element<0, std::tuple<Types...>>::type; |
| 606 | using data_type = |
| 607 | typename std::aligned_storage<data_size, data_align>::type; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 608 | using helper_type = detail::variant_helper<Types...>; |
| 609 | |
| 610 | std::size_t type_index; |
| 611 | data_type data; |
| 612 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 613 | public: |
| 614 | VARIANT_INLINE variant() noexcept( |
| 615 | std::is_nothrow_default_constructible<first_type>::value) : |
| 616 | type_index(sizeof...(Types) - 1) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 617 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 618 | static_assert(std::is_default_constructible<first_type>::value, |
| 619 | "First type in variant must be default constructible to " |
| 620 | "allow default construction of variant"); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 621 | new (&data) first_type(); |
| 622 | } |
| 623 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 624 | VARIANT_INLINE variant(no_init) noexcept : type_index(detail::invalid_value) |
| 625 | { |
| 626 | } |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 627 | |
| 628 | // http://isocpp.org/blog/2012/11/universal-references-in-c11-scott-meyers |
| 629 | template <typename T, typename Traits = detail::value_traits<T, Types...>, |
| 630 | typename Enable = typename std::enable_if<Traits::is_valid>::type> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 631 | VARIANT_INLINE variant(T&& val) noexcept( |
| 632 | std::is_nothrow_constructible<typename Traits::target_type, |
| 633 | T&&>::value) : |
| 634 | type_index(Traits::index) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 635 | { |
| 636 | new (&data) typename Traits::target_type(std::forward<T>(val)); |
| 637 | } |
| 638 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 639 | VARIANT_INLINE variant(variant<Types...> const& old) : |
| 640 | type_index(old.type_index) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 641 | { |
| 642 | helper_type::copy(old.type_index, &old.data, &data); |
| 643 | } |
| 644 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 645 | VARIANT_INLINE variant(variant<Types...>&& old) noexcept( |
| 646 | std::is_nothrow_move_constructible<std::tuple<Types...>>::value) : |
| 647 | type_index(old.type_index) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 648 | { |
| 649 | helper_type::move(old.type_index, &old.data, &data); |
| 650 | } |
| 651 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 652 | private: |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 653 | VARIANT_INLINE void copy_assign(variant<Types...> const& rhs) |
| 654 | { |
| 655 | helper_type::destroy(type_index, &data); |
| 656 | type_index = detail::invalid_value; |
| 657 | helper_type::copy(rhs.type_index, &rhs.data, &data); |
| 658 | type_index = rhs.type_index; |
| 659 | } |
| 660 | |
| 661 | VARIANT_INLINE void move_assign(variant<Types...>&& rhs) |
| 662 | { |
| 663 | helper_type::destroy(type_index, &data); |
| 664 | type_index = detail::invalid_value; |
| 665 | helper_type::move(rhs.type_index, &rhs.data, &data); |
| 666 | type_index = rhs.type_index; |
| 667 | } |
| 668 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 669 | public: |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 670 | VARIANT_INLINE variant<Types...>& operator=(variant<Types...>&& other) |
| 671 | { |
| 672 | move_assign(std::move(other)); |
| 673 | return *this; |
| 674 | } |
| 675 | |
| 676 | VARIANT_INLINE variant<Types...>& operator=(variant<Types...> const& other) |
| 677 | { |
| 678 | copy_assign(other); |
| 679 | return *this; |
| 680 | } |
| 681 | |
| 682 | // conversions |
| 683 | // move-assign |
| 684 | template <typename T> |
| 685 | VARIANT_INLINE variant<Types...>& operator=(T&& rhs) noexcept |
| 686 | { |
| 687 | variant<Types...> temp(std::forward<T>(rhs)); |
| 688 | move_assign(std::move(temp)); |
| 689 | return *this; |
| 690 | } |
| 691 | |
| 692 | // copy-assign |
| 693 | template <typename T> |
| 694 | VARIANT_INLINE variant<Types...>& operator=(T const& rhs) |
| 695 | { |
| 696 | variant<Types...> temp(rhs); |
| 697 | copy_assign(temp); |
| 698 | return *this; |
| 699 | } |
| 700 | |
| 701 | template <typename T, typename std::enable_if< |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 702 | (detail::direct_type<T, Types...>::index != |
| 703 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 704 | VARIANT_INLINE bool is() const |
| 705 | { |
| 706 | return type_index == detail::direct_type<T, Types...>::index; |
| 707 | } |
| 708 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 709 | template <typename T, |
| 710 | typename std::enable_if< |
| 711 | (detail::direct_type<recursive_wrapper<T>, Types...>::index != |
| 712 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 713 | VARIANT_INLINE bool is() const |
| 714 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 715 | return type_index == |
| 716 | detail::direct_type<recursive_wrapper<T>, Types...>::index; |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 717 | } |
| 718 | |
| 719 | VARIANT_INLINE bool valid() const |
| 720 | { |
| 721 | return type_index != detail::invalid_value; |
| 722 | } |
| 723 | |
| 724 | template <typename T, typename... Args> |
| 725 | VARIANT_INLINE void set(Args&&... args) |
| 726 | { |
| 727 | helper_type::destroy(type_index, &data); |
| 728 | type_index = detail::invalid_value; |
| 729 | new (&data) T(std::forward<Args>(args)...); |
| 730 | type_index = detail::direct_type<T, Types...>::index; |
| 731 | } |
| 732 | |
| 733 | // get_unchecked<T>() |
| 734 | template <typename T, typename std::enable_if< |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 735 | (detail::direct_type<T, Types...>::index != |
| 736 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 737 | VARIANT_INLINE T& get_unchecked() |
| 738 | { |
| 739 | return *reinterpret_cast<T*>(&data); |
| 740 | } |
| 741 | |
| 742 | #ifdef HAS_EXCEPTIONS |
| 743 | // get<T>() |
| 744 | template <typename T, typename std::enable_if< |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 745 | (detail::direct_type<T, Types...>::index != |
| 746 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 747 | VARIANT_INLINE T& get() |
| 748 | { |
| 749 | if (type_index == detail::direct_type<T, Types...>::index) |
| 750 | { |
| 751 | return *reinterpret_cast<T*>(&data); |
| 752 | } |
| 753 | else |
| 754 | { |
| 755 | throw bad_variant_access("in get<T>()"); |
| 756 | } |
| 757 | } |
| 758 | #endif |
| 759 | |
| 760 | template <typename T, typename std::enable_if< |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 761 | (detail::direct_type<T, Types...>::index != |
| 762 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 763 | VARIANT_INLINE T const& get_unchecked() const |
| 764 | { |
| 765 | return *reinterpret_cast<T const*>(&data); |
| 766 | } |
| 767 | |
| 768 | #ifdef HAS_EXCEPTIONS |
| 769 | template <typename T, typename std::enable_if< |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 770 | (detail::direct_type<T, Types...>::index != |
| 771 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 772 | VARIANT_INLINE T const& get() const |
| 773 | { |
| 774 | if (type_index == detail::direct_type<T, Types...>::index) |
| 775 | { |
| 776 | return *reinterpret_cast<T const*>(&data); |
| 777 | } |
| 778 | else |
| 779 | { |
| 780 | throw bad_variant_access("in get<T>()"); |
| 781 | } |
| 782 | } |
| 783 | #endif |
| 784 | |
| 785 | // get_unchecked<T>() - T stored as recursive_wrapper<T> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 786 | template <typename T, |
| 787 | typename std::enable_if< |
| 788 | (detail::direct_type<recursive_wrapper<T>, Types...>::index != |
| 789 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 790 | VARIANT_INLINE T& get_unchecked() |
| 791 | { |
| 792 | return (*reinterpret_cast<recursive_wrapper<T>*>(&data)).get(); |
| 793 | } |
| 794 | |
| 795 | #ifdef HAS_EXCEPTIONS |
| 796 | // get<T>() - T stored as recursive_wrapper<T> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 797 | template <typename T, |
| 798 | typename std::enable_if< |
| 799 | (detail::direct_type<recursive_wrapper<T>, Types...>::index != |
| 800 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 801 | VARIANT_INLINE T& get() |
| 802 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 803 | if (type_index == |
| 804 | detail::direct_type<recursive_wrapper<T>, Types...>::index) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 805 | { |
| 806 | return (*reinterpret_cast<recursive_wrapper<T>*>(&data)).get(); |
| 807 | } |
| 808 | else |
| 809 | { |
| 810 | throw bad_variant_access("in get<T>()"); |
| 811 | } |
| 812 | } |
| 813 | #endif |
| 814 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 815 | template <typename T, |
| 816 | typename std::enable_if< |
| 817 | (detail::direct_type<recursive_wrapper<T>, Types...>::index != |
| 818 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 819 | VARIANT_INLINE T const& get_unchecked() const |
| 820 | { |
| 821 | return (*reinterpret_cast<recursive_wrapper<T> const*>(&data)).get(); |
| 822 | } |
| 823 | |
| 824 | #ifdef HAS_EXCEPTIONS |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 825 | template <typename T, |
| 826 | typename std::enable_if< |
| 827 | (detail::direct_type<recursive_wrapper<T>, Types...>::index != |
| 828 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 829 | VARIANT_INLINE T const& get() const |
| 830 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 831 | if (type_index == |
| 832 | detail::direct_type<recursive_wrapper<T>, Types...>::index) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 833 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 834 | return (*reinterpret_cast<recursive_wrapper<T> const*>(&data)) |
| 835 | .get(); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 836 | } |
| 837 | else |
| 838 | { |
| 839 | throw bad_variant_access("in get<T>()"); |
| 840 | } |
| 841 | } |
| 842 | #endif |
| 843 | |
| 844 | // get_unchecked<T>() - T stored as std::reference_wrapper<T> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 845 | template < |
| 846 | typename T, |
| 847 | typename std::enable_if< |
| 848 | (detail::direct_type<std::reference_wrapper<T>, Types...>::index != |
| 849 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 850 | VARIANT_INLINE T& get_unchecked() |
| 851 | { |
| 852 | return (*reinterpret_cast<std::reference_wrapper<T>*>(&data)).get(); |
| 853 | } |
| 854 | |
| 855 | #ifdef HAS_EXCEPTIONS |
| 856 | // get<T>() - T stored as std::reference_wrapper<T> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 857 | template < |
| 858 | typename T, |
| 859 | typename std::enable_if< |
| 860 | (detail::direct_type<std::reference_wrapper<T>, Types...>::index != |
| 861 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 862 | VARIANT_INLINE T& get() |
| 863 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 864 | if (type_index == |
| 865 | detail::direct_type<std::reference_wrapper<T>, Types...>::index) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 866 | { |
| 867 | return (*reinterpret_cast<std::reference_wrapper<T>*>(&data)).get(); |
| 868 | } |
| 869 | else |
| 870 | { |
| 871 | throw bad_variant_access("in get<T>()"); |
| 872 | } |
| 873 | } |
| 874 | #endif |
| 875 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 876 | template <typename T, |
| 877 | typename std::enable_if< |
| 878 | (detail::direct_type<std::reference_wrapper<T const>, |
| 879 | Types...>::index != |
| 880 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 881 | VARIANT_INLINE T const& get_unchecked() const |
| 882 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 883 | return (*reinterpret_cast<std::reference_wrapper<T const> const*>( |
| 884 | &data)) |
| 885 | .get(); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 886 | } |
| 887 | |
| 888 | #ifdef HAS_EXCEPTIONS |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 889 | template <typename T, |
| 890 | typename std::enable_if< |
| 891 | (detail::direct_type<std::reference_wrapper<T const>, |
| 892 | Types...>::index != |
| 893 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 894 | VARIANT_INLINE T const& get() const |
| 895 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 896 | if (type_index == detail::direct_type<std::reference_wrapper<T const>, |
| 897 | Types...>::index) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 898 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 899 | return (*reinterpret_cast<std::reference_wrapper<T const> const*>( |
| 900 | &data)) |
| 901 | .get(); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 902 | } |
| 903 | else |
| 904 | { |
| 905 | throw bad_variant_access("in get<T>()"); |
| 906 | } |
| 907 | } |
| 908 | #endif |
| 909 | |
| 910 | // This function is deprecated because it returns an internal index field. |
| 911 | // Use which() instead. |
| 912 | MAPBOX_VARIANT_DEPRECATED VARIANT_INLINE std::size_t get_type_index() const |
| 913 | { |
| 914 | return type_index; |
| 915 | } |
| 916 | |
| 917 | VARIANT_INLINE int which() const noexcept |
| 918 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 919 | return static_cast<int>(sizeof...(Types) - type_index - 1); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 920 | } |
| 921 | |
| 922 | template <typename T, typename std::enable_if< |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 923 | (detail::direct_type<T, Types...>::index != |
| 924 | detail::invalid_value)>::type* = nullptr> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 925 | VARIANT_INLINE static constexpr int which() noexcept |
| 926 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 927 | return static_cast<int>(sizeof...(Types) - |
| 928 | detail::direct_type<T, Types...>::index - 1); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 929 | } |
| 930 | |
| 931 | // visitor |
| 932 | // unary |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 933 | template <typename F, typename V, |
| 934 | typename R = |
| 935 | typename detail::result_of_unary_visit<F, first_type>::type> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 936 | auto VARIANT_INLINE static visit(V const& v, F&& f) |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 937 | -> decltype(detail::dispatcher<F, V, R, Types...>::apply_const( |
| 938 | v, std::forward<F>(f))) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 939 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 940 | return detail::dispatcher<F, V, R, Types...>::apply_const( |
| 941 | v, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 942 | } |
| 943 | // non-const |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 944 | template <typename F, typename V, |
| 945 | typename R = |
| 946 | typename detail::result_of_unary_visit<F, first_type>::type> |
| 947 | auto VARIANT_INLINE static visit(V& v, F&& f) -> decltype( |
| 948 | detail::dispatcher<F, V, R, Types...>::apply(v, std::forward<F>(f))) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 949 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 950 | return detail::dispatcher<F, V, R, Types...>::apply(v, |
| 951 | std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 952 | } |
| 953 | |
| 954 | // binary |
| 955 | // const |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 956 | template <typename F, typename V, |
| 957 | typename R = |
| 958 | typename detail::result_of_binary_visit<F, first_type>::type> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 959 | auto VARIANT_INLINE static binary_visit(V const& v0, V const& v1, F&& f) |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 960 | -> decltype(detail::binary_dispatcher<F, V, R, Types...>::apply_const( |
| 961 | v0, v1, std::forward<F>(f))) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 962 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 963 | return detail::binary_dispatcher<F, V, R, Types...>::apply_const( |
| 964 | v0, v1, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 965 | } |
| 966 | // non-const |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 967 | template <typename F, typename V, |
| 968 | typename R = |
| 969 | typename detail::result_of_binary_visit<F, first_type>::type> |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 970 | auto VARIANT_INLINE static binary_visit(V& v0, V& v1, F&& f) |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 971 | -> decltype(detail::binary_dispatcher<F, V, R, Types...>::apply( |
| 972 | v0, v1, std::forward<F>(f))) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 973 | { |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 974 | return detail::binary_dispatcher<F, V, R, Types...>::apply( |
| 975 | v0, v1, std::forward<F>(f)); |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 976 | } |
| 977 | |
| 978 | ~variant() noexcept // no-throw destructor |
| 979 | { |
| 980 | helper_type::destroy(type_index, &data); |
| 981 | } |
| 982 | |
| 983 | // comparison operators |
| 984 | // equality |
| 985 | VARIANT_INLINE bool operator==(variant const& rhs) const |
| 986 | { |
| 987 | assert(valid() && rhs.valid()); |
| 988 | if (this->which() != rhs.which()) |
| 989 | { |
| 990 | return false; |
| 991 | } |
| 992 | detail::comparer<variant, detail::equal_comp> visitor(*this); |
| 993 | return visit(rhs, visitor); |
| 994 | } |
| 995 | |
| 996 | VARIANT_INLINE bool operator!=(variant const& rhs) const |
| 997 | { |
| 998 | return !(*this == rhs); |
| 999 | } |
| 1000 | |
| 1001 | // less than |
| 1002 | VARIANT_INLINE bool operator<(variant const& rhs) const |
| 1003 | { |
| 1004 | assert(valid() && rhs.valid()); |
| 1005 | if (this->which() != rhs.which()) |
| 1006 | { |
| 1007 | return this->which() < rhs.which(); |
| 1008 | } |
| 1009 | detail::comparer<variant, detail::less_comp> visitor(*this); |
| 1010 | return visit(rhs, visitor); |
| 1011 | } |
| 1012 | VARIANT_INLINE bool operator>(variant const& rhs) const |
| 1013 | { |
| 1014 | return rhs < *this; |
| 1015 | } |
| 1016 | VARIANT_INLINE bool operator<=(variant const& rhs) const |
| 1017 | { |
| 1018 | return !(*this > rhs); |
| 1019 | } |
| 1020 | VARIANT_INLINE bool operator>=(variant const& rhs) const |
| 1021 | { |
| 1022 | return !(*this < rhs); |
| 1023 | } |
| 1024 | }; |
| 1025 | |
| 1026 | // unary visitor interface |
| 1027 | // const |
| 1028 | template <typename F, typename V> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 1029 | auto VARIANT_INLINE apply_visitor(F&& f, V const& v) |
| 1030 | -> decltype(V::visit(v, std::forward<F>(f))) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 1031 | { |
| 1032 | return V::visit(v, std::forward<F>(f)); |
| 1033 | } |
| 1034 | |
| 1035 | // non-const |
| 1036 | template <typename F, typename V> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 1037 | auto VARIANT_INLINE apply_visitor(F&& f, V& v) |
| 1038 | -> decltype(V::visit(v, std::forward<F>(f))) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 1039 | { |
| 1040 | return V::visit(v, std::forward<F>(f)); |
| 1041 | } |
| 1042 | |
| 1043 | // binary visitor interface |
| 1044 | // const |
| 1045 | template <typename F, typename V> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 1046 | auto VARIANT_INLINE apply_visitor(F&& f, V const& v0, V const& v1) |
| 1047 | -> decltype(V::binary_visit(v0, v1, std::forward<F>(f))) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 1048 | { |
| 1049 | return V::binary_visit(v0, v1, std::forward<F>(f)); |
| 1050 | } |
| 1051 | |
| 1052 | // non-const |
| 1053 | template <typename F, typename V> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 1054 | auto VARIANT_INLINE apply_visitor(F&& f, V& v0, V& v1) |
| 1055 | -> decltype(V::binary_visit(v0, v1, std::forward<F>(f))) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 1056 | { |
| 1057 | return V::binary_visit(v0, v1, std::forward<F>(f)); |
| 1058 | } |
| 1059 | |
Patrick Venture | 0b5d1e0 | 2018-08-31 09:12:15 -0700 | [diff] [blame] | 1060 | // getter interface |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 1061 | |
| 1062 | #ifdef HAS_EXCEPTIONS |
| 1063 | template <typename ResultType, typename T> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 1064 | auto get(T& var) -> decltype(var.template get<ResultType>()) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 1065 | { |
| 1066 | return var.template get<ResultType>(); |
| 1067 | } |
| 1068 | #endif |
| 1069 | |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 1070 | template <typename ResultType, typename T> ResultType& get_unchecked(T& var) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 1071 | { |
| 1072 | return var.template get_unchecked<ResultType>(); |
| 1073 | } |
| 1074 | |
| 1075 | #ifdef HAS_EXCEPTIONS |
| 1076 | template <typename ResultType, typename T> |
Andrew Geissler | 072da3e | 2018-01-18 07:21:42 -0800 | [diff] [blame] | 1077 | auto get(T const& var) -> decltype(var.template get<ResultType>()) |
Patrick Williams | ceefb31 | 2016-09-11 21:12:42 -0500 | [diff] [blame] | 1078 | { |
| 1079 | return var.template get<ResultType>(); |
| 1080 | } |
| 1081 | #endif |
| 1082 | |
| 1083 | template <typename ResultType, typename T> |
| 1084 | ResultType const& get_unchecked(T const& var) |
| 1085 | { |
| 1086 | return var.template get_unchecked<ResultType>(); |
| 1087 | } |
| 1088 | } // namespace util |
| 1089 | } // namespace mapbox |
| 1090 | |
| 1091 | #endif // MAPBOX_UTIL_VARIANT_HPP |