ceph/src/boost/boost/outcome/basic_result.hpp

   1 /* A very simple result type
   2 (C) 2017-2019 Niall Douglas <http://www.nedproductions.biz/> (14 commits)
   3 File Created: June 2017
   4
   5
   6 Boost Software License - Version 1.0 - August 17th, 2003
   7
   8 Permission is hereby granted, free of charge, to any person or organization
   9 obtaining a copy of the software and accompanying documentation covered by
  10 this license (the "Software") to use, reproduce, display, distribute,
  11 execute, and transmit the Software, and to prepare derivative works of the
  12 Software, and to permit third-parties to whom the Software is furnished to
  13 do so, all subject to the following:
  14
  15 The copyright notices in the Software and this entire statement, including
  16 the above license grant, this restriction and the following disclaimer,
  17 must be included in all copies of the Software, in whole or in part, and
  18 all derivative works of the Software, unless such copies or derivative
  19 works are solely in the form of machine-executable object code generated by
  20 a source language processor.
  21
  22 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  23 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
  25 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  26 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  27 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  28 DEALINGS IN THE SOFTWARE.
  29 */
  30
  31 #ifndef BOOST_OUTCOME_BASIC_RESULT_HPP
  32 #define BOOST_OUTCOME_BASIC_RESULT_HPP
  33
  34 #include "config.hpp"
  35 #include "convert.hpp"
  36 #include "detail/basic_result_final.hpp"
  37
  38 #include "policy/all_narrow.hpp"
  39 #include "policy/terminate.hpp"
  40
  41 #ifdef __clang__
  42 #pragma clang diagnostic push
  43 #pragma clang diagnostic ignored "-Wdocumentation"  // Standardese markup confuses clang
  44 #endif
  45
  46 BOOST_OUTCOME_V2_NAMESPACE_EXPORT_BEGIN
  47
  48 template <class R, class S, class NoValuePolicy>                                                                                                                                  //
  49 #if !defined(__GNUC__) || __GNUC__ >= 10                                                                                                                                          // GCC's constraints implementation is buggy
  50 BOOST_OUTCOME_REQUIRES(trait::type_can_be_used_in_basic_result<R> &&trait::type_can_be_used_in_basic_result<S> && (std::is_void<S>::value || std::is_default_constructible<S>::value))  //
  51 #endif
  52 class basic_result;
  53
  54 namespace detail
  55 {
  56   // These are reused by basic_outcome to save load on the compiler
  57   template <class value_type, class error_type> struct result_predicates
  58   {
  59     // Predicate for the implicit constructors to be available. Weakened to allow result<int, C enum>.
  60     static constexpr bool implicit_constructors_enabled =                                                                               //
  61     !(trait::is_error_type<std::decay_t<value_type>>::value && trait::is_error_type<std::decay_t<error_type>>::value)                   // both value and error types are not whitelisted error types
  62     && ((!detail::is_implicitly_constructible<value_type, error_type> && !detail::is_implicitly_constructible<error_type, value_type>)  // if value and error types cannot be constructed into one another
  63         || (trait::is_error_type<std::decay_t<error_type>>::value                                                                       // if error type is a whitelisted error type
  64             && !detail::is_implicitly_constructible<error_type, value_type>                                                             // AND which cannot be constructed from the value type
  65             && std::is_integral<value_type>::value));                                                                                   // AND the value type is some integral type
  66
  67     // Predicate for the value converting constructor to be available. Weakened to allow result<int, C enum>.
  68     template <class T>
  69     static constexpr bool enable_value_converting_constructor =                                                      //
  70     implicit_constructors_enabled                                                                                    //
  71     && !is_in_place_type_t<std::decay_t<T>>::value                                                                   // not in place construction
  72     && !trait::is_error_type_enum<error_type, std::decay_t<T>>::value                                                // not an enum valid for my error type
  73     && ((detail::is_implicitly_constructible<value_type, T> && !detail::is_implicitly_constructible<error_type, T>)  // is unambiguously for value type
  74         || (std::is_same<value_type, std::decay_t<T>>::value                                                         // OR is my value type exactly
  75             && detail::is_implicitly_constructible<value_type, T>) );                                                // and my value type is constructible from this ref form of T
  76
  77
  78     // Predicate for the error converting constructor to be available. Weakened to allow result<int, C enum>.
  79     template <class T>
  80     static constexpr bool enable_error_converting_constructor =                                                      //
  81     implicit_constructors_enabled                                                                                    //
  82     && !is_in_place_type_t<std::decay_t<T>>::value                                                                   // not in place construction
  83     && !trait::is_error_type_enum<error_type, std::decay_t<T>>::value                                                // not an enum valid for my error type
  84     && ((!detail::is_implicitly_constructible<value_type, T> && detail::is_implicitly_constructible<error_type, T>)  // is unambiguously for error type
  85         || (std::is_same<error_type, std::decay_t<T>>::value                                                         // OR is my error type exactly
  86             && detail::is_implicitly_constructible<error_type, T>) );                                                // and my error type is constructible from this ref form of T
  87
  88     // Predicate for the error condition converting constructor to be available.
  89     template <class ErrorCondEnum>
  90     static constexpr bool enable_error_condition_converting_constructor =                                                                       //
  91     !is_in_place_type_t<std::decay_t<ErrorCondEnum>>::value                                                                                     // not in place construction
  92     && trait::is_error_type_enum<error_type, std::decay_t<ErrorCondEnum>>::value                                                                // is an error condition enum
  93     /*&& !detail::is_implicitly_constructible<value_type, ErrorCondEnum> && !detail::is_implicitly_constructible<error_type, ErrorCondEnum>*/;  // not constructible via any other means
  94
  95     // Predicate for the converting constructor from a compatible input to be available.
  96     template <class T, class U, class V>
  97     static constexpr bool enable_compatible_conversion =                                                                       //
  98     (std::is_void<T>::value || detail::is_explicitly_constructible<value_type, typename basic_result<T, U, V>::value_type>)    // if our value types are constructible
  99     &&(std::is_void<U>::value || detail::is_explicitly_constructible<error_type, typename basic_result<T, U, V>::error_type>)  // if our error types are constructible
 100     ;
 101
 102     // Predicate for the converting constructor from a make_error_code() of the input to be available.
 103     template <class T, class U, class V>
 104     static constexpr bool enable_make_error_code_compatible_conversion =                                                        //
 105     trait::is_error_code_available<std::decay_t<error_type>>::value                                                             // if error type has an error code
 106     && !enable_compatible_conversion<T, U, V>                                                                                   // and the normal compatible conversion is not available
 107     && (std::is_void<T>::value || detail::is_explicitly_constructible<value_type, typename basic_result<T, U, V>::value_type>)  // and if our value types are constructible
 108     &&detail::is_explicitly_constructible<error_type, typename trait::is_error_code_available<U>::type>;                        // and our error type is constructible from a make_error_code()
 109
 110     // Predicate for the converting constructor from a make_exception_ptr() of the input to be available.
 111     template <class T, class U, class V>
 112     static constexpr bool enable_make_exception_ptr_compatible_conversion =                                                     //
 113     trait::is_exception_ptr_available<std::decay_t<error_type>>::value                                                          // if error type has an exception ptr
 114     && !enable_compatible_conversion<T, U, V>                                                                                   // and the normal compatible conversion is not available
 115     && (std::is_void<T>::value || detail::is_explicitly_constructible<value_type, typename basic_result<T, U, V>::value_type>)  // and if our value types are constructible
 116     &&detail::is_explicitly_constructible<error_type, typename trait::is_exception_ptr_available<U>::type>;                     // and our error type is constructible from a make_exception_ptr()
 117
 118     // Predicate for the implicit converting inplace constructor from a compatible input to be available.
 119     struct disable_inplace_value_error_constructor;
 120     template <class... Args>
 121     using choose_inplace_value_error_constructor = std::conditional_t<                                       //
 122     std::is_constructible<value_type, Args...>::value && std::is_constructible<error_type, Args...>::value,  //
 123     disable_inplace_value_error_constructor,                                                                 //
 124     std::conditional_t<                                                                                      //
 125     std::is_constructible<value_type, Args...>::value,                                                       //
 126     value_type,                                                                                              //
 127     std::conditional_t<                                                                                      //
 128     std::is_constructible<error_type, Args...>::value,                                                       //
 129     error_type,                                                                                              //
 130     disable_inplace_value_error_constructor>>>;
 131     template <class... Args>
 132     static constexpr bool enable_inplace_value_error_constructor = implicit_constructors_enabled  //
 133                                                                    && !std::is_same<choose_inplace_value_error_constructor<Args...>, disable_inplace_value_error_constructor>::value;
 134   };
 135
 136   template <class T, class U> constexpr inline const U &extract_value_from_success(const success_type<U> &v) { return v.value(); }
 137   template <class T, class U> constexpr inline U &&extract_value_from_success(success_type<U> &&v) { return static_cast<success_type<U> &&>(v).value(); }
 138   template <class T> constexpr inline T extract_value_from_success(const success_type<void> & /*unused*/) { return T{}; }
 139
 140   template <class T, class U, class V> constexpr inline const U &extract_error_from_failure(const failure_type<U, V> &v) { return v.error(); }
 141   template <class T, class U, class V> constexpr inline U &&extract_error_from_failure(failure_type<U, V> &&v) { return static_cast<failure_type<U, V> &&>(v).error(); }
 142   template <class T, class V> constexpr inline T extract_error_from_failure(const failure_type<void, V> & /*unused*/) { return T{}; }
 143
 144   template <class T> struct is_basic_result
 145   {
 146     static constexpr bool value = false;
 147   };
 148   template <class R, class S, class T> struct is_basic_result<basic_result<R, S, T>>
 149   {
 150     static constexpr bool value = true;
 151   };
 152 }  // namespace detail
 153
 154 /*! AWAITING HUGO JSON CONVERSION TOOL
 155 type alias template <class T> is_basic_result. Potential doc page: `is_basic_result<T>`
 156 */
 157 template <class T> using is_basic_result = detail::is_basic_result<std::decay_t<T>>;
 158 /*! AWAITING HUGO JSON CONVERSION TOOL
 159 SIGNATURE NOT RECOGNISED
 160 */
 161 template <class T> static constexpr bool is_basic_result_v = detail::is_basic_result<std::decay_t<T>>::value;
 162
 163 /*! AWAITING HUGO JSON CONVERSION TOOL
 164 SIGNATURE NOT RECOGNISED
 165 */
 166 namespace hooks
 167 {
 168   /*! AWAITING HUGO JSON CONVERSION TOOL
 169 SIGNATURE NOT RECOGNISED
 170 */
 171   template <class T, class U> constexpr inline void hook_result_construction(T * /*unused*/, U && /*unused*/) noexcept {}
 172   /*! AWAITING HUGO JSON CONVERSION TOOL
 173 SIGNATURE NOT RECOGNISED
 174 */
 175   template <class T, class U> constexpr inline void hook_result_copy_construction(T * /*unused*/, U && /*unused*/) noexcept {}
 176   /*! AWAITING HUGO JSON CONVERSION TOOL
 177 SIGNATURE NOT RECOGNISED
 178 */
 179   template <class T, class U> constexpr inline void hook_result_move_construction(T * /*unused*/, U && /*unused*/) noexcept {}
 180   /*! AWAITING HUGO JSON CONVERSION TOOL
 181 SIGNATURE NOT RECOGNISED
 182 */
 183   template <class T, class U, class... Args> constexpr inline void hook_result_in_place_construction(T * /*unused*/, in_place_type_t<U> /*unused*/, Args &&... /*unused*/) noexcept {}
 184
 185   /*! AWAITING HUGO JSON CONVERSION TOOL
 186 SIGNATURE NOT RECOGNISED
 187 */
 188   template <class R, class S, class NoValuePolicy> constexpr inline uint16_t spare_storage(const detail::basic_result_final<R, S, NoValuePolicy> *r) noexcept { return (r->_state._status >> detail::status_2byte_shift) & 0xffff; }
 189   /*! AWAITING HUGO JSON CONVERSION TOOL
 190 SIGNATURE NOT RECOGNISED
 191 */
 192   template <class R, class S, class NoValuePolicy> constexpr inline void set_spare_storage(detail::basic_result_final<R, S, NoValuePolicy> *r, uint16_t v) noexcept { r->_state._status |= (v << detail::status_2byte_shift); }
 193 }  // namespace hooks
 194
 195 /*! AWAITING HUGO JSON CONVERSION TOOL
 196 type definition template <class R, class S, class NoValuePolicy> basic_result. Potential doc page: `basic_result<T, E, NoValuePolicy>`
 197 */
 198 template <class R, class S, class NoValuePolicy>                                                                                                                                  //
 199 #if !defined(__GNUC__) || __GNUC__ >= 10                                                                                                                                          // GCC's constraints implementation is buggy
 200 BOOST_OUTCOME_REQUIRES(trait::type_can_be_used_in_basic_result<R> &&trait::type_can_be_used_in_basic_result<S> && (std::is_void<S>::value || std::is_default_constructible<S>::value))  //
 201 #endif
 202 class BOOST_OUTCOME_NODISCARD basic_result : public detail::basic_result_final<R, S, NoValuePolicy>
 203 {
 204   static_assert(trait::type_can_be_used_in_basic_result<R>, "The type R cannot be used in a basic_result");
 205   static_assert(trait::type_can_be_used_in_basic_result<S>, "The type S cannot be used in a basic_result");
 206   static_assert(std::is_void<S>::value || std::is_default_constructible<S>::value, "The type S must be void or default constructible");
 207
 208   using base = detail::basic_result_final<R, S, NoValuePolicy>;
 209
 210   struct implicit_constructors_disabled_tag
 211   {
 212   };
 213   struct value_converting_constructor_tag
 214   {
 215   };
 216   struct error_converting_constructor_tag
 217   {
 218   };
 219   struct error_condition_converting_constructor_tag
 220   {
 221   };
 222   struct explicit_valueornone_converting_constructor_tag
 223   {
 224   };
 225   struct explicit_valueorerror_converting_constructor_tag
 226   {
 227   };
 228   struct explicit_compatible_copy_conversion_tag
 229   {
 230   };
 231   struct explicit_compatible_move_conversion_tag
 232   {
 233   };
 234   struct explicit_make_error_code_compatible_copy_conversion_tag
 235   {
 236   };
 237   struct explicit_make_error_code_compatible_move_conversion_tag
 238   {
 239   };
 240   struct explicit_make_exception_ptr_compatible_copy_conversion_tag
 241   {
 242   };
 243   struct explicit_make_exception_ptr_compatible_move_conversion_tag
 244   {
 245   };
 246
 247 public:
 248   using value_type = R;
 249   using error_type = S;
 250
 251   using value_type_if_enabled = typename base::_value_type;
 252   using error_type_if_enabled = typename base::_error_type;
 253
 254   template <class T, class U = S, class V = NoValuePolicy> using rebind = basic_result<T, U, V>;
 255
 256 protected:
 257   // Requirement predicates for result.
 258   struct predicate
 259   {
 260     using base = detail::result_predicates<value_type, error_type>;
 261
 262     // Predicate for any constructors to be available at all
 263     static constexpr bool constructors_enabled = !std::is_same<std::decay_t<value_type>, std::decay_t<error_type>>::value;
 264
 265     // Predicate for implicit constructors to be available at all
 266     static constexpr bool implicit_constructors_enabled = constructors_enabled && base::implicit_constructors_enabled;
 267
 268     // Predicate for the value converting constructor to be available.
 269     template <class T>
 270     static constexpr bool enable_value_converting_constructor =  //
 271     constructors_enabled                                         //
 272     && !std::is_same<std::decay_t<T>, basic_result>::value       // not my type
 273     && base::template enable_value_converting_constructor<T>;
 274
 275     // Predicate for the error converting constructor to be available.
 276     template <class T>
 277     static constexpr bool enable_error_converting_constructor =  //
 278     constructors_enabled                                         //
 279     && !std::is_same<std::decay_t<T>, basic_result>::value       // not my type
 280     && base::template enable_error_converting_constructor<T>;
 281
 282     // Predicate for the error condition converting constructor to be available.
 283     template <class ErrorCondEnum>
 284     static constexpr bool enable_error_condition_converting_constructor =  //
 285     constructors_enabled                                                   //
 286     && !std::is_same<std::decay_t<ErrorCondEnum>, basic_result>::value     // not my type
 287     && base::template enable_error_condition_converting_constructor<ErrorCondEnum>;
 288
 289     // Predicate for the converting constructor from a compatible input to be available.
 290     template <class T, class U, class V>
 291     static constexpr bool enable_compatible_conversion =          //
 292     constructors_enabled                                          //
 293     && !std::is_same<basic_result<T, U, V>, basic_result>::value  // not my type
 294     && base::template enable_compatible_conversion<T, U, V>;
 295
 296     // Predicate for the converting constructor from a make_error_code() of the input to be available.
 297     template <class T, class U, class V>
 298     static constexpr bool enable_make_error_code_compatible_conversion =  //
 299     constructors_enabled                                                  //
 300     && !std::is_same<basic_result<T, U, V>, basic_result>::value          // not my type
 301     && base::template enable_make_error_code_compatible_conversion<T, U, V>;
 302
 303     // Predicate for the converting constructor from a make_exception_ptr() of the input to be available.
 304     template <class T, class U, class V>
 305     static constexpr bool enable_make_exception_ptr_compatible_conversion =  //
 306     constructors_enabled                                                     //
 307     && !std::is_same<basic_result<T, U, V>, basic_result>::value             // not my type
 308     && base::template enable_make_exception_ptr_compatible_conversion<T, U, V>;
 309
 310     // Predicate for the inplace construction of value to be available.
 311     template <class... Args>
 312     static constexpr bool enable_inplace_value_constructor =  //
 313     constructors_enabled                                      //
 314     && (std::is_void<value_type>::value                       //
 315         || std::is_constructible<value_type, Args...>::value);
 316
 317     // Predicate for the inplace construction of error to be available.
 318     template <class... Args>
 319     static constexpr bool enable_inplace_error_constructor =  //
 320     constructors_enabled                                      //
 321     && (std::is_void<error_type>::value                       //
 322         || std::is_constructible<error_type, Args...>::value);
 323
 324     // Predicate for the implicit converting inplace constructor to be available.
 325     template <class... Args>
 326     static constexpr bool enable_inplace_value_error_constructor =  //
 327     constructors_enabled                                            //
 328     &&base::template enable_inplace_value_error_constructor<Args...>;
 329     template <class... Args> using choose_inplace_value_error_constructor = typename base::template choose_inplace_value_error_constructor<Args...>;
 330   };
 331
 332 public:
 333   /*! AWAITING HUGO JSON CONVERSION TOOL
 334 SIGNATURE NOT RECOGNISED
 335 */
 336   basic_result() = delete;
 337   /*! AWAITING HUGO JSON CONVERSION TOOL
 338 SIGNATURE NOT RECOGNISED
 339 */
 340   basic_result(basic_result && /*unused*/) = default;  // NOLINT
 341   /*! AWAITING HUGO JSON CONVERSION TOOL
 342 SIGNATURE NOT RECOGNISED
 343 */
 344   basic_result(const basic_result & /*unused*/) = default;
 345   /*! AWAITING HUGO JSON CONVERSION TOOL
 346 SIGNATURE NOT RECOGNISED
 347 */
 348   basic_result &operator=(basic_result && /*unused*/) = default;  // NOLINT
 349   /*! AWAITING HUGO JSON CONVERSION TOOL
 350 SIGNATURE NOT RECOGNISED
 351 */
 352   basic_result &operator=(const basic_result & /*unused*/) = default;
 353   ~basic_result() = default;
 354
 355   /*! AWAITING HUGO JSON CONVERSION TOOL
 356 SIGNATURE NOT RECOGNISED
 357 */
 358   BOOST_OUTCOME_TEMPLATE(class Arg, class... Args)
 359   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(!predicate::constructors_enabled && (sizeof...(Args) >= 0)))
 360   basic_result(Arg && /*unused*/, Args &&... /*unused*/) = delete;  // NOLINT basic_result<T, T> is NOT SUPPORTED, see docs!
 361
 362   /*! AWAITING HUGO JSON CONVERSION TOOL
 363 SIGNATURE NOT RECOGNISED
 364 */
 365   BOOST_OUTCOME_TEMPLATE(class T)
 366   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED((predicate::constructors_enabled && !predicate::implicit_constructors_enabled  //
 367                                    && (detail::is_implicitly_constructible<value_type, T> || detail::is_implicitly_constructible<error_type, T>) )))
 368   basic_result(T && /*unused*/, implicit_constructors_disabled_tag /*unused*/ = implicit_constructors_disabled_tag()) = delete;  // NOLINT Implicit constructors disabled, use explicit in_place_type<T>, success() or failure(). see docs!
 369
 370   /*! AWAITING HUGO JSON CONVERSION TOOL
 371 SIGNATURE NOT RECOGNISED
 372 */
 373   BOOST_OUTCOME_TEMPLATE(class T)
 374   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_value_converting_constructor<T>))
 375   constexpr basic_result(T &&t, value_converting_constructor_tag /*unused*/ = value_converting_constructor_tag()) noexcept(std::is_nothrow_constructible<value_type, T>::value)  // NOLINT
 376       : base{in_place_type<typename base::value_type>, static_cast<T &&>(t)}
 377   {
 378     using namespace hooks;
 379     hook_result_construction(this, static_cast<T &&>(t));
 380   }
 381   /*! AWAITING HUGO JSON CONVERSION TOOL
 382 SIGNATURE NOT RECOGNISED
 383 */
 384   BOOST_OUTCOME_TEMPLATE(class T)
 385   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_error_converting_constructor<T>))
 386   constexpr basic_result(T &&t, error_converting_constructor_tag /*unused*/ = error_converting_constructor_tag()) noexcept(std::is_nothrow_constructible<error_type, T>::value)  // NOLINT
 387       : base{in_place_type<typename base::error_type>, static_cast<T &&>(t)}
 388   {
 389     using namespace hooks;
 390     hook_result_construction(this, static_cast<T &&>(t));
 391   }
 392   /*! AWAITING HUGO JSON CONVERSION TOOL
 393 SIGNATURE NOT RECOGNISED
 394 */
 395   BOOST_OUTCOME_TEMPLATE(class ErrorCondEnum)
 396   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TEXPR(error_type(make_error_code(ErrorCondEnum()))),  //
 397                     BOOST_OUTCOME_TPRED(predicate::template enable_error_condition_converting_constructor<ErrorCondEnum>))
 398   constexpr basic_result(ErrorCondEnum &&t, error_condition_converting_constructor_tag /*unused*/ = error_condition_converting_constructor_tag()) noexcept(noexcept(error_type(make_error_code(static_cast<ErrorCondEnum &&>(t)))))  // NOLINT
 399       : base{in_place_type<typename base::error_type>, make_error_code(t)}
 400   {
 401     using namespace hooks;
 402     hook_result_construction(this, static_cast<ErrorCondEnum &&>(t));
 403   }
 404
 405   /*! AWAITING HUGO JSON CONVERSION TOOL
 406 SIGNATURE NOT RECOGNISED
 407 */
 408   BOOST_OUTCOME_TEMPLATE(class T)
 409   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(convert::value_or_error<basic_result, std::decay_t<T>>::enable_result_inputs || !is_basic_result_v<T>),  //
 410                     BOOST_OUTCOME_TEXPR(convert::value_or_error<basic_result, std::decay_t<T>>{}(std::declval<T>())))
 411   constexpr explicit basic_result(T &&o, explicit_valueorerror_converting_constructor_tag /*unused*/ = explicit_valueorerror_converting_constructor_tag())  // NOLINT
 412       : basic_result{convert::value_or_error<basic_result, std::decay_t<T>>{}(static_cast<T &&>(o))}
 413   {
 414   }
 415   /*! AWAITING HUGO JSON CONVERSION TOOL
 416 SIGNATURE NOT RECOGNISED
 417 */
 418   BOOST_OUTCOME_TEMPLATE(class T, class U, class V)
 419   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_compatible_conversion<T, U, V>))
 420   constexpr explicit basic_result(const basic_result<T, U, V> &o, explicit_compatible_copy_conversion_tag /*unused*/ = explicit_compatible_copy_conversion_tag()) noexcept(std::is_nothrow_constructible<value_type, T>::value &&std::is_nothrow_constructible<error_type, U>::value)
 421       : base{typename base::compatible_conversion_tag(), o}
 422   {
 423     using namespace hooks;
 424     hook_result_copy_construction(this, o);
 425   }
 426   /*! AWAITING HUGO JSON CONVERSION TOOL
 427 SIGNATURE NOT RECOGNISED
 428 */
 429   BOOST_OUTCOME_TEMPLATE(class T, class U, class V)
 430   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_compatible_conversion<T, U, V>))
 431   constexpr explicit basic_result(basic_result<T, U, V> &&o, explicit_compatible_move_conversion_tag /*unused*/ = explicit_compatible_move_conversion_tag()) noexcept(std::is_nothrow_constructible<value_type, T>::value &&std::is_nothrow_constructible<error_type, U>::value)
 432       : base{typename base::compatible_conversion_tag(), static_cast<basic_result<T, U, V> &&>(o)}
 433   {
 434     using namespace hooks;
 435     hook_result_move_construction(this, static_cast<basic_result<T, U, V> &&>(o));
 436   }
 437   /*! AWAITING HUGO JSON CONVERSION TOOL
 438 SIGNATURE NOT RECOGNISED
 439 */
 440   BOOST_OUTCOME_TEMPLATE(class T, class U, class V)
 441   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_make_error_code_compatible_conversion<T, U, V>))
 442   constexpr explicit basic_result(const basic_result<T, U, V> &o, explicit_make_error_code_compatible_copy_conversion_tag /*unused*/ = explicit_make_error_code_compatible_copy_conversion_tag()) noexcept(std::is_nothrow_constructible<value_type, T>::value &&noexcept(make_error_code(std::declval<U>())))
 443       : base{typename base::make_error_code_compatible_conversion_tag(), o}
 444   {
 445     using namespace hooks;
 446     hook_result_copy_construction(this, o);
 447   }
 448   /*! AWAITING HUGO JSON CONVERSION TOOL
 449 SIGNATURE NOT RECOGNISED
 450 */
 451   BOOST_OUTCOME_TEMPLATE(class T, class U, class V)
 452   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_make_error_code_compatible_conversion<T, U, V>))
 453   constexpr explicit basic_result(basic_result<T, U, V> &&o, explicit_make_error_code_compatible_move_conversion_tag /*unused*/ = explicit_make_error_code_compatible_move_conversion_tag()) noexcept(std::is_nothrow_constructible<value_type, T>::value &&noexcept(make_error_code(std::declval<U>())))
 454       : base{typename base::make_error_code_compatible_conversion_tag(), static_cast<basic_result<T, U, V> &&>(o)}
 455   {
 456     using namespace hooks;
 457     hook_result_move_construction(this, static_cast<basic_result<T, U, V> &&>(o));
 458   }
 459   /*! AWAITING HUGO JSON CONVERSION TOOL
 460 SIGNATURE NOT RECOGNISED
 461 */
 462   BOOST_OUTCOME_TEMPLATE(class T, class U, class V)
 463   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_make_exception_ptr_compatible_conversion<T, U, V>))
 464   constexpr explicit basic_result(const basic_result<T, U, V> &o, explicit_make_exception_ptr_compatible_copy_conversion_tag /*unused*/ = explicit_make_exception_ptr_compatible_copy_conversion_tag()) noexcept(std::is_nothrow_constructible<value_type, T>::value &&noexcept(make_exception_ptr(std::declval<U>())))
 465       : base{typename base::make_exception_ptr_compatible_conversion_tag(), o}
 466   {
 467     using namespace hooks;
 468     hook_result_copy_construction(this, o);
 469   }
 470   /*! AWAITING HUGO JSON CONVERSION TOOL
 471 SIGNATURE NOT RECOGNISED
 472 */
 473   BOOST_OUTCOME_TEMPLATE(class T, class U, class V)
 474   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_make_exception_ptr_compatible_conversion<T, U, V>))
 475   constexpr explicit basic_result(basic_result<T, U, V> &&o, explicit_make_exception_ptr_compatible_move_conversion_tag /*unused*/ = explicit_make_exception_ptr_compatible_move_conversion_tag()) noexcept(std::is_nothrow_constructible<value_type, T>::value  &&noexcept(make_exception_ptr(std::declval<U>())))
 476       : base{typename base::make_exception_ptr_compatible_conversion_tag(), static_cast<basic_result<T, U, V> &&>(o)}
 477   {
 478     using namespace hooks;
 479     hook_result_move_construction(this, static_cast<basic_result<T, U, V> &&>(o));
 480   }
 481
 482   /*! AWAITING HUGO JSON CONVERSION TOOL
 483 SIGNATURE NOT RECOGNISED
 484 */
 485   BOOST_OUTCOME_TEMPLATE(class... Args)
 486   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_inplace_value_constructor<Args...>))
 487   constexpr explicit basic_result(in_place_type_t<value_type_if_enabled> _, Args &&... args) noexcept(std::is_nothrow_constructible<value_type, Args...>::value)
 488       : base{_, static_cast<Args &&>(args)...}
 489   {
 490     using namespace hooks;
 491     hook_result_in_place_construction(this, in_place_type<value_type>, static_cast<Args &&>(args)...);
 492   }
 493   /*! AWAITING HUGO JSON CONVERSION TOOL
 494 SIGNATURE NOT RECOGNISED
 495 */
 496   BOOST_OUTCOME_TEMPLATE(class U, class... Args)
 497   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_inplace_value_constructor<std::initializer_list<U>, Args...>))
 498   constexpr explicit basic_result(in_place_type_t<value_type_if_enabled> _, std::initializer_list<U> il, Args &&... args) noexcept(std::is_nothrow_constructible<value_type, std::initializer_list<U>, Args...>::value)
 499       : base{_, il, static_cast<Args &&>(args)...}
 500   {
 501     using namespace hooks;
 502     hook_result_in_place_construction(this, in_place_type<value_type>, il, static_cast<Args &&>(args)...);
 503   }
 504   /*! AWAITING HUGO JSON CONVERSION TOOL
 505 SIGNATURE NOT RECOGNISED
 506 */
 507   BOOST_OUTCOME_TEMPLATE(class... Args)
 508   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_inplace_error_constructor<Args...>))
 509   constexpr explicit basic_result(in_place_type_t<error_type_if_enabled> _, Args &&... args) noexcept(std::is_nothrow_constructible<error_type, Args...>::value)
 510       : base{_, static_cast<Args &&>(args)...}
 511   {
 512     using namespace hooks;
 513     hook_result_in_place_construction(this, in_place_type<error_type>, static_cast<Args &&>(args)...);
 514   }
 515   /*! AWAITING HUGO JSON CONVERSION TOOL
 516 SIGNATURE NOT RECOGNISED
 517 */
 518   BOOST_OUTCOME_TEMPLATE(class U, class... Args)
 519   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_inplace_error_constructor<std::initializer_list<U>, Args...>))
 520   constexpr explicit basic_result(in_place_type_t<error_type_if_enabled> _, std::initializer_list<U> il, Args &&... args) noexcept(std::is_nothrow_constructible<error_type, std::initializer_list<U>, Args...>::value)
 521       : base{_, il, static_cast<Args &&>(args)...}
 522   {
 523     using namespace hooks;
 524     hook_result_in_place_construction(this, in_place_type<error_type>, il, static_cast<Args &&>(args)...);
 525   }
 526   /*! AWAITING HUGO JSON CONVERSION TOOL
 527 SIGNATURE NOT RECOGNISED
 528 */
 529   BOOST_OUTCOME_TEMPLATE(class A1, class A2, class... Args)
 530   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_inplace_value_error_constructor<A1, A2, Args...>))
 531   constexpr basic_result(A1 &&a1, A2 &&a2, Args &&... args) noexcept(noexcept(typename predicate::template choose_inplace_value_error_constructor<A1, A2, Args...>(std::declval<A1>(), std::declval<A2>(), std::declval<Args>()...)))
 532       : basic_result(in_place_type<typename predicate::template choose_inplace_value_error_constructor<A1, A2, Args...>>, static_cast<A1 &&>(a1), static_cast<A2 &&>(a2), static_cast<Args &&>(args)...)
 533   {
 534     /* I was a little surprised that the below is needed given that we forward to another constructor.
 535     But it turns out that ADL only fires on the first constructor for some reason.
 536     */
 537     using namespace hooks;
 538     // hook_result_in_place_construction(in_place_type<typename predicate::template choose_inplace_value_error_constructor<A1, A2, Args...>>, this);
 539   }
 540
 541   /*! AWAITING HUGO JSON CONVERSION TOOL
 542 SIGNATURE NOT RECOGNISED
 543 */
 544   constexpr basic_result(const success_type<void> &o) noexcept(std::is_nothrow_default_constructible<value_type>::value)  // NOLINT
 545       : base{in_place_type<value_type_if_enabled>}
 546   {
 547     using namespace hooks;
 548     hook_result_copy_construction(this, o);
 549   }
 550   /*! AWAITING HUGO JSON CONVERSION TOOL
 551 SIGNATURE NOT RECOGNISED
 552 */
 553   BOOST_OUTCOME_TEMPLATE(class T)
 554   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_compatible_conversion<T, void, void>))
 555   constexpr basic_result(const success_type<T> &o) noexcept(std::is_nothrow_constructible<value_type, T>::value)  // NOLINT
 556       : base{in_place_type<value_type_if_enabled>, detail::extract_value_from_success<value_type>(o)}
 557   {
 558     using namespace hooks;
 559     hook_result_copy_construction(this, o);
 560   }
 561   /*! AWAITING HUGO JSON CONVERSION TOOL
 562 SIGNATURE NOT RECOGNISED
 563 */
 564   BOOST_OUTCOME_TEMPLATE(class T)
 565   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(!std::is_void<T>::value && predicate::template enable_compatible_conversion<T, void, void>))
 566   constexpr basic_result(success_type<T> &&o) noexcept(std::is_nothrow_constructible<value_type, T>::value)  // NOLINT
 567       : base{in_place_type<value_type_if_enabled>, detail::extract_value_from_success<value_type>(static_cast<success_type<T> &&>(o))}
 568   {
 569     using namespace hooks;
 570     hook_result_move_construction(this, static_cast<success_type<T> &&>(o));
 571   }
 572   /*! AWAITING HUGO JSON CONVERSION TOOL
 573 SIGNATURE NOT RECOGNISED
 574 */
 575   BOOST_OUTCOME_TEMPLATE(class T)
 576   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_compatible_conversion<void, T, void>))
 577   constexpr basic_result(const failure_type<T> &o, explicit_compatible_copy_conversion_tag /*unused*/ = explicit_compatible_copy_conversion_tag()) noexcept(std::is_nothrow_constructible<error_type, T>::value)  // NOLINT
 578       : base{in_place_type<error_type_if_enabled>, detail::extract_error_from_failure<error_type>(o)}
 579   {
 580     using namespace hooks;
 581     hook_result_copy_construction(this, o);
 582   }
 583   /*! AWAITING HUGO JSON CONVERSION TOOL
 584 SIGNATURE NOT RECOGNISED
 585 */
 586   BOOST_OUTCOME_TEMPLATE(class T)
 587   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_compatible_conversion<void, T, void>))
 588   constexpr basic_result(failure_type<T> &&o, explicit_compatible_move_conversion_tag /*unused*/ = explicit_compatible_move_conversion_tag()) noexcept(std::is_nothrow_constructible<error_type, T>::value)  // NOLINT
 589       : base{in_place_type<error_type_if_enabled>, detail::extract_error_from_failure<error_type>(static_cast<failure_type<T> &&>(o))}
 590   {
 591     using namespace hooks;
 592     hook_result_move_construction(this, static_cast<failure_type<T> &&>(o));
 593   }
 594   /*! AWAITING HUGO JSON CONVERSION TOOL
 595 SIGNATURE NOT RECOGNISED
 596 */
 597   BOOST_OUTCOME_TEMPLATE(class T)
 598   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_make_error_code_compatible_conversion<void, T, void>))
 599   constexpr basic_result(const failure_type<T> &o, explicit_make_error_code_compatible_copy_conversion_tag /*unused*/ = explicit_make_error_code_compatible_copy_conversion_tag()) noexcept(noexcept(make_error_code(std::declval<T>())))  // NOLINT
 600       : base{in_place_type<error_type_if_enabled>, make_error_code(detail::extract_error_from_failure<error_type>(o))}
 601   {
 602     using namespace hooks;
 603     hook_result_copy_construction(this, o);
 604   }
 605   /*! AWAITING HUGO JSON CONVERSION TOOL
 606 SIGNATURE NOT RECOGNISED
 607 */
 608   BOOST_OUTCOME_TEMPLATE(class T)
 609   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_make_error_code_compatible_conversion<void, T, void>))
 610   constexpr basic_result(failure_type<T> &&o, explicit_make_error_code_compatible_move_conversion_tag /*unused*/ = explicit_make_error_code_compatible_move_conversion_tag()) noexcept(noexcept(make_error_code(std::declval<T>())))  // NOLINT
 611       : base{in_place_type<error_type_if_enabled>, make_error_code(detail::extract_error_from_failure<error_type>(static_cast<failure_type<T> &&>(o)))}
 612   {
 613     using namespace hooks;
 614     hook_result_move_construction(this, static_cast<failure_type<T> &&>(o));
 615   }
 616   /*! AWAITING HUGO JSON CONVERSION TOOL
 617 SIGNATURE NOT RECOGNISED
 618 */
 619   BOOST_OUTCOME_TEMPLATE(class T)
 620   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_make_exception_ptr_compatible_conversion<void, T, void>))
 621   constexpr basic_result(const failure_type<T> &o, explicit_make_exception_ptr_compatible_copy_conversion_tag /*unused*/ = explicit_make_exception_ptr_compatible_copy_conversion_tag()) noexcept(noexcept(make_exception_ptr(std::declval<T>())))  // NOLINT
 622       : base{in_place_type<error_type_if_enabled>, make_exception_ptr(detail::extract_error_from_failure<error_type>(o))}
 623   {
 624     using namespace hooks;
 625     hook_result_copy_construction(this, o);
 626   }
 627   /*! AWAITING HUGO JSON CONVERSION TOOL
 628 SIGNATURE NOT RECOGNISED
 629 */
 630   BOOST_OUTCOME_TEMPLATE(class T)
 631   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(predicate::template enable_make_exception_ptr_compatible_conversion<void, T, void>))
 632   constexpr basic_result(failure_type<T> &&o, explicit_make_exception_ptr_compatible_move_conversion_tag /*unused*/ = explicit_make_exception_ptr_compatible_move_conversion_tag()) noexcept(noexcept(make_exception_ptr(std::declval<T>())))  // NOLINT
 633       : base{in_place_type<error_type_if_enabled>, make_exception_ptr(detail::extract_error_from_failure<error_type>(static_cast<failure_type<T> &&>(o)))}
 634   {
 635     using namespace hooks;
 636     hook_result_move_construction(this, static_cast<failure_type<T> &&>(o));
 637   }
 638
 639   /*! AWAITING HUGO JSON CONVERSION TOOL
 640 SIGNATURE NOT RECOGNISED
 641 */
 642   constexpr void swap(basic_result &o) noexcept((std::is_void<value_type>::value || detail::is_nothrow_swappable<value_type>::value)  //
 643                                                 && (std::is_void<error_type>::value || detail::is_nothrow_swappable<error_type>::value))
 644   {
 645     constexpr bool value_throws = !std::is_void<value_type>::value && !detail::is_nothrow_swappable<value_type>::value;
 646     constexpr bool error_throws = !std::is_void<error_type>::value && !detail::is_nothrow_swappable<error_type>::value;
 647     detail::basic_result_storage_swap<value_throws, error_throws>(*this, o);
 648   }
 649
 650   /*! AWAITING HUGO JSON CONVERSION TOOL
 651 SIGNATURE NOT RECOGNISED
 652 */
 653   auto as_failure() const & {
 654     return failure(this->assume_error()); }
 655   /*! AWAITING HUGO JSON CONVERSION TOOL
 656 SIGNATURE NOT RECOGNISED
 657 */
 658   auto as_failure() && {
 659     return failure(static_cast<basic_result &&>(*this).assume_error()); }
 660 };
 661
 662 /*! AWAITING HUGO JSON CONVERSION TOOL
 663 SIGNATURE NOT RECOGNISED
 664 */
 665 template <class R, class S, class P> inline void swap(basic_result<R, S, P> &a, basic_result<R, S, P> &b) noexcept(noexcept(a.swap(b)))
 666 {
 667   a.swap(b);
 668 }
 669
 670 #if !defined(NDEBUG)
 671 // Check is trivial in all ways except default constructibility
 672 // static_assert(std::is_trivial<basic_result<int, long, policy::all_narrow>>::value, "result<int> is not trivial!");
 673 // static_assert(std::is_trivially_default_constructible<basic_result<int, long, policy::all_narrow>>::value, "result<int> is not trivially default constructible!");
 674 static_assert(std::is_trivially_copyable<basic_result<int, long, policy::all_narrow>>::value, "result<int> is not trivially copyable!");
 675 static_assert(std::is_trivially_assignable<basic_result<int, long, policy::all_narrow>, basic_result<int, long, policy::all_narrow>>::value, "result<int> is not trivially assignable!");
 676 static_assert(std::is_trivially_destructible<basic_result<int, long, policy::all_narrow>>::value, "result<int> is not trivially destructible!");
 677 static_assert(std::is_trivially_copy_constructible<basic_result<int, long, policy::all_narrow>>::value, "result<int> is not trivially copy constructible!");
 678 static_assert(std::is_trivially_move_constructible<basic_result<int, long, policy::all_narrow>>::value, "result<int> is not trivially move constructible!");
 679 static_assert(std::is_trivially_copy_assignable<basic_result<int, long, policy::all_narrow>>::value, "result<int> is not trivially copy assignable!");
 680 static_assert(std::is_trivially_move_assignable<basic_result<int, long, policy::all_narrow>>::value, "result<int> is not trivially move assignable!");
 681 // Also check is standard layout
 682 static_assert(std::is_standard_layout<basic_result<int, long, policy::all_narrow>>::value, "result<int> is not a standard layout type!");
 683 #endif
 684
 685 BOOST_OUTCOME_V2_NAMESPACE_END
 686
 687 #ifdef __clang__
 688 #pragma clang diagnostic pop
 689 #endif
 690
 691 #endif