outcome/experimental/status_outcome.hpp

0001 /* A less simple result type
0002 (C) 2018-2024 Niall Douglas <http://www.nedproductions.biz/> (17 commits)
0003 File Created: Apr 2018
0004
0005
0006 Boost Software License - Version 1.0 - August 17th, 2003
0007
0008 Permission is hereby granted, free of charge, to any person or organization
0009 obtaining a copy of the software and accompanying documentation covered by
0010 this license (the "Software") to use, reproduce, display, distribute,
0011 execute, and transmit the Software, and to prepare derivative works of the
0012 Software, and to permit third-parties to whom the Software is furnished to
0013 do so, all subject to the following:
0014
0015 The copyright notices in the Software and this entire statement, including
0016 the above license grant, this restriction and the following disclaimer,
0017 must be included in all copies of the Software, in whole or in part, and
0018 all derivative works of the Software, unless such copies or derivative
0019 works are solely in the form of machine-executable object code generated by
0020 a source language processor.
0021
0022 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0023 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0024 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
0025 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
0026 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
0027 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
0028 DEALINGS IN THE SOFTWARE.
0029 */
0030
0031 #ifndef BOOST_OUTCOME_EXPERIMENTAL_STATUS_OUTCOME_HPP
0032 #define BOOST_OUTCOME_EXPERIMENTAL_STATUS_OUTCOME_HPP
0033
0034 #include "../basic_outcome.hpp"
0035
0036 #include "../detail/trait_std_exception.hpp"
0037 #include "status_result.hpp"
0038
0039 #include "boost/exception_ptr.hpp"
0040
0041 BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_BEGIN
0042 template <class DomainType> inline std::exception_ptr basic_outcome_failure_exception_from_error(const status_code<DomainType> &sc)
0043 {
0044   (void) sc;
0045 #ifndef BOOST_NO_EXCEPTIONS
0046   try
0047   {
0048     sc.throw_exception();
0049   }
0050   catch(...)
0051   {
0052     return std::current_exception();
0053   }
0054 #endif
0055   return {};
0056 }
0057 BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_END
0058
0059 BOOST_OUTCOME_V2_NAMESPACE_EXPORT_BEGIN
0060
0061 namespace experimental
0062 {
0063   namespace policy
0064   {
0065     template <class T, class EC, class E>
0066     using default_status_outcome_policy = std::conditional_t<  //
0067     std::is_void<EC>::value && std::is_void<E>::value,         //
0068     BOOST_OUTCOME_V2_NAMESPACE::policy::terminate,                   //
0069     std::conditional_t<(is_status_code<EC>::value || is_errored_status_code<EC>::value) &&
0070                        (std::is_void<E>::value || BOOST_OUTCOME_V2_NAMESPACE::trait::is_exception_ptr_available<E>::value),  //
0071                        status_code_throw<T, EC, E>,                                                                    //
0072                        BOOST_OUTCOME_V2_NAMESPACE::policy::fail_to_compile_observers                                         //
0073                        >>;
0074   }  // namespace policy
0075
0076   /*! AWAITING HUGO JSON CONVERSION TOOL
0077 SIGNATURE NOT RECOGNISED
0078 */
0079   template <class R, class S = erased_errored_status_code<typename system_code::value_type>, class P = std::exception_ptr,
0080             class NoValuePolicy = policy::default_status_outcome_policy<R, S, P>>  //
0081   using status_outcome = basic_outcome<R, S, P, NoValuePolicy>;
0082
0083   /*! AWAITING HUGO JSON CONVERSION TOOL
0084 SIGNATURE NOT RECOGNISED
0085 */
0086   BOOST_OUTCOME_TEMPLATE(class R, class S, class P, class NoValuePolicy)
0087   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(std::is_copy_constructible<R>::value &&std::is_copy_constructible<P>::value &&
0088                                   (is_status_code<S>::value || is_errored_status_code<S>::value)))
0089   inline basic_outcome<R, S, P, NoValuePolicy> clone(const basic_outcome<R, S, P, NoValuePolicy> &v)
0090   {
0091     if(v)
0092     {
0093       return success_type<R>(v.assume_value());
0094     }
0095     if(v.has_error() && v.has_exception())
0096     {
0097       return failure_type<S, P>(v.assume_error().clone(), v.assume_exception(), hooks::spare_storage(&v));
0098     }
0099     if(v.has_exception())
0100     {
0101       return failure_type<S, P>(in_place_type<P>, v.assume_exception(), hooks::spare_storage(&v));
0102     }
0103     return failure_type<S, P>(in_place_type<S>, v.assume_error().clone(), hooks::spare_storage(&v));
0104   }
0105
0106   /*! AWAITING HUGO JSON CONVERSION TOOL
0107 SIGNATURE NOT RECOGNISED
0108 */
0109   BOOST_OUTCOME_TEMPLATE(class S, class P, class NoValuePolicy)
0110   BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(std::is_copy_constructible<P>::value && (is_status_code<S>::value || is_errored_status_code<S>::value)))
0111   inline basic_outcome<void, S, P, NoValuePolicy> clone(const basic_outcome<void, S, P, NoValuePolicy> &v)
0112   {
0113     if(v)
0114     {
0115       return success_type<void>();
0116     }
0117     if(v.has_error() && v.has_exception())
0118     {
0119       return failure_type<S, P>(v.assume_error().clone(), v.assume_exception(), hooks::spare_storage(&v));
0120     }
0121     if(v.has_exception())
0122     {
0123       return failure_type<S, P>(in_place_type<P>, v.assume_exception(), hooks::spare_storage(&v));
0124     }
0125     return failure_type<S, P>(in_place_type<S>, v.assume_error().clone(), hooks::spare_storage(&v));
0126   }
0127
0128   namespace policy
0129   {
0130     template <class T, class DomainType, class E> struct status_code_throw<T, status_code<DomainType>, E> : base
0131     {
0132       using _base = base;
0133       template <class Impl> static constexpr void wide_value_check(Impl &&self)
0134       {
0135         if(!base::_has_value(static_cast<Impl &&>(self)))
0136         {
0137           if(base::_has_exception(static_cast<Impl &&>(self)))
0138           {
0139             BOOST_OUTCOME_V2_NAMESPACE::policy::detail::_rethrow_exception<trait::is_exception_ptr_available<E>::value>(
0140             base::_exception<T, status_code<DomainType>, E, status_code_throw>(static_cast<Impl &&>(self)));  // NOLINT
0141           }
0142           if(base::_has_error(static_cast<Impl &&>(self)))
0143           {
0144 #ifndef BOOST_NO_EXCEPTIONS
0145             base::_error(static_cast<Impl &&>(self)).throw_exception();
0146 #else
0147             BOOST_OUTCOME_THROW_EXCEPTION("wide value check failed");
0148 #endif
0149           }
0150         }
0151       }
0152       template <class Impl> static constexpr void wide_error_check(Impl &&self) { _base::narrow_error_check(static_cast<Impl &&>(self)); }
0153       template <class Impl> static constexpr void wide_exception_check(Impl &&self) { _base::narrow_exception_check(static_cast<Impl &&>(self)); }
0154     };
0155     template <class T, class DomainType, class E>
0156     struct status_code_throw<T, errored_status_code<DomainType>, E> : status_code_throw<T, status_code<DomainType>, E>
0157     {
0158       status_code_throw() = default;
0159       using status_code_throw<T, status_code<DomainType>, E>::status_code_throw;
0160     };
0161   }  // namespace policy
0162
0163 }  // namespace experimental
0164
0165 BOOST_OUTCOME_V2_NAMESPACE_END
0166
0167 #endif