/* Says how to convert value, error and exception types
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(C) 2017-2020 Niall Douglas <http://www.nedproductions.biz/> (12 commits)
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File Created: Nov 2017
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Boost Software License - Version 1.0 - August 17th, 2003
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Permission is hereby granted, free of charge, to any person or organization
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obtaining a copy of the software and accompanying documentation covered by
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this license (the "Software") to use, reproduce, display, distribute,
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execute, and transmit the Software, and to prepare derivative works of the
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Software, and to permit third-parties to whom the Software is furnished to
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do so, all subject to the following:
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The copyright notices in the Software and this entire statement, including
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the above license grant, this restriction and the following disclaimer,
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must be included in all copies of the Software, in whole or in part, and
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all derivative works of the Software, unless such copies or derivative
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works are solely in the form of machine-executable object code generated by
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a source language processor.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
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SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
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FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
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ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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DEALINGS IN THE SOFTWARE.
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*/
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#ifndef BOOST_OUTCOME_CONVERT_HPP
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#define BOOST_OUTCOME_CONVERT_HPP
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#include "detail/basic_result_storage.hpp"
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BOOST_OUTCOME_V2_NAMESPACE_EXPORT_BEGIN
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namespace concepts
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{
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#if defined(__cpp_concepts)
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#if !defined(_MSC_VER) && !defined(__clang__) && (__GNUC__ < 9 || __cplusplus < 202000L)
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#define BOOST_OUTCOME_GCC6_CONCEPT_BOOL bool
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#else
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#define BOOST_OUTCOME_GCC6_CONCEPT_BOOL
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#endif
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namespace detail
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{
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template <class T, class U> concept BOOST_OUTCOME_GCC6_CONCEPT_BOOL SameHelper = std::is_same<T, U>::value;
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template <class T, class U> concept BOOST_OUTCOME_GCC6_CONCEPT_BOOL same_as = detail::SameHelper<T, U> &&detail::SameHelper<U, T>;
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template <class T, class U> concept BOOST_OUTCOME_GCC6_CONCEPT_BOOL convertible = std::is_convertible<T, U>::value;
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template <class T, class U> concept BOOST_OUTCOME_GCC6_CONCEPT_BOOL base_of = std::is_base_of<T, U>::value;
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} // namespace detail
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/* The `value_or_none` concept.
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\requires That `U::value_type` exists and that `std::declval<U>().has_value()` returns a `bool` and `std::declval<U>().value()` exists.
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*/
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template <class U> concept BOOST_OUTCOME_GCC6_CONCEPT_BOOL value_or_none = requires(U a)
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{
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{
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a.has_value()
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}
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->detail::same_as<bool>;
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{a.value()};
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};
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/* The `value_or_error` concept.
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\requires That `U::value_type` and `U::error_type` exist;
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that `std::declval<U>().has_value()` returns a `bool`, `std::declval<U>().value()` and `std::declval<U>().error()` exists.
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*/
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template <class U> concept BOOST_OUTCOME_GCC6_CONCEPT_BOOL value_or_error = requires(U a)
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{
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{
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a.has_value()
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}
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->detail::same_as<bool>;
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{a.value()};
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{a.error()};
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};
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#else
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namespace detail
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{
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struct no_match
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{
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};
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inline no_match match_value_or_none(...);
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inline no_match match_value_or_error(...);
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BOOST_OUTCOME_TEMPLATE(class U)
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BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TEXPR(std::declval<U>().has_value()), BOOST_OUTCOME_TEXPR(std::declval<U>().value()))
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inline U match_value_or_none(U &&);
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BOOST_OUTCOME_TEMPLATE(class U)
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BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TEXPR(std::declval<U>().has_value()), BOOST_OUTCOME_TEXPR(std::declval<U>().value()), BOOST_OUTCOME_TEXPR(std::declval<U>().error()))
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inline U match_value_or_error(U &&);
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template <class U>
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static constexpr bool value_or_none =
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!std::is_same<no_match, decltype(match_value_or_none(std::declval<BOOST_OUTCOME_V2_NAMESPACE::detail::devoid<U>>()))>::value;
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template <class U>
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static constexpr bool value_or_error =
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!std::is_same<no_match, decltype(match_value_or_error(std::declval<BOOST_OUTCOME_V2_NAMESPACE::detail::devoid<U>>()))>::value;
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} // namespace detail
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/* The `value_or_none` concept.
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\requires That `U::value_type` exists and that `std::declval<U>().has_value()` returns a `bool` and `std::declval<U>().value()` exists.
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*/
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template <class U> static constexpr bool value_or_none = detail::value_or_none<U>;
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/* The `value_or_error` concept.
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\requires That `U::value_type` and `U::error_type` exist;
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that `std::declval<U>().has_value()` returns a `bool`, `std::declval<U>().value()` and `std::declval<U>().error()` exists.
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*/
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template <class U> static constexpr bool value_or_error = detail::value_or_error<U>;
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#endif
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} // namespace concepts
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namespace convert
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{
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#if BOOST_OUTCOME_ENABLE_LEGACY_SUPPORT_FOR < 220
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#if defined(__cpp_concepts)
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template <class U> concept BOOST_OUTCOME_GCC6_CONCEPT_BOOL ValueOrNone = concepts::value_or_none<U>;
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template <class U> concept BOOST_OUTCOME_GCC6_CONCEPT_BOOL ValueOrError = concepts::value_or_error<U>;
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#else
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template <class U> static constexpr bool ValueOrNone = concepts::value_or_none<U>;
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template <class U> static constexpr bool ValueOrError = concepts::value_or_error<U>;
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#endif
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#endif
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namespace detail
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{
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template <class T, class X> struct make_type
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{
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template <class U> static constexpr T value(U &&v) { return T{in_place_type<typename T::value_type>, static_cast<U &&>(v).value()}; }
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template <class U> static constexpr T error(U &&v) { return T{in_place_type<typename T::error_type>, static_cast<U &&>(v).error()}; }
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static constexpr T error() { return T{in_place_type<typename T::error_type>}; }
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};
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template <class T> struct make_type<T, void>
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{
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template <class U> static constexpr T value(U && /*unused*/) { return T{in_place_type<typename T::value_type>}; }
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template <class U> static constexpr T error(U && /*unused*/) { return T{in_place_type<typename T::error_type>}; }
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static constexpr T error() { return T{in_place_type<typename T::error_type>}; }
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};
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} // namespace detail
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/*! AWAITING HUGO JSON CONVERSION TOOL
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type definition value_or_error. Potential doc page: NOT FOUND
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*/
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template <class T, class U> struct value_or_error
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{
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static constexpr bool enable_result_inputs = false;
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static constexpr bool enable_outcome_inputs = false;
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BOOST_OUTCOME_TEMPLATE(class X)
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BOOST_OUTCOME_TREQUIRES(
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BOOST_OUTCOME_TPRED(std::is_same<U, std::decay_t<X>>::value //
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&&concepts::value_or_error<U> //
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&& (std::is_void<typename std::decay_t<X>::value_type>::value ||
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BOOST_OUTCOME_V2_NAMESPACE::detail::is_explicitly_constructible<typename T::value_type, typename std::decay_t<X>::value_type>) //
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&&(std::is_void<typename std::decay_t<X>::error_type>::value ||
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BOOST_OUTCOME_V2_NAMESPACE::detail::is_explicitly_constructible<typename T::error_type, typename std::decay_t<X>::error_type>) ))
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constexpr T operator()(X &&v)
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{
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return v.has_value() ? detail::make_type<T, typename T::value_type>::value(static_cast<X &&>(v)) :
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detail::make_type<T, typename U::error_type>::error(static_cast<X &&>(v));
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}
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};
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} // namespace convert
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BOOST_OUTCOME_V2_NAMESPACE_END
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#endif
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