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- // Copyright David Abrahams, Daniel Wallin 2003.
- // Distributed under the Boost Software License, Version 1.0.
- // (See accompanying file LICENSE_1_0.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt)
- #ifndef BOOST_PARAMETER_DEDUCED_HPP
- #define BOOST_PARAMETER_DEDUCED_HPP
- #include <boost/parameter/aux_/use_default.hpp>
- namespace boost { namespace parameter {
- // This metafunction can be used to describe the treatment of particular
- // named parameters for the purposes of overload elimination with SFINAE,
- // by placing specializations in the parameters<...> list.
- //
- // If a keyword k is specified with deduced<...>, that keyword
- // will be automatically deduced from the argument list.
- template <typename Tag>
- struct deduced
- {
- typedef Tag key_type;
- };
- }}
- #include <boost/parameter/config.hpp>
- #if defined(BOOST_PARAMETER_CAN_USE_MP11)
- #include <boost/mp11/integral.hpp>
- #else
- #include <boost/mpl/bool.hpp>
- #endif
- namespace boost { namespace parameter { namespace aux {
- template <typename T>
- struct is_deduced_aux
- #if defined(BOOST_PARAMETER_CAN_USE_MP11)
- : ::boost::mp11::mp_false
- #else
- : ::boost::mpl::false_
- #endif
- {
- };
- template <typename Tag>
- struct is_deduced_aux< ::boost::parameter::deduced<Tag> >
- #if defined(BOOST_PARAMETER_CAN_USE_MP11)
- : ::boost::mp11::mp_true
- #else
- : ::boost::mpl::true_
- #endif
- {
- };
- template <typename T>
- struct is_deduced0
- : ::boost::parameter::aux::is_deduced_aux<typename T::key_type>::type
- {
- };
- }}} // namespace boost::parameter::aux
- #include <boost/parameter/required.hpp>
- #include <boost/parameter/optional.hpp>
- #if defined(BOOST_PARAMETER_CAN_USE_MP11)
- #include <boost/mp11/utility.hpp>
- #else
- #include <boost/mpl/if.hpp>
- #endif
- namespace boost { namespace parameter { namespace aux {
- //
- // tag_type, has_default, and predicate --
- //
- // These metafunctions accept a ParameterSpec and extract the
- // keyword tag, whether or not a default is supplied for the
- // parameter, and the predicate that the corresponding actual
- // argument type is required match.
- //
- // a ParameterSpec is a specialization of either keyword<...>,
- // required<...>, optional<...>
- //
- template <typename T>
- #if defined(BOOST_PARAMETER_CAN_USE_MP11)
- using has_default = ::boost::mp11::mp_if<
- ::boost::parameter::aux::is_required<T>
- , ::boost::mp11::mp_false
- , ::boost::mp11::mp_true
- >;
- #else
- struct has_default
- : ::boost::mpl::if_<
- ::boost::parameter::aux::is_required<T>
- , ::boost::mpl::false_
- , ::boost::mpl::true_
- >::type
- {
- };
- #endif
- template <typename T>
- #if defined(BOOST_PARAMETER_CAN_USE_MP11)
- using is_deduced = ::boost::mp11::mp_if<
- ::boost::mp11::mp_if<
- ::boost::parameter::aux::is_optional<T>
- , ::boost::mp11::mp_true
- , ::boost::parameter::aux::is_required<T>
- >
- , ::boost::parameter::aux::is_deduced0<T>
- , ::boost::mp11::mp_false
- >;
- #else
- struct is_deduced
- : ::boost::mpl::if_<
- typename ::boost::mpl::if_<
- ::boost::parameter::aux::is_optional<T>
- , ::boost::mpl::true_
- , ::boost::parameter::aux::is_required<T>
- >::type
- , ::boost::parameter::aux::is_deduced0<T>
- , ::boost::mpl::false_
- >::type
- {
- };
- #endif // BOOST_PARAMETER_CAN_USE_MP11
- }}} // namespace boost::parameter::aux
- #endif // include guard
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