| // 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_AUX_PACK_PREDICATE_HPP |
| #define BOOST_PARAMETER_AUX_PACK_PREDICATE_HPP |
| |
| namespace boost { namespace parameter { namespace aux { |
| |
| // helper for get_predicate<...>, below |
| template <typename T> |
| struct get_predicate_or_default |
| { |
| typedef T type; |
| }; |
| |
| // helper for predicate<...>, below |
| template <typename T> |
| struct get_predicate |
| : ::boost::parameter::aux |
| ::get_predicate_or_default<typename T::predicate> |
| { |
| }; |
| }}} // namespace boost::parameter::aux |
| |
| #include <boost/parameter/aux_/use_default.hpp> |
| #include <boost/parameter/aux_/always_true_predicate.hpp> |
| |
| namespace boost { namespace parameter { namespace aux { |
| |
| template <> |
| struct get_predicate_or_default< ::boost::parameter::aux::use_default> |
| { |
| typedef ::boost::parameter::aux::always_true_predicate type; |
| }; |
| }}} // namespace boost::parameter::aux |
| |
| #include <boost/parameter/required.hpp> |
| #include <boost/parameter/optional.hpp> |
| #include <boost/parameter/config.hpp> |
| |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| #include <boost/mp11/integral.hpp> |
| #include <boost/mp11/utility.hpp> |
| #else |
| #include <boost/mpl/bool.hpp> |
| #include <boost/mpl/if.hpp> |
| #include <boost/mpl/eval_if.hpp> |
| #include <boost/mpl/identity.hpp> |
| #endif |
| |
| namespace boost { namespace parameter { namespace aux { |
| |
| template <typename T> |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| using predicate = ::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::get_predicate<T> |
| , ::boost::mp11::mp_identity< |
| ::boost::parameter::aux::always_true_predicate |
| > |
| >; |
| #else |
| struct predicate |
| : ::boost::mpl::eval_if< |
| typename ::boost::mpl::if_< |
| ::boost::parameter::aux::is_optional<T> |
| , ::boost::mpl::true_ |
| , ::boost::parameter::aux::is_required<T> |
| >::type |
| , ::boost::parameter::aux::get_predicate<T> |
| , ::boost::mpl::identity< |
| ::boost::parameter::aux::always_true_predicate |
| > |
| > |
| { |
| }; |
| #endif // BOOST_PARAMETER_CAN_USE_MP11 |
| }}} // namespace boost::parameter::aux |
| |
| #endif // include guard |
| |