1 // Copyright David Abrahams, Daniel Wallin 2003. 2 // Distributed under the Boost Software License, Version 1.0. 3 // (See accompanying file LICENSE_1_0.txt or copy at 4 // http://www.boost.org/LICENSE_1_0.txt) 5 6 #ifndef BOOST_PARAMETER_AUX_PACK_MAKE_ITEMS_HPP 7 #define BOOST_PARAMETER_AUX_PACK_MAKE_ITEMS_HPP 8 9 #include <boost/parameter/aux_/void.hpp> 10 #include <boost/parameter/aux_/pack/item.hpp> 11 #include <boost/parameter/config.hpp> 12 13 #if defined(BOOST_PARAMETER_CAN_USE_MP11) 14 #include <boost/mp11/utility.hpp> 15 #include <type_traits> 16 #else 17 #include <boost/mpl/eval_if.hpp> 18 #include <boost/mpl/identity.hpp> 19 #include <boost/type_traits/is_same.hpp> 20 #endif 21 22 namespace boost { namespace parameter { namespace aux { 23 24 // Creates a item typelist. 25 template <typename Spec, typename Arg, typename Tail> 26 #if defined(BOOST_PARAMETER_CAN_USE_MP11) 27 using make_items = ::boost::mp11::mp_if< 28 ::std::is_same<Arg,::boost::parameter::void_> 29 , ::boost::mp11::mp_identity< ::boost::parameter::void_> 30 , ::boost::parameter::aux::make_item<Spec,Arg,Tail> 31 >; 32 #else 33 struct make_items 34 : ::boost::mpl::eval_if< 35 ::boost::is_same<Arg,::boost::parameter::void_> 36 , ::boost::mpl::identity< ::boost::parameter::void_> 37 , ::boost::parameter::aux::make_item<Spec,Arg,Tail> 38 > 39 { 40 }; 41 #endif 42 }}} // namespace boost::parameter::aux 43 44 #endif // include guard 45 46