| // Copyright David Abrahams 2005. |
| // 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_RESULT_OF0_DWA2005511_HPP |
| #define BOOST_PARAMETER_AUX_RESULT_OF0_DWA2005511_HPP |
| |
| #include <boost/parameter/aux_/use_default_tag.hpp> |
| #include <boost/parameter/config.hpp> |
| #include <boost/utility/result_of.hpp> |
| |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| #include <boost/mp11/utility.hpp> |
| #include <type_traits> |
| #else |
| #include <boost/mpl/if.hpp> |
| #include <boost/type_traits/is_void.hpp> |
| #endif |
| |
| namespace boost { namespace parameter { namespace aux { |
| |
| // A metafunction returning the result of invoking |
| // a nullary function object of the given type. |
| template <typename F> |
| class result_of0 |
| { |
| #if defined(BOOST_NO_RESULT_OF) |
| typedef typename F::result_type result_of_F; |
| #else |
| typedef typename ::boost::result_of<F()>::type result_of_F; |
| #endif |
| |
| public: |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| using type = ::boost::mp11::mp_if< |
| ::std::is_void<result_of_F> |
| #else |
| typedef typename ::boost::mpl::if_< |
| ::boost::is_void<result_of_F> |
| #endif |
| , ::boost::parameter::aux::use_default_tag |
| , result_of_F |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| >; |
| #else |
| >::type type; |
| #endif |
| }; |
| }}} // namespace boost::parameter::aux |
| |
| #endif // include guard |
| |