42 lines
1.1 KiB
C++
42 lines
1.1 KiB
C++
|
/*!
|
||
|
@file
|
||
|
Defines `boost::hana::Metafunction`.
|
||
|
|
||
|
@copyright Louis Dionne 2013-2016
|
||
|
Distributed under the Boost Software License, Version 1.0.
|
||
|
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
|
||
|
*/
|
||
|
|
||
|
#ifndef BOOST_HANA_CONCEPT_METAFUNCTION_HPP
|
||
|
#define BOOST_HANA_CONCEPT_METAFUNCTION_HPP
|
||
|
|
||
|
#include <boost/hana/fwd/concept/metafunction.hpp>
|
||
|
|
||
|
#include <boost/hana/config.hpp>
|
||
|
#include <boost/hana/core/tag_of.hpp>
|
||
|
#include <boost/hana/detail/integral_constant.hpp>
|
||
|
|
||
|
|
||
|
BOOST_HANA_NAMESPACE_BEGIN
|
||
|
namespace detail {
|
||
|
template <typename F, typename Tag = typename tag_of<F>::type>
|
||
|
struct metafunction_dispatch
|
||
|
: hana::integral_constant<bool,
|
||
|
Metafunction<Tag>::value
|
||
|
>
|
||
|
{ };
|
||
|
|
||
|
template <typename F>
|
||
|
struct metafunction_dispatch<F, F>
|
||
|
: hana::integral_constant<bool, false>
|
||
|
{ };
|
||
|
}
|
||
|
|
||
|
template <typename F>
|
||
|
struct Metafunction
|
||
|
: detail::metafunction_dispatch<F>
|
||
|
{ };
|
||
|
BOOST_HANA_NAMESPACE_END
|
||
|
|
||
|
#endif // !BOOST_HANA_CONCEPT_METAFUNCTION_HPP
|