hana/concept/integral_constant.hpp

0001 /*!
0002 @file
0003 Defines `boost::hana::IntegralConstant`.
0004
0005 Copyright Louis Dionne 2013-2022
0006 Distributed under the Boost Software License, Version 1.0.
0007 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
0008  */
0009
0010 #ifndef BOOST_HANA_CONCEPT_INTEGRAL_CONSTANT_HPP
0011 #define BOOST_HANA_CONCEPT_INTEGRAL_CONSTANT_HPP
0012
0013 #include <boost/hana/fwd/concept/integral_constant.hpp>
0014
0015 #include <boost/hana/config.hpp>
0016 #include <boost/hana/core/tag_of.hpp>
0017 #include <boost/hana/detail/integral_constant.hpp>
0018
0019
0020 namespace boost { namespace hana {
0021     namespace detail {
0022         template <typename C, typename Tag = typename tag_of<C>::type>
0023         struct integral_constant_dispatch
0024             : hana::integral_constant<bool,
0025                 hana::IntegralConstant<Tag>::value
0026             >
0027         { };
0028
0029         template <typename C>
0030         struct integral_constant_dispatch<C, C>
0031             : hana::integral_constant<bool, false>
0032         { };
0033     }
0034
0035     //! @cond
0036     template <typename C>
0037     struct IntegralConstant
0038         : detail::integral_constant_dispatch<C>
0039     { };
0040     //! @endcond
0041 }} // end namespace boost::hana
0042
0043 #endif // !BOOST_HANA_CONCEPT_INTEGRAL_CONSTANT_HPP