3 Defines `boost::hana::Group`.
5 @copyright Louis Dionne 2013-2016
6 Distributed under the Boost Software License, Version 1.0.
7 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
10 #ifndef BOOST_HANA_CONCEPT_GROUP_HPP
11 #define BOOST_HANA_CONCEPT_GROUP_HPP
13 #include <boost/hana/fwd/concept/group.hpp>
15 #include <boost/hana/config.hpp>
16 #include <boost/hana/core/default.hpp>
17 #include <boost/hana/core/tag_of.hpp>
18 #include <boost/hana/minus.hpp>
19 #include <boost/hana/negate.hpp>
22 BOOST_HANA_NAMESPACE_BEGIN
25 using Tag = typename tag_of<G>::type;
26 static constexpr bool value = !is_default<negate_impl<Tag>>::value ||
27 !is_default<minus_impl<Tag, Tag>>::value;
29 BOOST_HANA_NAMESPACE_END
31 #endif // !BOOST_HANA_CONCEPT_GROUP_HPP