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/*!
@file
Defines `boost::hana::Monoid`.
@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_MONOID_HPP
#define BOOST_HANA_CONCEPT_MONOID_HPP
#include <boost/hana/fwd/concept/monoid.hpp>
#include <boost/hana/config.hpp>
#include <boost/hana/core/default.hpp>
#include <boost/hana/core/tag_of.hpp>
#include <boost/hana/plus.hpp>
#include <boost/hana/zero.hpp>
BOOST_HANA_NAMESPACE_BEGIN
template <typename M>
struct Monoid {
using Tag = typename tag_of<M>::type;
static constexpr bool value = !is_default<zero_impl<Tag>>::value &&
!is_default<plus_impl<Tag, Tag>>::value;
};
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_CONCEPT_MONOID_HPP
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