| 12345678910111213141516171819202122232425262728293031323334 | /*!@fileDefines `boost::hana::Monoid`.@copyright Louis Dionne 2013-2017Distributed 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/detail/integral_constant.hpp>#include <boost/hana/plus.hpp>#include <boost/hana/zero.hpp>BOOST_HANA_NAMESPACE_BEGIN    template <typename M>    struct Monoid        : hana::integral_constant<bool,            !is_default<zero_impl<typename tag_of<M>::type>>::value &&            !is_default<plus_impl<typename tag_of<M>::type,                                  typename tag_of<M>::type>>::value        >    { };BOOST_HANA_NAMESPACE_END#endif // !BOOST_HANA_CONCEPT_MONOID_HPP
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