36 lines
1.0 KiB
C++
36 lines
1.0 KiB
C++
/*!
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@file
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Defines `boost::hana::Comonad`.
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@copyright Louis Dionne 2013-2017
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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*/
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#ifndef BOOST_HANA_CONCEPT_COMONAD_HPP
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#define BOOST_HANA_CONCEPT_COMONAD_HPP
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#include <boost/hana/fwd/concept/comonad.hpp>
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#include <boost/hana/config.hpp>
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#include <boost/hana/core/default.hpp>
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#include <boost/hana/core/tag_of.hpp>
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#include <boost/hana/detail/integral_constant.hpp>
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#include <boost/hana/duplicate.hpp>
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#include <boost/hana/extend.hpp>
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#include <boost/hana/extract.hpp>
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namespace boost { namespace hana {
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template <typename W>
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struct Comonad
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: hana::integral_constant<bool,
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!is_default<extract_impl<typename tag_of<W>::type>>::value &&
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(!is_default<duplicate_impl<typename tag_of<W>::type>>::value ||
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!is_default<extend_impl<typename tag_of<W>::type>>::value)
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>
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{ };
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}} // end namespace boost::hana
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#endif // !BOOST_HANA_CONCEPT_COMONAD_HPP
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