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Diffstat (limited to 'boost/hana/concept/comonad.hpp')
| -rw-r--r-- | boost/hana/concept/comonad.hpp | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/boost/hana/concept/comonad.hpp b/boost/hana/concept/comonad.hpp new file mode 100644 index 0000000000..4aff1ab648 --- /dev/null +++ b/boost/hana/concept/comonad.hpp @@ -0,0 +1,33 @@ +/*! +@file +Defines `boost::hana::Comonad`. + +@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_COMONAD_HPP +#define BOOST_HANA_CONCEPT_COMONAD_HPP + +#include <boost/hana/fwd/concept/comonad.hpp> + +#include <boost/hana/config.hpp> +#include <boost/hana/core/default.hpp> +#include <boost/hana/core/tag_of.hpp> +#include <boost/hana/duplicate.hpp> +#include <boost/hana/extend.hpp> +#include <boost/hana/extract.hpp> + + +BOOST_HANA_NAMESPACE_BEGIN + template <typename W> + struct Comonad { + using Tag = typename tag_of<W>::type; + static constexpr bool value = !is_default<extract_impl<Tag>>::value && + (!is_default<duplicate_impl<Tag>>::value || + !is_default<extend_impl<Tag>>::value); + }; +BOOST_HANA_NAMESPACE_END + +#endif // !BOOST_HANA_CONCEPT_COMONAD_HPP |