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Diffstat (limited to 'boost/hana/concept/monad_plus.hpp')
| -rw-r--r-- | boost/hana/concept/monad_plus.hpp | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/boost/hana/concept/monad_plus.hpp b/boost/hana/concept/monad_plus.hpp new file mode 100644 index 0000000000..22c67ca255 --- /dev/null +++ b/boost/hana/concept/monad_plus.hpp @@ -0,0 +1,31 @@ +/*! +@file +Defines `boost::hana::MonadPlus`. + +@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_MONAD_PLUS_HPP +#define BOOST_HANA_CONCEPT_MONAD_PLUS_HPP + +#include <boost/hana/fwd/concept/monad_plus.hpp> + +#include <boost/hana/concat.hpp> +#include <boost/hana/config.hpp> +#include <boost/hana/core/default.hpp> +#include <boost/hana/core/tag_of.hpp> +#include <boost/hana/empty.hpp> + + +BOOST_HANA_NAMESPACE_BEGIN + template <typename M> + struct MonadPlus { + using Tag = typename tag_of<M>::type; + static constexpr bool value = !is_default<concat_impl<Tag>>::value && + !is_default<empty_impl<Tag>>::value; + }; +BOOST_HANA_NAMESPACE_END + +#endif // !BOOST_HANA_CONCEPT_MONAD_PLUS_HPP |