3 Defines operators for Monads.
5 @copyright Louis Dionne 2013-2016
6 Distributed under the Boost Software License, Version 1.0.
7 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
10 #ifndef BOOST_HANA_DETAIL_OPERATORS_MONAD_HPP
11 #define BOOST_HANA_DETAIL_OPERATORS_MONAD_HPP
13 #include <boost/hana/config.hpp>
14 #include <boost/hana/core/tag_of.hpp>
15 #include <boost/hana/fwd/chain.hpp>
17 #include <type_traits>
20 BOOST_HANA_NAMESPACE_BEGIN namespace detail {
21 template <typename Tag>
22 struct monad_operators {
23 static constexpr bool value = false;
27 template <typename Xs, typename F, typename = typename std::enable_if<
28 detail::monad_operators<typename hana::tag_of<Xs>::type>::value
30 constexpr auto operator|(Xs&& xs, F&& f)
31 { return hana::chain(static_cast<Xs&&>(xs), static_cast<F&&>(f)); }
32 } // end namespace operators
33 } BOOST_HANA_NAMESPACE_END
35 #endif // !BOOST_HANA_DETAIL_OPERATORS_MONAD_HPP