Boost C++ Libraries

boost/hana/reverse_fold.hpp

/*!
@file
Defines `boost::hana::reverse_fold`.

Copyright Louis Dionne 2013-2022
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_REVERSE_FOLD_HPP
#define BOOST_HANA_REVERSE_FOLD_HPP

#include <boost/hana/fwd/reverse_fold.hpp>

#include <boost/hana/config.hpp>
#include <boost/hana/fold_right.hpp>
#include <boost/hana/functional/flip.hpp>


namespace boost { namespace hana {
    //! @cond
    template <typename Xs, typename S, typename F>
    constexpr decltype(auto) reverse_fold_t::operator()(Xs&& xs, S&& s, F&& f) const {
        return hana::fold_right(static_cast<Xs&&>(xs),
                                static_cast<S&&>(s),
                                hana::flip(static_cast<F&&>(f)));
    }

    template <typename Xs, typename F>
    constexpr decltype(auto) reverse_fold_t::operator()(Xs&& xs, F&& f) const {
        return hana::fold_right(static_cast<Xs&&>(xs),
                                hana::flip(static_cast<F&&>(f)));
    }
    //! @endcond
}} // end namespace boost::hana

#endif // !BOOST_HANA_REVERSE_FOLD_HPP