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Defines `boost::hana::Sequence`.

@copyright Louis Dionne 2013-2017
Distributed under the Boost Software License, Version 1.0.
(See accompanying file or copy at


#include <boost/hana/fwd/concept/sequence.hpp>

#include <boost/hana/config.hpp>
#include <boost/hana/core/tag_of.hpp>
#include <boost/hana/core/when.hpp>
#include <boost/hana/detail/integral_constant.hpp>

namespace boost { namespace hana {
    namespace detail {
        template <typename S, typename Tag = typename hana::tag_of<S>::type>
        struct sequence_dispatch
            : hana::integral_constant<bool,
        { };

        template <typename S>
        struct sequence_dispatch<S, S>
            : hana::integral_constant<bool, false>
        { };

    //! @cond
    template <typename S, bool condition>
    struct Sequence<S, when<condition>>
        : detail::sequence_dispatch<S>
    { };
    //! @endcond
}} // end namespace boost::hana