#ifndef BOOST_MPL_STABLE_PARTITION_HPP_INCLUDED

#define BOOST_MPL_STABLE_PARTITION_HPP_INCLUDED

// Copyright Eric Friedman 2002-2003

// Copyright Aleksey Gurtovoy 2004

//

// Distributed under the Boost Software License, Version 1.0. 

// (See accompanying file LICENSE_1_0.txt or copy at 

// http://www.boost.org/LICENSE_1_0.txt)

//

// See http://www.boost.org/libs/mpl for documentation.

// $Id: stable_partition.hpp 49267 2008-10-11 06:19:02Z agurtovoy $

// $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $

// $Revision: 49267 $

#include <boost/mpl/fold.hpp>

#include <boost/mpl/reverse_fold.hpp>

#include <boost/mpl/protect.hpp>

#include <boost/mpl/aux_/partition_op.hpp>

#include <boost/mpl/aux_/inserter_algorithm.hpp>

#include <boost/mpl/aux_/na.hpp>

namespace boost { namespace mpl {

namespace aux {

template <

      typename Sequence

    , typename Pred

    , typename In

    , typename In2

    , typename In1 = typename if_na<In,In2>::type

    >

struct stable_partition_impl

    : fold<

          Sequence

        , pair< typename In1::state, typename In2::state >

        , protect< partition_op< 

              Pred

            , typename In1::operation

            , typename In2::operation

            > >

        >

{

};

template <

      typename Sequence

    , typename Pred

    , typename In

    , typename In2

    , typename In1 = typename if_na<In,In2>::type

    >

struct reverse_stable_partition_impl

    : reverse_fold<

          Sequence

        , pair< typename In1::state, typename In2::state >

        , protect< partition_op< 

              Pred

            , typename In1::operation

            , typename In2::operation

            > >

        >

{

};

} // namespace aux

BOOST_MPL_AUX_INSERTER_ALGORITHM_DEF(4, stable_partition)

}}

#endif // BOOST_MPL_STABLE_PARTITION_HPP_INCLUDED