// NO INCLUDE GUARDS, THE HEADER IS INTENDED FOR MULTIPLE INCLUSION!

#if !defined(BOOST_PP_IS_ITERATING)

// Copyright Aleksey Gurtovoy 2000-2004

//

// 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.

// $Source: /cvsroot/boost/boost/boost/mpl/aux_/reverse_fold_impl_body.hpp,v $

// $Date: 2004/10/24 08:18:03 $

// $Revision: 1.3 $

#   include <boost/mpl/limits/unrolling.hpp>

#   include <boost/mpl/aux_/preprocessor/repeat.hpp>

#   include <boost/mpl/aux_/config/ctps.hpp>

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

#   include <boost/preprocessor/arithmetic/sub.hpp>

#   include <boost/preprocessor/iterate.hpp>

#   include <boost/preprocessor/dec.hpp>

#   include <boost/preprocessor/inc.hpp>

#   include <boost/preprocessor/cat.hpp>

// local macros, #undef-ined at the end of the header

#   define AUX778076_ITER_FOLD_FORWARD_STEP(unused, n_, unused2) \

    typedef typename apply2< \

          ForwardOp \

        , BOOST_PP_CAT(fwd_state,n_) \

        , AUX778076_FOLD_IMPL_OP(BOOST_PP_CAT(iter,n_)) \

        >::type BOOST_PP_CAT(fwd_state,BOOST_PP_INC(n_)); \

    typedef typename mpl::next<BOOST_PP_CAT(iter,n_)>::type \

        BOOST_PP_CAT(iter,BOOST_PP_INC(n_)); \

    /**/

#   define AUX778076_ITER_FOLD_BACKWARD_STEP_FUNC(n_) \

    typedef typename apply2< \

          BackwardOp \

        , BOOST_PP_CAT(bkwd_state,n_) \

        , AUX778076_FOLD_IMPL_OP(BOOST_PP_CAT(iter,BOOST_PP_DEC(n_))) \

        >::type BOOST_PP_CAT(bkwd_state,BOOST_PP_DEC(n_)); \

    /**/

#   define AUX778076_ITER_FOLD_BACKWARD_STEP(unused, n_, j) \

    AUX778076_ITER_FOLD_BACKWARD_STEP_FUNC( \

          BOOST_PP_SUB_D(1,j,n_) \

        ) \

    /**/

#   define AUX778076_FIRST_BACKWARD_STATE_TYPEDEF(n_) \

    typedef typename nested_chunk::state BOOST_PP_CAT(bkwd_state,n_);

    /**/

#   define AUX778076_FOLD_IMPL_NAME \

    BOOST_PP_CAT(AUX778076_FOLD_IMPL_NAME_PREFIX,_impl) \

    /**/

#   define AUX778076_FOLD_CHUNK_NAME \

    BOOST_PP_CAT(AUX778076_FOLD_IMPL_NAME_PREFIX,_chunk) \

    /**/

namespace boost { namespace mpl { namespace aux {

/// forward declaration

template<

      BOOST_MPL_AUX_NTTP_DECL(long, N)

    , typename First

    , typename Last

    , typename State

    , typename BackwardOp

    , typename ForwardOp

    > 

struct AUX778076_FOLD_IMPL_NAME;

#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) \

    && !defined(BOOST_MPL_CFG_NO_NONTYPE_TEMPLATE_PARTIAL_SPEC)

#   define BOOST_PP_ITERATION_PARAMS_1 \

    (3,(0, BOOST_MPL_LIMIT_UNROLLING, <boost/mpl/aux_/reverse_fold_impl_body.hpp>))

#   include BOOST_PP_ITERATE()

// implementation for N that exceeds BOOST_MPL_LIMIT_UNROLLING

template<

      BOOST_MPL_AUX_NTTP_DECL(long, N)

    , typename First

    , typename Last

    , typename State

    , typename BackwardOp

    , typename ForwardOp

    > 

struct AUX778076_FOLD_IMPL_NAME

{

    typedef First iter0;

    typedef State fwd_state0;

    BOOST_MPL_PP_REPEAT(

          BOOST_MPL_LIMIT_UNROLLING

        , AUX778076_ITER_FOLD_FORWARD_STEP

        , unused

        )

    typedef AUX778076_FOLD_IMPL_NAME<

          ( (N - BOOST_MPL_LIMIT_UNROLLING) < 0 ? 0 : N - BOOST_MPL_LIMIT_UNROLLING )

        , BOOST_PP_CAT(iter,BOOST_MPL_LIMIT_UNROLLING)

        , Last

        , BOOST_PP_CAT(fwd_state,BOOST_MPL_LIMIT_UNROLLING)

        , BackwardOp

        , ForwardOp

        > nested_chunk;

    AUX778076_FIRST_BACKWARD_STATE_TYPEDEF(BOOST_MPL_LIMIT_UNROLLING)

    BOOST_MPL_PP_REPEAT(

          BOOST_MPL_LIMIT_UNROLLING

        , AUX778076_ITER_FOLD_BACKWARD_STEP

        , BOOST_MPL_LIMIT_UNROLLING

        )

    typedef bkwd_state0 state;

    typedef typename nested_chunk::iterator iterator;

};

// fallback implementation for sequences of unknown size

template<

      typename First

    , typename Last

    , typename State

    , typename BackwardOp

    , typename ForwardOp

    > 

struct AUX778076_FOLD_IMPL_NAME<-1,First,Last,State,BackwardOp,ForwardOp>

{

    typedef AUX778076_FOLD_IMPL_NAME<

          -1

        , typename mpl::next<First>::type

        , Last

        , typename apply2<ForwardOp,State,AUX778076_FOLD_IMPL_OP(First)>::type

        , BackwardOp

        , ForwardOp

        > nested_step;

    typedef typename apply2<

          BackwardOp

        , typename nested_step::state

        , AUX778076_FOLD_IMPL_OP(First)

        >::type state;

    typedef typename nested_step::iterator iterator;

};

template<

      typename Last

    , typename State

    , typename BackwardOp

    , typename ForwardOp

    > 

struct AUX778076_FOLD_IMPL_NAME<-1,Last,Last,State,BackwardOp,ForwardOp>

{

    typedef State state;

    typedef Last iterator;

};

#else // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

template< BOOST_MPL_AUX_NTTP_DECL(long, N) >

struct AUX778076_FOLD_CHUNK_NAME;

#   define BOOST_PP_ITERATION_PARAMS_1 \

    (3,(0, BOOST_MPL_LIMIT_UNROLLING, <boost/mpl/aux_/reverse_fold_impl_body.hpp>))

#   include BOOST_PP_ITERATE()

// implementation for N that exceeds BOOST_MPL_LIMIT_UNROLLING

template< BOOST_MPL_AUX_NTTP_DECL(long, N) > 

struct AUX778076_FOLD_CHUNK_NAME

{

    template<

          typename First

        , typename Last

        , typename State

        , typename BackwardOp

        , typename ForwardOp

        > 

    struct result_

    {

        typedef First iter0;

        typedef State fwd_state0;

        BOOST_MPL_PP_REPEAT(

              BOOST_MPL_LIMIT_UNROLLING

            , AUX778076_ITER_FOLD_FORWARD_STEP

            , unused

            )

        typedef AUX778076_FOLD_IMPL_NAME<

              ( (N - BOOST_MPL_LIMIT_UNROLLING) < 0 ? 0 : N - BOOST_MPL_LIMIT_UNROLLING )

            , BOOST_PP_CAT(iter,BOOST_MPL_LIMIT_UNROLLING)

            , Last

            , BOOST_PP_CAT(fwd_state,BOOST_MPL_LIMIT_UNROLLING)

            , BackwardOp

            , ForwardOp

            > nested_chunk;

        AUX778076_FIRST_BACKWARD_STATE_TYPEDEF(BOOST_MPL_LIMIT_UNROLLING)

        BOOST_MPL_PP_REPEAT(

              BOOST_MPL_LIMIT_UNROLLING

            , AUX778076_ITER_FOLD_BACKWARD_STEP

            , BOOST_MPL_LIMIT_UNROLLING

            )

        typedef bkwd_state0 state;

        typedef typename nested_chunk::iterator iterator;

    };

};

// fallback implementation for sequences of unknown size

template<

      typename First

    , typename Last

    , typename State

    , typename BackwardOp

    , typename ForwardOp

    > 

struct BOOST_PP_CAT(AUX778076_FOLD_IMPL_NAME_PREFIX,_step);

template<

      typename Last

    , typename State

    >

struct BOOST_PP_CAT(AUX778076_FOLD_IMPL_NAME_PREFIX,_null_step)

{

    typedef Last iterator;

    typedef State state;

};

template<> 

struct AUX778076_FOLD_CHUNK_NAME<-1>

{

    template<

          typename First

        , typename Last

        , typename State

        , typename BackwardOp

        , typename ForwardOp

        > 

    struct result_

    {

        typedef typename if_<

              typename is_same<First,Last>::type

            , BOOST_PP_CAT(AUX778076_FOLD_IMPL_NAME_PREFIX,_null_step)<Last,State>

            , BOOST_PP_CAT(AUX778076_FOLD_IMPL_NAME_PREFIX,_step)<First,Last,State,BackwardOp,ForwardOp>

            >::type res_;

        typedef typename res_::state state;

        typedef typename res_::iterator iterator;

    };

#if defined(BOOST_MPL_CFG_MSVC_60_ETI_BUG)

    /// ETI workaround

    template<> struct result_<int,int,int,int,int>

    {

        typedef int state;

        typedef int iterator;

    };

#endif

};

template<

      typename First

    , typename Last

    , typename State

    , typename BackwardOp

    , typename ForwardOp

    > 

struct BOOST_PP_CAT(AUX778076_FOLD_IMPL_NAME_PREFIX,_step)

{

    typedef AUX778076_FOLD_CHUNK_NAME<-1>::template result_<

          typename mpl::next<First>::type

        , Last

        , typename apply2<ForwardOp,State,AUX778076_FOLD_IMPL_OP(First)>::type

        , BackwardOp

        , ForwardOp

        > nested_step;

    typedef typename apply2<

          BackwardOp

        , typename nested_step::state

        , AUX778076_FOLD_IMPL_OP(First)

        >::type state;

    typedef typename nested_step::iterator iterator;

};

template<

      BOOST_MPL_AUX_NTTP_DECL(long, N)

    , typename First

    , typename Last

    , typename State

    , typename BackwardOp

    , typename ForwardOp

    > 

struct AUX778076_FOLD_IMPL_NAME

    : AUX778076_FOLD_CHUNK_NAME<N>

        ::template result_<First,Last,State,BackwardOp,ForwardOp>

{

};

#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

}}}

#   undef AUX778076_FIRST_BACKWARD_STATE_TYPEDEF

#   undef AUX778076_ITER_FOLD_BACKWARD_STEP

#   undef AUX778076_ITER_FOLD_BACKWARD_STEP_FUNC

#   undef AUX778076_ITER_FOLD_FORWARD_STEP

#undef AUX778076_FOLD_IMPL_OP

#undef AUX778076_FOLD_IMPL_NAME_PREFIX

///// iteration

#else

#   define n_ BOOST_PP_FRAME_ITERATION(1)

#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) \

    && !defined(BOOST_MPL_CFG_NO_NONTYPE_TEMPLATE_PARTIAL_SPEC)

template<

      typename First

    , typename Last

    , typename State

    , typename BackwardOp

    , typename ForwardOp

    >

struct AUX778076_FOLD_IMPL_NAME<n_,First,Last,State,BackwardOp,ForwardOp>

{

    typedef First iter0;

    typedef State fwd_state0;

    BOOST_MPL_PP_REPEAT(

          n_

        , AUX778076_ITER_FOLD_FORWARD_STEP

        , unused

        )

    typedef BOOST_PP_CAT(fwd_state,n_) BOOST_PP_CAT(bkwd_state,n_);

    BOOST_MPL_PP_REPEAT(

          n_

        , AUX778076_ITER_FOLD_BACKWARD_STEP

        , n_

        )

    typedef bkwd_state0 state;

    typedef BOOST_PP_CAT(iter,n_) iterator;

};

#else

template<> struct AUX778076_FOLD_CHUNK_NAME<n_>

{

    template<

          typename First

        , typename Last

        , typename State

        , typename BackwardOp

        , typename ForwardOp

        >

    struct result_

    {

        typedef First iter0;

        typedef State fwd_state0;

        BOOST_MPL_PP_REPEAT(

              n_

            , AUX778076_ITER_FOLD_FORWARD_STEP

            , unused

            )

        typedef BOOST_PP_CAT(fwd_state,n_) BOOST_PP_CAT(bkwd_state,n_);

        BOOST_MPL_PP_REPEAT(

              n_

            , AUX778076_ITER_FOLD_BACKWARD_STEP

            , n_

            )

        typedef bkwd_state0 state;

        typedef BOOST_PP_CAT(iter,n_) iterator;

    };

#if defined(BOOST_MPL_CFG_MSVC_60_ETI_BUG)

    /// ETI workaround

    template<> struct result_<int,int,int,int,int>

    {

        typedef int state;

        typedef int iterator;

    };

#endif

};

#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

#   undef n_

#endif // BOOST_PP_IS_ITERATING