  , typename BackwardOp
        , typename ForwardOp
        >
    struct result_
    {
        typedef First iter0;
        typedef State fwd_state0;
        typedef typename apply2< ForwardOp,fwd_state0,iter0 >::type fwd_state1;
        typedef typename mpl::next<iter0>::type iter1;
        typedef typename apply2< ForwardOp,fwd_state1,iter1 >::type fwd_state2;
        typedef typename mpl::next<iter1>::type iter2;
        typedef typename apply2< ForwardOp,fwd_state2,iter2 >::type fwd_state3;
        typedef typename mpl::next<iter2>::type iter3;
        typedef typename apply2< ForwardOp,fwd_state3,iter3 >::type fwd_state4;
        typedef typename mpl::next<iter3>::type iter4;
        

        typedef reverse_iter_fold_impl<
              ( (N - 4) < 0 ? 0 : N - 4 )
            , iter4
            , Last
            , fwd_state4
            , BackwardOp
            , ForwardOp
            > nested_chunk;

        typedef typename nested_chunk::state bkwd_state4;
        typedef typename apply2< BackwardOp,bkwd_state4,iter3 >::type bkwd_state3;
        typedef typename apply2< BackwardOp,bkwd_state3,iter2 >::type bkwd_state2;
        typedef typename apply2< BackwardOp,bkwd_state2,iter1 >::type bkwd_state1;
        typedef typename apply2< BackwardOp,bkwd_state1,iter0 >::type bkwd_state0;
        

        typedef bkwd_state0 state;
        typedef typename nested_chunk::iterator iterator;
    };
};

template<
      typename First
    , typename Last
    , typename State
    , typename BackwardOp
    , typename ForwardOp
    >
struct reverse_iter_fold_step;

template<
      typename Last
    , typename State
    >
struct reverse_iter_fold_null_step
{
    typedef Last iterator;
    typedef State state;
};

template<>
struct reverse_iter_fold_chunk< -1 >
{
    template<
          typename First
        , typename Last
        , typename State
        , typename BackwardOp
        , typename ForwardOp
        >
    struct result_
    {
        typedef typename if_<
              typename is_same< First,Last >::