#ifndef BOOST_MPL_COPY_IF_HPP_INCLUDED

#define BOOST_MPL_COPY_IF_HPP_INCLUDED

// Copyright Aleksey Gurtovoy 2000-2004

// Copyright David Abrahams 2003-2004

//

// 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: copy_if.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/apply.hpp>

#include <boost/mpl/eval_if.hpp>

#include <boost/mpl/identity.hpp>

#include <boost/mpl/protect.hpp>

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

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

namespace boost { namespace mpl {

namespace aux {

template<

      typename Operation

    , typename Predicate

    >

struct copy_if_op

{

    template< typename Sequence, typename T > struct apply

#if !defined(BOOST_MPL_CFG_NO_NESTED_FORWARDING)

        : eval_if<

              typename apply1<Predicate,T>::type

            , apply2<Operation,Sequence,T>

            , identity<Sequence>

            >

    {

#else

    {

        typedef typename eval_if<

              typename apply1<Predicate,T>::type

            , apply2<Operation,Sequence,T>

            , identity<Sequence>

            >::type type;

#endif

    };

};

template<

      typename Sequence

    , typename Predicate

    , typename Inserter

    >

struct copy_if_impl

    : fold<

          Sequence

        , typename Inserter::state

        , protect< aux::copy_if_op<

              typename Inserter::operation

            , Predicate

            > >

        >

{

};

template<

      typename Sequence

    , typename Predicate

    , typename Inserter

    >

struct reverse_copy_if_impl

    : reverse_fold<

          Sequence

        , typename Inserter::state

        , protect< aux::copy_if_op<

              typename Inserter::operation

            , Predicate

            > >

        >

{

};

} // namespace aux

BOOST_MPL_AUX_INSERTER_ALGORITHM_DEF(3, copy_if)

}}

#endif // BOOST_MPL_COPY_IF_HPP_INCLUDED