insert_range_impl.hpp

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//-----------------------------------------------------------------------------
// boost mpl/insert_range_impl.hpp header file
// See http://www.boost.org for updates, documentation, and revision history.
//-----------------------------------------------------------------------------
//
// Copyright (c) 2000-02
// Aleksey Gurtovoy
//
// Permission to use, copy, modify, distribute and sell this software
// and its documentation for any purpose is hereby granted without fee, 
// provided that the above copyright notice appears in all copies and 
// that both the copyright notice and this permission notice appear in 
// supporting documentation. No representations are made about the 
// suitability of this software for any purpose. It is provided "as is" 
// without express or implied warranty.

#ifndef BOOST_MPL_AUX_INSERT_RANGE_IMPL_HPP_INCLUDED
#define BOOST_MPL_AUX_INSERT_RANGE_IMPL_HPP_INCLUDED

#include "boost/mpl/iter_fold_backward.hpp"
#include "boost/mpl/fold_backward.hpp"
#include "boost/mpl/clear.hpp"
#include "boost/mpl/push_front.hpp"
#include "boost/mpl/identity.hpp"
#include "boost/mpl/apply_if.hpp"
#include "boost/mpl/aux_/void_spec.hpp"
#include "boost/mpl/aux_/iter_push_front.hpp"
#include "boost/mpl/aux_/traits_lambda_spec.hpp"
#include "boost/type_traits/same_traits.hpp"

namespace boost {
namespace mpl {

// default implementation; conrete sequences might override it by 
// specializing either the |insert_range_traits| or the primary 
// |insert_range| template

namespace aux {

template<
      typename Pos
    , typename Range
    >
struct iter_range_inserter
{
    template< typename Sequence, typename Iterator > struct apply
    {
        typedef typename aux::iter_push_front<
              typename apply_if<
                  is_same<Pos,typename Iterator::next>
                , fold_backward< Range, Sequence, push_front<_,_> >
                , identity<Sequence>
                >::type
            , Iterator
            >::type type;
    };
};

} // namespace aux


template< typename Tag >
struct insert_range_traits
{
    template<
          typename Sequence
        , typename Pos
        , typename Range
        >
    struct algorithm
    {
        typedef typename iter_fold_backward<
              Sequence
            , typename clear<Sequence>::type
            , aux::iter_range_inserter<Pos,Range>
            >::type type;
    };
};

BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(3,insert_range_traits)

} // namespace mpl
} // namespace boost

#endif // BOOST_MPL_AUX_INSERT_RANGE_IMPL_HPP_INCLUDED