/*=============================================================================
Copyright (c) 2003 Joel de Guzman
Copyright (c) 2004 Peder Holt
Copyright (c) 2005 Eric Niebler
Use, modification and distribution is subject to 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)
==============================================================================*/
#if !defined(FUSION_ITERATOR_DETAIL_CONS_ITERATOR_NEXT_TRAITS_HPP)
#define FUSION_ITERATOR_DETAIL_CONS_ITERATOR_NEXT_TRAITS_HPP
#include <boost/spirit/fusion/detail/config.hpp>
#include <boost/spirit/fusion/iterator/next.hpp>
#include <boost/spirit/fusion/iterator/equal_to.hpp>
#include <boost/mpl/eval_if.hpp>
#include <boost/mpl/identity.hpp>
#include <boost/type_traits/is_const.hpp>
#include <boost/type_traits/add_const.hpp>
namespace boost { namespace fusion
{
struct cons_iterator_tag;
template <typename Cons>
struct cons_iterator;
namespace cons_detail
{
template <typename Iterator>
struct next_traits_impl
{
typedef typename Iterator::cons_type cons_type;
typedef typename cons_type::cdr_type cdr_type;
typedef cons_iterator<
typename mpl::eval_if<
is_const<cons_type>
, add_const<cdr_type>
, mpl::identity<cdr_type>
>::type>
type;
static type
call(Iterator const& i)
{
return type(detail::ref(i.cons.cdr));
}
};
}
namespace meta
{
template <typename Tag>
struct next_impl;
template <>
struct next_impl<cons_iterator_tag>
{
template <typename Iterator>
struct apply : cons_detail::next_traits_impl<Iterator> {};
};
}
}}
#endif