/*=============================================================================
Copyright (c) 2003 Joel de Guzman
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_DEREF_TRAITS_HPP)
#define FUSION_ITERATOR_DETAIL_CONS_ITERATOR_DEREF_TRAITS_HPP
#include <boost/spirit/fusion/detail/config.hpp>
#include <boost/mpl/eval_if.hpp>
#include <boost/type_traits/is_const.hpp>
#include <boost/type_traits/add_const.hpp>
#include <boost/type_traits/add_reference.hpp>
namespace boost { namespace fusion
{
struct cons_iterator_tag;
namespace cons_detail
{
template <typename Iterator>
struct deref_traits_impl
{
typedef typename Iterator::cons_type cons_type;
typedef typename cons_type::car_type value_type;
typedef typename mpl::eval_if<
is_const<cons_type>
, add_reference<typename add_const<value_type>::type>
, add_reference<value_type> >::type
type;
static type
call(Iterator const& i)
{
return detail::ref(i.cons.car);
}
};
}
namespace meta
{
template <typename Tag>
struct deref_impl;
template <>
struct deref_impl<cons_iterator_tag>
{
template <typename Iterator>
struct apply : cons_detail::deref_traits_impl<Iterator> {};
};
}
}}
#endif