/*=============================================================================
    Copyright (c) 2007 Tobias Schwinger

    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)
==============================================================================*/

#if !defined(BOOST_FUSION_ITERATOR_RANGE_AT_IMPL_HPP_INCLUDED)
#define BOOST_FUSION_ITERATOR_RANGE_AT_IMPL_HPP_INCLUDED

#include <boost/fusion/support/config.hpp>
#include <boost/fusion/iterator/advance.hpp>
#include <boost/fusion/iterator/deref.hpp>

namespace boost {
namespace fusion {
struct iterator_range_tag;

namespace extension {
template <typename Tag>
struct at_impl;

template <>
struct at_impl<iterator_range_tag>
{
    template <typename Seq, typename N>
    struct apply
    {
        typedef typename Seq::begin_type begin_type;
        typedef typename result_of::advance<begin_type,N>::type pos;
        typedef typename result_of::deref<pos>::type type;

        BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
        static type
        call(Seq& s)
        {
            return * fusion::advance<N>(s.first);
        }
    };
};
}
}
}

#endif
