/*=============================================================================
    Copyright (c) 2001-2011 Joel de Guzman

    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(FUSION_DISTANCE_IMPL_09172005_0751)
#define FUSION_DISTANCE_IMPL_09172005_0751

#include <boost/fusion/support/config.hpp>
#include <boost/mpl/minus.hpp>

namespace boost {
namespace fusion {
struct vector_iterator_tag;

namespace extension {
template <typename Tag>
struct distance_impl;

template <>
struct distance_impl<vector_iterator_tag>
{
    template <typename First, typename Last>
    struct apply : mpl::minus<typename Last::index, typename First::index>
    {
        BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
        static typename mpl::minus<
        typename Last::index, typename First::index>::type
        call(First const&, Last const&)
        {
            typedef typename mpl::minus<
            typename Last::index, typename First::index>::type
            result;
            return result();
        }
    };
};
}
}
}

#endif
