/*=============================================================================
    Copyright (c) 2011 Eric Niebler

    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_SINGLE_VIEW_DISTANCE_IMPL_JUL_07_2011_1348PM)
#define BOOST_FUSION_SINGLE_VIEW_DISTANCE_IMPL_JUL_07_2011_1348PM

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

namespace boost {
namespace fusion {
struct single_view_iterator_tag;

namespace extension {
template<typename Tag>
struct distance_impl;

template<>
struct distance_impl<single_view_iterator_tag>
{
    template<typename First, typename Last>
    struct apply
        : mpl::minus<typename Last::position, typename First::position>
    {
        typedef typename mpl::minus<typename Last::position,
                typename First::position>::type type;

        BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
        static type
        call(First const& /*first*/, Last const& /*last*/)
        {
            return type();
        }
    };
};
}

}
}

#endif
