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/*=============================================================================
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_09172005_0730)
#define FUSION_DISTANCE_09172005_0730
#include <boost/fusion/support/config.hpp>
#include <boost/mpl/int.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/eval_if.hpp>
#include <boost/mpl/next.hpp>
#include <boost/mpl/identity.hpp>
#include <boost/fusion/iterator/next.hpp>
#include <boost/fusion/iterator/equal_to.hpp>
namespace boost { namespace fusion { namespace distance_detail
{
// Default distance implementation, linear
// search for the Last iterator.
template <typename First, typename Last>
struct linear_distance;
template <typename First, typename Last>
struct next_distance
{
typedef typename
mpl::next<
typename linear_distance<
typename result_of::next<First>::type
, Last
>::type
>::type
type;
};
template <typename First, typename Last>
struct linear_distance
: mpl::eval_if<
result_of::equal_to<First, Last>
, mpl::identity<mpl::int_<0> >
, next_distance<First, Last>
>::type
{
typedef typename
mpl::eval_if<
result_of::equal_to<First, Last>
, mpl::identity<mpl::int_<0> >
, next_distance<First, Last>
>::type
type;
BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
static type
call(First const&, Last const&)
{
return type();
}
};
}}}
#endif