1/*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
3
4 Distributed under the Boost Software License, Version 1.0. (See accompanying
5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6==============================================================================*/
7#if !defined(FUSION_DISTANCE_IMPL_09172005_0751)
8#define FUSION_DISTANCE_IMPL_09172005_0751
9
10#include <boost/fusion/support/config.hpp>
11#include <boost/mpl/minus.hpp>
12
13namespace boost { namespace fusion
14{
15 struct vector_iterator_tag;
16
17 namespace extension
18 {
19 template <typename Tag>
20 struct distance_impl;
21
22 template <>
23 struct distance_impl<vector_iterator_tag>
24 {
25 template <typename First, typename Last>
26 struct apply : mpl::minus<typename Last::index, typename First::index>
27 {
28 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
29 static typename mpl::minus<
30 typename Last::index, typename First::index>::type
31 call(First const&, Last const&)
32 {
33 typedef typename mpl::minus<
34 typename Last::index, typename First::index>::type
35 result;
36 return result();
37 }
38 };
39 };
40 }
41}}
42
43#endif
44