Chris@16
|
1 /*=============================================================================
|
Chris@16
|
2 Copyright (c) 2001-2011 Joel de Guzman
|
Chris@16
|
3
|
Chris@16
|
4 Distributed under the Boost Software License, Version 1.0. (See accompanying
|
Chris@16
|
5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
Chris@16
|
6 ==============================================================================*/
|
Chris@16
|
7 #if !defined(FUSION_DISTANCE_09172005_0721)
|
Chris@16
|
8 #define FUSION_DISTANCE_09172005_0721
|
Chris@16
|
9
|
Chris@16
|
10 #include <boost/fusion/iterator/detail/distance.hpp>
|
Chris@16
|
11 #include <boost/fusion/support/category_of.hpp>
|
Chris@16
|
12
|
Chris@16
|
13 #include <boost/mpl/int.hpp>
|
Chris@16
|
14 #include <boost/mpl/assert.hpp>
|
Chris@16
|
15 #include <boost/type_traits/is_same.hpp>
|
Chris@16
|
16
|
Chris@16
|
17 #include <boost/fusion/support/tag_of.hpp>
|
Chris@16
|
18
|
Chris@16
|
19 namespace boost { namespace fusion
|
Chris@16
|
20 {
|
Chris@16
|
21 struct random_access_traversal_tag;
|
Chris@16
|
22
|
Chris@16
|
23 // Special tags:
|
Chris@16
|
24 struct iterator_facade_tag; // iterator facade tag
|
Chris@16
|
25 struct boost_array_iterator_tag; // boost::array iterator tag
|
Chris@16
|
26 struct mpl_iterator_tag; // mpl sequence iterator tag
|
Chris@16
|
27 struct std_pair_iterator_tag; // std::pair iterator tag
|
Chris@16
|
28
|
Chris@16
|
29 namespace extension
|
Chris@16
|
30 {
|
Chris@16
|
31 template <typename Tag>
|
Chris@16
|
32 struct distance_impl
|
Chris@16
|
33 {
|
Chris@16
|
34 // default implementation
|
Chris@16
|
35 template <typename First, typename Last>
|
Chris@16
|
36 struct apply : distance_detail::linear_distance<First, Last>
|
Chris@16
|
37 {};
|
Chris@16
|
38 };
|
Chris@16
|
39
|
Chris@16
|
40 template <>
|
Chris@16
|
41 struct distance_impl<iterator_facade_tag>
|
Chris@16
|
42 {
|
Chris@16
|
43 template <typename First, typename Last>
|
Chris@16
|
44 struct apply : First::template distance<First, Last> {};
|
Chris@16
|
45 };
|
Chris@16
|
46
|
Chris@16
|
47 template <>
|
Chris@16
|
48 struct distance_impl<boost_array_iterator_tag>;
|
Chris@16
|
49
|
Chris@16
|
50 template <>
|
Chris@16
|
51 struct distance_impl<mpl_iterator_tag>;
|
Chris@16
|
52
|
Chris@16
|
53 template <>
|
Chris@16
|
54 struct distance_impl<std_pair_iterator_tag>;
|
Chris@16
|
55 }
|
Chris@16
|
56
|
Chris@16
|
57 namespace result_of
|
Chris@16
|
58 {
|
Chris@16
|
59 template <typename First, typename Last>
|
Chris@16
|
60 struct distance
|
Chris@16
|
61 : extension::distance_impl<typename detail::tag_of<First>::type>::
|
Chris@16
|
62 template apply<First, Last>
|
Chris@16
|
63 {
|
Chris@16
|
64 typedef typename extension::distance_impl<typename detail::tag_of<First>::type>::
|
Chris@16
|
65 template apply<First, Last>::type distance_application;
|
Chris@16
|
66 BOOST_STATIC_CONSTANT(int, value = distance_application::value);
|
Chris@16
|
67 };
|
Chris@16
|
68 }
|
Chris@16
|
69
|
Chris@16
|
70 template <typename First, typename Last>
|
Chris@16
|
71 inline typename result_of::distance<First, Last>::type
|
Chris@16
|
72 distance(First const& a, Last const& b)
|
Chris@16
|
73 {
|
Chris@16
|
74 return result_of::distance<First, Last>::call(a,b);
|
Chris@16
|
75 }
|
Chris@16
|
76 }}
|
Chris@16
|
77
|
Chris@16
|
78 #endif
|