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_EQUAL_TO_05052005_1208)
8#define FUSION_EQUAL_TO_05052005_1208
9
10#include <boost/fusion/support/config.hpp>
11#include <boost/type_traits/is_same.hpp>
12#include <boost/fusion/support/tag_of.hpp>
13#include <boost/type_traits/add_const.hpp>
14#include <boost/fusion/support/is_iterator.hpp>
15#include <boost/mpl/and.hpp>
16#include <boost/utility/enable_if.hpp>
17
18namespace boost { namespace fusion
19{
20 // Special tags:
21 struct iterator_facade_tag; // iterator facade tag
22 struct boost_array_iterator_tag; // boost::array iterator tag
23 struct mpl_iterator_tag; // mpl sequence iterator tag
24 struct std_pair_iterator_tag; // std::pair iterator tag
25
26 namespace extension
27 {
28 template <typename Tag>
29 struct equal_to_impl
30 {
31 // default implementation
32 template <typename I1, typename I2>
33 struct apply
34 : is_same<typename add_const<I1>::type, typename add_const<I2>::type>
35 {};
36 };
37
38 template <>
39 struct equal_to_impl<iterator_facade_tag>
40 {
41 template <typename It1, typename It2, typename Tag1, typename Tag2>
42 struct dispatch : mpl::false_ {};
43
44 template <typename It1, typename It2, typename Tag>
45 struct dispatch<It1, It2, Tag, Tag> // same tag
46 : It1::template equal_to<It1, It2>
47 {};
48
49 template<typename It1, typename It2>
50 struct apply : dispatch<It1, It2,
51 typename It1::fusion_tag, typename It2::fusion_tag>
52 {};
53 };
54
55 template <>
56 struct equal_to_impl<boost_array_iterator_tag>;
57
58 template <>
59 struct equal_to_impl<mpl_iterator_tag>;
60
61 template <>
62 struct equal_to_impl<std_pair_iterator_tag>;
63 }
64
65 namespace result_of
66 {
67 template <typename I1, typename I2>
68 struct equal_to
69 : extension::equal_to_impl<typename detail::tag_of<I1>::type>::
70 template apply<I1, I2>
71 {};
72 }
73
74 namespace iterator_operators
75 {
76 template <typename Iter1, typename Iter2>
77 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
78 inline typename
79 boost::enable_if<
80 mpl::and_<is_fusion_iterator<Iter1>, is_fusion_iterator<Iter2> >
81 , bool
82 >::type
83 operator==(Iter1 const&, Iter2 const&)
84 {
85 return result_of::equal_to<Iter1, Iter2>::value;
86 }
87
88 template <typename Iter1, typename Iter2>
89 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
90 inline typename
91 boost::enable_if<
92 mpl::and_<is_fusion_iterator<Iter1>, is_fusion_iterator<Iter2> >
93 , bool
94 >::type
95 operator!=(Iter1 const&, Iter2 const&)
96 {
97 return !result_of::equal_to<Iter1, Iter2>::value;
98 }
99 }
100
101 using iterator_operators::operator==;
102 using iterator_operators::operator!=;
103}}
104
105#endif
106
107

source code of include/boost/fusion/iterator/equal_to.hpp