1
2#ifndef BOOST_MPL_AUX_FILTER_ITER_HPP_INCLUDED
3#define BOOST_MPL_AUX_FILTER_ITER_HPP_INCLUDED
4
5// Copyright Aleksey Gurtovoy 2000-2004
6//
7// Distributed under the Boost Software License, Version 1.0.
8// (See accompanying file LICENSE_1_0.txt or copy at
9// http://www.boost.org/LICENSE_1_0.txt)
10//
11// See http://www.boost.org/libs/mpl for documentation.
12
13// $Id$
14// $Date$
15// $Revision$
16
17#include <boost/mpl/find_if.hpp>
18#include <boost/mpl/iterator_range.hpp>
19#include <boost/mpl/iterator_tags.hpp>
20#include <boost/mpl/deref.hpp>
21#include <boost/mpl/aux_/lambda_spec.hpp>
22#include <boost/mpl/aux_/config/ctps.hpp>
23#include <boost/type_traits/is_same.hpp>
24
25namespace boost { namespace mpl {
26
27namespace aux {
28
29template<
30 typename Iterator
31 , typename LastIterator
32 , typename Predicate
33 >
34struct filter_iter;
35
36template<
37 typename Iterator
38 , typename LastIterator
39 , typename Predicate
40 >
41struct next_filter_iter
42{
43 typedef typename find_if<
44 iterator_range<Iterator,LastIterator>
45 , Predicate
46 >::type base_iter_;
47
48 typedef filter_iter<base_iter_,LastIterator,Predicate> type;
49};
50
51#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
52
53template<
54 typename Iterator
55 , typename LastIterator
56 , typename Predicate
57 >
58struct filter_iter
59{
60 typedef Iterator base;
61 typedef forward_iterator_tag category;
62 typedef typename aux::next_filter_iter<
63 typename mpl::next<base>::type
64 , LastIterator
65 , Predicate
66 >::type next;
67
68 typedef typename deref<base>::type type;
69};
70
71template<
72 typename LastIterator
73 , typename Predicate
74 >
75struct filter_iter< LastIterator,LastIterator,Predicate >
76{
77 typedef LastIterator base;
78 typedef forward_iterator_tag category;
79};
80
81#else
82
83template< bool >
84struct filter_iter_impl
85{
86 template<
87 typename Iterator
88 , typename LastIterator
89 , typename Predicate
90 >
91 struct result_
92 {
93 typedef Iterator base;
94 typedef forward_iterator_tag category;
95 typedef typename next_filter_iter<
96 typename mpl::next<Iterator>::type
97 , LastIterator
98 , Predicate
99 >::type next;
100
101 typedef typename deref<base>::type type;
102 };
103};
104
105template<>
106struct filter_iter_impl< true >
107{
108 template<
109 typename Iterator
110 , typename LastIterator
111 , typename Predicate
112 >
113 struct result_
114 {
115 typedef Iterator base;
116 typedef forward_iterator_tag category;
117 };
118};
119
120template<
121 typename Iterator
122 , typename LastIterator
123 , typename Predicate
124 >
125struct filter_iter
126 : filter_iter_impl<
127 ::boost::is_same<Iterator,LastIterator>::value
128 >::template result_< Iterator,LastIterator,Predicate >
129{
130};
131
132#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
133
134} // namespace aux
135
136BOOST_MPL_AUX_PASS_THROUGH_LAMBDA_SPEC(3, aux::filter_iter)
137
138}}
139
140#endif // BOOST_MPL_AUX_FILTER_ITER_HPP_INCLUDED
141