1// Boost.Range library
2//
3// Copyright Thorsten Ottosen, Neil Groves 2006 - 2008. Use, modification and
4// distribution is subject to the Boost Software License, Version
5// 1.0. (See accompanying file LICENSE_1_0.txt or copy at
6// http://www.boost.org/LICENSE_1_0.txt)
7//
8// For more information, see http://www.boost.org/libs/range/
9//
10
11#ifndef BOOST_RANGE_ADAPTOR_MAP_HPP
12#define BOOST_RANGE_ADAPTOR_MAP_HPP
13
14#include <boost/range/adaptor/transformed.hpp>
15#include <boost/range/iterator_range.hpp>
16#include <boost/range/value_type.hpp>
17#include <boost/range/reference.hpp>
18#include <boost/range/concepts.hpp>
19
20namespace boost
21{
22 namespace range_detail
23 {
24 struct map_keys_forwarder {};
25 struct map_values_forwarder {};
26
27 template< class Map >
28 struct select_first
29 {
30 typedef BOOST_DEDUCED_TYPENAME range_reference<const Map>::type argument_type;
31 typedef const BOOST_DEDUCED_TYPENAME range_value<const Map>::type::first_type& result_type;
32
33 result_type operator()( argument_type r ) const
34 {
35 return r.first;
36 }
37 };
38
39 template< class Map >
40 struct select_second_mutable
41 {
42 typedef BOOST_DEDUCED_TYPENAME range_reference<Map>::type argument_type;
43 typedef BOOST_DEDUCED_TYPENAME range_value<Map>::type::second_type& result_type;
44
45 result_type operator()( argument_type r ) const
46 {
47 return r.second;
48 }
49 };
50
51 template< class Map >
52 struct select_second_const
53 {
54 typedef BOOST_DEDUCED_TYPENAME range_reference<const Map>::type argument_type;
55 typedef const BOOST_DEDUCED_TYPENAME range_value<const Map>::type::second_type& result_type;
56
57 result_type operator()( argument_type r ) const
58 {
59 return r.second;
60 }
61 };
62
63 template<class StdPairRng>
64 class select_first_range
65 : public transformed_range<
66 select_first<StdPairRng>,
67 const StdPairRng>
68 {
69 typedef transformed_range<select_first<StdPairRng>, const StdPairRng> base;
70 public:
71 typedef select_first<StdPairRng> transform_fn_type;
72 typedef const StdPairRng source_range_type;
73
74 select_first_range(transform_fn_type fn, source_range_type& rng)
75 : base(fn, rng)
76 {
77 }
78
79 select_first_range(const base& other) : base(other) {}
80 };
81
82 template<class StdPairRng>
83 class select_second_mutable_range
84 : public transformed_range<
85 select_second_mutable<StdPairRng>,
86 StdPairRng>
87 {
88 typedef transformed_range<select_second_mutable<StdPairRng>, StdPairRng> base;
89 public:
90 typedef select_second_mutable<StdPairRng> transform_fn_type;
91 typedef StdPairRng source_range_type;
92
93 select_second_mutable_range(transform_fn_type fn, source_range_type& rng)
94 : base(fn, rng)
95 {
96 }
97
98 select_second_mutable_range(const base& other) : base(other) {}
99 };
100
101 template<class StdPairRng>
102 class select_second_const_range
103 : public transformed_range<
104 select_second_const<StdPairRng>,
105 const StdPairRng>
106 {
107 typedef transformed_range<select_second_const<StdPairRng>, const StdPairRng> base;
108 public:
109 typedef select_second_const<StdPairRng> transform_fn_type;
110 typedef const StdPairRng source_range_type;
111
112 select_second_const_range(transform_fn_type fn, source_range_type& rng)
113 : base(fn, rng)
114 {
115 }
116
117 select_second_const_range(const base& other) : base(other) {}
118 };
119
120 template< class StdPairRng >
121 inline select_first_range<StdPairRng>
122 operator|( const StdPairRng& r, map_keys_forwarder )
123 {
124 BOOST_RANGE_CONCEPT_ASSERT((
125 SinglePassRangeConcept<const StdPairRng>));
126
127 return operator|( r,
128 boost::adaptors::transformed( select_first<StdPairRng>() ) );
129 }
130
131 template< class StdPairRng >
132 inline select_second_mutable_range<StdPairRng>
133 operator|( StdPairRng& r, map_values_forwarder )
134 {
135 BOOST_RANGE_CONCEPT_ASSERT((SinglePassRangeConcept<StdPairRng>));
136
137 return operator|( r,
138 boost::adaptors::transformed( select_second_mutable<StdPairRng>() ) );
139 }
140
141 template< class StdPairRng >
142 inline select_second_const_range<StdPairRng>
143 operator|( const StdPairRng& r, map_values_forwarder )
144 {
145 BOOST_RANGE_CONCEPT_ASSERT((
146 SinglePassRangeConcept<const StdPairRng>));
147
148 return operator|( r,
149 boost::adaptors::transformed( select_second_const<StdPairRng>() ) );
150 }
151
152 } // 'range_detail'
153
154 using range_detail::select_first_range;
155 using range_detail::select_second_mutable_range;
156 using range_detail::select_second_const_range;
157
158 namespace adaptors
159 {
160 namespace
161 {
162 const range_detail::map_keys_forwarder map_keys =
163 range_detail::map_keys_forwarder();
164
165 const range_detail::map_values_forwarder map_values =
166 range_detail::map_values_forwarder();
167 }
168
169 template<class StdPairRange>
170 inline select_first_range<StdPairRange>
171 keys(const StdPairRange& rng)
172 {
173 BOOST_RANGE_CONCEPT_ASSERT((
174 SinglePassRangeConcept<const StdPairRange>));
175
176 return select_first_range<StdPairRange>(
177 range_detail::select_first<StdPairRange>(), rng );
178 }
179
180 template<class StdPairRange>
181 inline select_second_const_range<StdPairRange>
182 values(const StdPairRange& rng)
183 {
184 BOOST_RANGE_CONCEPT_ASSERT((
185 SinglePassRangeConcept<const StdPairRange>));
186
187 return select_second_const_range<StdPairRange>(
188 range_detail::select_second_const<StdPairRange>(), rng );
189 }
190
191 template<class StdPairRange>
192 inline select_second_mutable_range<StdPairRange>
193 values(StdPairRange& rng)
194 {
195 BOOST_RANGE_CONCEPT_ASSERT((SinglePassRangeConcept<StdPairRange>));
196
197 return select_second_mutable_range<StdPairRange>(
198 range_detail::select_second_mutable<StdPairRange>(), rng );
199 }
200 } // 'adaptors'
201
202}
203
204#endif
205