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1 | // Boost.Range library |
2 | // | |
3 | // Copyright Neil Groves 2007. 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_REPLACED_IF_IMPL_HPP_INCLUDED | |
12 | #define BOOST_RANGE_ADAPTOR_REPLACED_IF_IMPL_HPP_INCLUDED | |
13 | ||
14 | #include <boost/config.hpp> | |
15 | #include <boost/range/adaptor/argument_fwd.hpp> | |
16 | #include <boost/range/iterator_range.hpp> | |
17 | #include <boost/range/begin.hpp> | |
18 | #include <boost/range/end.hpp> | |
19 | #include <boost/range/value_type.hpp> | |
20 | #include <boost/range/concepts.hpp> | |
21 | #include <boost/iterator/iterator_adaptor.hpp> | |
22 | #include <boost/iterator/transform_iterator.hpp> | |
23 | #include <boost/optional/optional.hpp> | |
24 | ||
25 | namespace boost | |
26 | { | |
27 | namespace range_detail | |
28 | { | |
29 | template< class Pred, class Value > | |
30 | class replace_value_if | |
31 | { | |
32 | public: | |
33 | typedef const Value& result_type; | |
34 | typedef const Value& first_argument_type; | |
35 | ||
36 | // Rationale: | |
37 | // required to allow the iterator to be default constructible. | |
38 | replace_value_if() | |
39 | { | |
40 | } | |
41 | ||
42 | replace_value_if(const Pred& pred, const Value& to) | |
43 | : m_impl(data(pred, to)) | |
44 | { | |
45 | } | |
46 | ||
47 | const Value& operator()(const Value& x) const | |
48 | { | |
49 | return m_impl->m_pred(x) ? m_impl->m_to : x; | |
50 | } | |
51 | ||
52 | private: | |
53 | struct data | |
54 | { | |
55 | data(const Pred& p, const Value& t) | |
56 | : m_pred(p), m_to(t) | |
57 | { | |
58 | } | |
59 | ||
60 | Pred m_pred; | |
61 | Value m_to; | |
62 | }; | |
63 | boost::optional<data> m_impl; | |
64 | }; | |
65 | ||
66 | template< class Pred, class R > | |
67 | class replaced_if_range : | |
68 | public boost::iterator_range< | |
69 | boost::transform_iterator< | |
70 | replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type >, | |
71 | BOOST_DEDUCED_TYPENAME range_iterator<R>::type > > | |
72 | { | |
73 | private: | |
74 | typedef replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type > Fn; | |
75 | ||
76 | typedef boost::iterator_range< | |
77 | boost::transform_iterator< | |
78 | replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type >, | |
79 | BOOST_DEDUCED_TYPENAME range_iterator<R>::type > > base_t; | |
80 | ||
81 | public: | |
82 | typedef BOOST_DEDUCED_TYPENAME range_value<R>::type value_type; | |
83 | ||
84 | replaced_if_range( R& r, const Pred& pred, value_type to ) | |
85 | : base_t( make_transform_iterator( boost::begin(r), Fn(pred, to) ), | |
86 | make_transform_iterator( boost::end(r), Fn(pred, to) ) ) | |
87 | { } | |
88 | }; | |
89 | ||
90 | template< class Pred, class T > | |
91 | class replace_if_holder | |
92 | { | |
93 | public: | |
94 | replace_if_holder( const Pred& pred, const T& to ) | |
95 | : m_pred(pred), m_to(to) | |
96 | { } | |
97 | ||
98 | const Pred& pred() const { return m_pred; } | |
99 | const T& to() const { return m_to; } | |
100 | ||
101 | private: | |
102 | Pred m_pred; | |
103 | T m_to; | |
104 | }; | |
105 | ||
106 | template< class Pred, class SinglePassRange > | |
107 | inline replaced_if_range<Pred, SinglePassRange> | |
108 | operator|( | |
109 | SinglePassRange& r, | |
110 | const replace_if_holder< | |
111 | Pred, | |
112 | BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type>& f) | |
113 | { | |
114 | BOOST_RANGE_CONCEPT_ASSERT(( | |
115 | SinglePassRangeConcept<SinglePassRange>)); | |
116 | ||
117 | return replaced_if_range<Pred, SinglePassRange>( | |
118 | r, f.pred(), f.to()); | |
119 | } | |
120 | ||
121 | template< class Pred, class SinglePassRange > | |
122 | inline replaced_if_range<Pred, const SinglePassRange> | |
123 | operator|( | |
124 | const SinglePassRange& r, | |
125 | const replace_if_holder< | |
126 | Pred, | |
127 | BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type>& f) | |
128 | { | |
129 | BOOST_RANGE_CONCEPT_ASSERT(( | |
130 | SinglePassRangeConcept<const SinglePassRange>)); | |
131 | ||
132 | return replaced_if_range<Pred, const SinglePassRange>( | |
133 | r, f.pred(), f.to()); | |
134 | } | |
135 | } // 'range_detail' | |
136 | ||
137 | using range_detail::replaced_if_range; | |
138 | ||
139 | namespace adaptors | |
140 | { | |
141 | namespace | |
142 | { | |
143 | const range_detail::forwarder2TU<range_detail::replace_if_holder> | |
144 | replaced_if = | |
145 | range_detail::forwarder2TU<range_detail::replace_if_holder>(); | |
146 | } | |
147 | ||
148 | template<class Pred, class SinglePassRange> | |
149 | inline replaced_if_range<Pred, SinglePassRange> | |
150 | replace_if(SinglePassRange& rng, Pred pred, | |
151 | BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type to) | |
152 | { | |
153 | BOOST_RANGE_CONCEPT_ASSERT(( | |
154 | SinglePassRangeConcept<SinglePassRange>)); | |
155 | ||
156 | return range_detail::replaced_if_range<Pred, SinglePassRange>( | |
157 | rng, pred, to); | |
158 | } | |
159 | ||
160 | template<class Pred, class SinglePassRange> | |
161 | inline replaced_if_range<Pred, const SinglePassRange> | |
162 | replace_if( | |
163 | const SinglePassRange& rng, | |
164 | Pred pred, | |
165 | BOOST_DEDUCED_TYPENAME range_value<const SinglePassRange>::type to) | |
166 | { | |
167 | BOOST_RANGE_CONCEPT_ASSERT(( | |
168 | SinglePassRangeConcept<const SinglePassRange>)); | |
169 | ||
170 | return range_detail::replaced_if_range<Pred, const SinglePassRange>( | |
171 | rng, pred, to); | |
172 | } | |
173 | } // 'adaptors' | |
174 | ||
175 | } // 'boost' | |
176 | ||
177 | #endif // include guard |