1 | /* |
2 | Copyright (c) Marshall Clow 2008-2012. |
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 | |
8 | /// \file copy_if.hpp |
9 | /// \brief Copy a subset of a sequence to a new sequence |
10 | /// \author Marshall Clow |
11 | |
12 | #ifndef BOOST_ALGORITHM_COPY_IF_HPP |
13 | #define BOOST_ALGORITHM_COPY_IF_HPP |
14 | |
15 | #include <algorithm> // for std::copy_if, if available |
16 | #include <boost/range/begin.hpp> |
17 | #include <boost/range/end.hpp> |
18 | |
19 | namespace boost { namespace algorithm { |
20 | |
21 | /// \fn copy_if ( InputIterator first, InputIterator last, OutputIterator result, Predicate p ) |
22 | /// \brief Copies all the elements from the input range that satisfy the |
23 | /// predicate to the output range. |
24 | /// \return The updated output iterator |
25 | /// |
26 | /// \param first The start of the input sequence |
27 | /// \param last One past the end of the input sequence |
28 | /// \param result An output iterator to write the results into |
29 | /// \param p A predicate for testing the elements of the range |
30 | /// \note This function is part of the C++2011 standard library. |
31 | /// We will use the standard one if it is available, |
32 | /// otherwise we have our own implementation. |
33 | template<typename InputIterator, typename OutputIterator, typename Predicate> |
34 | OutputIterator copy_if ( InputIterator first, InputIterator last, OutputIterator result, Predicate p ) |
35 | { |
36 | for ( ; first != last; ++first ) |
37 | if (p(*first)) |
38 | *result++ = *first; |
39 | return result; |
40 | } |
41 | |
42 | /// \fn copy_if ( const Range &r, OutputIterator result, Predicate p ) |
43 | /// \brief Copies all the elements from the input range that satisfy the |
44 | /// predicate to the output range. |
45 | /// \return The updated output iterator |
46 | /// |
47 | /// \param r The input range |
48 | /// \param result An output iterator to write the results into |
49 | /// \param p A predicate for testing the elements of the range |
50 | /// |
51 | template<typename Range, typename OutputIterator, typename Predicate> |
52 | OutputIterator copy_if ( const Range &r, OutputIterator result, Predicate p ) |
53 | { |
54 | return boost::algorithm::copy_if (boost::begin (r), boost::end(r), result, p); |
55 | } |
56 | |
57 | |
58 | /// \fn copy_while ( InputIterator first, InputIterator last, OutputIterator result, Predicate p ) |
59 | /// \brief Copies all the elements at the start of the input range that |
60 | /// satisfy the predicate to the output range. |
61 | /// \return The updated input and output iterators |
62 | /// |
63 | /// \param first The start of the input sequence |
64 | /// \param last One past the end of the input sequence |
65 | /// \param result An output iterator to write the results into |
66 | /// \param p A predicate for testing the elements of the range |
67 | /// |
68 | template<typename InputIterator, typename OutputIterator, typename Predicate> |
69 | std::pair<InputIterator, OutputIterator> |
70 | copy_while ( InputIterator first, InputIterator last, OutputIterator result, Predicate p ) |
71 | { |
72 | for ( ; first != last && p(*first); ++first ) |
73 | *result++ = *first; |
74 | return std::make_pair(first, result); |
75 | } |
76 | |
77 | /// \fn copy_while ( const Range &r, OutputIterator result, Predicate p ) |
78 | /// \brief Copies all the elements at the start of the input range that |
79 | /// satisfy the predicate to the output range. |
80 | /// \return The updated input and output iterators |
81 | /// |
82 | /// \param r The input range |
83 | /// \param result An output iterator to write the results into |
84 | /// \param p A predicate for testing the elements of the range |
85 | /// |
86 | template<typename Range, typename OutputIterator, typename Predicate> |
87 | std::pair<typename boost::range_iterator<const Range>::type, OutputIterator> |
88 | copy_while ( const Range &r, OutputIterator result, Predicate p ) |
89 | { |
90 | return boost::algorithm::copy_while (boost::begin (r), boost::end(r), result, p); |
91 | } |
92 | |
93 | |
94 | /// \fn copy_until ( InputIterator first, InputIterator last, OutputIterator result, Predicate p ) |
95 | /// \brief Copies all the elements at the start of the input range that do not |
96 | /// satisfy the predicate to the output range. |
97 | /// \return The updated output iterator |
98 | /// |
99 | /// \param first The start of the input sequence |
100 | /// \param last One past the end of the input sequence |
101 | /// \param result An output iterator to write the results into |
102 | /// \param p A predicate for testing the elements of the range |
103 | /// |
104 | template<typename InputIterator, typename OutputIterator, typename Predicate> |
105 | std::pair<InputIterator, OutputIterator> |
106 | copy_until ( InputIterator first, InputIterator last, OutputIterator result, Predicate p ) |
107 | { |
108 | for ( ; first != last && !p(*first); ++first ) |
109 | *result++ = *first; |
110 | return std::make_pair(first, result); |
111 | } |
112 | |
113 | /// \fn copy_until ( const Range &r, OutputIterator result, Predicate p ) |
114 | /// \brief Copies all the elements at the start of the input range that do not |
115 | /// satisfy the predicate to the output range. |
116 | /// \return The updated output iterator |
117 | /// |
118 | /// \param r The input range |
119 | /// \param result An output iterator to write the results into |
120 | /// \param p A predicate for testing the elements of the range |
121 | /// |
122 | template<typename Range, typename OutputIterator, typename Predicate> |
123 | std::pair<typename boost::range_iterator<const Range>::type, OutputIterator> |
124 | copy_until ( const Range &r, OutputIterator result, Predicate p ) |
125 | { |
126 | return boost::algorithm::copy_until (boost::begin (r), boost::end(r), result, p); |
127 | } |
128 | |
129 | }} // namespace boost and algorithm |
130 | |
131 | #endif // BOOST_ALGORITHM_COPY_IF_HPP |
132 | |