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 |