1 | */* * |

2 | * Copyright (c) Marshall Clow 2011-2012.* |

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 partition_point.hpp* |

9 | */// \brief Find the partition point in a sequence* |

10 | */// \author Marshall Clow* |

11 | |

12 | __#ifndef BOOST_ALGORITHM_PARTITION_POINT_HPP__ |

13 | __#define BOOST_ALGORITHM_PARTITION_POINT_HPP__ |

14 | |

15 | __#include <algorithm> // for std::partition_point, if available__ |

16 | |

17 | __#include <boost/range/begin.hpp>__ |

18 | __#include <boost/range/end.hpp>__ |

19 | |

20 | **namespace** boost { **namespace** algorithm { |

21 | |

22 | */// \fn partition_point ( ForwardIterator first, ForwardIterator last, Predicate p )* |

23 | */// \brief Given a partitioned range, returns the partition point, i.e, the first element * |

24 | */// that does not satisfy p* |

25 | */// * |

26 | */// \param first The start of the input sequence* |

27 | */// \param last One past the end of the input sequence* |

28 | */// \param p The predicate to test the values with* |

29 | */// \note This function is part of the C++2011 standard library.* |

30 | */// We will use the standard one if it is available, * |

31 | */// otherwise we have our own implementation.* |

32 | **template** <**typename** ForwardIterator, **typename** Predicate> |

33 | ForwardIterator partition_point ( ForwardIterator first, ForwardIterator last, Predicate p ) |

34 | { |

35 | std::size_t dist = std::distance ( first, last ); |

36 | **while** ( first != last ) { |

37 | std::size_t d2 = dist / `2`; |

38 | ForwardIterator ret_val = first; |

39 | std::advance (ret_val, d2); |

40 | **if** (p (*ret_val)) { |

41 | first = ++ret_val; |

42 | dist -= d2 + `1`; |

43 | } |

44 | **else** { |

45 | last = ret_val; |

46 | dist = d2; |

47 | } |

48 | } |

49 | **return** first; |

50 | } |

51 | |

52 | */// \fn partition_point ( Range &r, Predicate p )* |

53 | */// \brief Given a partitioned range, returns the partition point* |

54 | */// * |

55 | */// \param r The input range* |

56 | */// \param p The predicate to test the values with* |

57 | *///* |

58 | **template** <**typename** Range, **typename** Predicate> |

59 | **typename** boost::range_iterator<Range>::type partition_point ( Range &r, Predicate p ) |

60 | { |

61 | **return** boost::algorithm::partition_point (boost::begin(r), boost::end(r), p); |

62 | } |

63 | |

64 | |

65 | }} |

66 | |

67 | __#endif // BOOST_ALGORITHM_PARTITION_POINT_HPP__ |

68 | |