ceph/src/boost/libs/geometry/include/boost/geometry/algorithms/detail/num_distinct_consecutive_points.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2014, Oracle and/or its affiliates.
   4
   5 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
   6
   7 // Licensed under the Boost Software License version 1.0.
   8 // http://www.boost.org/users/license.html
   9
  10 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_NUM_DISTINCT_CONSECUTIVE_POINTS_HPP
  11 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_NUM_DISTINCT_CONSECUTIVE_POINTS_HPP
  12
  13 #include <cstddef>
  14
  15 #include <algorithm>
  16
  17 #include <boost/range.hpp>
  18
  19
  20
  21 namespace boost { namespace geometry
  22 {
  23
  24
  25 #ifndef DOXYGEN_NO_DETAIL
  26 namespace detail
  27 {
  28
  29
  30 // returns the number of distinct values in the range;
  31 // return values are 0u through MaximumNumber, where MaximumNumber
  32 // corresponds to MaximumNumber or more distinct values
  33 //
  34 // FUTURE: take into account topologically closed ranges;
  35 //         add appropriate template parameter(s) to control whether
  36 //         the closing point for topologically closed ranges is to be
  37 //         accounted for separately or not
  38 template
  39 <
  40     typename Range,
  41     std::size_t MaximumNumber,
  42     bool AllowDuplicates /* true */,
  43     typename NotEqualTo
  44 >
  45 struct num_distinct_consecutive_points
  46 {
  47     static inline std::size_t apply(Range const& range)
  48     {
  49         typedef typename boost::range_iterator<Range const>::type iterator;
  50
  51         std::size_t const size = boost::size(range);
  52
  53         if ( size < 2u )
  54         {
  55             return (size < MaximumNumber) ? size : MaximumNumber;
  56         }
  57
  58         iterator current = boost::begin(range);
  59         std::size_t counter(0);
  60         do
  61         {
  62             ++counter;
  63             iterator next = std::find_if(current,
  64                                          boost::end(range),
  65                                          NotEqualTo(*current));
  66             current = next;
  67         }
  68         while ( current != boost::end(range) && counter <= MaximumNumber );
  69
  70         return counter;
  71     }
  72 };
  73
  74
  75 template <typename Range, std::size_t MaximumNumber, typename NotEqualTo>
  76 struct num_distinct_consecutive_points<Range, MaximumNumber, false, NotEqualTo>
  77 {
  78     static inline std::size_t apply(Range const& range)
  79     {
  80         std::size_t const size = boost::size(range);
  81         return (size < MaximumNumber) ? size : MaximumNumber;
  82     }
  83 };
  84
  85
  86 } // namespace detail
  87 #endif // DOXYGEN_NO_DETAIL
  88
  89
  90 }} // namespace boost::geometry
  91
  92
  93 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_NUM_DISTINCT_CONSECUTIVE_POINTS_HPP