ceph/src/boost/boost/geometry/iterators/concatenate_iterator.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2014-2021, Oracle and/or its affiliates.
   4 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
   5 // Contributed and/or modified by Adam Wulkiewicz, 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_ITERATORS_CONCATENATE_ITERATOR_HPP
  11 #define BOOST_GEOMETRY_ITERATORS_CONCATENATE_ITERATOR_HPP
  12
  13
  14 #include <type_traits>
  15
  16 #include <boost/iterator/iterator_facade.hpp>
  17 #include <boost/iterator/iterator_categories.hpp>
  18
  19
  20 namespace boost { namespace geometry
  21 {
  22
  23
  24
  25 template
  26 <
  27     typename Iterator1,
  28     typename Iterator2,
  29     typename Value,
  30     typename Reference = Value&
  31 >
  32 class concatenate_iterator
  33     : public boost::iterator_facade
  34         <
  35             concatenate_iterator<Iterator1, Iterator2, Value, Reference>,
  36             Value,
  37             boost::bidirectional_traversal_tag,
  38             Reference
  39         >
  40 {
  41 private:
  42     Iterator1 m_it1, m_end1;
  43     Iterator2 m_begin2, m_it2;
  44
  45 public:
  46     typedef Iterator1 first_iterator_type;
  47     typedef Iterator2 second_iterator_type;
  48
  49     // default constructor
  50     concatenate_iterator() = default;
  51
  52     // for begin
  53     concatenate_iterator(Iterator1 it1, Iterator1 end1,
  54                          Iterator2 begin2, Iterator2 it2)
  55         : m_it1(it1), m_end1(end1), m_begin2(begin2), m_it2(it2)
  56     {}
  57
  58     // for end
  59     concatenate_iterator(Iterator1 end1, Iterator2 begin2, Iterator2 end2)
  60         : m_it1(end1), m_end1(end1), m_begin2(begin2), m_it2(end2)
  61     {}
  62
  63     template
  64     <
  65         typename OtherIt1,
  66         typename OtherIt2,
  67         typename OtherValue,
  68         typename OtherReference,
  69         std::enable_if_t
  70             <
  71                 std::is_convertible<OtherIt1, Iterator1>::value
  72                 && std::is_convertible<OtherIt2, Iterator2>::value,
  73                 int
  74             > = 0
  75     >
  76     concatenate_iterator(concatenate_iterator
  77                          <
  78                              OtherIt1,
  79                              OtherIt2,
  80                              OtherValue,
  81                              OtherReference
  82                          > const& other)
  83         : m_it1(other.m_it1)
  84         , m_end1(other.m_end1)
  85         , m_begin2(other.m_begin2)
  86         , m_it2(other.m_it2)
  87     {}
  88
  89     concatenate_iterator(concatenate_iterator const& other) = default;
  90
  91     concatenate_iterator& operator=(concatenate_iterator const& other) = default;
  92
  93 private:
  94     friend class boost::iterator_core_access;
  95
  96     template <typename It1, typename It2, typename V, typename R>
  97     friend class concatenate_iterator;
  98
  99     inline Reference dereference() const
 100     {
 101         if ( m_it1 == m_end1 )
 102         {
 103             return *m_it2;
 104         }
 105         return *m_it1;
 106     }
 107
 108     template
 109     <
 110         typename OtherIt1,
 111         typename OtherIt2,
 112         typename OtherValue,
 113         typename OtherReference
 114     >
 115     inline bool equal(concatenate_iterator
 116                       <
 117                           OtherIt1,
 118                           OtherIt2,
 119                           OtherValue,
 120                           OtherReference
 121                       > const& other) const
 122     {
 123         return m_it1 == other.m_it1 && m_it2 == other.m_it2;
 124     }
 125
 126     inline void increment()
 127     {
 128         if ( m_it1 == m_end1 )
 129         {
 130             ++m_it2;
 131         }
 132         else
 133         {
 134             ++m_it1;
 135         }
 136     }
 137
 138     inline void decrement()
 139     {
 140         if ( m_it2 == m_begin2 )
 141         {
 142             --m_it1;
 143         }
 144         else
 145         {
 146             --m_it2;
 147         }
 148     }
 149 };
 150
 151
 152
 153 }} // namespace boost::geometry
 154
 155 #endif // BOOST_GEOMETRY_ITERATORS_CONCATENATE_ITERATOR_HPP