boost/boost/iterator/permutation_iterator.hpp

   1 // (C) Copyright Toon Knapen    2001.\r
   2 // (C) Copyright David Abrahams 2003.\r
   3 // (C) Copyright Roland Richter 2003.\r
   4 // Distributed under the Boost Software License, Version 1.0. (See\r
   5 // accompanying file LICENSE_1_0.txt or copy at\r
   6 // http://www.boost.org/LICENSE_1_0.txt)\r
   7 \r
   8 #ifndef BOOST_PERMUTATION_ITERATOR_HPP\r
   9 #define BOOST_PERMUTATION_ITERATOR_HPP\r
  10 \r
  11 #include <iterator>\r
  12 \r
  13 #include <boost/iterator/iterator_adaptor.hpp>\r
  14 \r
  15 \r
  16 namespace boost\r
  17 {\r
  18 \r
  19 template< class ElementIterator\r
  20         , class IndexIterator>\r
  21 class permutation_iterator\r
  22   : public iterator_adaptor< \r
  23              permutation_iterator<ElementIterator, IndexIterator>\r
  24            , IndexIterator, typename detail::iterator_traits<ElementIterator>::value_type\r
  25            , use_default, typename detail::iterator_traits<ElementIterator>::reference>\r
  26 {\r
  27   typedef iterator_adaptor< \r
  28             permutation_iterator<ElementIterator, IndexIterator>\r
  29           , IndexIterator, typename detail::iterator_traits<ElementIterator>::value_type\r
  30           , use_default, typename detail::iterator_traits<ElementIterator>::reference> super_t;\r
  31 \r
  32   friend class iterator_core_access;\r
  33 \r
  34 public:\r
  35   permutation_iterator() : m_elt_iter() {}\r
  36 \r
  37   explicit permutation_iterator(ElementIterator x, IndexIterator y) \r
  38       : super_t(y), m_elt_iter(x) {}\r
  39 \r
  40   template<class OtherElementIterator, class OtherIndexIterator>\r
  41   permutation_iterator(\r
  42       permutation_iterator<OtherElementIterator, OtherIndexIterator> const& r\r
  43       , typename enable_if_convertible<OtherElementIterator, ElementIterator>::type* = 0\r
  44       , typename enable_if_convertible<OtherIndexIterator, IndexIterator>::type* = 0\r
  45       )\r
  46     : super_t(r.base()), m_elt_iter(r.m_elt_iter)\r
  47   {}\r
  48 \r
  49 private:\r
  50     typename super_t::reference dereference() const\r
  51         { return *(m_elt_iter + *this->base()); }\r
  52 \r
  53 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS\r
  54     template <class,class> friend class permutation_iterator;\r
  55 #else\r
  56  public:\r
  57 #endif \r
  58     ElementIterator m_elt_iter;\r
  59 };\r
  60 \r
  61 \r
  62 template <class ElementIterator, class IndexIterator>\r
  63 permutation_iterator<ElementIterator, IndexIterator> \r
  64 make_permutation_iterator( ElementIterator e, IndexIterator i )\r
  65 {\r
  66     return permutation_iterator<ElementIterator, IndexIterator>( e, i );\r
  67 }\r
  68 \r
  69 \r
  70 } // namespace boost\r
  71 \r
  72 #endif\r