1// (C) Copyright Toon Knapen 2001.
2// (C) Copyright David Abrahams 2003.
3// (C) Copyright Roland Richter 2003.
4// Distributed under the Boost Software License, Version 1.0. (See
5// accompanying file LICENSE_1_0.txt or copy at
6// http://www.boost.org/LICENSE_1_0.txt)
7
8#ifndef BOOST_PERMUTATION_ITERATOR_HPP
9#define BOOST_PERMUTATION_ITERATOR_HPP
10
11#include <iterator>
12
13#include <boost/iterator/iterator_adaptor.hpp>
14
15
16namespace boost {
17namespace iterators {
18
19template< class ElementIterator
20 , class IndexIterator>
21class permutation_iterator
22 : public iterator_adaptor<
23 permutation_iterator<ElementIterator, IndexIterator>
24 , IndexIterator, typename std::iterator_traits<ElementIterator>::value_type
25 , use_default, typename std::iterator_traits<ElementIterator>::reference>
26{
27 typedef iterator_adaptor<
28 permutation_iterator<ElementIterator, IndexIterator>
29 , IndexIterator, typename std::iterator_traits<ElementIterator>::value_type
30 , use_default, typename std::iterator_traits<ElementIterator>::reference> super_t;
31
32 friend class iterator_core_access;
33
34public:
35 permutation_iterator() : m_elt_iter() {}
36
37 explicit permutation_iterator(ElementIterator x, IndexIterator y)
38 : super_t(y), m_elt_iter(x) {}
39
40 template<class OtherElementIterator, class OtherIndexIterator>
41 permutation_iterator(
42 permutation_iterator<OtherElementIterator, OtherIndexIterator> const& r
43 , typename enable_if_convertible<OtherElementIterator, ElementIterator>::type* = 0
44 , typename enable_if_convertible<OtherIndexIterator, IndexIterator>::type* = 0
45 )
46 : super_t(r.base()), m_elt_iter(r.m_elt_iter)
47 {}
48
49private:
50 typename super_t::reference dereference() const
51 { return *(m_elt_iter + *this->base()); }
52
53#ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
54 template <class,class> friend class permutation_iterator;
55#else
56 public:
57#endif
58 ElementIterator m_elt_iter;
59};
60
61
62template <class ElementIterator, class IndexIterator>
63inline permutation_iterator<ElementIterator, IndexIterator>
64make_permutation_iterator( ElementIterator e, IndexIterator i )
65{
66 return permutation_iterator<ElementIterator, IndexIterator>( e, i );
67}
68
69} // namespace iterators
70
71using iterators::permutation_iterator;
72using iterators::make_permutation_iterator;
73
74} // namespace boost
75
76#endif
77

source code of include/boost/iterator/permutation_iterator.hpp