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
16 namespace boost {
17 namespace iterators {
18
19 template< class ElementIterator
20 , class IndexIterator>
21 class 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
34 public:
permutation_iterator()35 permutation_iterator() : m_elt_iter() {}
36
permutation_iterator(ElementIterator x,IndexIterator y)37 explicit permutation_iterator(ElementIterator x, IndexIterator y)
38 : super_t(y), m_elt_iter(x) {}
39
40 template<class OtherElementIterator, class OtherIndexIterator>
permutation_iterator(permutation_iterator<OtherElementIterator,OtherIndexIterator> const & r,typename enable_if_convertible<OtherElementIterator,ElementIterator>::type * =0,typename enable_if_convertible<OtherIndexIterator,IndexIterator>::type * =0)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
49 private:
dereference() const50 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
62 template <class ElementIterator, class IndexIterator>
63 inline permutation_iterator<ElementIterator, IndexIterator>
make_permutation_iterator(ElementIterator e,IndexIterator i)64 make_permutation_iterator( ElementIterator e, IndexIterator i )
65 {
66 return permutation_iterator<ElementIterator, IndexIterator>( e, i );
67 }
68
69 } // namespace iterators
70
71 using iterators::permutation_iterator;
72 using iterators::make_permutation_iterator;
73
74 } // namespace boost
75
76 #endif
77