1 // (C) Copyright Jens Maurer 2001.
2 // Distributed under the Boost Software License, Version 1.0. (See
3 // accompanying file LICENSE_1_0.txt or copy at
4 // http://www.boost.org/LICENSE_1_0.txt)
5 //
6 // Revision History:
7 
8 // 15 Nov 2001   Jens Maurer
9 //      created.
10 
11 //  See http://www.boost.org/libs/utility/iterator_adaptors.htm for documentation.
12 
13 #ifndef BOOST_ITERATOR_ADAPTOR_GENERATOR_ITERATOR_HPP
14 #define BOOST_ITERATOR_ADAPTOR_GENERATOR_ITERATOR_HPP
15 
16 #include <boost/iterator/iterator_facade.hpp>
17 #include <boost/ref.hpp>
18 
19 namespace boost {
20 namespace iterators {
21 
22 template<class Generator>
23 class generator_iterator
24   : public iterator_facade<
25         generator_iterator<Generator>
26       , typename Generator::result_type
27       , single_pass_traversal_tag
28       , typename Generator::result_type const&
29     >
30 {
31     typedef iterator_facade<
32         generator_iterator<Generator>
33       , typename Generator::result_type
34       , single_pass_traversal_tag
35       , typename Generator::result_type const&
36     > super_t;
37 
38  public:
39     generator_iterator() {}
40     generator_iterator(Generator* g) : m_g(g), m_value((*m_g)()) {}
41 
42     void increment()
43     {
44         m_value = (*m_g)();
45     }
46 
47     const typename Generator::result_type&
48     dereference() const
49     {
50         return m_value;
51     }
52 
53     bool equal(generator_iterator const& y) const
54     {
55         return this->m_g == y.m_g && this->m_value == y.m_value;
56     }
57 
58  private:
59     Generator* m_g;
60     typename Generator::result_type m_value;
61 };
62 
63 template<class Generator>
64 struct generator_iterator_generator
65 {
66   typedef generator_iterator<Generator> type;
67 };
68 
69 template <class Generator>
70 inline generator_iterator<Generator>
71 make_generator_iterator(Generator & gen)
72 {
73   typedef generator_iterator<Generator> result_t;
74   return result_t(&gen);
75 }
76 
77 } // namespace iterators
78 
79 using iterators::generator_iterator;
80 using iterators::generator_iterator_generator;
81 using iterators::make_generator_iterator;
82 
83 } // namespace boost
84 
85 #endif // BOOST_ITERATOR_ADAPTOR_GENERATOR_ITERATOR_HPP
86