1 /*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
3 Copyright (c) 2005 Eric Niebler
5 Distributed under the Boost Software License, Version 1.0. (See accompanying
6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7 ==============================================================================*/
8 #if !defined(FUSION_CONS_ITERATOR_07172005_0849)
9 #define FUSION_CONS_ITERATOR_07172005_0849
11 #include <boost/type_traits/add_const.hpp>
12 #include <boost/fusion/support/iterator_base.hpp>
13 #include <boost/fusion/container/list/detail/deref_impl.hpp>
14 #include <boost/fusion/container/list/detail/next_impl.hpp>
15 #include <boost/fusion/container/list/detail/value_of_impl.hpp>
16 #include <boost/fusion/container/list/detail/equal_to_impl.hpp>
17 #include <boost/fusion/container/list/list_fwd.hpp>
19 namespace boost { namespace fusion
22 struct cons_iterator_tag;
23 struct forward_traversal_tag;
25 template <typename Cons>
26 struct cons_iterator_identity;
28 template <typename Cons = nil_>
29 struct cons_iterator : iterator_base<cons_iterator<Cons> >
31 typedef cons_iterator_tag fusion_tag;
32 typedef forward_traversal_tag category;
33 typedef Cons cons_type;
34 typedef cons_iterator_identity<
35 typename add_const<Cons>::type>
38 explicit cons_iterator(cons_type& in_cons)
44 // silence MSVC warning C4512: assignment operator could not be generated
45 cons_iterator& operator= (cons_iterator const&);
48 struct nil_iterator : iterator_base<nil_iterator>
50 typedef forward_traversal_tag category;
51 typedef cons_iterator_tag fusion_tag;
52 typedef nil_ cons_type;
53 typedef cons_iterator_identity<
54 add_const<nil_>::type>
57 explicit nil_iterator(nil_ const&) {}
61 struct cons_iterator<nil_> : nil_iterator
64 explicit cons_iterator(nil_ const&) {}
68 struct cons_iterator<nil_ const> : nil_iterator
71 explicit cons_iterator(nil_ const&) {}
75 struct cons_iterator<list<> > : nil_iterator
78 explicit cons_iterator(nil_ const&) {}
82 struct cons_iterator<list<> const> : nil_iterator
85 explicit cons_iterator(nil_ const&) {}