boost/fusion/container/list/cons_iterator.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   3     Copyright (c) 2005 Eric Niebler
   4
   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
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/type_traits/add_const.hpp>
  13 #include <boost/fusion/support/iterator_base.hpp>
  14 #include <boost/fusion/container/list/detail/deref_impl.hpp>
  15 #include <boost/fusion/container/list/detail/next_impl.hpp>
  16 #include <boost/fusion/container/list/detail/value_of_impl.hpp>
  17 #include <boost/fusion/container/list/detail/equal_to_impl.hpp>
  18 #include <boost/fusion/container/list/list_fwd.hpp>
  19
  20 namespace boost { namespace fusion
  21 {
  22     struct nil_;
  23     struct cons_iterator_tag;
  24     struct forward_traversal_tag;
  25
  26     template <typename Cons>
  27     struct cons_iterator_identity;
  28
  29     template <typename Cons = nil_>
  30     struct cons_iterator : iterator_base<cons_iterator<Cons> >
  31     {
  32         typedef cons_iterator_tag fusion_tag;
  33         typedef forward_traversal_tag category;
  34         typedef Cons cons_type;
  35         typedef cons_iterator_identity<
  36             typename add_const<Cons>::type>
  37         identity;
  38
  39         BOOST_FUSION_GPU_ENABLED
  40         explicit cons_iterator(cons_type& in_cons)
  41             : cons(in_cons) {}
  42
  43         cons_type& cons;
  44
  45     private:
  46         // silence MSVC warning C4512: assignment operator could not be generated
  47         cons_iterator& operator= (cons_iterator const&);
  48     };
  49
  50     struct nil_iterator : iterator_base<nil_iterator>
  51     {
  52         typedef forward_traversal_tag category;
  53         typedef cons_iterator_tag fusion_tag;
  54         typedef nil_ cons_type;
  55         typedef cons_iterator_identity<
  56             add_const<nil_>::type>
  57         identity;
  58         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  59         nil_iterator() {}
  60         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  61         explicit nil_iterator(nil_ const&) {}
  62     };
  63
  64     template <>
  65     struct cons_iterator<nil_> : nil_iterator
  66     {
  67         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  68         cons_iterator() {}
  69         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  70         explicit cons_iterator(nil_ const&) {}
  71     };
  72
  73     template <>
  74     struct cons_iterator<nil_ const> : nil_iterator
  75     {
  76         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  77         cons_iterator() {}
  78         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  79         explicit cons_iterator(nil_ const&) {}
  80     };
  81
  82     template <>
  83     struct cons_iterator<list<> > : nil_iterator
  84     {
  85         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  86         cons_iterator() {}
  87         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  88         explicit cons_iterator(nil_ const&) {}
  89     };
  90
  91     template <>
  92     struct cons_iterator<list<> const> : nil_iterator
  93     {
  94         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  95         cons_iterator() {}
  96         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  97         explicit cons_iterator(nil_ const&) {}
  98     };
  99 }}
 100
 101 #endif