cons_iterator.hpp 3.5 KB

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  1. /*=============================================================================
  2. Copyright (c) 2001-2011 Joel de Guzman
  3. Copyright (c) 2005 Eric Niebler
  4. Distributed under the Boost Software License, Version 1.0. (See accompanying
  5. file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  6. ==============================================================================*/
  7. #if !defined(FUSION_CONS_ITERATOR_07172005_0849)
  8. #define FUSION_CONS_ITERATOR_07172005_0849
  9. #include <boost/fusion/support/config.hpp>
  10. #include <boost/type_traits/add_const.hpp>
  11. #include <boost/fusion/support/iterator_base.hpp>
  12. #include <boost/fusion/container/list/detail/deref_impl.hpp>
  13. #include <boost/fusion/container/list/detail/next_impl.hpp>
  14. #include <boost/fusion/container/list/detail/value_of_impl.hpp>
  15. #include <boost/fusion/container/list/detail/equal_to_impl.hpp>
  16. #include <boost/fusion/container/list/list_fwd.hpp>
  17. namespace boost { namespace fusion
  18. {
  19. struct nil_;
  20. struct cons_iterator_tag;
  21. struct forward_traversal_tag;
  22. template <typename Cons>
  23. struct cons_iterator_identity;
  24. #ifdef _MSC_VER
  25. # pragma warning(push)
  26. # pragma warning(disable: 4512) // assignment operator could not be generated.
  27. #endif
  28. template <typename Cons = nil_>
  29. struct cons_iterator : iterator_base<cons_iterator<Cons> >
  30. {
  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>
  36. identity;
  37. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  38. explicit cons_iterator(cons_type& in_cons) BOOST_NOEXCEPT
  39. : cons(in_cons) {}
  40. cons_type& cons;
  41. };
  42. #ifdef _MSC_VER
  43. # pragma warning(pop)
  44. #endif
  45. struct nil_iterator : iterator_base<nil_iterator>
  46. {
  47. typedef forward_traversal_tag category;
  48. typedef cons_iterator_tag fusion_tag;
  49. typedef nil_ cons_type;
  50. typedef cons_iterator_identity<
  51. add_const<nil_>::type>
  52. identity;
  53. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  54. nil_iterator() BOOST_NOEXCEPT {}
  55. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  56. explicit nil_iterator(nil_ const&) BOOST_NOEXCEPT {}
  57. };
  58. template <>
  59. struct cons_iterator<nil_> : nil_iterator
  60. {
  61. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  62. cons_iterator() BOOST_NOEXCEPT {}
  63. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  64. explicit cons_iterator(nil_ const&) BOOST_NOEXCEPT {}
  65. };
  66. template <>
  67. struct cons_iterator<nil_ const> : nil_iterator
  68. {
  69. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  70. cons_iterator() BOOST_NOEXCEPT {}
  71. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  72. explicit cons_iterator(nil_ const&) BOOST_NOEXCEPT {}
  73. };
  74. template <>
  75. struct cons_iterator<list<> > : nil_iterator
  76. {
  77. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  78. cons_iterator() BOOST_NOEXCEPT {}
  79. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  80. explicit cons_iterator(nil_ const&) BOOST_NOEXCEPT {}
  81. };
  82. template <>
  83. struct cons_iterator<list<> const> : nil_iterator
  84. {
  85. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  86. cons_iterator() BOOST_NOEXCEPT {}
  87. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  88. explicit cons_iterator(nil_ const&) BOOST_NOEXCEPT {}
  89. };
  90. }}
  91. #ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
  92. namespace std
  93. {
  94. template <typename Cons>
  95. struct iterator_traits< ::boost::fusion::cons_iterator<Cons> >
  96. { };
  97. }
  98. #endif
  99. #endif