members.hpp 5.7 KB

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  1. #ifndef BOOST_DESCRIBE_DATA_MEMBERS_HPP_INCLUDED
  2. #define BOOST_DESCRIBE_DATA_MEMBERS_HPP_INCLUDED
  3. // Copyright 2020 Peter Dimov
  4. // Distributed under the Boost Software License, Version 1.0.
  5. // https://www.boost.org/LICENSE_1_0.txt
  6. #include <boost/describe/modifiers.hpp>
  7. #include <boost/describe/bases.hpp>
  8. #include <boost/describe/detail/void_t.hpp>
  9. #include <boost/describe/detail/cx_streq.hpp>
  10. #include <boost/describe/detail/config.hpp>
  11. #if defined(BOOST_DESCRIBE_CXX11)
  12. #include <boost/mp11/algorithm.hpp>
  13. #include <boost/mp11/utility.hpp>
  14. #include <boost/mp11/integral.hpp>
  15. #include <boost/mp11/list.hpp>
  16. #include <boost/mp11/bind.hpp>
  17. #include <type_traits>
  18. namespace boost
  19. {
  20. namespace describe
  21. {
  22. namespace detail
  23. {
  24. // _describe_members<T>
  25. template<class T> using _describe_public_members = decltype( boost_public_member_descriptor_fn( static_cast<T**>(0) ) );
  26. template<class T> using _describe_protected_members = decltype( boost_protected_member_descriptor_fn( static_cast<T**>(0) ) );
  27. template<class T> using _describe_private_members = decltype( boost_private_member_descriptor_fn( static_cast<T**>(0) ) );
  28. template<class T> using _describe_members = mp11::mp_append<_describe_public_members<T>, _describe_protected_members<T>, _describe_private_members<T>>;
  29. // describe_inherited_members<T>
  30. // T: type
  31. // V: list of virtual bases visited so far
  32. template<class T, class V> struct describe_inherited_members_impl;
  33. template<class T, class V> using describe_inherited_members = typename describe_inherited_members_impl<T, V>::type;
  34. // L: list of base class descriptors
  35. // T: derived type
  36. // V: list of virtual bases visited so far
  37. template<class L, class T, class V> struct describe_inherited_members2_impl;
  38. template<class L, class T, class V> using describe_inherited_members2 = typename describe_inherited_members2_impl<L, T, V>::type;
  39. template<class T, class V> struct describe_inherited_members_impl
  40. {
  41. using R1 = describe_inherited_members2<describe_bases<T, mod_any_access>, T, V>;
  42. using R2 = _describe_members<T>;
  43. using type = mp11::mp_append<R1, R2>;
  44. };
  45. template<template<class...> class L, class T, class V> struct describe_inherited_members2_impl<L<>, T, V>
  46. {
  47. using type = L<>;
  48. };
  49. template<class D1, class D2> using name_matches = mp11::mp_bool< cx_streq( D1::name, D2::name ) >;
  50. template<class D, class L> using name_is_hidden = mp11::mp_any_of_q<L, mp11::mp_bind_front<name_matches, D>>;
  51. constexpr unsigned cx_max( unsigned m1, unsigned m2 )
  52. {
  53. return m1 > m2? m1: m2;
  54. }
  55. template<class T, unsigned Bm> struct update_modifiers
  56. {
  57. template<class D> struct fn
  58. {
  59. using L = _describe_members<T>;
  60. static constexpr unsigned hidden = name_is_hidden<D, L>::value? mod_hidden: 0;
  61. static constexpr unsigned mods = D::modifiers;
  62. static constexpr unsigned access = cx_max( mods & mod_any_access, Bm & mod_any_access );
  63. static constexpr decltype(D::pointer) pointer = D::pointer;
  64. static constexpr decltype(D::name) name = D::name;
  65. static constexpr unsigned modifiers = ( mods & ~mod_any_access ) | access | mod_inherited | hidden;
  66. };
  67. };
  68. template<class T, unsigned Bm> template<class D> constexpr decltype(D::pointer) update_modifiers<T, Bm>::fn<D>::pointer;
  69. template<class T, unsigned Bm> template<class D> constexpr decltype(D::name) update_modifiers<T, Bm>::fn<D>::name;
  70. template<class T, unsigned Bm> template<class D> constexpr unsigned update_modifiers<T, Bm>::fn<D>::modifiers;
  71. template<class D> struct gather_virtual_bases_impl;
  72. template<class D> using gather_virtual_bases = typename gather_virtual_bases_impl<D>::type;
  73. template<class D> struct gather_virtual_bases_impl
  74. {
  75. using B = typename D::type;
  76. static constexpr unsigned M = D::modifiers;
  77. using R1 = mp11::mp_transform<gather_virtual_bases, describe_bases<B, mod_any_access>>;
  78. using R2 = mp11::mp_apply<mp11::mp_append, R1>;
  79. using type = mp11::mp_if_c<(M & mod_virtual) != 0, mp11::mp_push_front<R2, B>, R2>;
  80. };
  81. template<template<class...> class L, class D1, class... D, class T, class V> struct describe_inherited_members2_impl<L<D1, D...>, T, V>
  82. {
  83. using B = typename D1::type;
  84. static constexpr unsigned M = D1::modifiers;
  85. using R1 = mp11::mp_if_c<(M & mod_virtual) && mp11::mp_contains<V, B>::value, L<>, describe_inherited_members<B, V>>;
  86. using R2 = mp11::mp_transform_q<update_modifiers<T, M>, R1>;
  87. using V2 = mp11::mp_append<V, gather_virtual_bases<D1>>;
  88. using R3 = describe_inherited_members2<L<D...>, T, V2>;
  89. using type = mp11::mp_append<R2, R3>;
  90. };
  91. // describe_members<T, M>
  92. template<class T, unsigned M> using describe_members = mp11::mp_eval_if_c<(M & mod_inherited) == 0, _describe_members<T>, describe_inherited_members, T, mp11::mp_list<>>;
  93. // member_filter
  94. template<unsigned M> struct member_filter
  95. {
  96. template<class T> using fn = mp11::mp_bool<
  97. (M & mod_any_access & T::modifiers) != 0 &&
  98. ( (M & mod_any_member) != 0 || (M & mod_static) == (T::modifiers & mod_static) ) &&
  99. ( (M & mod_any_member) != 0 || (M & mod_function) == (T::modifiers & mod_function) ) &&
  100. (M & mod_hidden) >= (T::modifiers & mod_hidden)
  101. >;
  102. };
  103. // has_describe_members
  104. template<class T, class En = void> struct has_describe_members: std::false_type
  105. {
  106. };
  107. template<class T> struct has_describe_members<T, void_t<_describe_members<T>>>: std::true_type
  108. {
  109. };
  110. } // namespace detail
  111. template<class T, unsigned M> using describe_members = mp11::mp_copy_if_q<detail::describe_members<T, M>, detail::member_filter<M>>;
  112. template<class T> using has_describe_members = detail::has_describe_members<T>;
  113. } // namespace describe
  114. } // namespace boost
  115. #endif // !defined(BOOST_DESCRIBE_CXX11)
  116. #endif // #ifndef BOOST_DESCRIBE_DATA_MEMBERS_HPP_INCLUDED