1#ifndef BOOST_DESCRIBE_DATA_MEMBERS_HPP_INCLUDED
2#define BOOST_DESCRIBE_DATA_MEMBERS_HPP_INCLUDED
3
4// Copyright 2020 Peter Dimov
5// Distributed under the Boost Software License, Version 1.0.
6// https://www.boost.org/LICENSE_1_0.txt
7
8#include <boost/describe/modifiers.hpp>
9#include <boost/describe/bases.hpp>
10#include <boost/describe/detail/void_t.hpp>
11#include <boost/describe/detail/cx_streq.hpp>
12#include <boost/describe/detail/config.hpp>
13
14#if defined(BOOST_DESCRIBE_CXX11)
15
16#include <boost/mp11/algorithm.hpp>
17#include <boost/mp11/utility.hpp>
18#include <boost/mp11/integral.hpp>
19#include <boost/mp11/list.hpp>
20#include <boost/mp11/bind.hpp>
21#include <type_traits>
22
23namespace boost
24{
25namespace describe
26{
27namespace detail
28{
29
30// _describe_members<T>
31
32template<class T> using _describe_public_members = decltype( boost_public_member_descriptor_fn( static_cast<T**>(0) ) );
33template<class T> using _describe_protected_members = decltype( boost_protected_member_descriptor_fn( static_cast<T**>(0) ) );
34template<class T> using _describe_private_members = decltype( boost_private_member_descriptor_fn( static_cast<T**>(0) ) );
35
36template<class T> using _describe_members = mp11::mp_append<_describe_public_members<T>, _describe_protected_members<T>, _describe_private_members<T>>;
37
38// describe_inherited_members<T>
39
40// T: type
41// V: list of virtual bases visited so far
42template<class T, class V> struct describe_inherited_members_impl;
43template<class T, class V> using describe_inherited_members = typename describe_inherited_members_impl<T, V>::type;
44
45// L: list of base class descriptors
46// T: derived type
47// V: list of virtual bases visited so far
48template<class L, class T, class V> struct describe_inherited_members2_impl;
49template<class L, class T, class V> using describe_inherited_members2 = typename describe_inherited_members2_impl<L, T, V>::type;
50
51template<class T, class V> struct describe_inherited_members_impl
52{
53 using R1 = describe_inherited_members2<describe_bases<T, mod_any_access>, T, V>;
54 using R2 = _describe_members<T>;
55
56 using type = mp11::mp_append<R1, R2>;
57};
58
59template<template<class...> class L, class T, class V> struct describe_inherited_members2_impl<L<>, T, V>
60{
61 using type = L<>;
62};
63
64template<class D1, class D2> using name_matches = mp11::mp_bool< cx_streq( D1::name, D2::name ) >;
65
66template<class D, class L> using name_is_hidden = mp11::mp_any_of_q<L, mp11::mp_bind_front<name_matches, D>>;
67
68constexpr unsigned cx_max( unsigned m1, unsigned m2 )
69{
70 return m1 > m2? m1: m2;
71}
72
73template<class T, unsigned Bm> struct update_modifiers
74{
75 template<class D> struct fn
76 {
77 using L = _describe_members<T>;
78 static constexpr unsigned hidden = name_is_hidden<D, L>::value? mod_hidden: 0;
79
80 static constexpr unsigned mods = D::modifiers;
81 static constexpr unsigned access = cx_max( m1: mods & mod_any_access, m2: Bm & mod_any_access );
82
83 static constexpr decltype(D::pointer) pointer = D::pointer;
84 static constexpr decltype(D::name) name = D::name;
85 static constexpr unsigned modifiers = ( mods & ~mod_any_access ) | access | mod_inherited | hidden;
86 };
87};
88
89#ifndef __cpp_inline_variables
90template<class T, unsigned Bm> template<class D> constexpr decltype(D::pointer) update_modifiers<T, Bm>::fn<D>::pointer;
91template<class T, unsigned Bm> template<class D> constexpr decltype(D::name) update_modifiers<T, Bm>::fn<D>::name;
92template<class T, unsigned Bm> template<class D> constexpr unsigned update_modifiers<T, Bm>::fn<D>::modifiers;
93#endif
94
95template<class D> struct gather_virtual_bases_impl;
96template<class D> using gather_virtual_bases = typename gather_virtual_bases_impl<D>::type;
97
98template<class D> struct gather_virtual_bases_impl
99{
100 using B = typename D::type;
101 static constexpr unsigned M = D::modifiers;
102
103 using R1 = mp11::mp_transform<gather_virtual_bases, describe_bases<B, mod_any_access>>;
104 using R2 = mp11::mp_apply<mp11::mp_append, R1>;
105
106 using type = mp11::mp_if_c<(M & mod_virtual) != 0, mp11::mp_push_front<R2, B>, R2>;
107};
108
109template<template<class...> class L, class D1, class... D, class T, class V> struct describe_inherited_members2_impl<L<D1, D...>, T, V>
110{
111 using B = typename D1::type;
112 static constexpr unsigned M = D1::modifiers;
113
114 using R1 = mp11::mp_if_c<(M & mod_virtual) && mp11::mp_contains<V, B>::value, L<>, describe_inherited_members<B, V>>;
115
116 using R2 = mp11::mp_transform_q<update_modifiers<T, M>, R1>;
117
118 using V2 = mp11::mp_append<V, gather_virtual_bases<D1>>;
119 using R3 = describe_inherited_members2<L<D...>, T, V2>;
120
121 using type = mp11::mp_append<R2, R3>;
122};
123
124// describe_members<T, M>
125
126template<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<>>;
127
128// member_filter
129
130template<unsigned M> struct member_filter
131{
132 template<class T> using fn = mp11::mp_bool<
133 (M & mod_any_access & T::modifiers) != 0 &&
134 ( (M & mod_any_member) != 0 || (M & mod_static) == (T::modifiers & mod_static) ) &&
135 ( (M & mod_any_member) != 0 || (M & mod_function) == (T::modifiers & mod_function) ) &&
136 (M & mod_hidden) >= (T::modifiers & mod_hidden)
137 >;
138};
139
140// has_describe_members
141
142template<class T, class En = void> struct has_describe_members: std::false_type
143{
144};
145
146template<class T> struct has_describe_members<T, void_t<_describe_members<T>>>: std::true_type
147{
148};
149
150} // namespace detail
151
152template<class T, unsigned M> using describe_members = mp11::mp_copy_if_q<detail::describe_members<T, M>, detail::member_filter<M>>;
153
154template<class T> using has_describe_members = detail::has_describe_members<T>;
155
156} // namespace describe
157} // namespace boost
158
159#endif // !defined(BOOST_DESCRIBE_CXX11)
160
161#endif // #ifndef BOOST_DESCRIBE_DATA_MEMBERS_HPP_INCLUDED
162