1// Boost.TypeErasure library
2//
3// Copyright 2015 Steven Watanabe
4//
5// Distributed under the Boost Software License Version 1.0. (See
6// accompanying file LICENSE_1_0.txt or copy at
7// http://www.boost.org/LICENSE_1_0.txt)
8//
9// $Id$
10
11#ifndef BOOST_TYPE_ERASURE_DETAIL_DYNAMIC_VTABLE_HPP_INCLUDED
12#define BOOST_TYPE_ERASURE_DETAIL_DYNAMIC_VTABLE_HPP_INCLUDED
13
14#include <boost/type_erasure/detail/get_placeholders.hpp>
15#include <boost/type_erasure/detail/rebind_placeholders.hpp>
16#include <boost/type_erasure/detail/normalize.hpp>
17#include <boost/type_erasure/detail/adapt_to_vtable.hpp>
18#include <boost/type_erasure/detail/vtable.hpp>
19#include <boost/type_erasure/static_binding.hpp>
20#include <boost/type_erasure/register_binding.hpp>
21#include <boost/mpl/transform.hpp>
22#include <boost/mpl/at.hpp>
23#include <boost/mpl/set.hpp>
24#include <boost/mpl/for_each.hpp>
25#include <boost/mpl/index_of.hpp>
26#include <typeinfo>
27
28namespace boost {
29namespace type_erasure {
30namespace detail {
31
32#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_CONSTEXPR) && !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS)
33
34template<class P>
35struct dynamic_binding_impl {
36 const std::type_info * type;
37 dynamic_binding_impl() = default;
38 constexpr dynamic_binding_impl(const std::type_info * t) : type(t) {}
39};
40
41template<class T>
42struct dynamic_binding_element {
43 typedef const std::type_info * type;
44};
45
46template<class Table>
47struct append_to_key {
48 template<class P>
49 void operator()(P) {
50 key->push_back(static_cast<const dynamic_binding_impl<P>*>(table)->type);
51 }
52 const Table * table;
53 key_type * key;
54};
55
56template<class... P>
57struct dynamic_vtable : dynamic_binding_impl<P>... {
58 dynamic_vtable() = default;
59 constexpr dynamic_vtable(typename dynamic_binding_element<P>::type ...t) : dynamic_binding_impl<P>(t)... {}
60 template<class F>
61 typename F::type lookup(F*) const {
62 key_type key;
63#ifndef BOOST_TYPE_ERASURE_USE_MP11
64 typedef typename ::boost::type_erasure::detail::get_placeholders<F, ::boost::mpl::set0<> >::type placeholders;
65#else
66 typedef typename ::boost::type_erasure::detail::get_placeholders<F, ::boost::mp11::mp_list<> >::type placeholders;
67#endif
68 typedef typename ::boost::mpl::fold<
69 placeholders,
70 ::boost::mpl::map0<>,
71 ::boost::type_erasure::detail::counting_map_appender
72 >::type placeholder_map;
73 key.push_back(x: &typeid(typename ::boost::type_erasure::detail::rebind_placeholders<F, placeholder_map>::type));
74 ::boost::mpl::for_each<placeholders>(append_to_key<dynamic_vtable>{this, &key});
75 return reinterpret_cast<typename F::type>(lookup_function_impl(key));
76 }
77 template<class Bindings>
78 void init() {
79 *this = dynamic_vtable(&typeid(typename boost::mpl::at<Bindings, P>::type)...);
80 }
81 template<class Bindings, class Src>
82 void convert_from(const Src& src) {
83#ifndef BOOST_TYPE_ERASURE_USE_MP11
84 *this = dynamic_vtable(
85 (&src.lookup((::boost::type_erasure::typeid_<typename ::boost::mpl::at<Bindings, P>::type>*)0)())...);
86#else
87 *this = dynamic_vtable(
88 (&src.lookup((::boost::type_erasure::typeid_< ::boost::mp11::mp_second< ::boost::mp11::mp_map_find<Bindings, P> > >*)0)())...);
89#endif
90 }
91};
92
93template<class L>
94struct make_dynamic_vtable_impl;
95
96template<class... P>
97struct make_dynamic_vtable_impl<stored_arg_pack<P...> >
98{
99 typedef dynamic_vtable<P...> type;
100};
101
102template<class PlaceholderList>
103struct make_dynamic_vtable
104 : make_dynamic_vtable_impl<typename make_arg_pack<PlaceholderList>::type>
105{};
106
107#else
108
109template<class Bindings>
110struct dynamic_vtable_initializer
111{
112 dynamic_vtable_initializer(const std::type_info**& ptr) : types(&ptr) {}
113 template<class P>
114 void operator()(P)
115 {
116 *(*types)++ = &typeid(typename ::boost::mpl::at<Bindings, P>::type);
117 }
118 const ::std::type_info*** types;
119};
120
121template<class Placeholders>
122struct dynamic_vtable
123{
124 const ::std::type_info * types[(::boost::mpl::size<Placeholders>::value)];
125 struct append_to_key
126 {
127 append_to_key(const std::type_info * const * t, key_type* k) : types(t), key(k) {}
128 template<class P>
129 void operator()(P)
130 {
131 key->push_back(types[(::boost::mpl::index_of<Placeholders, P>::type::value)]);
132 }
133 const std::type_info * const * types;
134 key_type * key;
135 };
136 template<class F>
137 typename F::type lookup(F*) const {
138 key_type key;
139 typedef typename ::boost::type_erasure::detail::get_placeholders<F, ::boost::mpl::set0<> >::type placeholders;
140 typedef typename ::boost::mpl::fold<
141 placeholders,
142 ::boost::mpl::map0<>,
143 ::boost::type_erasure::detail::counting_map_appender
144 >::type placeholder_map;
145 key.push_back(&typeid(typename ::boost::type_erasure::detail::rebind_placeholders<F, placeholder_map>::type));
146 ::boost::mpl::for_each<placeholders>(append_to_key(types, &key));
147 return reinterpret_cast<typename F::type>(lookup_function_impl(key));
148 }
149 template<class Bindings>
150 void init()
151 {
152 const std::type_info* ptr = types;
153 ::boost::mpl::for_each<Placeholders>(dynamic_vtable_initializer<Bindings>(ptr));
154 }
155 template<class Bindings, class Src>
156 struct converter
157 {
158 converter(const std::type_info**& t, const Src& s) : types(&t), src(&s) {}
159 template<class P>
160 void operator()(P)
161 {
162 *(*types)++ = &src->lookup((::boost::type_erasure::typeid_<typename ::boost::mpl::at<Bindings, P>::type>*)0)();
163 }
164 const std::type_info*** types;
165 const Src * src;
166 };
167 template<class Bindings, class Src>
168 void convert_from(const Src& src) {
169 const ::std::type_info** ptr = types;
170 ::boost::mpl::for_each<Placeholders>(converter<Bindings, Src>(ptr, src));
171 }
172};
173
174template<class Placeholders>
175struct make_dynamic_vtable
176{
177 typedef dynamic_vtable<Placeholders> type;
178};
179
180#endif
181
182}
183}
184}
185
186#endif
187

source code of boost/libs/type_erasure/include/boost/type_erasure/detail/dynamic_vtable.hpp