summaryrefslogtreecommitdiff
path: root/boost/type_erasure/detail/vtable.hpp
blob: b30a15a06156a9781f74a99285754bd14fd64c38 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
// Boost.TypeErasure library
//
// Copyright 2011 Steven Watanabe
//
// Distributed under the Boost Software License Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// $Id$

#if !defined(BOOST_PP_IS_ITERATING)

#ifndef BOOST_TYPE_ERASURE_DETAIL_VTABLE_HPP_INCLUDED
#define BOOST_TYPE_ERASURE_DETAIL_VTABLE_HPP_INCLUDED

#include <boost/config.hpp>
#include <boost/mpl/at.hpp>
#include <boost/mpl/size.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/iteration/iterate.hpp>
#include <boost/preprocessor/repetition/enum.hpp>
#include <boost/preprocessor/repetition/enum_params.hpp>
#include <boost/preprocessor/repetition/enum_trailing.hpp>
#include <boost/preprocessor/repetition/enum_trailing_params.hpp>
#include <boost/preprocessor/repetition/repeat.hpp>
#include <boost/type_erasure/detail/rebind_placeholders.hpp>
#include <boost/type_erasure/config.hpp>

namespace boost {
namespace type_erasure {
namespace detail {

#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_CONSTEXPR) && !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS)

template<class... T>
struct stored_arg_pack;

template<class It, class End, class... T>
struct make_arg_pack_impl
{
    typedef typename make_arg_pack_impl<
        typename ::boost::mpl::next<It>::type,
        End,
        T...,
        typename ::boost::mpl::deref<It>::type
    >::type type;
};

template<class End, class... T>
struct make_arg_pack_impl<End, End, T...>
{
    typedef stored_arg_pack<T...> type;
};

template<class Seq>
struct make_arg_pack
{
    typedef typename make_arg_pack_impl<
        typename ::boost::mpl::begin<Seq>::type,
        typename ::boost::mpl::end<Seq>::type
    >::type type;
};

template<class Args>
struct make_vtable_impl;

template<class Seq>
struct make_vtable
{
    typedef typename ::boost::type_erasure::detail::make_vtable_impl<
        typename ::boost::type_erasure::detail::make_arg_pack<Seq>::type
    >::type type;
};

template<class Table, class Args>
struct make_vtable_init_impl;

template<class Seq, class Table>
struct make_vtable_init
{
    typedef typename make_vtable_init_impl<
        Table,
        typename ::boost::type_erasure::detail::make_arg_pack<Seq>::type
    >::type type;
};

template<class T>
struct vtable_entry
{
    typename T::type value;
    vtable_entry() = default;
    constexpr vtable_entry(typename T::type arg) : value(arg) {}
};

template<class... T>
struct compare_vtable;

template<>
struct compare_vtable<> {
    template<class S>
    static bool apply(const S& s1, const S& s2)
    {
        return true;
    }
};

template<class T0, class... T>
struct compare_vtable<T0, T...> {
    template<class S>
    static bool apply(const S& s1, const S& s2)
    {
        return static_cast<const vtable_entry<T0>&>(s1).value ==
            static_cast<const vtable_entry<T0>&>(s2).value &&
            compare_vtable<T...>::apply(s1, s2);
    }
};

template<class... T>
struct vtable_storage : vtable_entry<T>...
{
    vtable_storage() = default;

    constexpr vtable_storage(typename T::type... arg)
        : vtable_entry<T>(arg)... {}

    template<class Bindings, class Src>
    void convert_from(const Src& src)
    {
        *this = vtable_storage(
            src.lookup(
                (typename ::boost::type_erasure::detail::rebind_placeholders<
                T, Bindings
            >::type*)0)...);
    }

    bool operator==(const vtable_storage& other) const
    { return compare_vtable<T...>::apply(*this, other); }

    template<class U>
    typename U::type lookup(U*) const
    {
        return static_cast<const vtable_entry<U>*>(this)->value;
    }
};

// Provide this specialization manually.
// gcc 4.7.2 fails to instantiate the primary template.
template<>
struct vtable_storage<>
{
    vtable_storage() = default;

    template<class Bindings, class Src>
    void convert_from(const Src& src) {}

    bool operator==(const vtable_storage& other) const
    { return true; }
};

template<class... T>
struct make_vtable_impl<stored_arg_pack<T...> >
{
    typedef vtable_storage<T...> type;
};

template<class Table, class... T>
struct vtable_init
{
    static constexpr Table value = Table(T::value...);
};

template<class Table, class... T>
constexpr Table vtable_init<Table, T...>::value;

template<class Table, class... T>
struct make_vtable_init_impl<Table, stored_arg_pack<T...> >
{
    typedef vtable_init<Table, T...> type;
};

#else

template<int N>
struct make_vtable_impl;

template<class Seq>
struct make_vtable
{
    typedef typename make_vtable_impl<
        (::boost::mpl::size<Seq>::value)>::template apply<Seq>::type type;
};

template<int N>
struct make_vtable_init_impl;

template<class Seq, class Table>
struct make_vtable_init
{
    typedef typename make_vtable_init_impl<
        (::boost::mpl::size<Seq>::value)>::template apply<Seq, Table>::type type;
};

#define BOOST_PP_FILENAME_1 <boost/type_erasure/detail/vtable.hpp>
#define BOOST_PP_ITERATION_LIMITS (0, BOOST_TYPE_ERASURE_MAX_FUNCTIONS)
#include BOOST_PP_ITERATE()

#endif

}
}
}

#endif

#else

#define N BOOST_PP_ITERATION()

#define BOOST_TYPE_ERASURE_VTABLE_ENTRY(z, n, data)                     \
    typename BOOST_PP_CAT(T, n)::type BOOST_PP_CAT(t, n);               \
    typename BOOST_PP_CAT(T, n)::type lookup(BOOST_PP_CAT(T, n)*) const \
    {                                                                   \
        return BOOST_PP_CAT(t, n);                                      \
    }

#define BOOST_TYPE_ERASURE_VTABLE_COMPARE(z, n, data)                   \
    && BOOST_PP_CAT(t, n) == other.BOOST_PP_CAT(t, n)

#define BOOST_TYPE_ERASURE_VTABLE_INIT(z, n, data)  \
    BOOST_PP_CAT(data, n)::value

#define BOOST_TYPE_ERASURE_AT(z, n, data)       \
    typename ::boost::mpl::at_c<data, n>::type

#define BOOST_TYPE_ERASURE_CONVERT_ELEMENT(z, n, data)                  \
    BOOST_PP_CAT(t, n) = src.lookup(                                    \
        (typename ::boost::type_erasure::detail::rebind_placeholders<   \
            BOOST_PP_CAT(T, n), Bindings                                \
        >::type*)0                                                      \
    );

#if N != 0
template<BOOST_PP_ENUM_PARAMS(N, class T)>
#else
template<class D = void>
#endif
struct BOOST_PP_CAT(vtable_storage, N)
{
    BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_VTABLE_ENTRY, ~)

    template<class Bindings, class Src>
    void convert_from(const Src& src)
    {
        BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_CONVERT_ELEMENT, ~)
    }

    bool operator==(const BOOST_PP_CAT(vtable_storage, N)& other) const
    { return true BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_VTABLE_COMPARE, ~); }
};

template<>
struct make_vtable_impl<N>
{
    template<class Seq>
    struct apply
    {
        typedef ::boost::type_erasure::detail::BOOST_PP_CAT(vtable_storage, N)<
            BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_AT, Seq)
        > type;
    };
};
template<class Table BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)>
struct BOOST_PP_CAT(vtable_init, N)
{
    static const Table value;
};

template<class Table BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)>
const Table BOOST_PP_CAT(vtable_init, N)<
    Table BOOST_PP_ENUM_TRAILING_PARAMS(N, T)>::value =
{
    BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_VTABLE_INIT, T)
};

template<>
struct make_vtable_init_impl<N>
{
    template<class Seq, class Table>
    struct apply
    {
        typedef ::boost::type_erasure::detail::BOOST_PP_CAT(vtable_init, N)<
            Table
            BOOST_PP_ENUM_TRAILING(N, BOOST_TYPE_ERASURE_AT, Seq)
        > type;
    };
};

#undef BOOST_TYPE_ERASURE_CONVERT_ELEMENT
#undef BOOST_TYPE_ERASURE_AT
#undef BOOST_TYPE_ERASURE_VTABLE_INIT
#undef BOOST_TYPE_ERASURE_VTABLE_COMPARE
#undef BOOST_TYPE_ERASURE_VTABLE_ENTRY
#undef N

#endif