summaryrefslogtreecommitdiff
path: root/boost/type_erasure/free.hpp
blob: a2a6a7100aa79aee872ef75d029a7904a4b16d2e (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
306
307
308
309
310
311
312
313
// Boost.TypeErasure library
//
// Copyright 2012 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)
//
// $Id$

#ifndef BOOST_TYPE_ERASURE_FREE_HPP_INCLUDED
#define BOOST_TYPE_ERASURE_FREE_HPP_INCLUDED

#include <boost/detail/workaround.hpp>
#include <boost/preprocessor/repetition/enum.hpp>
#include <boost/preprocessor/repetition/enum_trailing.hpp>
#include <boost/preprocessor/repetition/enum_params.hpp>
#include <boost/preprocessor/repetition/enum_shifted_params.hpp>
#include <boost/preprocessor/repetition/enum_params_with_a_default.hpp>
#include <boost/preprocessor/repetition/enum_binary_params.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/type_traits/remove_cv.hpp>
#include <boost/mpl/eval_if.hpp>
#include <boost/mpl/identity.hpp>
#include <boost/mpl/int.hpp>
#include <boost/mpl/next.hpp>
#include <boost/type_erasure/detail/macro.hpp>
#include <boost/type_erasure/detail/const.hpp>
#include <boost/type_erasure/config.hpp>
#include <boost/type_erasure/derived.hpp>
#include <boost/type_erasure/rebind_any.hpp>
#include <boost/type_erasure/param.hpp>
#include <boost/type_erasure/is_placeholder.hpp>
#include <boost/type_erasure/call.hpp>
#include <boost/type_erasure/concept_interface.hpp>

#if defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) || \
    defined(BOOST_NO_CXX11_RVALUE_REFERENCES) || \
    defined(BOOST_TYPE_ERASURE_DOXYGEN) || \
    BOOST_WORKAROUND(BOOST_MSVC, == 1800)

namespace boost {
namespace type_erasure {
namespace detail {

template<BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(BOOST_TYPE_ERASURE_MAX_ARITY, class T, void)>
struct first_placeholder {
    typedef typename ::boost::mpl::eval_if<is_placeholder<T0>,
        ::boost::mpl::identity<T0>,
        first_placeholder<BOOST_PP_ENUM_SHIFTED_PARAMS(BOOST_TYPE_ERASURE_MAX_ARITY, T)>
    >::type type;
};

template<>
struct first_placeholder<> {};

template<BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(BOOST_TYPE_ERASURE_MAX_ARITY, class T, void)>
struct first_placeholder_index :
    ::boost::mpl::eval_if<is_placeholder<T0>,
        ::boost::mpl::int_<0>,
        ::boost::mpl::next<first_placeholder_index<BOOST_PP_ENUM_SHIFTED_PARAMS(BOOST_TYPE_ERASURE_MAX_ARITY, T)> >
    >::type
{};

}
}
}

/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_FREE_QUALIFIED_ID(seq, N) \
    BOOST_TYPE_ERASURE_QUALIFIED_NAME(seq)<R(BOOST_PP_ENUM_PARAMS(N, T))>

/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_FREE_UNQUALIFIED_PARAM_TYPE(z, n, data) \
    typename ::boost::remove_cv<typename ::boost::remove_reference<BOOST_PP_CAT(T, n)>::type>::type

/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_FREE_PARAM_TYPE(z, n, data)                      \
    typename ::boost::mpl::eval_if_c<(_boost_type_erasure_free_p_idx::value == n), \
        ::boost::type_erasure::detail::maybe_const_this_param<BOOST_PP_CAT(T, n), Base>,    \
        ::boost::type_erasure::as_param<Base, BOOST_PP_CAT(T, n)>           \
    >::type BOOST_PP_CAT(t, n)

#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES

/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_FREE_FORWARD_I(z, n, data) ::std::forward<BOOST_PP_CAT(T, n)>(BOOST_PP_CAT(t, n))
/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_FREE_FORWARD(n) BOOST_PP_ENUM(n, BOOST_TYPE_ERASURE_FREE_FORWARD_I, ~)
/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_FREE_FORWARD_PARAM_I(z, n, data) \
    ::std::forward<typename ::boost::mpl::eval_if_c<(_boost_type_erasure_free_p_idx::value == n), \
        ::boost::type_erasure::detail::maybe_const_this_param<BOOST_PP_CAT(T, n), Base>,    \
        ::boost::type_erasure::as_param<Base, BOOST_PP_CAT(T, n)>           \
    >::type>(BOOST_PP_CAT(t, n))

#else

#define BOOST_TYPE_ERASURE_FREE_FORWARD(n) BOOST_PP_ENUM_PARAMS(n, t)
#define BOOST_TYPE_ERASURE_FREE_FORWARD_PARAM_I(z, n, data) BOOST_PP_CAT(t, n)

#endif

/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_FREE_II(qual_name, concept_name, function_name, N)  \
    BOOST_TYPE_ERASURE_OPEN_NAMESPACE(qual_name)                        \
                                                                        \
    template<class Sig>                                                 \
    struct concept_name;                                                \
                                                                        \
    template<class R BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)>         \
    struct concept_name<R(BOOST_PP_ENUM_PARAMS(N, T))> {                \
        static R apply(BOOST_PP_ENUM_BINARY_PARAMS(N, T, t))            \
        { return function_name(BOOST_TYPE_ERASURE_FREE_FORWARD(N)); }   \
    };                                                                  \
                                                                        \
    template<BOOST_PP_ENUM_PARAMS(N, class T)>                          \
    struct concept_name<void(BOOST_PP_ENUM_PARAMS(N, T))> {             \
        static void apply(BOOST_PP_ENUM_BINARY_PARAMS(N, T, t))         \
        { function_name(BOOST_TYPE_ERASURE_FREE_FORWARD(N)); }          \
    };                                                                  \
                                                                        \
    BOOST_TYPE_ERASURE_CLOSE_NAMESPACE(qual_name)                       \
                                                                        \
    namespace boost {                                                   \
    namespace type_erasure {                                            \
                                                                        \
    template<class R BOOST_PP_ENUM_TRAILING_PARAMS(N, class T), class Base> \
    struct concept_interface<                                           \
        BOOST_TYPE_ERASURE_FREE_QUALIFIED_ID(qual_name, N),             \
        Base,                                                           \
        typename ::boost::type_erasure::detail::first_placeholder<      \
            BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_FREE_UNQUALIFIED_PARAM_TYPE, ~)>::type  \
    > : Base {                                                          \
        typedef typename ::boost::type_erasure::detail::first_placeholder_index<    \
            BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_FREE_UNQUALIFIED_PARAM_TYPE, ~)>::type  \
            _boost_type_erasure_free_p_idx;                             \
        friend typename ::boost::type_erasure::rebind_any<Base, R>::type function_name(  \
            BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_FREE_PARAM_TYPE, ~))    \
        {                                                               \
            return ::boost::type_erasure::call(                         \
                BOOST_TYPE_ERASURE_FREE_QUALIFIED_ID(qual_name, N)()    \
                BOOST_PP_ENUM_TRAILING(N, BOOST_TYPE_ERASURE_FREE_FORWARD_PARAM_I, ~)); \
        }                                                               \
    };                                                                  \
                                                                        \
    }                                                                   \
    }

#else

namespace boost {
namespace type_erasure {
    
template<int... N>
struct index_list {};

namespace detail {
    
template<class... T>
struct first_placeholder;

template<class T0, class... T>
struct first_placeholder<T0, T...> {
    typedef typename ::boost::mpl::eval_if<is_placeholder<T0>,
        ::boost::mpl::identity<T0>,
        first_placeholder<T...>
    >::type type;
};

template<>
struct first_placeholder<> {};

template<class... T>
struct first_placeholder_index;

template<class T0, class... T>
struct first_placeholder_index<T0, T...> :
    ::boost::mpl::eval_if<is_placeholder<T0>,
        ::boost::mpl::int_<0>,
        ::boost::mpl::next<first_placeholder_index<T...> >
    >::type
{};

template<class Sig>
struct transform_free_signature;

template<class T, int N>
struct push_back_index;

template<int... N, int X>
struct push_back_index<index_list<N...>, X>
{
    typedef index_list<N..., X> type;
};

template<int N>
struct make_index_list {
    typedef typename push_back_index<
        typename make_index_list<N-1>::type,
        N-1
    >::type type;
};

template<>
struct make_index_list<0> {
    typedef index_list<> type;
};

}
}
}

/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_FREE_II(qual_name, concept_name, function_name, N)  \
    BOOST_TYPE_ERASURE_OPEN_NAMESPACE(qual_name)                        \
                                                                        \
    template<class Sig>                                                 \
    struct concept_name;                                                \
                                                                        \
    template<class R, class... T>                                       \
    struct concept_name<R(T...)> {                                      \
        static R apply(T... t)                                          \
        { return function_name(std::forward<T>(t)...); }                \
    };                                                                  \
                                                                        \
    template<class... T>                                                \
    struct concept_name<void(T...)> {                                   \
        static void apply(T... t)                                       \
        { function_name(std::forward<T>(t)...); }                       \
    };                                                                  \
                                                                        \
    BOOST_TYPE_ERASURE_CLOSE_NAMESPACE(qual_name)                       \
                                                                        \
    namespace boost {                                                   \
    namespace type_erasure {                                            \
                                                                        \
    template<class Sig, class Base, class Idx>                          \
    struct inject ## concept_name;                                      \
    template<class R, class... T, class Base, int... I>                 \
    struct inject ## concept_name<R(T...), Base, index_list<I...> > : Base {\
        typedef typename ::boost::type_erasure::detail::first_placeholder_index<    \
            typename ::boost::remove_cv<                                \
                typename ::boost::remove_reference<T>::type             \
            >::type...                                                  \
        >::type _boost_type_erasure_free_p_idx;                         \
        friend typename ::boost::type_erasure::rebind_any<Base, R>::type\
        function_name(                                                  \
            typename ::boost::mpl::eval_if_c<(_boost_type_erasure_free_p_idx::value == I), \
                ::boost::type_erasure::detail::maybe_const_this_param<T, Base>, \
                ::boost::type_erasure::as_param<Base, T>                \
            >::type... t)                                               \
       {                                                                \
            return ::boost::type_erasure::call(                         \
                BOOST_TYPE_ERASURE_QUALIFIED_NAME(qual_name)<R(T...)>(),\
                std::forward<typename ::boost::mpl::eval_if_c<(_boost_type_erasure_free_p_idx::value == I), \
                    ::boost::type_erasure::detail::maybe_const_this_param<T, Base>, \
                    ::boost::type_erasure::as_param<Base, T>            \
                >::type>(t)...);                                        \
        }                                                               \
    };                                                                  \
                                                                        \
    template<class R, class... T, class Base>                           \
    struct concept_interface<                                           \
        BOOST_TYPE_ERASURE_QUALIFIED_NAME(qual_name)<R(T...)>,          \
        Base,                                                           \
        typename ::boost::type_erasure::detail::first_placeholder<      \
            typename ::boost::remove_cv<typename ::boost::remove_reference<T>::type>::type...>::type  \
    > :  inject ## concept_name<R(T...), Base, typename ::boost::type_erasure::detail::make_index_list<sizeof...(T)>::type>\
    {};                                                                 \
                                                                        \
    }                                                                   \
    }

#endif
    
/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_FREE_I(namespace_name, concept_name, function_name, N)\
    BOOST_TYPE_ERASURE_FREE_II(namespace_name, concept_name, function_name, N)

/**
 * \brief Defines a primitive concept for a free function.
 *
 * \param qualified_name should be a preprocessor sequence
 * of the form (namespace1)(namespace2)...(concept_name).
 * \param function_name is the name of the function.
 * \param N is the number of arguments of the function.
 *
 * The declaration of the concept is
 * \code
 * template<class Sig>
 * struct ::namespace1::namespace2::...::concept_name;
 * \endcode
 * where Sig is a function type giving the
 * signature of the function.
 *
 * This macro can only be used in the global namespace.
 *
 * Example:
 *
 * \code
 * BOOST_TYPE_ERASURE_FREE((boost)(has_to_string), to_string, 1)
 * \endcode
 */
#define BOOST_TYPE_ERASURE_FREE(qualified_name, function_name, N)                           \
    BOOST_TYPE_ERASURE_FREE_I(                                                              \
        qualified_name,                                                                     \
        BOOST_PP_SEQ_ELEM(BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(qualified_name)), qualified_name), \
        function_name,                                                                             \
        N)

#endif