1 // Boost.TypeErasure library
2 //
3 // Copyright 2011 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 #if !defined(BOOST_PP_IS_ITERATING)
12
13 #ifndef BOOST_TYPE_ERASURE_CHECK_MATCH_HPP_INCLUDED
14 #define BOOST_TYPE_ERASURE_CHECK_MATCH_HPP_INCLUDED
15
16 #include <boost/mpl/vector.hpp>
17 #include <boost/mpl/bool.hpp>
18 #include <boost/mpl/is_sequence.hpp>
19 #include <boost/mpl/find_if.hpp>
20 #include <boost/mpl/not.hpp>
21 #include <boost/mpl/end.hpp>
22 #include <boost/type_traits/is_same.hpp>
23 #include <boost/preprocessor/cat.hpp>
24 #include <boost/preprocessor/iteration/iterate.hpp>
25 #include <boost/preprocessor/repetition/repeat.hpp>
26 #include <boost/preprocessor/repetition/enum_params.hpp>
27 #include <boost/preprocessor/repetition/enum_trailing_params.hpp>
28 #include <boost/preprocessor/repetition/enum_trailing_binary_params.hpp>
29 #include <boost/type_erasure/detail/extract_concept.hpp>
30 #include <boost/type_erasure/relaxed.hpp>
31 #include <boost/type_erasure/detail/access.hpp>
32
33 namespace boost {
34 namespace type_erasure {
35
36 #ifndef BOOST_TYPE_ERASURE_DOXYGEN
37
38 template<class T>
39 struct typeid_;
40
41 template<class Concept>
42 class binding;
43
44 #endif
45
46 namespace detail {
47
48 template<class P, class T, class Table>
maybe_check_table(const T & arg,const Table * & table,boost::mpl::true_)49 bool maybe_check_table(const T& arg, const Table*& table, boost::mpl::true_)
50 {
51 if(table == 0) {
52 table = &::boost::type_erasure::detail::access::table(arg);
53 return true;
54 } else {
55 return table->template find< ::boost::type_erasure::typeid_<P> >()() ==
56 ::boost::type_erasure::detail::access::table(arg).
57 template find< ::boost::type_erasure::typeid_<P> >()();
58 }
59 }
60
61 template<class P, class T, class Table>
maybe_check_table(const T &,const Table * &,boost::mpl::false_)62 bool maybe_check_table(const T&, const Table*&, boost::mpl::false_)
63 {
64 return true;
65 }
66
67 template<class Concept, class T>
68 struct should_check :
69 boost::mpl::and_<
70 ::boost::type_erasure::is_placeholder<T>,
71 ::boost::type_erasure::is_relaxed<Concept>
72 >
73 {};
74
75 }
76
77 #ifdef BOOST_TYPE_ERASURE_DOXYGEN
78
79 /**
80 * If @ref relaxed is in @c Concept, checks whether the
81 * arguments to @c f match the types specified by
82 * @c binding. If @ref relaxed is not in @c Concept,
83 * returns true. If @c binding is not specified, it will
84 * be deduced from the arguments.
85 */
86 template<class Concept, class Op, class... U>
87 bool check_match(const binding<Concept>& binding_arg, const Op& f, U&&... args);
88
89 /**
90 * \overload
91 */
92 template<class Op, class... U>
93 bool check_match(const Op& f, U&&... args);
94
95 #else
96
97 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
98
99 namespace detail {
100
101 template<class Concept, class R>
check_table(const::boost::type_erasure::binding<Concept> *,R (*)())102 bool check_table(const ::boost::type_erasure::binding<Concept>* /*t*/, R(*)())
103 {
104 return true;
105 }
106
107 template<class Concept, class R, class T0, class... T, class U0, class... U>
check_table(const::boost::type_erasure::binding<Concept> * t,R (*)(T0,T...),const U0 & arg0,const U &...arg)108 bool check_table(
109 const ::boost::type_erasure::binding<Concept>* t,
110 R(*)(T0, T...),
111 const U0& arg0,
112 const U&... arg)
113 {
114 typedef typename ::boost::remove_cv<
115 typename ::boost::remove_reference<T0>::type
116 >::type t0;
117 if(!::boost::type_erasure::detail::maybe_check_table<t0>(
118 arg0,
119 t,
120 ::boost::type_erasure::detail::should_check<Concept, t0>()))
121 return false;
122
123 return check_table(t, static_cast<void(*)(T...)>(0), arg...);
124 }
125
126 }
127
128 template<class Concept, class Op, class... U>
check_match(const::boost::type_erasure::binding<Concept> & table,const Op &,U &&...arg)129 bool check_match(
130 const ::boost::type_erasure::binding<Concept>& table,
131 const Op&,
132 U&&... arg)
133 {
134
135 return ::boost::type_erasure::detail::check_table(
136 &table,
137 static_cast<typename ::boost::type_erasure::detail::get_signature<Op>::type*>(0),
138 arg...);
139 }
140
141 #ifndef BOOST_TYPE_ERASURE_USE_MP11
142
143 template<
144 class Op,
145 class... U
146 >
check_match(const Op &,U &&...arg)147 bool check_match(
148 const Op&,
149 U&&... arg)
150 {
151 const ::boost::type_erasure::binding<
152 typename ::boost::type_erasure::detail::extract_concept<
153 typename ::boost::type_erasure::detail::get_signature<Op>::type, U...>::type>* p = 0;
154
155 return ::boost::type_erasure::detail::check_table(
156 p, static_cast<typename ::boost::type_erasure::detail::get_signature<Op>::type*>(0), arg...);
157 }
158
159 #else
160
161 namespace detail {
162
163 template<class T>
164 struct get_args;
165
166 template<class R, class ... T>
167 struct get_args<R(T...)> { typedef ::boost::mp11::mp_list<T...> type; };
168
169 template<class Sig>
170 using get_args_t = typename get_args<Sig>::type;
171
172 }
173
174 template<
175 class Op,
176 class... U
177 >
check_match(const Op &,U &&...arg)178 bool check_match(
179 const Op&,
180 U&&... arg)
181 {
182 const ::boost::type_erasure::binding<
183 ::boost::type_erasure::detail::extract_concept_t<
184 ::boost::type_erasure::detail::get_args_t<
185 typename ::boost::type_erasure::detail::get_signature<Op>::type
186 >,
187 ::boost::mp11::mp_list< ::boost::remove_reference_t<U>...> > >* p = 0;
188
189 return ::boost::type_erasure::detail::check_table(
190 p, static_cast<typename ::boost::type_erasure::detail::get_signature<Op>::type*>(0), arg...);
191 }
192
193 #endif
194
195 #else
196
197 #define BOOST_PP_FILENAME_1 <boost/type_erasure/check_match.hpp>
198 #define BOOST_PP_ITERATION_LIMITS (0, BOOST_TYPE_ERASURE_MAX_ARITY)
199 #include BOOST_PP_ITERATE()
200
201 #endif
202
203 #endif
204
205 }
206 }
207
208 #endif
209
210 #else
211
212 namespace detail {
213
214 #define N BOOST_PP_ITERATION()
215
216 #define BOOST_TYPE_ERASURE_CHECK_TABLE(z, n, data) \
217 typedef typename ::boost::remove_cv< \
218 typename ::boost::remove_reference<BOOST_PP_CAT(T, n)>::type \
219 >::type BOOST_PP_CAT(t, n); \
220 if(!::boost::type_erasure::detail::maybe_check_table<BOOST_PP_CAT(t, n)>( \
221 BOOST_PP_CAT(arg, n), \
222 t, \
223 ::boost::type_erasure::detail::should_check<Concept, BOOST_PP_CAT(t, n)>())) \
224 return false;
225
226 template<
227 class Concept,
228 class R
229 BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
230 BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)>
231 bool
BOOST_PP_CAT(check_table,N)232 BOOST_PP_CAT(check_table, N)(
233 const ::boost::type_erasure::binding<Concept>* t,
234 R (*)(BOOST_PP_ENUM_PARAMS(N, T))
235 BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, const U, &arg))
236 {
237 BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_CHECK_TABLE, ~)
238 return true;
239 }
240
241 #if N != 0
242
243 template<class Sig BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)>
244 struct BOOST_PP_CAT(do_extract_concept, N);
245
246 template<
247 class R
248 BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
249 BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
250 >
BOOST_PP_CAT(do_extract_concept,N)251 struct BOOST_PP_CAT(do_extract_concept, N)<
252 R(BOOST_PP_ENUM_PARAMS(N, T))
253 BOOST_PP_ENUM_TRAILING_PARAMS(N, U)
254 >
255 : ::boost::type_erasure::detail::BOOST_PP_CAT(extract_concept, N)<
256 BOOST_PP_ENUM_PARAMS(N, T)
257 BOOST_PP_ENUM_TRAILING_PARAMS(N, U)>
258 {};
259
260 #endif
261
262 }
263
264 #ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
265 #define RREF &
266 #else
267 #define RREF &&
268 #endif
269
270 template<
271 class Concept,
272 class Op
273 BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
274 >
check_match(const::boost::type_erasure::binding<Concept> & table,const Op & BOOST_PP_ENUM_TRAILING_BINARY_PARAMS (N,U,RREF arg))275 bool check_match(
276 const ::boost::type_erasure::binding<Concept>& table,
277 const Op&
278 BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, RREF arg))
279 {
280
281 return ::boost::type_erasure::detail::BOOST_PP_CAT(check_table, N)(
282 &table,
283 (typename ::boost::type_erasure::detail::get_signature<Op>::type*)0
284 BOOST_PP_ENUM_TRAILING_PARAMS(N, arg));
285 }
286
287 #if N != 0
288
289 template<
290 class Op
291 BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
292 >
check_match(const Op & BOOST_PP_ENUM_TRAILING_BINARY_PARAMS (N,U,RREF arg))293 bool check_match(
294 const Op&
295 BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, RREF arg))
296 {
297 const ::boost::type_erasure::binding<
298 typename ::boost::type_erasure::detail::BOOST_PP_CAT(do_extract_concept, N)<
299 typename ::boost::type_erasure::detail::get_signature<Op>::type,
300 BOOST_PP_ENUM_PARAMS(N, U)>::type>* p = 0;
301
302 return ::boost::type_erasure::detail::BOOST_PP_CAT(check_table, N)(
303 p,
304 (typename ::boost::type_erasure::detail::get_signature<Op>::type*)0
305 BOOST_PP_ENUM_TRAILING_PARAMS(N, arg));
306 }
307
308 #undef RREF
309 #undef BOOST_TYPE_ERASURE_CHECK_TABLE
310 #undef N
311
312 #endif
313
314 #endif
315