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
33namespace boost {
34namespace type_erasure {
35
36#ifndef BOOST_TYPE_ERASURE_DOXYGEN
37
38template<class T>
39struct typeid_;
40
41template<class Concept>
42class binding;
43
44#endif
45
46namespace detail {
47
48template<class P, class T, class Table>
49bool 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
61template<class P, class T, class Table>
62bool maybe_check_table(const T&, const Table*&, boost::mpl::false_)
63{
64 return true;
65}
66
67template<class Concept, class T>
68struct 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 */
86template<class Concept, class Op, class... U>
87bool check_match(const binding<Concept>& binding_arg, const Op& f, U&&... args);
88
89/**
90 * \overload
91 */
92template<class Op, class... U>
93bool 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
99namespace detail {
100
101template<class Concept, class R>
102bool check_table(const ::boost::type_erasure::binding<Concept>* /*t*/, R(*)())
103{
104 return true;
105}
106
107template<class Concept, class R, class T0, class... T, class U0, class... U>
108bool 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
128template<class Concept, class Op, class... U>
129bool 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
143template<
144 class Op,
145 class... U
146>
147bool 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
161namespace detail {
162
163template<class T>
164struct get_args;
165
166template<class R, class ... T>
167struct get_args<R(T...)> { typedef ::boost::mp11::mp_list<T...> type; };
168
169template<class Sig>
170using get_args_t = typename get_args<Sig>::type;
171
172}
173
174template<
175 class Op,
176 class... U
177>
178bool 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
212namespace 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
226template<
227 class Concept,
228 class R
229 BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
230 BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)>
231bool
232BOOST_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
243template<class Sig BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)>
244struct BOOST_PP_CAT(do_extract_concept, N);
245
246template<
247 class R
248 BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
249 BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
250>
251struct 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
270template<
271 class Concept,
272 class Op
273 BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
274>
275bool 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
289template<
290 class Op
291 BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
292>
293bool 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

source code of boost/libs/type_erasure/include/boost/type_erasure/check_match.hpp