1
2#if !defined(BOOST_PP_IS_ITERATING)
3
4///// header body
5
6//-----------------------------------------------------------------------------
7// boost variant/detail/substitute.hpp header file
8// See http://www.boost.org for updates, documentation, and revision history.
9//-----------------------------------------------------------------------------
10//
11// Copyright (c) 2003
12// Eric Friedman
13//
14// Distributed under the Boost Software License, Version 1.0. (See
15// accompanying file LICENSE_1_0.txt or copy at
16// http://www.boost.org/LICENSE_1_0.txt)
17
18#ifndef BOOST_VARIANT_DETAIL_SUBSTITUTE_HPP
19#define BOOST_VARIANT_DETAIL_SUBSTITUTE_HPP
20
21#include <boost/mpl/aux_/config/ctps.hpp>
22
23#include <boost/variant/detail/substitute_fwd.hpp>
24#include <boost/variant/variant_fwd.hpp> // for BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
25#include <boost/mpl/aux_/lambda_arity_param.hpp>
26#include <boost/mpl/aux_/preprocessor/params.hpp>
27#include <boost/mpl/aux_/preprocessor/repeat.hpp>
28#include <boost/mpl/int_fwd.hpp>
29#include <boost/mpl/limits/arity.hpp>
30#include <boost/preprocessor/cat.hpp>
31#include <boost/preprocessor/empty.hpp>
32#include <boost/preprocessor/arithmetic/inc.hpp>
33#include <boost/preprocessor/iterate.hpp>
34
35namespace boost {
36namespace detail { namespace variant {
37
38#if !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
39
40///////////////////////////////////////////////////////////////////////////////
41// (detail) metafunction substitute
42//
43// Substitutes one type for another in the given type expression.
44//
45
46//
47// primary template
48//
49template <
50 typename T, typename Dest, typename Source
51 BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(
52 typename Arity /* = ... (see substitute_fwd.hpp) */
53 )
54 >
55struct substitute
56{
57 typedef T type;
58};
59
60//
61// tag substitution specializations
62//
63
64#define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG(CV_) \
65 template <typename Dest, typename Source> \
66 struct substitute< \
67 CV_ Source \
68 , Dest \
69 , Source \
70 BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>) \
71 > \
72 { \
73 typedef CV_ Dest type; \
74 }; \
75 /**/
76
77BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG( BOOST_PP_EMPTY() )
78BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG(const)
79BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG(volatile)
80BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG(const volatile)
81
82#undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_SUBSTITUTE_TAG
83
84//
85// pointer specializations
86//
87#define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER(CV_) \
88 template <typename T, typename Dest, typename Source> \
89 struct substitute< \
90 T * CV_ \
91 , Dest \
92 , Source \
93 BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>) \
94 > \
95 { \
96 typedef typename substitute< \
97 T, Dest, Source \
98 >::type * CV_ type; \
99 }; \
100 /**/
101
102BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER( BOOST_PP_EMPTY() )
103BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER(const)
104BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER(volatile)
105BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER(const volatile)
106
107#undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL_HANDLE_POINTER
108
109//
110// reference specializations
111//
112template <typename T, typename Dest, typename Source>
113struct substitute<
114 T&
115 , Dest
116 , Source
117 BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>)
118 >
119{
120 typedef typename substitute<
121 T, Dest, Source
122 >::type & type;
123};
124
125//
126// template expression (i.e., F<...>) specializations
127//
128
129#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
130template <
131 template <typename...> class F
132 , typename... Ts
133 , typename Dest
134 , typename Source
135 BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(typename Arity)
136 >
137struct substitute<
138 F<Ts...>
139 , Dest
140 , Source
141 BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(Arity)
142 >
143{
144 typedef F<typename substitute<
145 Ts, Dest, Source
146 >::type...> type;
147};
148
149//
150// function specializations
151//
152template <
153 typename R
154 , typename... A
155 , typename Dest
156 , typename Source
157 >
158struct substitute<
159 R (*)(A...)
160 , Dest
161 , Source
162 BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>)
163 >
164{
165private:
166 typedef typename substitute< R, Dest, Source >::type r;
167
168public:
169 typedef r (*type)(typename substitute<
170 A, Dest, Source
171 >::type...);
172};
173#else
174
175#define BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF_IMPL(N) \
176 typedef typename substitute< \
177 BOOST_PP_CAT(U,N), Dest, Source \
178 >::type BOOST_PP_CAT(u,N); \
179 /**/
180
181#define BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF(z, N, _) \
182 BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF_IMPL( BOOST_PP_INC(N) ) \
183 /**/
184
185#define BOOST_PP_ITERATION_LIMITS (0,BOOST_MPL_LIMIT_METAFUNCTION_ARITY)
186#define BOOST_PP_FILENAME_1 <boost/variant/detail/substitute.hpp>
187#include BOOST_PP_ITERATE()
188
189#undef BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF_IMPL
190#undef BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF
191
192#endif // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
193#endif // !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
194
195}} // namespace detail::variant
196} // namespace boost
197
198#endif // BOOST_VARIANT_DETAIL_SUBSTITUTE_HPP
199
200///// iteration, depth == 1
201
202#elif BOOST_PP_ITERATION_DEPTH() == 1
203#define i BOOST_PP_FRAME_ITERATION(1)
204
205#if i > 0
206
207//
208// template specializations
209//
210template <
211 template < BOOST_MPL_PP_PARAMS(i,typename P) > class T
212 , BOOST_MPL_PP_PARAMS(i,typename U)
213 , typename Dest
214 , typename Source
215 >
216struct substitute<
217 T< BOOST_MPL_PP_PARAMS(i,U) >
218 , Dest
219 , Source
220 BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<( i )>)
221 >
222{
223private:
224 BOOST_MPL_PP_REPEAT(i, BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF, _)
225
226public:
227 typedef T< BOOST_MPL_PP_PARAMS(i,u) > type;
228};
229
230//
231// function specializations
232//
233template <
234 typename R
235 , BOOST_MPL_PP_PARAMS(i,typename U)
236 , typename Dest
237 , typename Source
238 >
239struct substitute<
240 R (*)( BOOST_MPL_PP_PARAMS(i,U) )
241 , Dest
242 , Source
243 BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>)
244 >
245{
246private:
247 typedef typename substitute< R, Dest, Source >::type r;
248 BOOST_MPL_PP_REPEAT(i, BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF, _)
249
250public:
251 typedef r (*type)( BOOST_MPL_PP_PARAMS(i,u) );
252};
253
254#elif i == 0
255
256//
257// zero-arg function specialization
258//
259template <
260 typename R, typename Dest, typename Source
261 >
262struct substitute<
263 R (*)( void )
264 , Dest
265 , Source
266 BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>)
267 >
268{
269private:
270 typedef typename substitute< R, Dest, Source >::type r;
271
272public:
273 typedef r (*type)( void );
274};
275
276#endif // i
277
278#undef i
279#endif // BOOST_PP_IS_ITERATING
280