1 | // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) |
2 | // (C) Copyright 2003-2007 Jonathan Turkanis |
3 | // Distributed under the Boost Software License, Version 1.0. (See accompanying |
4 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) |
5 | |
6 | // See http://www.boost.org/libs/iostreams for documentation. |
7 | |
8 | // |
9 | // Contains metafunctions char_type_of, category_of and mode_of used for |
10 | // deducing the i/o category and i/o mode of a model of Filter or Device. |
11 | // |
12 | // Also contains several utility metafunctions, functions and macros. |
13 | // |
14 | |
15 | #ifndef BOOST_IOSTREAMS_IO_TRAITS_HPP_INCLUDED |
16 | #define BOOST_IOSTREAMS_IO_TRAITS_HPP_INCLUDED |
17 | |
18 | #if defined(_MSC_VER) && (_MSC_VER >= 1020) |
19 | # pragma once |
20 | #endif |
21 | |
22 | #include <iosfwd> // stream types, char_traits. |
23 | #include <boost/config.hpp> // partial spec, deduced typename. |
24 | #include <boost/detail/workaround.hpp> |
25 | #include <boost/iostreams/categories.hpp> |
26 | #include <boost/iostreams/detail/bool_trait_def.hpp> |
27 | #include <boost/iostreams/detail/config/wide_streams.hpp> |
28 | #include <boost/iostreams/detail/is_iterator_range.hpp> |
29 | #include <boost/iostreams/detail/select.hpp> |
30 | #include <boost/iostreams/detail/select_by_size.hpp> |
31 | #include <boost/iostreams/detail/wrap_unwrap.hpp> |
32 | #include <boost/iostreams/traits_fwd.hpp> |
33 | #include <boost/mpl/bool.hpp> |
34 | #include <boost/mpl/eval_if.hpp> |
35 | #include <boost/mpl/identity.hpp> |
36 | #include <boost/mpl/int.hpp> |
37 | #include <boost/mpl/or.hpp> |
38 | #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) |
39 | # include <boost/range/iterator_range.hpp> |
40 | # include <boost/range/value_type.hpp> |
41 | #endif // #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) |
42 | #include <boost/ref.hpp> |
43 | #include <boost/type_traits/is_convertible.hpp> |
44 | |
45 | // Must come last. |
46 | #include <boost/iostreams/detail/config/disable_warnings.hpp> |
47 | |
48 | namespace boost { namespace iostreams { |
49 | |
50 | //----------Definitions of predicates for streams and stream buffers----------// |
51 | |
52 | #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //--------------------------------// |
53 | |
54 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_istream, std::basic_istream, 2) |
55 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ostream, std::basic_ostream, 2) |
56 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_iostream, std::basic_iostream, 2) |
57 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_streambuf, std::basic_streambuf, 2) |
58 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ifstream, std::basic_ifstream, 2) |
59 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ofstream, std::basic_ofstream, 2) |
60 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_fstream, std::basic_fstream, 2) |
61 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_filebuf, std::basic_filebuf, 2) |
62 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_istringstream, std::basic_istringstream, 3) |
63 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ostringstream, std::basic_ostringstream, 3) |
64 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_stringstream, std::basic_stringstream, 3) |
65 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_stringbuf, std::basic_stringbuf, 3) |
66 | |
67 | #else // #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //-----------------------// |
68 | |
69 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_istream, std::istream, 0) |
70 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ostream, std::ostream, 0) |
71 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_iostream, std::iostream, 0) |
72 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_streambuf, std::streambuf, 0) |
73 | |
74 | #endif // #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //----------------------// |
75 | |
76 | template<typename T> |
77 | struct is_std_io |
78 | : mpl::or_< is_istream<T>, is_ostream<T>, is_streambuf<T> > |
79 | { }; |
80 | |
81 | template<typename T> |
82 | struct is_std_file_device |
83 | : mpl::or_< |
84 | is_ifstream<T>, |
85 | is_ofstream<T>, |
86 | is_fstream<T>, |
87 | is_filebuf<T> |
88 | > |
89 | { }; |
90 | |
91 | template<typename T> |
92 | struct is_std_string_device |
93 | : mpl::or_< |
94 | is_istringstream<T>, |
95 | is_ostringstream<T>, |
96 | is_stringstream<T>, |
97 | is_stringbuf<T> |
98 | > |
99 | { }; |
100 | |
101 | template<typename Device, typename Tr, typename Alloc> |
102 | struct stream; |
103 | |
104 | template<typename T, typename Tr, typename Alloc, typename Mode> |
105 | class stream_buffer; |
106 | |
107 | template< typename Mode, typename Ch, typename Tr, |
108 | typename Alloc, typename Access > |
109 | class filtering_stream; |
110 | |
111 | template< typename Mode, typename Ch, typename Tr, |
112 | typename Alloc, typename Access > |
113 | class wfiltering_stream; |
114 | |
115 | template< typename Mode, typename Ch, typename Tr, |
116 | typename Alloc, typename Access > |
117 | class filtering_streambuf; |
118 | |
119 | template< typename Mode, typename Ch, typename Tr, |
120 | typename Alloc, typename Access > |
121 | class filtering_wstreambuf; |
122 | |
123 | namespace detail { |
124 | |
125 | template<typename T, typename Tr> |
126 | class linked_streambuf; |
127 | |
128 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_boost_stream, |
129 | boost::iostreams::stream, |
130 | 3 ) |
131 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_boost_stream_buffer, |
132 | boost::iostreams::stream_buffer, |
133 | 4 ) |
134 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_stream_impl, |
135 | boost::iostreams::filtering_stream, |
136 | 5 ) |
137 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_wstream_impl, |
138 | boost::iostreams::wfiltering_stream, |
139 | 5 ) |
140 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_streambuf_impl, |
141 | boost::iostreams::filtering_streambuf, |
142 | 5 ) |
143 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_wstreambuf_impl, |
144 | boost::iostreams::filtering_wstreambuf, |
145 | 5 ) |
146 | BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_linked, linked_streambuf, 2) |
147 | |
148 | template<typename T> |
149 | struct is_filtering_stream |
150 | : mpl::or_< |
151 | is_filtering_stream_impl<T>, |
152 | is_filtering_wstream_impl<T> |
153 | > |
154 | { }; |
155 | |
156 | template<typename T> |
157 | struct is_filtering_streambuf |
158 | : mpl::or_< |
159 | is_filtering_streambuf_impl<T>, |
160 | is_filtering_wstreambuf_impl<T> |
161 | > |
162 | { }; |
163 | |
164 | template<typename T> |
165 | struct is_boost |
166 | : mpl::or_< |
167 | is_boost_stream<T>, |
168 | is_boost_stream_buffer<T>, |
169 | is_filtering_stream<T>, |
170 | is_filtering_streambuf<T> |
171 | > |
172 | { }; |
173 | |
174 | } // End namespace detail. |
175 | |
176 | //------------------Definitions of char_type_of-------------------------------// |
177 | |
178 | namespace detail { |
179 | |
180 | template<typename T> |
181 | struct member_char_type { typedef typename T::char_type type; }; |
182 | |
183 | } // End namespace detail. |
184 | |
185 | #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //---------------------------// |
186 | # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //-------------------------------// |
187 | |
188 | template<typename T> |
189 | struct char_type_of |
190 | : detail::member_char_type< |
191 | typename detail::unwrapped_type<T>::type |
192 | > |
193 | { }; |
194 | |
195 | # else // # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //---------------------// |
196 | |
197 | template<typename T> |
198 | struct char_type_of { |
199 | typedef typename detail::unwrapped_type<T>::type U; |
200 | typedef typename |
201 | mpl::eval_if< |
202 | is_std_io<U>, |
203 | mpl::identity<char>, |
204 | detail::member_char_type<U> |
205 | >::type type; |
206 | }; |
207 | |
208 | # endif // # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //--------------------// |
209 | |
210 | template<typename Iter> |
211 | struct char_type_of< iterator_range<Iter> > { |
212 | typedef typename iterator_value<Iter>::type type; |
213 | }; |
214 | |
215 | #else // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //------------------// |
216 | |
217 | template<typename T> |
218 | struct char_type_of { |
219 | template<typename U> |
220 | struct get_value_type { |
221 | #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) |
222 | typedef typename range_value<U>::type type; |
223 | #endif // #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) |
224 | }; |
225 | typedef typename |
226 | mpl::eval_if< |
227 | is_iterator_range<T>, |
228 | get_value_type<T>, |
229 | detail::member_char_type< |
230 | BOOST_DEDUCED_TYPENAME detail::unwrapped_type<T>::type |
231 | > |
232 | >::type type; |
233 | }; |
234 | |
235 | #endif // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //-----------------// |
236 | |
237 | //------------------Definitions of category_of--------------------------------// |
238 | |
239 | namespace detail { |
240 | |
241 | template<typename T> |
242 | struct member_category { typedef typename T::category type; }; |
243 | |
244 | } // End namespace detail. |
245 | |
246 | template<typename T> |
247 | struct category_of { |
248 | template<typename U> |
249 | struct member_category { |
250 | typedef typename U::category type; |
251 | }; |
252 | typedef typename detail::unwrapped_type<T>::type U; |
253 | typedef typename |
254 | mpl::eval_if< |
255 | mpl::and_< |
256 | is_std_io<U>, |
257 | mpl::not_< detail::is_boost<U> > |
258 | >, |
259 | iostreams::select< // Disambiguation for Tru64 |
260 | is_filebuf<U>, filebuf_tag, |
261 | is_ifstream<U>, ifstream_tag, |
262 | is_ofstream<U>, ofstream_tag, |
263 | is_fstream<U>, fstream_tag, |
264 | is_stringbuf<U>, stringbuf_tag, |
265 | is_istringstream<U>, istringstream_tag, |
266 | is_ostringstream<U>, ostringstream_tag, |
267 | is_stringstream<U>, stringstream_tag, |
268 | is_streambuf<U>, generic_streambuf_tag, |
269 | is_iostream<U>, generic_iostream_tag, |
270 | is_istream<U>, generic_istream_tag, |
271 | is_ostream<U>, generic_ostream_tag |
272 | >, |
273 | detail::member_category<U> |
274 | >::type type; |
275 | }; |
276 | |
277 | // Partial specialization for reference wrappers |
278 | #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //---------------------------// |
279 | |
280 | template<typename T> |
281 | struct category_of< reference_wrapper<T> > |
282 | : category_of<T> |
283 | { }; |
284 | |
285 | #endif // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //-----------------// |
286 | |
287 | //------------------Definition of get_category--------------------------------// |
288 | |
289 | // |
290 | // Returns an object of type category_of<T>::type. |
291 | // |
292 | template<typename T> |
293 | inline typename category_of<T>::type get_category(const T&) |
294 | { typedef typename category_of<T>::type category; return category(); } |
295 | |
296 | //------------------Definition of int_type_of---------------------------------// |
297 | |
298 | template<typename T> |
299 | struct int_type_of { |
300 | #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES |
301 | typedef std::char_traits< |
302 | BOOST_DEDUCED_TYPENAME char_type_of<T>::type |
303 | > traits_type; |
304 | typedef typename traits_type::int_type type; |
305 | #else |
306 | typedef int type; |
307 | #endif |
308 | }; |
309 | |
310 | //------------------Definition of mode_of-------------------------------------// |
311 | |
312 | namespace detail { |
313 | |
314 | template<int N> struct io_mode_impl; |
315 | |
316 | #define BOOST_IOSTREAMS_MODE_HELPER(tag_, id_) \ |
317 | case_<id_> io_mode_impl_helper(tag_); \ |
318 | template<> struct io_mode_impl<id_> { typedef tag_ type; }; \ |
319 | /**/ |
320 | BOOST_IOSTREAMS_MODE_HELPER(input, 1) |
321 | BOOST_IOSTREAMS_MODE_HELPER(output, 2) |
322 | BOOST_IOSTREAMS_MODE_HELPER(bidirectional, 3) |
323 | BOOST_IOSTREAMS_MODE_HELPER(input_seekable, 4) |
324 | BOOST_IOSTREAMS_MODE_HELPER(output_seekable, 5) |
325 | BOOST_IOSTREAMS_MODE_HELPER(seekable, 6) |
326 | BOOST_IOSTREAMS_MODE_HELPER(dual_seekable, 7) |
327 | BOOST_IOSTREAMS_MODE_HELPER(bidirectional_seekable, 8) |
328 | BOOST_IOSTREAMS_MODE_HELPER(dual_use, 9) |
329 | #undef BOOST_IOSTREAMS_MODE_HELPER |
330 | |
331 | template<typename T> |
332 | struct io_mode_id { |
333 | typedef typename category_of<T>::type category; |
334 | BOOST_SELECT_BY_SIZE(int, value, detail::io_mode_impl_helper(category())); |
335 | }; |
336 | |
337 | } // End namespace detail. |
338 | |
339 | template<typename T> // Borland 5.6.4 requires this circumlocution. |
340 | struct mode_of : detail::io_mode_impl< detail::io_mode_id<T>::value > { }; |
341 | |
342 | // Partial specialization for reference wrappers |
343 | #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //---------------------------// |
344 | |
345 | template<typename T> |
346 | struct mode_of< reference_wrapper<T> > |
347 | : mode_of<T> |
348 | { }; |
349 | |
350 | #endif // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //-----------------// |
351 | |
352 | //------------------Definition of is_device, is_filter and is_direct----------// |
353 | |
354 | namespace detail { |
355 | |
356 | template<typename T, typename Tag> |
357 | struct has_trait_impl { |
358 | typedef typename category_of<T>::type category; |
359 | BOOST_STATIC_CONSTANT(bool, value = (is_convertible<category, Tag>::value)); |
360 | }; |
361 | |
362 | template<typename T, typename Tag> |
363 | struct has_trait |
364 | : mpl::bool_<has_trait_impl<T, Tag>::value> |
365 | { }; |
366 | |
367 | } // End namespace detail. |
368 | |
369 | template<typename T> |
370 | struct is_device : detail::has_trait<T, device_tag> { }; |
371 | |
372 | template<typename T> |
373 | struct is_filter : detail::has_trait<T, filter_tag> { }; |
374 | |
375 | template<typename T> |
376 | struct is_direct : detail::has_trait<T, direct_tag> { }; |
377 | |
378 | //------------------Definition of BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS----------// |
379 | |
380 | #define BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS(Tr) \ |
381 | typedef Tr traits_type; \ |
382 | typedef typename traits_type::int_type int_type; \ |
383 | typedef typename traits_type::off_type off_type; \ |
384 | typedef typename traits_type::pos_type pos_type; \ |
385 | /**/ |
386 | |
387 | } } // End namespaces iostreams, boost. |
388 | |
389 | #include <boost/iostreams/detail/config/enable_warnings.hpp> |
390 | |
391 | #endif // #ifndef BOOST_IOSTREAMS_IO_TRAITS_HPP_INCLUDED |
392 | |