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1 | // (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000. |
2 | // Use, modification and distribution are subject to the Boost Software License, | |
3 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
4 | // http://www.boost.org/LICENSE_1_0.txt). | |
5 | // | |
6 | // See http://www.boost.org/libs/utility for most recent version including documentation. | |
7 | ||
8 | // compressed_pair: pair that "compresses" empty members | |
9 | // (see libs/utility/doc/html/compressed_pair.html) | |
10 | // | |
11 | // JM changes 25 Jan 2004: | |
12 | // For the case where T1 == T2 and both are empty, then first() and second() | |
13 | // should return different objects. | |
14 | // JM changes 25 Jan 2000: | |
15 | // Removed default arguments from compressed_pair_switch to get | |
16 | // C++ Builder 4 to accept them | |
17 | // rewriten swap to get gcc and C++ builder to compile. | |
18 | // added partial specialisations for case T1 == T2 to avoid duplicate constructor defs. | |
19 | ||
20 | #ifndef BOOST_DETAIL_COMPRESSED_PAIR_HPP | |
21 | #define BOOST_DETAIL_COMPRESSED_PAIR_HPP | |
22 | ||
23 | #include <algorithm> | |
24 | ||
25 | #include <boost/type_traits/remove_cv.hpp> | |
26 | #include <boost/type_traits/is_empty.hpp> | |
27 | #include <boost/type_traits/is_same.hpp> | |
28 | #include <boost/call_traits.hpp> | |
29 | ||
30 | #ifdef BOOST_MSVC | |
31 | # pragma warning(push) | |
32 | # pragma warning(disable:4512) | |
33 | #endif | |
34 | namespace boost | |
35 | { | |
36 | ||
37 | template <class T1, class T2> | |
38 | class compressed_pair; | |
39 | ||
40 | ||
41 | // compressed_pair | |
42 | ||
43 | namespace details | |
44 | { | |
45 | // JM altered 26 Jan 2000: | |
46 | template <class T1, class T2, bool IsSame, bool FirstEmpty, bool SecondEmpty> | |
47 | struct compressed_pair_switch; | |
48 | ||
49 | template <class T1, class T2> | |
50 | struct compressed_pair_switch<T1, T2, false, false, false> | |
51 | {static const int value = 0;}; | |
52 | ||
53 | template <class T1, class T2> | |
54 | struct compressed_pair_switch<T1, T2, false, true, true> | |
55 | {static const int value = 3;}; | |
56 | ||
57 | template <class T1, class T2> | |
58 | struct compressed_pair_switch<T1, T2, false, true, false> | |
59 | {static const int value = 1;}; | |
60 | ||
61 | template <class T1, class T2> | |
62 | struct compressed_pair_switch<T1, T2, false, false, true> | |
63 | {static const int value = 2;}; | |
64 | ||
65 | template <class T1, class T2> | |
66 | struct compressed_pair_switch<T1, T2, true, true, true> | |
67 | {static const int value = 4;}; | |
68 | ||
69 | template <class T1, class T2> | |
70 | struct compressed_pair_switch<T1, T2, true, false, false> | |
71 | {static const int value = 5;}; | |
72 | ||
73 | template <class T1, class T2, int Version> class compressed_pair_imp; | |
74 | ||
75 | #ifdef __GNUC__ | |
76 | // workaround for GCC (JM): | |
77 | using std::swap; | |
78 | #endif | |
79 | // | |
80 | // can't call unqualified swap from within classname::swap | |
81 | // as Koenig lookup rules will find only the classname::swap | |
82 | // member function not the global declaration, so use cp_swap | |
83 | // as a forwarding function (JM): | |
84 | template <typename T> | |
85 | inline void cp_swap(T& t1, T& t2) | |
86 | { | |
87 | #ifndef __GNUC__ | |
88 | using std::swap; | |
89 | #endif | |
90 | swap(t1, t2); | |
91 | } | |
92 | ||
93 | // 0 derive from neither | |
94 | ||
95 | template <class T1, class T2> | |
96 | class compressed_pair_imp<T1, T2, 0> | |
97 | { | |
98 | public: | |
99 | typedef T1 first_type; | |
100 | typedef T2 second_type; | |
101 | typedef typename call_traits<first_type>::param_type first_param_type; | |
102 | typedef typename call_traits<second_type>::param_type second_param_type; | |
103 | typedef typename call_traits<first_type>::reference first_reference; | |
104 | typedef typename call_traits<second_type>::reference second_reference; | |
105 | typedef typename call_traits<first_type>::const_reference first_const_reference; | |
106 | typedef typename call_traits<second_type>::const_reference second_const_reference; | |
107 | ||
108 | compressed_pair_imp() {} | |
109 | ||
110 | compressed_pair_imp(first_param_type x, second_param_type y) | |
111 | : first_(x), second_(y) {} | |
112 | ||
113 | compressed_pair_imp(first_param_type x) | |
114 | : first_(x) {} | |
115 | ||
116 | compressed_pair_imp(second_param_type y) | |
117 | : second_(y) {} | |
118 | ||
119 | first_reference first() {return first_;} | |
120 | first_const_reference first() const {return first_;} | |
121 | ||
122 | second_reference second() {return second_;} | |
123 | second_const_reference second() const {return second_;} | |
124 | ||
125 | void swap(::boost::compressed_pair<T1, T2>& y) | |
126 | { | |
127 | cp_swap(first_, y.first()); | |
128 | cp_swap(second_, y.second()); | |
129 | } | |
130 | private: | |
131 | first_type first_; | |
132 | second_type second_; | |
133 | }; | |
134 | ||
135 | // 1 derive from T1 | |
136 | ||
137 | template <class T1, class T2> | |
138 | class compressed_pair_imp<T1, T2, 1> | |
139 | : protected ::boost::remove_cv<T1>::type | |
140 | { | |
141 | public: | |
142 | typedef T1 first_type; | |
143 | typedef T2 second_type; | |
144 | typedef typename call_traits<first_type>::param_type first_param_type; | |
145 | typedef typename call_traits<second_type>::param_type second_param_type; | |
146 | typedef typename call_traits<first_type>::reference first_reference; | |
147 | typedef typename call_traits<second_type>::reference second_reference; | |
148 | typedef typename call_traits<first_type>::const_reference first_const_reference; | |
149 | typedef typename call_traits<second_type>::const_reference second_const_reference; | |
150 | ||
151 | compressed_pair_imp() {} | |
152 | ||
153 | compressed_pair_imp(first_param_type x, second_param_type y) | |
154 | : first_type(x), second_(y) {} | |
155 | ||
156 | compressed_pair_imp(first_param_type x) | |
157 | : first_type(x) {} | |
158 | ||
159 | compressed_pair_imp(second_param_type y) | |
160 | : second_(y) {} | |
161 | ||
162 | first_reference first() {return *this;} | |
163 | first_const_reference first() const {return *this;} | |
164 | ||
165 | second_reference second() {return second_;} | |
166 | second_const_reference second() const {return second_;} | |
167 | ||
168 | void swap(::boost::compressed_pair<T1,T2>& y) | |
169 | { | |
170 | // no need to swap empty base class: | |
171 | cp_swap(second_, y.second()); | |
172 | } | |
173 | private: | |
174 | second_type second_; | |
175 | }; | |
176 | ||
177 | // 2 derive from T2 | |
178 | ||
179 | template <class T1, class T2> | |
180 | class compressed_pair_imp<T1, T2, 2> | |
181 | : protected ::boost::remove_cv<T2>::type | |
182 | { | |
183 | public: | |
184 | typedef T1 first_type; | |
185 | typedef T2 second_type; | |
186 | typedef typename call_traits<first_type>::param_type first_param_type; | |
187 | typedef typename call_traits<second_type>::param_type second_param_type; | |
188 | typedef typename call_traits<first_type>::reference first_reference; | |
189 | typedef typename call_traits<second_type>::reference second_reference; | |
190 | typedef typename call_traits<first_type>::const_reference first_const_reference; | |
191 | typedef typename call_traits<second_type>::const_reference second_const_reference; | |
192 | ||
193 | compressed_pair_imp() {} | |
194 | ||
195 | compressed_pair_imp(first_param_type x, second_param_type y) | |
196 | : second_type(y), first_(x) {} | |
197 | ||
198 | compressed_pair_imp(first_param_type x) | |
199 | : first_(x) {} | |
200 | ||
201 | compressed_pair_imp(second_param_type y) | |
202 | : second_type(y) {} | |
203 | ||
204 | first_reference first() {return first_;} | |
205 | first_const_reference first() const {return first_;} | |
206 | ||
207 | second_reference second() {return *this;} | |
208 | second_const_reference second() const {return *this;} | |
209 | ||
210 | void swap(::boost::compressed_pair<T1,T2>& y) | |
211 | { | |
212 | // no need to swap empty base class: | |
213 | cp_swap(first_, y.first()); | |
214 | } | |
215 | ||
216 | private: | |
217 | first_type first_; | |
218 | }; | |
219 | ||
220 | // 3 derive from T1 and T2 | |
221 | ||
222 | template <class T1, class T2> | |
223 | class compressed_pair_imp<T1, T2, 3> | |
224 | : protected ::boost::remove_cv<T1>::type, | |
225 | protected ::boost::remove_cv<T2>::type | |
226 | { | |
227 | public: | |
228 | typedef T1 first_type; | |
229 | typedef T2 second_type; | |
230 | typedef typename call_traits<first_type>::param_type first_param_type; | |
231 | typedef typename call_traits<second_type>::param_type second_param_type; | |
232 | typedef typename call_traits<first_type>::reference first_reference; | |
233 | typedef typename call_traits<second_type>::reference second_reference; | |
234 | typedef typename call_traits<first_type>::const_reference first_const_reference; | |
235 | typedef typename call_traits<second_type>::const_reference second_const_reference; | |
236 | ||
237 | compressed_pair_imp() {} | |
238 | ||
239 | compressed_pair_imp(first_param_type x, second_param_type y) | |
240 | : first_type(x), second_type(y) {} | |
241 | ||
242 | compressed_pair_imp(first_param_type x) | |
243 | : first_type(x) {} | |
244 | ||
245 | compressed_pair_imp(second_param_type y) | |
246 | : second_type(y) {} | |
247 | ||
248 | first_reference first() {return *this;} | |
249 | first_const_reference first() const {return *this;} | |
250 | ||
251 | second_reference second() {return *this;} | |
252 | second_const_reference second() const {return *this;} | |
253 | // | |
254 | // no need to swap empty bases: | |
255 | void swap(::boost::compressed_pair<T1,T2>&) {} | |
256 | }; | |
257 | ||
258 | // JM | |
259 | // 4 T1 == T2, T1 and T2 both empty | |
260 | // Originally this did not store an instance of T2 at all | |
261 | // but that led to problems beause it meant &x.first() == &x.second() | |
262 | // which is not true for any other kind of pair, so now we store an instance | |
263 | // of T2 just in case the user is relying on first() and second() returning | |
264 | // different objects (albeit both empty). | |
265 | template <class T1, class T2> | |
266 | class compressed_pair_imp<T1, T2, 4> | |
267 | : protected ::boost::remove_cv<T1>::type | |
268 | { | |
269 | public: | |
270 | typedef T1 first_type; | |
271 | typedef T2 second_type; | |
272 | typedef typename call_traits<first_type>::param_type first_param_type; | |
273 | typedef typename call_traits<second_type>::param_type second_param_type; | |
274 | typedef typename call_traits<first_type>::reference first_reference; | |
275 | typedef typename call_traits<second_type>::reference second_reference; | |
276 | typedef typename call_traits<first_type>::const_reference first_const_reference; | |
277 | typedef typename call_traits<second_type>::const_reference second_const_reference; | |
278 | ||
279 | compressed_pair_imp() {} | |
280 | ||
281 | compressed_pair_imp(first_param_type x, second_param_type y) | |
282 | : first_type(x), m_second(y) {} | |
283 | ||
284 | compressed_pair_imp(first_param_type x) | |
285 | : first_type(x), m_second(x) {} | |
286 | ||
287 | first_reference first() {return *this;} | |
288 | first_const_reference first() const {return *this;} | |
289 | ||
290 | second_reference second() {return m_second;} | |
291 | second_const_reference second() const {return m_second;} | |
292 | ||
293 | void swap(::boost::compressed_pair<T1,T2>&) {} | |
294 | private: | |
295 | T2 m_second; | |
296 | }; | |
297 | ||
298 | // 5 T1 == T2 and are not empty: //JM | |
299 | ||
300 | template <class T1, class T2> | |
301 | class compressed_pair_imp<T1, T2, 5> | |
302 | { | |
303 | public: | |
304 | typedef T1 first_type; | |
305 | typedef T2 second_type; | |
306 | typedef typename call_traits<first_type>::param_type first_param_type; | |
307 | typedef typename call_traits<second_type>::param_type second_param_type; | |
308 | typedef typename call_traits<first_type>::reference first_reference; | |
309 | typedef typename call_traits<second_type>::reference second_reference; | |
310 | typedef typename call_traits<first_type>::const_reference first_const_reference; | |
311 | typedef typename call_traits<second_type>::const_reference second_const_reference; | |
312 | ||
313 | compressed_pair_imp() {} | |
314 | ||
315 | compressed_pair_imp(first_param_type x, second_param_type y) | |
316 | : first_(x), second_(y) {} | |
317 | ||
318 | compressed_pair_imp(first_param_type x) | |
319 | : first_(x), second_(x) {} | |
320 | ||
321 | first_reference first() {return first_;} | |
322 | first_const_reference first() const {return first_;} | |
323 | ||
324 | second_reference second() {return second_;} | |
325 | second_const_reference second() const {return second_;} | |
326 | ||
327 | void swap(::boost::compressed_pair<T1, T2>& y) | |
328 | { | |
329 | cp_swap(first_, y.first()); | |
330 | cp_swap(second_, y.second()); | |
331 | } | |
332 | private: | |
333 | first_type first_; | |
334 | second_type second_; | |
335 | }; | |
336 | ||
337 | } // details | |
338 | ||
339 | template <class T1, class T2> | |
340 | class compressed_pair | |
341 | : private ::boost::details::compressed_pair_imp<T1, T2, | |
342 | ::boost::details::compressed_pair_switch< | |
343 | T1, | |
344 | T2, | |
345 | ::boost::is_same<typename remove_cv<T1>::type, typename remove_cv<T2>::type>::value, | |
346 | ::boost::is_empty<T1>::value, | |
347 | ::boost::is_empty<T2>::value>::value> | |
348 | { | |
349 | private: | |
350 | typedef details::compressed_pair_imp<T1, T2, | |
351 | ::boost::details::compressed_pair_switch< | |
352 | T1, | |
353 | T2, | |
354 | ::boost::is_same<typename remove_cv<T1>::type, typename remove_cv<T2>::type>::value, | |
355 | ::boost::is_empty<T1>::value, | |
356 | ::boost::is_empty<T2>::value>::value> base; | |
357 | public: | |
358 | typedef T1 first_type; | |
359 | typedef T2 second_type; | |
360 | typedef typename call_traits<first_type>::param_type first_param_type; | |
361 | typedef typename call_traits<second_type>::param_type second_param_type; | |
362 | typedef typename call_traits<first_type>::reference first_reference; | |
363 | typedef typename call_traits<second_type>::reference second_reference; | |
364 | typedef typename call_traits<first_type>::const_reference first_const_reference; | |
365 | typedef typename call_traits<second_type>::const_reference second_const_reference; | |
366 | ||
367 | compressed_pair() : base() {} | |
368 | compressed_pair(first_param_type x, second_param_type y) : base(x, y) {} | |
369 | explicit compressed_pair(first_param_type x) : base(x) {} | |
370 | explicit compressed_pair(second_param_type y) : base(y) {} | |
371 | ||
372 | first_reference first() {return base::first();} | |
373 | first_const_reference first() const {return base::first();} | |
374 | ||
375 | second_reference second() {return base::second();} | |
376 | second_const_reference second() const {return base::second();} | |
377 | ||
378 | void swap(compressed_pair& y) { base::swap(y); } | |
379 | }; | |
380 | ||
381 | // JM | |
382 | // Partial specialisation for case where T1 == T2: | |
383 | // | |
384 | template <class T> | |
385 | class compressed_pair<T, T> | |
386 | : private details::compressed_pair_imp<T, T, | |
387 | ::boost::details::compressed_pair_switch< | |
388 | T, | |
389 | T, | |
390 | ::boost::is_same<typename remove_cv<T>::type, typename remove_cv<T>::type>::value, | |
391 | ::boost::is_empty<T>::value, | |
392 | ::boost::is_empty<T>::value>::value> | |
393 | { | |
394 | private: | |
395 | typedef details::compressed_pair_imp<T, T, | |
396 | ::boost::details::compressed_pair_switch< | |
397 | T, | |
398 | T, | |
399 | ::boost::is_same<typename remove_cv<T>::type, typename remove_cv<T>::type>::value, | |
400 | ::boost::is_empty<T>::value, | |
401 | ::boost::is_empty<T>::value>::value> base; | |
402 | public: | |
403 | typedef T first_type; | |
404 | typedef T second_type; | |
405 | typedef typename call_traits<first_type>::param_type first_param_type; | |
406 | typedef typename call_traits<second_type>::param_type second_param_type; | |
407 | typedef typename call_traits<first_type>::reference first_reference; | |
408 | typedef typename call_traits<second_type>::reference second_reference; | |
409 | typedef typename call_traits<first_type>::const_reference first_const_reference; | |
410 | typedef typename call_traits<second_type>::const_reference second_const_reference; | |
411 | ||
412 | compressed_pair() : base() {} | |
413 | compressed_pair(first_param_type x, second_param_type y) : base(x, y) {} | |
414 | #if !(defined(__SUNPRO_CC) && (__SUNPRO_CC <= 0x530)) | |
415 | explicit | |
416 | #endif | |
417 | compressed_pair(first_param_type x) : base(x) {} | |
418 | ||
419 | first_reference first() {return base::first();} | |
420 | first_const_reference first() const {return base::first();} | |
421 | ||
422 | second_reference second() {return base::second();} | |
423 | second_const_reference second() const {return base::second();} | |
424 | ||
425 | void swap(::boost::compressed_pair<T,T>& y) { base::swap(y); } | |
426 | }; | |
427 | ||
428 | template <class T1, class T2> | |
429 | inline | |
430 | void | |
431 | swap(compressed_pair<T1, T2>& x, compressed_pair<T1, T2>& y) | |
432 | { | |
433 | x.swap(y); | |
434 | } | |
435 | ||
436 | } // boost | |
437 | ||
438 | #ifdef BOOST_MSVC | |
439 | # pragma warning(pop) | |
440 | #endif | |
441 | ||
442 | #endif // BOOST_DETAIL_COMPRESSED_PAIR_HPP | |
443 |