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1 | //----------------------------------------------------------------------------- |
2 | // boost variant/variant.hpp header file | |
3 | // See http://www.boost.org for updates, documentation, and revision history. | |
4 | //----------------------------------------------------------------------------- | |
5 | // | |
6 | // Copyright (c) 2002-2003 Eric Friedman, Itay Maman | |
f67539c2 | 7 | // Copyright (c) 2012-2020 Antony Polukhin |
7c673cae FG |
8 | // |
9 | // Distributed under the Boost Software License, Version 1.0. (See | |
10 | // accompanying file LICENSE_1_0.txt or copy at | |
11 | // http://www.boost.org/LICENSE_1_0.txt) | |
12 | ||
13 | // Thanks to Adam Romanek for providing patches for exception-disabled env. | |
14 | ||
15 | #ifndef BOOST_VARIANT_VARIANT_HPP | |
16 | #define BOOST_VARIANT_VARIANT_HPP | |
17 | ||
18 | #include <cstddef> // for std::size_t | |
19 | #include <new> // for placement new | |
20 | ||
21 | #include <boost/type_index.hpp> | |
22 | ||
23 | #include <boost/variant/detail/config.hpp> | |
24 | #include <boost/mpl/aux_/value_wknd.hpp> | |
25 | ||
26 | #include <boost/variant/variant_fwd.hpp> | |
27 | #include <boost/variant/detail/backup_holder.hpp> | |
28 | #include <boost/variant/detail/enable_recursive_fwd.hpp> | |
29 | #include <boost/variant/detail/forced_return.hpp> | |
30 | #include <boost/variant/detail/initializer.hpp> | |
31 | #include <boost/variant/detail/make_variant_list.hpp> | |
32 | #include <boost/variant/detail/over_sequence.hpp> | |
33 | #include <boost/variant/detail/visitation_impl.hpp> | |
34 | #include <boost/variant/detail/hash_variant.hpp> | |
92f5a8d4 | 35 | #include <boost/variant/detail/std_hash.hpp> |
7c673cae | 36 | |
7c673cae FG |
37 | #include <boost/variant/detail/move.hpp> |
38 | ||
7c673cae | 39 | #include <boost/detail/reference_content.hpp> |
7c673cae | 40 | #include <boost/blank.hpp> |
11fdf7f2 | 41 | #include <boost/integer/common_factor_ct.hpp> |
7c673cae FG |
42 | #include <boost/static_assert.hpp> |
43 | #include <boost/preprocessor/cat.hpp> | |
44 | #include <boost/preprocessor/repeat.hpp> | |
20effc67 | 45 | #include <boost/type_traits/aligned_storage.hpp> |
7c673cae FG |
46 | #include <boost/type_traits/alignment_of.hpp> |
47 | #include <boost/type_traits/add_const.hpp> | |
48 | #include <boost/type_traits/has_nothrow_constructor.hpp> | |
49 | #include <boost/type_traits/has_nothrow_copy.hpp> | |
50 | #include <boost/type_traits/is_nothrow_move_assignable.hpp> | |
51 | #include <boost/type_traits/is_nothrow_move_constructible.hpp> | |
52 | #include <boost/type_traits/is_const.hpp> | |
53 | #include <boost/type_traits/is_same.hpp> | |
54 | #include <boost/type_traits/is_rvalue_reference.hpp> | |
55 | #include <boost/type_traits/is_constructible.hpp> | |
56 | #include <boost/type_traits/add_lvalue_reference.hpp> | |
20effc67 TL |
57 | #include <boost/type_traits/declval.hpp> |
58 | #include <boost/core/no_exceptions_support.hpp> | |
59 | #include <boost/core/enable_if.hpp> | |
7c673cae FG |
60 | #include <boost/variant/recursive_wrapper_fwd.hpp> |
61 | #include <boost/variant/static_visitor.hpp> | |
62 | ||
63 | #include <boost/mpl/assert.hpp> | |
64 | #include <boost/mpl/begin_end.hpp> | |
65 | #include <boost/mpl/bool.hpp> | |
66 | #include <boost/mpl/deref.hpp> | |
67 | #include <boost/mpl/empty.hpp> | |
68 | #include <boost/mpl/eval_if.hpp> | |
69 | #include <boost/mpl/find_if.hpp> | |
70 | #include <boost/mpl/fold.hpp> | |
71 | #include <boost/mpl/front.hpp> | |
72 | #include <boost/mpl/identity.hpp> | |
73 | #include <boost/mpl/if.hpp> | |
b32b8144 | 74 | #include <boost/mpl/insert_range.hpp> |
7c673cae FG |
75 | #include <boost/mpl/int.hpp> |
76 | #include <boost/mpl/is_sequence.hpp> | |
77 | #include <boost/mpl/iterator_range.hpp> | |
78 | #include <boost/mpl/iter_fold_if.hpp> | |
b32b8144 | 79 | #include <boost/mpl/list.hpp> |
7c673cae FG |
80 | #include <boost/mpl/logical.hpp> |
81 | #include <boost/mpl/max_element.hpp> | |
82 | #include <boost/mpl/next.hpp> | |
83 | #include <boost/mpl/not.hpp> | |
84 | #include <boost/mpl/pair.hpp> | |
85 | #include <boost/mpl/protect.hpp> | |
86 | #include <boost/mpl/push_front.hpp> | |
87 | #include <boost/mpl/same_as.hpp> | |
88 | #include <boost/mpl/size_t.hpp> | |
89 | #include <boost/mpl/sizeof.hpp> | |
90 | #include <boost/mpl/transform.hpp> | |
91 | ||
92 | /////////////////////////////////////////////////////////////////////////////// | |
93 | // Implementation Macros: | |
94 | // | |
95 | // BOOST_VARIANT_VISITATION_UNROLLING_LIMIT | |
96 | // Defined in boost/variant/detail/visitation_impl.hpp. | |
97 | // | |
98 | // BOOST_VARIANT_MINIMIZE_SIZE | |
99 | // When #defined, implementation employs all known means to minimize the | |
100 | // size of variant obje cts. However, often unsuccessful due to alignment | |
101 | // issues, and potentially harmful to runtime speed, so not enabled by | |
102 | // default. (TODO: Investigate further.) | |
103 | ||
104 | #if defined(BOOST_VARIANT_MINIMIZE_SIZE) | |
105 | # include <climits> // for SCHAR_MAX | |
106 | # include <boost/mpl/eval_if.hpp> | |
107 | # include <boost/mpl/equal_to.hpp> | |
108 | # include <boost/mpl/identity.hpp> | |
109 | # include <boost/mpl/int.hpp> | |
110 | # include <boost/mpl/if.hpp> | |
111 | # include <boost/mpl/less.hpp> | |
112 | # include <boost/mpl/long.hpp> | |
113 | # include <boost/mpl/O1_size.hpp> | |
114 | #endif | |
115 | ||
116 | ||
117 | namespace boost { | |
118 | ||
119 | namespace detail { namespace variant { | |
120 | ||
121 | /////////////////////////////////////////////////////////////////////////////// | |
122 | // (detail) metafunction max_value | |
123 | // | |
124 | // Finds the maximum value of the unary metafunction F over Sequence. | |
125 | // | |
126 | template <typename Sequence, typename F> | |
127 | struct max_value | |
128 | { | |
129 | private: // helpers, for metafunction result (below) | |
130 | ||
131 | typedef typename mpl::transform1<Sequence, F>::type transformed_; | |
132 | typedef typename mpl::max_element<transformed_ | |
f67539c2 | 133 | |
7c673cae FG |
134 | >::type max_it; |
135 | ||
136 | public: // metafunction result | |
137 | ||
138 | typedef typename mpl::deref<max_it>::type | |
139 | type; | |
140 | ||
141 | }; | |
142 | ||
143 | struct add_alignment | |
144 | { | |
145 | template <typename State, typename Item> | |
146 | struct apply | |
147 | : mpl::size_t< | |
11fdf7f2 | 148 | ::boost::integer::static_lcm< |
7c673cae FG |
149 | BOOST_MPL_AUX_VALUE_WKND(State)::value |
150 | , ::boost::alignment_of<Item>::value | |
151 | >::value | |
152 | > | |
153 | {}; | |
154 | }; | |
155 | ||
156 | /////////////////////////////////////////////////////////////////////////////// | |
157 | // (detail) metafunction find_fallback_type | |
158 | // | |
159 | // Provides a fallback (i.e., nothrow default-constructible) type from the | |
160 | // specified sequence, or no_fallback_type if not found. | |
161 | // | |
162 | // This implementation is designed to prefer boost::blank over other potential | |
163 | // fallback types, regardless of its position in the specified sequence. | |
164 | // | |
165 | ||
166 | class no_fallback_type; | |
167 | ||
168 | struct find_fallback_type_pred | |
169 | { | |
170 | template <typename Iterator> | |
171 | struct apply | |
172 | { | |
173 | private: | |
174 | typedef typename mpl::deref<Iterator>::type t_; | |
175 | ||
176 | public: | |
177 | typedef mpl::not_< has_nothrow_constructor<t_> > type; | |
178 | }; | |
179 | }; | |
180 | ||
181 | template <typename Types> | |
182 | struct find_fallback_type | |
183 | { | |
184 | private: // helpers, for metafunction result (below) | |
185 | ||
186 | typedef typename mpl::end<Types>::type end_it; | |
187 | ||
188 | // [Find the first suitable fallback type...] | |
189 | ||
190 | typedef typename mpl::iter_fold_if< | |
191 | Types | |
192 | , mpl::int_<0>, mpl::protect< mpl::next<> > | |
193 | , mpl::protect< find_fallback_type_pred > | |
194 | >::type first_result_; | |
195 | ||
196 | typedef typename first_result_::first first_result_index; | |
197 | typedef typename first_result_::second first_result_it; | |
198 | ||
199 | // [...now search the rest of the sequence for boost::blank...] | |
200 | ||
201 | typedef typename mpl::iter_fold_if< | |
202 | mpl::iterator_range< first_result_it,end_it > | |
203 | , first_result_index, mpl::protect< mpl::next<> > | |
204 | , mpl::protect< mpl::not_same_as<boost::blank> > | |
205 | >::type second_result_; | |
206 | ||
207 | typedef typename second_result_::second second_result_it; | |
208 | ||
209 | public: // metafunction result | |
210 | ||
211 | // [...and return the results of the search:] | |
212 | typedef typename mpl::eval_if< | |
213 | is_same< second_result_it,end_it > | |
214 | , mpl::if_< | |
215 | is_same< first_result_it,end_it > | |
216 | , mpl::pair< no_fallback_type,no_fallback_type > | |
217 | , first_result_ | |
218 | > | |
219 | , mpl::identity< second_result_ > | |
220 | >::type type; | |
221 | ||
222 | }; | |
223 | ||
224 | #ifndef BOOST_NO_CXX11_NOEXCEPT | |
225 | /////////////////////////////////////////////////////////////////////////////// | |
226 | // (detail) metafunction is_variant_move_noexcept_constructible | |
227 | // | |
228 | // Returns true_type if all the types are nothrow move constructible. | |
229 | // | |
230 | template <class Types> | |
231 | struct is_variant_move_noexcept_constructible { | |
232 | typedef typename boost::mpl::find_if< | |
233 | Types, mpl::not_<boost::is_nothrow_move_constructible<boost::mpl::_1> > | |
234 | >::type iterator_t; | |
235 | ||
236 | typedef typename boost::mpl::end<Types>::type end_t; | |
237 | typedef typename boost::is_same< | |
238 | iterator_t, end_t | |
239 | >::type type; | |
240 | }; | |
241 | ||
242 | /////////////////////////////////////////////////////////////////////////////// | |
243 | // (detail) metafunction is_variant_move_noexcept_assignable | |
244 | // | |
245 | // Returns true_type if all the types are nothrow move constructible. | |
246 | // | |
247 | template <class Types> | |
248 | struct is_variant_move_noexcept_assignable { | |
249 | typedef typename boost::mpl::find_if< | |
250 | Types, mpl::not_<boost::is_nothrow_move_assignable<boost::mpl::_1> > | |
251 | >::type iterator_t; | |
252 | ||
253 | typedef typename boost::mpl::end<Types>::type end_t; | |
254 | typedef typename boost::is_same< | |
255 | iterator_t, end_t | |
256 | >::type type; | |
257 | }; | |
258 | #endif // BOOST_NO_CXX11_NOEXCEPT | |
259 | ||
260 | /////////////////////////////////////////////////////////////////////////////// | |
261 | // (detail) metafunction is_variant_constructible_from | |
262 | // | |
263 | // Derives from true_type if at least one variant's type is constructible from T. | |
264 | // | |
265 | template <class T1, class T2> | |
266 | struct is_constructible_ext: | |
267 | boost::mpl::or_< | |
268 | boost::is_constructible< | |
269 | T1, | |
270 | T2 | |
271 | >, | |
272 | boost::is_constructible< | |
273 | T1, | |
274 | typename boost::add_lvalue_reference<T2>::type | |
275 | > | |
276 | > | |
277 | {}; | |
278 | ||
279 | template <class T, class Types> | |
280 | struct is_variant_constructible_from: | |
281 | boost::mpl::not_< boost::is_same< | |
282 | typename boost::mpl::find_if< | |
283 | Types, | |
284 | is_constructible_ext<boost::mpl::_1, T> | |
285 | >::type, | |
286 | typename boost::mpl::end<Types>::type | |
287 | > > | |
288 | {}; | |
289 | ||
290 | template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types> | |
291 | struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types >: | |
292 | boost::is_same< | |
293 | typename boost::mpl::find_if< | |
294 | typename boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::recursive_enabled_types, | |
295 | mpl::not_< is_variant_constructible_from< boost::mpl::_1, Types> > | |
296 | >::type, | |
297 | typename boost::mpl::end< typename boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::recursive_enabled_types >::type | |
298 | > | |
299 | {}; | |
300 | ||
301 | template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types> | |
302 | struct is_variant_constructible_from< const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>& , Types >: | |
303 | is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types > | |
304 | {}; | |
305 | ||
306 | template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types> | |
307 | struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>& , Types >: | |
308 | is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types > | |
309 | {}; | |
310 | ||
311 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
312 | ||
313 | template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types> | |
314 | struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>&& , Types >: | |
315 | is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types > | |
316 | {}; | |
317 | ||
318 | template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types> | |
319 | struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const && , Types >: | |
320 | is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types > | |
321 | {}; | |
322 | ||
323 | #endif // #ifndef BOOST_NO_CXX11_RVALUE_REFERENCE | |
324 | ||
325 | ||
326 | /////////////////////////////////////////////////////////////////////////////// | |
327 | // (detail) metafunction make_storage | |
328 | // | |
329 | // Provides an aligned storage type capable of holding any of the types | |
330 | // specified in the given type-sequence. | |
331 | // | |
332 | ||
333 | template <typename Types, typename NeverUsesBackupFlag> | |
334 | struct make_storage | |
335 | { | |
336 | private: // helpers, for metafunction result (below) | |
337 | ||
338 | typedef typename mpl::eval_if< | |
339 | NeverUsesBackupFlag | |
340 | , mpl::identity< Types > | |
341 | , mpl::push_front< | |
342 | Types, backup_holder<void*> | |
343 | > | |
344 | >::type types; | |
345 | ||
346 | typedef typename max_value< | |
347 | types, mpl::sizeof_<mpl::_1> | |
348 | >::type max_size; | |
349 | ||
20effc67 | 350 | #if !BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x0551)) |
7c673cae FG |
351 | |
352 | typedef typename mpl::fold< | |
353 | types | |
354 | , mpl::size_t<1> | |
355 | , add_alignment | |
356 | >::type max_alignment; | |
357 | ||
358 | #else // borland | |
359 | ||
360 | // temporary workaround -- use maximal alignment | |
361 | typedef mpl::size_t< -1 > max_alignment; | |
362 | ||
363 | #endif // borland workaround | |
364 | ||
365 | public: // metafunction result | |
366 | ||
367 | typedef ::boost::aligned_storage< | |
368 | BOOST_MPL_AUX_VALUE_WKND(max_size)::value | |
369 | , BOOST_MPL_AUX_VALUE_WKND(max_alignment)::value | |
370 | > type; | |
371 | }; | |
372 | ||
373 | /////////////////////////////////////////////////////////////////////////////// | |
374 | // (detail) class destroyer | |
375 | // | |
376 | // Internal visitor that destroys the value it visits. | |
377 | // | |
378 | struct destroyer | |
379 | : public static_visitor<> | |
380 | { | |
381 | public: // visitor interfaces | |
382 | ||
383 | template <typename T> | |
92f5a8d4 | 384 | void internal_visit(T& operand, int) const BOOST_NOEXCEPT |
7c673cae FG |
385 | { |
386 | operand.~T(); // must be noexcept | |
387 | ||
20effc67 | 388 | #if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x0551)) || \ |
7c673cae | 389 | BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) |
b32b8144 | 390 | (void)operand; // suppresses warnings |
7c673cae | 391 | #endif |
7c673cae FG |
392 | } |
393 | ||
394 | }; | |
395 | ||
396 | /////////////////////////////////////////////////////////////////////////////// | |
397 | // (detail) class template known_get | |
398 | // | |
399 | // Visitor that returns a reference to content of the specified type. | |
400 | // | |
401 | // Precondition: visited variant MUST contain logical content of type T. | |
402 | // | |
403 | template <typename T> | |
404 | class known_get | |
405 | : public static_visitor<T&> | |
406 | { | |
407 | ||
408 | public: // visitor interface | |
409 | ||
410 | T& operator()(T& operand) const BOOST_NOEXCEPT | |
411 | { | |
412 | return operand; | |
413 | } | |
414 | ||
415 | template <typename U> | |
416 | T& operator()(U&) const | |
417 | { | |
418 | // logical error to be here: see precondition above | |
419 | return ::boost::detail::variant::forced_return< T& >(); | |
420 | } | |
421 | }; | |
422 | ||
423 | /////////////////////////////////////////////////////////////////////////////// | |
424 | // (detail) class copy_into | |
425 | // | |
426 | // Internal visitor that copies the value it visits into the given buffer. | |
427 | // | |
428 | class copy_into | |
429 | : public static_visitor<> | |
430 | { | |
431 | private: // representation | |
432 | ||
433 | void* storage_; | |
434 | ||
435 | public: // structors | |
436 | ||
437 | explicit copy_into(void* storage) BOOST_NOEXCEPT | |
438 | : storage_(storage) | |
439 | { | |
440 | } | |
441 | ||
442 | public: // internal visitor interface | |
443 | ||
444 | template <typename T> | |
92f5a8d4 | 445 | void internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const |
7c673cae FG |
446 | { |
447 | new(storage_) T( operand.get() ); | |
7c673cae FG |
448 | } |
449 | ||
450 | template <typename T> | |
92f5a8d4 | 451 | void internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const |
7c673cae FG |
452 | { |
453 | new(storage_) T( operand.get() ); | |
7c673cae FG |
454 | } |
455 | ||
456 | template <typename T> | |
92f5a8d4 | 457 | void internal_visit(const T& operand, int) const |
7c673cae FG |
458 | { |
459 | new(storage_) T(operand); | |
7c673cae FG |
460 | } |
461 | ||
462 | }; | |
463 | ||
464 | /////////////////////////////////////////////////////////////////////////////// | |
465 | // (detail) class move_into | |
466 | // | |
467 | // Internal visitor that moves the value it visits into the given buffer. | |
468 | // | |
469 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
470 | class move_into | |
471 | : public static_visitor<> | |
472 | { | |
473 | private: // representation | |
474 | ||
475 | void* storage_; | |
476 | ||
477 | public: // structors | |
478 | ||
479 | explicit move_into(void* storage) BOOST_NOEXCEPT | |
480 | : storage_(storage) | |
481 | { | |
482 | } | |
483 | ||
484 | public: // internal visitor interface | |
485 | ||
486 | template <typename T> | |
92f5a8d4 | 487 | void internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const |
7c673cae FG |
488 | { |
489 | new(storage_) T( ::boost::detail::variant::move(operand.get()) ); | |
7c673cae FG |
490 | } |
491 | ||
492 | template <typename T> | |
92f5a8d4 | 493 | void internal_visit(T& operand, int) const BOOST_NOEXCEPT_IF(BOOST_NOEXCEPT_EXPR(T(boost::declval<T>()))) |
7c673cae FG |
494 | { |
495 | new(storage_) T(::boost::detail::variant::move(operand)); | |
7c673cae FG |
496 | } |
497 | }; | |
498 | #endif | |
499 | ||
500 | /////////////////////////////////////////////////////////////////////////////// | |
501 | // (detail) class assign_storage | |
502 | // | |
503 | // Internal visitor that assigns the given storage (which must be a | |
504 | // constructed value of the same type) to the value it visits. | |
505 | // | |
506 | struct assign_storage | |
507 | : public static_visitor<> | |
508 | { | |
509 | private: // representation | |
510 | ||
511 | const void* rhs_storage_; | |
512 | ||
513 | public: // structors | |
514 | ||
515 | explicit assign_storage(const void* rhs_storage) BOOST_NOEXCEPT | |
516 | : rhs_storage_(rhs_storage) | |
517 | { | |
518 | } | |
519 | ||
520 | public: // internal visitor interfaces | |
521 | ||
522 | template <typename T> | |
92f5a8d4 | 523 | void internal_visit(backup_holder<T>& lhs_content, long) const |
7c673cae FG |
524 | { |
525 | lhs_content.get() | |
526 | = static_cast< const backup_holder<T>* >(rhs_storage_)->get(); | |
7c673cae FG |
527 | } |
528 | ||
529 | template <typename T> | |
92f5a8d4 | 530 | void internal_visit(const backup_holder<T>& lhs_content, long) const |
7c673cae FG |
531 | { |
532 | lhs_content.get() | |
533 | = static_cast< const backup_holder<T>* >(rhs_storage_)->get(); | |
7c673cae FG |
534 | } |
535 | ||
536 | template <typename T> | |
92f5a8d4 | 537 | void internal_visit(T& lhs_content, int) const |
7c673cae FG |
538 | { |
539 | // NOTE TO USER : | |
540 | // Compile error here indicates one of variant's bounded types does | |
541 | // not meet the requirements of the Assignable concept. Thus, | |
542 | // variant is not Assignable. | |
543 | // | |
544 | // Hint: Are any of the bounded types const-qualified or references? | |
545 | // | |
546 | lhs_content = *static_cast< const T* >(rhs_storage_); | |
7c673cae FG |
547 | } |
548 | ||
549 | }; | |
550 | ||
551 | /////////////////////////////////////////////////////////////////////////////// | |
552 | // (detail) class move_storage | |
553 | // | |
554 | // Internal visitor that moves the given storage (which must be a | |
555 | // constructed value of the same type) to the value it visits. | |
556 | // | |
557 | struct move_storage | |
558 | : public static_visitor<> | |
559 | { | |
560 | private: // representation | |
561 | ||
562 | void* rhs_storage_; | |
563 | ||
564 | public: // structors | |
565 | ||
566 | explicit move_storage(void* rhs_storage) BOOST_NOEXCEPT | |
567 | : rhs_storage_(rhs_storage) | |
568 | { | |
569 | } | |
570 | ||
571 | public: // internal visitor interfaces | |
572 | ||
573 | template <typename T> | |
92f5a8d4 | 574 | void internal_visit(backup_holder<T>& lhs_content, long) const |
7c673cae FG |
575 | { |
576 | lhs_content.get() | |
577 | = ::boost::detail::variant::move(static_cast<backup_holder<T>* >(rhs_storage_)->get()); | |
7c673cae FG |
578 | } |
579 | ||
580 | template <typename T> | |
92f5a8d4 | 581 | void internal_visit(const backup_holder<T>& lhs_content, long) const |
7c673cae FG |
582 | { |
583 | lhs_content.get() | |
584 | = ::boost::detail::variant::move(static_cast<backup_holder<T>* >(rhs_storage_)->get()); | |
7c673cae FG |
585 | } |
586 | ||
587 | template <typename T> | |
92f5a8d4 | 588 | void internal_visit(T& lhs_content, int) const |
7c673cae FG |
589 | { |
590 | // NOTE TO USER : | |
591 | // Compile error here indicates one of variant's bounded types does | |
592 | // not meet the requirements of the Assignable concept. Thus, | |
593 | // variant is not Assignable. | |
594 | // | |
595 | // Hint: Are any of the bounded types const-qualified or references? | |
596 | // | |
597 | lhs_content = ::boost::detail::variant::move(*static_cast<T* >(rhs_storage_)); | |
7c673cae FG |
598 | } |
599 | ||
600 | }; | |
601 | ||
602 | /////////////////////////////////////////////////////////////////////////////// | |
603 | // (detail) class direct_assigner | |
604 | // | |
605 | // Generic static visitor that: if and only if the visited value is of the | |
606 | // specified type, assigns the given value to the visited value and returns | |
607 | // true; else returns false. | |
608 | // | |
609 | template <typename T> | |
610 | class direct_assigner | |
611 | : public static_visitor<bool> | |
612 | { | |
613 | private: // representation | |
614 | ||
615 | const T& rhs_; | |
616 | ||
617 | public: // structors | |
618 | ||
619 | explicit direct_assigner(const T& rhs) BOOST_NOEXCEPT | |
620 | : rhs_(rhs) | |
621 | { | |
622 | } | |
623 | ||
624 | public: // visitor interface | |
625 | ||
626 | bool operator()(T& lhs) | |
627 | { | |
628 | lhs = rhs_; | |
629 | return true; | |
630 | } | |
631 | ||
632 | template <typename U> | |
633 | bool operator()(U&) BOOST_NOEXCEPT | |
634 | { | |
635 | return false; | |
636 | } | |
637 | ||
638 | #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) | |
639 | private: | |
640 | // silence MSVC warning C4512: assignment operator could not be generated | |
641 | direct_assigner& operator= (direct_assigner const&); | |
642 | #endif | |
643 | }; | |
644 | ||
645 | /////////////////////////////////////////////////////////////////////////////// | |
646 | // (detail) class direct_mover | |
647 | // | |
648 | // Generic static visitor that: if and only if the visited value is of the | |
649 | // specified type, move assigns the given value to the visited value and returns | |
650 | // true; else returns false. | |
651 | // | |
652 | template <typename T> | |
653 | class direct_mover | |
654 | : public static_visitor<bool> | |
655 | { | |
656 | private: // representation | |
657 | ||
658 | T& rhs_; | |
659 | ||
660 | public: // structors | |
661 | ||
662 | explicit direct_mover(T& rhs) BOOST_NOEXCEPT | |
663 | : rhs_(rhs) | |
664 | { | |
665 | } | |
666 | ||
667 | public: // visitor interface | |
668 | ||
669 | bool operator()(T& lhs) | |
670 | { | |
671 | lhs = ::boost::detail::variant::move(rhs_); | |
672 | return true; | |
673 | } | |
674 | ||
675 | template <typename U> | |
676 | bool operator()(U&) BOOST_NOEXCEPT | |
677 | { | |
678 | return false; | |
679 | } | |
680 | ||
681 | #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) | |
682 | private: | |
683 | // silence MSVC warning C4512: assignment operator could not be generated | |
684 | direct_mover& operator= (direct_mover const&); | |
685 | #endif | |
686 | }; | |
687 | ||
688 | ||
689 | /////////////////////////////////////////////////////////////////////////////// | |
690 | // (detail) class backup_assigner | |
691 | // | |
692 | // Internal visitor that "assigns" the given value to the visited value, | |
693 | // using backup to recover if the destroy-copy sequence fails. | |
694 | // | |
695 | // NOTE: This needs to be a friend of variant, as it needs access to | |
696 | // indicate_which, indicate_backup_which, etc. | |
697 | // | |
698 | template <typename Variant> | |
699 | class backup_assigner | |
700 | : public static_visitor<> | |
701 | { | |
702 | private: // representation | |
703 | ||
704 | Variant& lhs_; | |
705 | int rhs_which_; | |
706 | const void* rhs_content_; | |
707 | void (*copy_rhs_content_)(void*, const void*); | |
708 | ||
709 | public: // structors | |
710 | ||
711 | template<class RhsT> | |
712 | backup_assigner(Variant& lhs, int rhs_which, const RhsT& rhs_content) | |
713 | : lhs_(lhs) | |
714 | , rhs_which_(rhs_which) | |
715 | , rhs_content_(&rhs_content) | |
716 | , copy_rhs_content_(&construct_impl<RhsT>) | |
717 | { | |
718 | } | |
719 | ||
720 | private: // helpers, for visitor interface (below) | |
721 | ||
722 | template<class RhsT> | |
723 | static void construct_impl(void* addr, const void* obj) | |
724 | { | |
725 | new(addr) RhsT(*static_cast<const RhsT*>(obj)); | |
726 | } | |
727 | ||
728 | template <typename LhsT> | |
729 | void backup_assign_impl( | |
730 | backup_holder<LhsT>& lhs_content | |
731 | , mpl::false_ // is_nothrow_move_constructible | |
732 | , long | |
733 | ) | |
734 | { | |
735 | // Move lhs content to backup... | |
736 | backup_holder<LhsT> backup_lhs_content(0); | |
737 | backup_lhs_content.swap(lhs_content); // nothrow | |
738 | ||
739 | // ...destroy lhs content... | |
740 | lhs_content.~backup_holder<LhsT>(); // nothrow | |
741 | ||
742 | BOOST_TRY | |
743 | { | |
744 | // ...and attempt to copy rhs content into lhs storage: | |
745 | copy_rhs_content_(lhs_.storage_.address(), rhs_content_); | |
746 | } | |
747 | BOOST_CATCH (...) | |
748 | { | |
749 | // In case of failure, copy backup pointer to lhs storage... | |
750 | new(lhs_.storage_.address()) | |
751 | backup_holder<LhsT>( 0 ); // nothrow | |
752 | ||
753 | static_cast<backup_holder<LhsT>* >(lhs_.storage_.address()) | |
754 | ->swap(backup_lhs_content); // nothrow | |
755 | ||
756 | // ...and rethrow: | |
757 | BOOST_RETHROW; | |
758 | } | |
759 | BOOST_CATCH_END | |
760 | ||
761 | // In case of success, indicate new content type: | |
762 | lhs_.indicate_which(rhs_which_); // nothrow | |
763 | } | |
764 | ||
765 | template <typename LhsT> | |
766 | void backup_assign_impl( | |
767 | LhsT& lhs_content | |
768 | , mpl::true_ // is_nothrow_move_constructible | |
769 | , int | |
770 | ) | |
771 | { | |
772 | // Move lhs content to backup... | |
773 | LhsT backup_lhs_content( | |
774 | ::boost::detail::variant::move(lhs_content) | |
775 | ); // nothrow | |
776 | ||
777 | // ...destroy lhs content... | |
778 | lhs_content.~LhsT(); // nothrow | |
779 | ||
780 | BOOST_TRY | |
781 | { | |
782 | // ...and attempt to copy rhs content into lhs storage: | |
783 | copy_rhs_content_(lhs_.storage_.address(), rhs_content_); | |
784 | } | |
785 | BOOST_CATCH (...) | |
786 | { | |
787 | // In case of failure, restore backup content to lhs storage... | |
788 | new(lhs_.storage_.address()) | |
789 | LhsT( | |
790 | ::boost::detail::variant::move(backup_lhs_content) | |
791 | ); // nothrow | |
792 | ||
793 | // ...and rethrow: | |
794 | BOOST_RETHROW; | |
795 | } | |
796 | BOOST_CATCH_END | |
797 | ||
798 | // In case of success, indicate new content type: | |
799 | lhs_.indicate_which(rhs_which_); // nothrow | |
800 | } | |
801 | ||
802 | template <typename LhsT> | |
803 | void backup_assign_impl( | |
804 | LhsT& lhs_content | |
805 | , mpl::false_ // is_nothrow_move_constructible | |
806 | , int | |
807 | ) | |
808 | { | |
809 | // Backup lhs content... | |
810 | LhsT* backup_lhs_ptr = new LhsT(lhs_content); | |
811 | ||
812 | // ...destroy lhs content... | |
813 | lhs_content.~LhsT(); // nothrow | |
814 | ||
815 | BOOST_TRY | |
816 | { | |
817 | // ...and attempt to copy rhs content into lhs storage: | |
818 | copy_rhs_content_(lhs_.storage_.address(), rhs_content_); | |
819 | } | |
820 | BOOST_CATCH (...) | |
821 | { | |
822 | // In case of failure, copy backup pointer to lhs storage... | |
823 | new(lhs_.storage_.address()) | |
824 | backup_holder<LhsT>( backup_lhs_ptr ); // nothrow | |
825 | ||
826 | // ...indicate now using backup... | |
827 | lhs_.indicate_backup_which( lhs_.which() ); // nothrow | |
828 | ||
829 | // ...and rethrow: | |
830 | BOOST_RETHROW; | |
831 | } | |
832 | BOOST_CATCH_END | |
833 | ||
834 | // In case of success, indicate new content type... | |
835 | lhs_.indicate_which(rhs_which_); // nothrow | |
836 | ||
837 | // ...and delete backup: | |
838 | delete backup_lhs_ptr; // nothrow | |
839 | } | |
840 | ||
841 | public: // visitor interface | |
842 | ||
843 | template <typename LhsT> | |
92f5a8d4 | 844 | void internal_visit(LhsT& lhs_content, int) |
7c673cae FG |
845 | { |
846 | typedef typename is_nothrow_move_constructible<LhsT>::type | |
847 | nothrow_move; | |
848 | ||
849 | backup_assign_impl( lhs_content, nothrow_move(), 1L); | |
7c673cae FG |
850 | } |
851 | ||
852 | #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) | |
853 | private: | |
854 | // silence MSVC warning C4512: assignment operator could not be generated | |
855 | backup_assigner& operator= (backup_assigner const&); | |
856 | #endif | |
857 | }; | |
858 | ||
859 | /////////////////////////////////////////////////////////////////////////////// | |
860 | // (detail) class swap_with | |
861 | // | |
862 | // Visitor that swaps visited value with content of given variant. | |
863 | // | |
864 | // Precondition: Given variant MUST have same logical type as visited value. | |
865 | // | |
866 | template <typename Variant> | |
867 | struct swap_with | |
868 | : public static_visitor<> | |
869 | { | |
870 | private: // representation | |
871 | ||
872 | Variant& toswap_; | |
873 | ||
874 | public: // structors | |
875 | ||
876 | explicit swap_with(Variant& toswap) BOOST_NOEXCEPT | |
877 | : toswap_(toswap) | |
878 | { | |
879 | } | |
880 | ||
881 | public: // internal visitor interfaces | |
882 | ||
883 | template <typename T> | |
884 | void operator()(T& operand) const | |
885 | { | |
886 | // Since the precondition ensures types are same, get T... | |
887 | known_get<T> getter; | |
888 | T& other = toswap_.apply_visitor(getter); | |
889 | ||
890 | // ...and swap: | |
891 | ::boost::detail::variant::move_swap( operand, other ); | |
892 | } | |
893 | ||
894 | private: | |
895 | swap_with& operator=(const swap_with&); | |
896 | ||
897 | }; | |
898 | ||
899 | /////////////////////////////////////////////////////////////////////////////// | |
900 | // (detail) class reflect | |
901 | // | |
902 | // Generic static visitor that performs a typeid on the value it visits. | |
903 | // | |
904 | ||
905 | class reflect | |
906 | : public static_visitor<const boost::typeindex::type_info&> | |
907 | { | |
908 | public: // visitor interfaces | |
909 | ||
910 | template <typename T> | |
911 | const boost::typeindex::type_info& operator()(const T&) const BOOST_NOEXCEPT | |
912 | { | |
913 | return boost::typeindex::type_id<T>().type_info(); | |
914 | } | |
915 | ||
916 | }; | |
917 | ||
918 | /////////////////////////////////////////////////////////////////////////////// | |
919 | // (detail) class comparer | |
920 | // | |
921 | // Generic static visitor that compares the content of the given lhs variant | |
922 | // with the visited rhs content using Comp. | |
923 | // | |
924 | // Precondition: lhs.which() == rhs.which() | |
925 | // | |
926 | template <typename Variant, typename Comp> | |
927 | class comparer | |
928 | : public static_visitor<bool> | |
929 | { | |
930 | private: // representation | |
931 | ||
932 | const Variant& lhs_; | |
933 | ||
934 | public: // structors | |
935 | ||
936 | explicit comparer(const Variant& lhs) BOOST_NOEXCEPT | |
937 | : lhs_(lhs) | |
938 | { | |
939 | } | |
940 | ||
941 | public: // visitor interfaces | |
942 | ||
943 | template <typename T> | |
944 | bool operator()(T& rhs_content) const | |
945 | { | |
946 | // Since the precondition ensures lhs and rhs types are same, get T... | |
947 | known_get<T> getter; | |
948 | const T& lhs_content = lhs_.apply_visitor(getter); | |
949 | ||
950 | // ...and compare lhs and rhs contents: | |
951 | return Comp()(lhs_content, rhs_content); | |
952 | } | |
953 | ||
954 | private: | |
955 | comparer& operator=(const comparer&); | |
956 | ||
957 | }; | |
958 | ||
959 | /////////////////////////////////////////////////////////////////////////////// | |
960 | // (detail) class equal_comp | |
961 | // | |
962 | // Generic function object compares lhs with rhs using operator==. | |
963 | // | |
964 | struct equal_comp | |
965 | { | |
966 | template <typename T> | |
967 | bool operator()(const T& lhs, const T& rhs) const | |
968 | { | |
969 | return lhs == rhs; | |
970 | } | |
971 | }; | |
972 | ||
973 | /////////////////////////////////////////////////////////////////////////////// | |
974 | // (detail) class less_comp | |
975 | // | |
976 | // Generic function object compares lhs with rhs using operator<. | |
977 | // | |
978 | struct less_comp | |
979 | { | |
980 | template <typename T> | |
981 | bool operator()(const T& lhs, const T& rhs) const | |
982 | { | |
983 | return lhs < rhs; | |
984 | } | |
985 | }; | |
986 | ||
987 | /////////////////////////////////////////////////////////////////////////////// | |
988 | // (detail) class template invoke_visitor | |
989 | // | |
990 | // Internal visitor that invokes the given visitor using: | |
991 | // * for wrappers (e.g., recursive_wrapper), the wrapper's held value. | |
992 | // * for all other values, the value itself. | |
993 | // | |
b32b8144 | 994 | template <typename Visitor, bool MoveSemantics> |
7c673cae FG |
995 | class invoke_visitor |
996 | { | |
997 | private: // representation | |
998 | ||
999 | Visitor& visitor_; | |
1000 | ||
1001 | public: // visitor typedefs | |
1002 | ||
1003 | typedef typename Visitor::result_type | |
1004 | result_type; | |
1005 | ||
1006 | public: // structors | |
1007 | ||
1008 | explicit invoke_visitor(Visitor& visitor) BOOST_NOEXCEPT | |
1009 | : visitor_(visitor) | |
1010 | { | |
1011 | } | |
1012 | ||
7c673cae FG |
1013 | public: // internal visitor interfaces |
1014 | ||
b32b8144 FG |
1015 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
1016 | ||
1017 | //using workaround with is_same<T, T> to prenvent compilation error, because we need to use T in enable_if to make SFINAE work | |
1018 | template <typename T> | |
1019 | typename enable_if_c<MoveSemantics && is_same<T, T>::value, result_type>::type internal_visit(T&& operand, int) | |
1020 | { | |
20effc67 | 1021 | return visitor_(::boost::move(operand)); |
b32b8144 FG |
1022 | } |
1023 | ||
1024 | //using workaround with is_same<T, T> to prenvent compilation error, because we need to use T in enable_if to make SFINAE work | |
1025 | template <typename T> | |
1026 | typename disable_if_c<MoveSemantics && is_same<T, T>::value, result_type>::type internal_visit(T&& operand, int) | |
1027 | { | |
1028 | return visitor_(operand); | |
1029 | } | |
1030 | ||
1031 | #else | |
1032 | ||
7c673cae FG |
1033 | template <typename T> |
1034 | result_type internal_visit(T& operand, int) | |
1035 | { | |
1036 | return visitor_(operand); | |
1037 | } | |
1038 | ||
20effc67 | 1039 | # if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x0564)) |
7c673cae FG |
1040 | template <typename T> |
1041 | result_type internal_visit(const T& operand, int) | |
1042 | { | |
1043 | return visitor_(operand); | |
1044 | } | |
b32b8144 FG |
1045 | # endif //BORLAND |
1046 | ||
1047 | #endif //RVALUE REFERENCES | |
7c673cae | 1048 | |
7c673cae FG |
1049 | public: // internal visitor interfaces, cont. |
1050 | ||
1051 | template <typename T> | |
92f5a8d4 | 1052 | result_type internal_visit(boost::recursive_wrapper<T>& operand, long) |
7c673cae FG |
1053 | { |
1054 | return internal_visit( operand.get(), 1L ); | |
1055 | } | |
1056 | ||
1057 | template <typename T> | |
92f5a8d4 | 1058 | result_type internal_visit(const boost::recursive_wrapper<T>& operand, long) |
7c673cae FG |
1059 | { |
1060 | return internal_visit( operand.get(), 1L ); | |
1061 | } | |
1062 | ||
1063 | template <typename T> | |
92f5a8d4 | 1064 | result_type internal_visit(boost::detail::reference_content<T>& operand, long) |
7c673cae FG |
1065 | { |
1066 | return internal_visit( operand.get(), 1L ); | |
1067 | } | |
1068 | ||
1069 | template <typename T> | |
92f5a8d4 | 1070 | result_type internal_visit(const boost::detail::reference_content<T>& operand, long) |
7c673cae FG |
1071 | { |
1072 | return internal_visit( operand.get(), 1L ); | |
1073 | } | |
1074 | ||
1075 | template <typename T> | |
92f5a8d4 | 1076 | result_type internal_visit(boost::detail::variant::backup_holder<T>& operand, long) |
7c673cae FG |
1077 | { |
1078 | return internal_visit( operand.get(), 1L ); | |
1079 | } | |
1080 | ||
1081 | template <typename T> | |
92f5a8d4 | 1082 | result_type internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) |
7c673cae FG |
1083 | { |
1084 | return internal_visit( operand.get(), 1L ); | |
1085 | } | |
1086 | ||
1087 | #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) | |
1088 | private: | |
1089 | // silence MSVC warning C4512: assignment operator could not be generated | |
1090 | invoke_visitor& operator= (invoke_visitor const&); | |
1091 | #endif | |
1092 | }; | |
1093 | ||
1094 | }} // namespace detail::variant | |
1095 | ||
1096 | /////////////////////////////////////////////////////////////////////////////// | |
1097 | // class template variant (concept inspired by Andrei Alexandrescu) | |
1098 | // | |
1099 | // See docs and boost/variant/variant_fwd.hpp for more information. | |
1100 | // | |
1101 | template < | |
1102 | typename T0_ | |
1103 | , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(typename T) | |
1104 | > | |
1105 | class variant | |
1106 | { | |
1107 | private: // helpers, for typedefs (below) | |
1108 | ||
1109 | typedef variant wknd_self_t; | |
1110 | ||
1111 | struct is_recursive_ | |
1112 | : detail::variant::is_recursive_flag<T0_> | |
1113 | { | |
1114 | }; | |
1115 | ||
1116 | typedef typename mpl::eval_if< | |
1117 | is_recursive_ | |
1118 | , T0_ | |
1119 | , mpl::identity< T0_ > | |
1120 | >::type unwrapped_T0_; | |
1121 | ||
1122 | struct is_sequence_based_ | |
1123 | : detail::variant::is_over_sequence<unwrapped_T0_> | |
1124 | { | |
1125 | }; | |
1126 | ||
1127 | #if !defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT) | |
1128 | ||
1129 | private: // helpers, for typedefs (below) | |
1130 | ||
1131 | typedef typename mpl::eval_if< | |
1132 | is_sequence_based_ | |
1133 | , unwrapped_T0_ // over_sequence<...>::type | |
1134 | , detail::variant::make_variant_list< | |
1135 | unwrapped_T0_ | |
1136 | , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(T) | |
1137 | > | |
1138 | >::type specified_types; | |
1139 | ||
1140 | BOOST_STATIC_ASSERT(( | |
1141 | ::boost::mpl::not_< mpl::empty<specified_types> >::value | |
1142 | )); | |
1143 | ||
1144 | public: // public typedefs | |
1145 | typedef typename mpl::eval_if< | |
1146 | is_recursive_ | |
1147 | , mpl::transform< | |
1148 | specified_types | |
1149 | , mpl::protect< | |
1150 | detail::variant::quoted_enable_recursive<wknd_self_t> | |
1151 | > | |
1152 | > | |
1153 | , mpl::identity< specified_types > | |
1154 | >::type recursive_enabled_types; // used by is_variant_constructible_from<> trait | |
1155 | ||
1156 | typedef typename mpl::transform< | |
1157 | recursive_enabled_types | |
1158 | , unwrap_recursive<mpl::_1> | |
1159 | >::type types; | |
1160 | ||
1161 | private: // internal typedefs | |
1162 | ||
1163 | typedef typename mpl::transform< | |
1164 | recursive_enabled_types | |
1165 | , mpl::protect< detail::make_reference_content<> > | |
1166 | >::type internal_types; | |
1167 | ||
1168 | typedef typename mpl::front< | |
1169 | internal_types | |
1170 | >::type internal_T0; | |
1171 | ||
1172 | #else // defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT) | |
1173 | ||
1174 | private: // helpers, for typedefs (below) | |
1175 | ||
1176 | typedef unwrapped_T0_ T0; | |
1177 | ||
1178 | #define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS(z,N,_) \ | |
1179 | typedef typename mpl::eval_if< \ | |
1180 | is_recursive_ \ | |
1181 | , detail::variant::enable_recursive< \ | |
1182 | BOOST_PP_CAT(T,N) \ | |
1183 | , wknd_self_t \ | |
1184 | > \ | |
1185 | , mpl::identity< BOOST_PP_CAT(T,N) > \ | |
1186 | >::type BOOST_PP_CAT(recursive_enabled_T,N); \ | |
1187 | /**/ | |
1188 | ||
1189 | BOOST_PP_REPEAT( | |
1190 | BOOST_VARIANT_LIMIT_TYPES | |
1191 | , BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS | |
1192 | , _ | |
1193 | ) | |
1194 | ||
1195 | #undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS | |
1196 | ||
1197 | #define BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS(z,N,_) \ | |
1198 | typedef typename unwrap_recursive< \ | |
1199 | BOOST_PP_CAT(recursive_enabled_T,N) \ | |
1200 | >::type BOOST_PP_CAT(public_T,N); \ | |
1201 | /**/ | |
1202 | ||
1203 | BOOST_PP_REPEAT( | |
1204 | BOOST_VARIANT_LIMIT_TYPES | |
1205 | , BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS | |
1206 | , _ | |
1207 | ) | |
1208 | ||
1209 | #undef BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS | |
1210 | ||
1211 | public: // public typedefs | |
1212 | ||
1213 | typedef typename detail::variant::make_variant_list< | |
1214 | BOOST_VARIANT_ENUM_PARAMS(public_T) | |
1215 | >::type types; | |
1216 | ||
1217 | private: // helpers, for internal typedefs (below) | |
1218 | ||
1219 | #define BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS(z,N,_) \ | |
1220 | typedef detail::make_reference_content< \ | |
1221 | BOOST_PP_CAT(recursive_enabled_T,N) \ | |
1222 | >::type BOOST_PP_CAT(internal_T,N); \ | |
1223 | /**/ | |
1224 | ||
1225 | BOOST_PP_REPEAT( | |
1226 | BOOST_VARIANT_LIMIT_TYPES | |
1227 | , BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS | |
1228 | , _ | |
1229 | ) | |
1230 | ||
1231 | #undef BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS | |
1232 | ||
1233 | private: // internal typedefs | |
1234 | ||
1235 | typedef typename detail::variant::make_variant_list< | |
1236 | BOOST_VARIANT_ENUM_PARAMS(internal_T) | |
1237 | >::type internal_types; | |
1238 | ||
1239 | private: // static precondition assertions | |
1240 | ||
1241 | // NOTE TO USER : | |
1242 | // variant< type-sequence > syntax is not supported on this compiler! | |
1243 | // | |
1244 | BOOST_MPL_ASSERT_NOT(( is_sequence_based_ )); | |
1245 | ||
1246 | #endif // BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT workaround | |
1247 | ||
1248 | private: // helpers, for representation (below) | |
1249 | ||
1250 | typedef typename detail::variant::find_fallback_type< | |
1251 | internal_types | |
1252 | >::type fallback_type_result_; | |
1253 | ||
1254 | typedef typename fallback_type_result_::first | |
1255 | fallback_type_index_; | |
1256 | typedef typename fallback_type_result_::second | |
1257 | fallback_type_; | |
1258 | ||
1259 | struct has_fallback_type_ | |
1260 | : mpl::not_< | |
1261 | is_same< fallback_type_, detail::variant::no_fallback_type > | |
1262 | > | |
1263 | { | |
1264 | }; | |
1265 | ||
1266 | typedef has_fallback_type_ | |
1267 | never_uses_backup_flag; | |
1268 | ||
1269 | typedef typename detail::variant::make_storage< | |
1270 | internal_types, never_uses_backup_flag | |
1271 | >::type storage_t; | |
1272 | ||
1273 | #ifndef BOOST_NO_CXX11_NOEXCEPT | |
1274 | typedef typename detail::variant::is_variant_move_noexcept_constructible< | |
1275 | internal_types | |
1276 | > variant_move_noexcept_constructible; | |
1277 | ||
1278 | typedef typename detail::variant::is_variant_move_noexcept_assignable< | |
1279 | internal_types | |
1280 | > variant_move_noexcept_assignable; | |
1281 | ||
1282 | #endif | |
1283 | ||
1284 | private: // helpers, for representation (below) | |
1285 | ||
1286 | // which_ on: | |
1287 | // * [0, size<internal_types>) indicates stack content | |
1288 | // * [-size<internal_types>, 0) indicates pointer to heap backup | |
1289 | // if which_ >= 0: | |
1290 | // * then which() -> which_ | |
1291 | // * else which() -> -(which_ + 1) | |
1292 | ||
1293 | #if !defined(BOOST_VARIANT_MINIMIZE_SIZE) | |
1294 | ||
1295 | typedef int which_t; | |
1296 | ||
1297 | #else // defined(BOOST_VARIANT_MINIMIZE_SIZE) | |
1298 | ||
1299 | // [if O1_size available, then attempt which_t size optimization...] | |
1300 | // [select signed char if fewer than SCHAR_MAX types, else signed int:] | |
1301 | typedef typename mpl::eval_if< | |
1302 | mpl::equal_to< mpl::O1_size<internal_types>, mpl::long_<-1> > | |
1303 | , mpl::identity< int > | |
1304 | , mpl::if_< | |
1305 | mpl::less< mpl::O1_size<internal_types>, mpl::int_<SCHAR_MAX> > | |
1306 | , signed char | |
1307 | , int | |
1308 | > | |
1309 | >::type which_t; | |
1310 | ||
1311 | #endif // BOOST_VARIANT_MINIMIZE_SIZE switch | |
1312 | ||
1313 | // representation -- private when possible | |
1314 | #if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) | |
1315 | private: | |
1316 | #else | |
1317 | public: | |
1318 | #endif | |
1319 | ||
1320 | which_t which_; | |
1321 | storage_t storage_; | |
1322 | ||
1323 | void indicate_which(int which_arg) BOOST_NOEXCEPT | |
1324 | { | |
1325 | which_ = static_cast<which_t>( which_arg ); | |
1326 | } | |
1327 | ||
1328 | void indicate_backup_which(int which_arg) BOOST_NOEXCEPT | |
1329 | { | |
1330 | which_ = static_cast<which_t>( -(which_arg + 1) ); | |
1331 | } | |
1332 | ||
1333 | private: // helpers, for queries (below) | |
1334 | ||
1335 | bool using_backup() const BOOST_NOEXCEPT | |
1336 | { | |
1337 | return which_ < 0; | |
1338 | } | |
1339 | ||
1340 | public: // queries | |
1341 | ||
1342 | int which() const BOOST_NOEXCEPT | |
1343 | { | |
1344 | // If using heap backup... | |
1345 | if (using_backup()) | |
1346 | // ...then return adjusted which_: | |
1347 | return -(which_ + 1); | |
1348 | ||
1349 | // Otherwise, return which_ directly: | |
1350 | return which_; | |
1351 | } | |
1352 | ||
1353 | private: // helpers, for structors (below) | |
1354 | ||
1355 | struct initializer | |
1356 | : BOOST_VARIANT_AUX_INITIALIZER_T( | |
1357 | recursive_enabled_types, recursive_enabled_T | |
1358 | ) | |
1359 | { | |
1360 | }; | |
1361 | ||
1362 | void destroy_content() BOOST_NOEXCEPT | |
1363 | { | |
1364 | detail::variant::destroyer visitor; | |
1365 | this->internal_apply_visitor(visitor); | |
1366 | } | |
1367 | ||
1368 | public: // structors | |
1369 | ||
1370 | ~variant() BOOST_NOEXCEPT | |
1371 | { | |
1372 | destroy_content(); | |
1373 | } | |
1374 | ||
f67539c2 | 1375 | variant() |
7c673cae FG |
1376 | #if !(defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x5130)) |
1377 | BOOST_NOEXCEPT_IF(boost::has_nothrow_constructor<internal_T0>::value) | |
1378 | #endif | |
1379 | { | |
1380 | #ifdef _MSC_VER | |
1381 | #pragma warning( push ) | |
f67539c2 TL |
1382 | // behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized |
1383 | #pragma warning( disable : 4345 ) | |
7c673cae FG |
1384 | #endif |
1385 | // NOTE TO USER : | |
1386 | // Compile error from here indicates that the first bound | |
1387 | // type is not default-constructible, and so variant cannot | |
1388 | // support its own default-construction. | |
1389 | // | |
1390 | new( storage_.address() ) internal_T0(); | |
1391 | indicate_which(0); // zero is the index of the first bounded type | |
1392 | #ifdef _MSC_VER | |
1393 | #pragma warning( pop ) | |
1394 | #endif | |
1395 | } | |
1396 | ||
1397 | private: // helpers, for structors, cont. (below) | |
1398 | ||
1399 | class convert_copy_into | |
1400 | : public static_visitor<int> | |
1401 | { | |
1402 | private: // representation | |
1403 | ||
1404 | void* storage_; | |
1405 | ||
1406 | public: // structors | |
1407 | ||
1408 | explicit convert_copy_into(void* storage) BOOST_NOEXCEPT | |
1409 | : storage_(storage) | |
1410 | { | |
1411 | } | |
1412 | ||
1413 | public: // internal visitor interfaces (below) | |
1414 | ||
1415 | template <typename T> | |
1416 | int internal_visit(T& operand, int) const | |
1417 | { | |
1418 | // NOTE TO USER : | |
f67539c2 | 1419 | // Compile error here indicates one of the source variant's types |
7c673cae FG |
1420 | // cannot be unambiguously converted to the destination variant's |
1421 | // types (or that no conversion exists). | |
1422 | // | |
1423 | return initializer::initialize(storage_, operand); | |
1424 | } | |
1425 | ||
20effc67 | 1426 | # if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x0564)) |
7c673cae FG |
1427 | template <typename T> |
1428 | result_type internal_visit(const T& operand, int) const | |
1429 | { | |
1430 | return initializer::initialize(storage_, operand); | |
1431 | } | |
1432 | # endif | |
1433 | ||
1434 | template <typename T> | |
1435 | int internal_visit(boost::detail::reference_content<T>& operand, long) const | |
1436 | { | |
1437 | return internal_visit( operand.get(), 1L ); | |
1438 | } | |
1439 | ||
1440 | template <typename T> | |
1441 | int internal_visit(const boost::detail::reference_content<T>& operand, long) const | |
1442 | { | |
1443 | return internal_visit( operand.get(), 1L ); | |
1444 | } | |
1445 | ||
1446 | template <typename T> | |
1447 | int internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const | |
1448 | { | |
1449 | return internal_visit( operand.get(), 1L ); | |
1450 | } | |
1451 | ||
1452 | template <typename T> | |
1453 | int internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const | |
1454 | { | |
1455 | return internal_visit( operand.get(), 1L ); | |
1456 | } | |
1457 | ||
1458 | template <typename T> | |
1459 | int internal_visit(boost::recursive_wrapper<T>& operand, long) const | |
1460 | { | |
1461 | return internal_visit( operand.get(), 1L ); | |
1462 | } | |
1463 | ||
1464 | template <typename T> | |
1465 | int internal_visit(const boost::recursive_wrapper<T>& operand, long) const | |
1466 | { | |
1467 | return internal_visit( operand.get(), 1L ); | |
1468 | } | |
1469 | ||
1470 | }; | |
1471 | ||
1472 | friend class convert_copy_into; | |
1473 | ||
1474 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
1475 | class convert_move_into | |
1476 | : public static_visitor<int> | |
1477 | { | |
1478 | private: // representation | |
1479 | ||
1480 | void* storage_; | |
1481 | ||
1482 | public: // structors | |
1483 | ||
1484 | explicit convert_move_into(void* storage) BOOST_NOEXCEPT | |
1485 | : storage_(storage) | |
1486 | { | |
1487 | } | |
1488 | ||
1489 | public: // internal visitor interfaces (below) | |
1490 | ||
1491 | template <typename T> | |
1492 | int internal_visit(T& operand, int) const | |
1493 | { | |
1494 | // NOTE TO USER : | |
f67539c2 | 1495 | // Compile error here indicates one of the source variant's types |
7c673cae FG |
1496 | // cannot be unambiguously converted to the destination variant's |
1497 | // types (or that no conversion exists). | |
1498 | // | |
1499 | return initializer::initialize(storage_, detail::variant::move(operand) ); | |
1500 | } | |
1501 | ||
1502 | template <typename T> | |
1503 | int internal_visit(boost::detail::reference_content<T>& operand, long) const | |
1504 | { | |
1505 | return internal_visit( operand.get(), 1L ); | |
1506 | } | |
1507 | ||
1508 | template <typename T> | |
1509 | int internal_visit(const boost::detail::reference_content<T>& operand, long) const | |
1510 | { | |
1511 | return internal_visit( operand.get(), 1L ); | |
1512 | } | |
1513 | ||
1514 | template <typename T> | |
1515 | int internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const | |
1516 | { | |
1517 | return internal_visit( operand.get(), 1L ); | |
1518 | } | |
1519 | ||
1520 | template <typename T> | |
1521 | int internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const | |
1522 | { | |
1523 | return internal_visit( operand.get(), 1L ); | |
1524 | } | |
1525 | ||
1526 | template <typename T> | |
1527 | int internal_visit(boost::recursive_wrapper<T>& operand, long) const | |
1528 | { | |
1529 | return internal_visit( operand.get(), 1L ); | |
1530 | } | |
1531 | ||
1532 | template <typename T> | |
1533 | int internal_visit(const boost::recursive_wrapper<T>& operand, long) const | |
1534 | { | |
1535 | return internal_visit( operand.get(), 1L ); | |
1536 | } | |
1537 | }; | |
1538 | ||
1539 | friend class convert_move_into; | |
1540 | #endif | |
1541 | ||
f67539c2 | 1542 | private: // helpers, for structors, below |
7c673cae FG |
1543 | |
1544 | template <typename T> | |
1545 | void convert_construct( | |
1546 | T& operand | |
1547 | , int | |
1548 | , mpl::false_ = mpl::false_() // is_foreign_variant | |
1549 | ) | |
1550 | { | |
1551 | // NOTE TO USER : | |
f67539c2 | 1552 | // Compile error here indicates that the given type is not |
7c673cae FG |
1553 | // unambiguously convertible to one of the variant's types |
1554 | // (or that no conversion exists). | |
1555 | // | |
1556 | indicate_which( | |
1557 | initializer::initialize( | |
1558 | storage_.address() | |
1559 | , operand | |
1560 | ) | |
1561 | ); | |
1562 | } | |
1563 | ||
1564 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
1565 | template <typename T> | |
1566 | typename boost::enable_if<boost::is_rvalue_reference<T&&> >::type convert_construct( | |
1567 | T&& operand | |
1568 | , int | |
1569 | , mpl::false_ = mpl::false_() // is_foreign_variant | |
1570 | ) | |
1571 | { | |
1572 | // NOTE TO USER : | |
f67539c2 | 1573 | // Compile error here indicates that the given type is not |
7c673cae FG |
1574 | // unambiguously convertible to one of the variant's types |
1575 | // (or that no conversion exists). | |
1576 | // | |
1577 | indicate_which( | |
1578 | initializer::initialize( | |
1579 | storage_.address() | |
1580 | , detail::variant::move(operand) | |
1581 | ) | |
1582 | ); | |
1583 | } | |
1584 | #endif | |
1585 | ||
1586 | template <typename Variant> | |
1587 | void convert_construct( | |
1588 | Variant& operand | |
1589 | , long | |
1590 | , mpl::true_// is_foreign_variant | |
1591 | ) | |
1592 | { | |
1593 | convert_copy_into visitor(storage_.address()); | |
1594 | indicate_which( | |
1595 | operand.internal_apply_visitor(visitor) | |
1596 | ); | |
1597 | } | |
1598 | ||
1599 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
1600 | template <typename Variant> | |
1601 | typename boost::enable_if<boost::is_rvalue_reference<Variant&&> >::type convert_construct( | |
1602 | Variant&& operand | |
1603 | , long | |
1604 | , mpl::true_// is_foreign_variant | |
1605 | ) | |
1606 | { | |
1607 | convert_move_into visitor(storage_.address()); | |
1608 | indicate_which( | |
1609 | operand.internal_apply_visitor(visitor) | |
1610 | ); | |
1611 | } | |
1612 | #endif | |
1613 | ||
1614 | template <typename Variant> | |
1615 | void convert_construct_variant(Variant& operand) | |
1616 | { | |
1617 | // [Determine if the given variant is itself a bounded type, or if its | |
1618 | // content needs to be converted (i.e., it is a 'foreign' variant):] | |
1619 | // | |
1620 | ||
1621 | typedef typename mpl::find_if< | |
1622 | types | |
1623 | , is_same< | |
1624 | add_const<mpl::_1> | |
1625 | , const Variant | |
1626 | > | |
1627 | >::type found_it; | |
1628 | ||
1629 | typedef typename mpl::end<types>::type not_found; | |
1630 | typedef typename is_same< | |
1631 | found_it, not_found | |
1632 | >::type is_foreign_variant; | |
1633 | ||
1634 | // Convert construct from operand: | |
1635 | convert_construct( | |
1636 | operand, 1L | |
1637 | , is_foreign_variant() | |
1638 | ); | |
1639 | } | |
1640 | ||
1641 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
1642 | template <typename Variant> | |
1643 | typename boost::enable_if<boost::is_rvalue_reference<Variant&&> >::type convert_construct_variant(Variant&& operand) | |
1644 | { | |
1645 | // [Determine if the given variant is itself a bounded type, or if its | |
1646 | // content needs to be converted (i.e., it is a 'foreign' variant):] | |
1647 | // | |
1648 | ||
1649 | typedef typename mpl::find_if< | |
1650 | types | |
1651 | , is_same< | |
1652 | add_const<mpl::_1> | |
1653 | , const Variant | |
1654 | > | |
1655 | >::type found_it; | |
1656 | ||
1657 | typedef typename mpl::end<types>::type not_found; | |
1658 | typedef typename is_same< | |
1659 | found_it, not_found | |
1660 | >::type is_foreign_variant; | |
1661 | ||
1662 | // Convert move construct from operand: | |
1663 | convert_construct( | |
1664 | detail::variant::move(operand), 1L | |
1665 | , is_foreign_variant() | |
1666 | ); | |
1667 | } | |
1668 | #endif | |
1669 | ||
1670 | template <BOOST_VARIANT_ENUM_PARAMS(typename U)> | |
1671 | typename boost::enable_if<mpl::or_< | |
1672 | boost::is_same<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>, variant>, | |
1673 | boost::detail::variant::is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>&, internal_types> | |
1674 | > >::type convert_construct( | |
1675 | boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>& operand | |
1676 | , long | |
1677 | ) | |
1678 | { | |
1679 | convert_construct_variant(operand); | |
1680 | } | |
1681 | ||
1682 | template <BOOST_VARIANT_ENUM_PARAMS(typename U)> | |
1683 | typename boost::enable_if<mpl::or_< | |
1684 | boost::is_same<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>, variant>, | |
1685 | boost::detail::variant::is_variant_constructible_from<const boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>&, internal_types> | |
1686 | > >::type convert_construct( | |
1687 | const boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>& operand | |
1688 | , long | |
1689 | ) | |
1690 | { | |
f67539c2 | 1691 | convert_construct_variant(operand); |
7c673cae FG |
1692 | } |
1693 | ||
1694 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
1695 | template <BOOST_VARIANT_ENUM_PARAMS(typename U)> | |
1696 | typename boost::enable_if<mpl::or_< | |
1697 | boost::is_same<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>, variant>, | |
1698 | boost::detail::variant::is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>&&, internal_types> | |
1699 | > >::type convert_construct( | |
1700 | boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>&& operand | |
1701 | , long | |
1702 | ) | |
1703 | { | |
f67539c2 | 1704 | convert_construct_variant( detail::variant::move(operand) ); |
7c673cae FG |
1705 | } |
1706 | #endif | |
1707 | ||
1708 | public: // structors, cont. | |
1709 | ||
1710 | template <typename T> | |
1711 | variant(const T& operand, | |
b32b8144 FG |
1712 | typename boost::enable_if<mpl::or_< |
1713 | mpl::and_< | |
1714 | mpl::not_< boost::is_same<T, variant> >, | |
1715 | boost::detail::variant::is_variant_constructible_from<const T&, internal_types> | |
f67539c2 TL |
1716 | >, |
1717 | boost::is_same<T, boost::recursive_variant_> >, | |
1718 | bool >::type = true) | |
7c673cae FG |
1719 | { |
1720 | convert_construct(operand, 1L); | |
1721 | } | |
1722 | ||
1723 | template <typename T> | |
1724 | variant( | |
1725 | T& operand | |
b32b8144 FG |
1726 | , typename boost::enable_if<mpl::or_< |
1727 | mpl::and_< | |
1728 | mpl::not_< is_const<T> >, | |
1729 | mpl::not_< boost::is_same<T, variant> >, | |
1730 | boost::detail::variant::is_variant_constructible_from<T&, internal_types> | |
1731 | >, | |
f67539c2 TL |
1732 | boost::is_same<T, boost::recursive_variant_> >, |
1733 | bool >::type = true | |
7c673cae FG |
1734 | ) |
1735 | { | |
1736 | convert_construct(operand, 1L); | |
1737 | } | |
1738 | ||
1739 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
1740 | template <class T> | |
1741 | variant(T&& operand, | |
b32b8144 FG |
1742 | typename boost::enable_if<mpl::or_< |
1743 | mpl::and_< | |
1744 | boost::is_rvalue_reference<T&&>, | |
1745 | mpl::not_< boost::is_const<T> >, | |
1746 | mpl::not_< boost::is_same<T, variant> >, | |
1747 | boost::detail::variant::is_variant_constructible_from<T&&, internal_types> | |
1748 | >, | |
f67539c2 TL |
1749 | boost::is_same<T, boost::recursive_variant_> >, |
1750 | bool >::type = true) | |
7c673cae FG |
1751 | { |
1752 | convert_construct( detail::variant::move(operand), 1L); | |
1753 | } | |
1754 | #endif | |
1755 | ||
1756 | public: // structors, cont. | |
1757 | ||
1758 | // [MSVC6 requires copy constructor appear after template constructors] | |
1759 | variant(const variant& operand) | |
1760 | { | |
1761 | // Copy the value of operand into *this... | |
1762 | detail::variant::copy_into visitor( storage_.address() ); | |
1763 | operand.internal_apply_visitor(visitor); | |
1764 | ||
1765 | // ...and activate the *this's primary storage on success: | |
1766 | indicate_which(operand.which()); | |
1767 | } | |
1768 | ||
1769 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
1770 | variant(variant&& operand) BOOST_NOEXCEPT_IF(variant_move_noexcept_constructible::type::value) | |
1771 | { | |
1772 | // Move the value of operand into *this... | |
1773 | detail::variant::move_into visitor( storage_.address() ); | |
1774 | operand.internal_apply_visitor(visitor); | |
1775 | ||
1776 | // ...and activate the *this's primary storage on success: | |
1777 | indicate_which(operand.which()); | |
1778 | } | |
1779 | #endif | |
1780 | ||
1781 | private: // helpers, for modifiers (below) | |
1782 | ||
1783 | # if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) | |
1784 | template <typename Variant> | |
1785 | friend class detail::variant::backup_assigner; | |
1786 | # endif | |
1787 | ||
1788 | // class assigner | |
1789 | // | |
1790 | // Internal visitor that "assigns" the visited value to the given variant | |
1791 | // by appropriate destruction and copy-construction. | |
1792 | // | |
1793 | ||
1794 | class assigner | |
1795 | : public static_visitor<> | |
1796 | { | |
1797 | protected: // representation | |
1798 | ||
1799 | variant& lhs_; | |
1800 | const int rhs_which_; | |
1801 | ||
1802 | public: // structors | |
1803 | ||
1804 | assigner(variant& lhs, int rhs_which) BOOST_NOEXCEPT | |
1805 | : lhs_(lhs) | |
1806 | , rhs_which_(rhs_which) | |
1807 | { | |
1808 | } | |
1809 | ||
1810 | protected: // helpers, for internal visitor interface (below) | |
1811 | ||
1812 | template <typename RhsT, typename B1, typename B2> | |
1813 | void assign_impl( | |
1814 | const RhsT& rhs_content | |
1815 | , mpl::true_ // has_nothrow_copy | |
1816 | , B1 // is_nothrow_move_constructible | |
1817 | , B2 // has_fallback_type | |
1818 | ) const BOOST_NOEXCEPT | |
1819 | { | |
1820 | // Destroy lhs's content... | |
1821 | lhs_.destroy_content(); // nothrow | |
1822 | ||
1823 | // ...copy rhs content into lhs's storage... | |
1824 | new(lhs_.storage_.address()) | |
1825 | RhsT( rhs_content ); // nothrow | |
1826 | ||
1827 | // ...and indicate new content type: | |
1828 | lhs_.indicate_which(rhs_which_); // nothrow | |
1829 | } | |
1830 | ||
1831 | template <typename RhsT, typename B> | |
1832 | void assign_impl( | |
1833 | const RhsT& rhs_content | |
1834 | , mpl::false_ // has_nothrow_copy | |
1835 | , mpl::true_ // is_nothrow_move_constructible | |
1836 | , B // has_fallback_type | |
1837 | ) const | |
1838 | { | |
1839 | // Attempt to make a temporary copy (so as to move it below)... | |
1840 | RhsT temp(rhs_content); | |
1841 | ||
1842 | // ...and upon success destroy lhs's content... | |
1843 | lhs_.destroy_content(); // nothrow | |
1844 | ||
1845 | // ...move the temporary copy into lhs's storage... | |
1846 | new(lhs_.storage_.address()) | |
1847 | RhsT( detail::variant::move(temp) ); // nothrow | |
1848 | ||
1849 | // ...and indicate new content type: | |
1850 | lhs_.indicate_which(rhs_which_); // nothrow | |
1851 | } | |
1852 | ||
1853 | void construct_fallback() const BOOST_NOEXCEPT { | |
1854 | // In case of failure, default-construct fallback type in lhs's storage... | |
1855 | new (lhs_.storage_.address()) | |
1856 | fallback_type_; // nothrow | |
1857 | ||
1858 | // ...indicate construction of fallback type... | |
1859 | lhs_.indicate_which( | |
1860 | BOOST_MPL_AUX_VALUE_WKND(fallback_type_index_)::value | |
1861 | ); // nothrow | |
1862 | } | |
1863 | ||
1864 | template <typename RhsT> | |
1865 | void assign_impl( | |
1866 | const RhsT& rhs_content | |
1867 | , mpl::false_ // has_nothrow_copy | |
1868 | , mpl::false_ // is_nothrow_move_constructible | |
1869 | , mpl::true_ // has_fallback_type | |
1870 | ) const | |
1871 | { | |
1872 | // Destroy lhs's content... | |
1873 | lhs_.destroy_content(); // nothrow | |
1874 | ||
1875 | BOOST_TRY | |
1876 | { | |
1877 | // ...and attempt to copy rhs's content into lhs's storage: | |
1878 | new(lhs_.storage_.address()) | |
1879 | RhsT( rhs_content ); | |
1880 | } | |
1881 | BOOST_CATCH (...) | |
1882 | { | |
1883 | construct_fallback(); | |
1884 | ||
1885 | // ...and rethrow: | |
1886 | BOOST_RETHROW; | |
1887 | } | |
1888 | BOOST_CATCH_END | |
1889 | ||
1890 | // In the event of success, indicate new content type: | |
1891 | lhs_.indicate_which(rhs_which_); // nothrow | |
1892 | } | |
1893 | ||
1894 | template <typename RhsT> | |
1895 | void assign_impl( | |
1896 | const RhsT& rhs_content | |
1897 | , mpl::false_ // has_nothrow_copy | |
1898 | , mpl::false_ // is_nothrow_move_constructible | |
1899 | , mpl::false_ // has_fallback_type | |
1900 | ) const | |
1901 | { | |
1902 | detail::variant::backup_assigner<wknd_self_t> | |
1903 | visitor(lhs_, rhs_which_, rhs_content); | |
1904 | lhs_.internal_apply_visitor(visitor); | |
1905 | } | |
1906 | ||
1907 | public: // internal visitor interfaces | |
1908 | ||
1909 | template <typename RhsT> | |
92f5a8d4 | 1910 | void internal_visit(const RhsT& rhs_content, int) const |
7c673cae FG |
1911 | { |
1912 | typedef typename has_nothrow_copy<RhsT>::type | |
1913 | nothrow_copy; | |
1914 | typedef typename mpl::or_< // reduces compile-time | |
1915 | nothrow_copy | |
1916 | , is_nothrow_move_constructible<RhsT> | |
1917 | >::type nothrow_move_constructor; | |
1918 | ||
1919 | assign_impl( | |
1920 | rhs_content | |
1921 | , nothrow_copy() | |
1922 | , nothrow_move_constructor() | |
1923 | , has_fallback_type_() | |
1924 | ); | |
7c673cae FG |
1925 | } |
1926 | ||
1927 | #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) | |
1928 | private: | |
1929 | // silence MSVC warning C4512: assignment operator could not be generated | |
1930 | assigner& operator= (assigner const&); | |
1931 | #endif | |
1932 | }; | |
f67539c2 | 1933 | |
7c673cae | 1934 | friend class assigner; |
f67539c2 | 1935 | |
7c673cae FG |
1936 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES |
1937 | // class move_assigner | |
1938 | // | |
1939 | // Internal visitor that "move assigns" the visited value to the given variant | |
1940 | // by appropriate destruction and move-construction. | |
1941 | // | |
1942 | ||
1943 | class move_assigner | |
1944 | : public assigner | |
1945 | { | |
1946 | public: // structors | |
1947 | ||
1948 | move_assigner(variant& lhs, int rhs_which) BOOST_NOEXCEPT | |
1949 | : assigner(lhs, rhs_which) | |
1950 | { | |
1951 | } | |
1952 | ||
1953 | private: // helpers, for internal visitor interface (below) | |
f67539c2 | 1954 | |
7c673cae FG |
1955 | template <typename RhsT, typename B2> |
1956 | void assign_impl( | |
1957 | RhsT& rhs_content | |
1958 | , mpl::true_ // has_nothrow_copy | |
1959 | , mpl::false_ // is_nothrow_move_constructible | |
1960 | , B2 // has_fallback_type | |
1961 | ) const BOOST_NOEXCEPT | |
1962 | { | |
1963 | assigner::assign_impl(rhs_content, mpl::true_(), mpl::false_(), B2()); | |
1964 | } | |
1965 | ||
1966 | template <typename RhsT, typename B, typename B2> | |
1967 | void assign_impl( | |
1968 | RhsT& rhs_content | |
1969 | , B // has_nothrow_copy | |
1970 | , mpl::true_ // is_nothrow_move_constructible | |
1971 | , B2 // has_fallback_type | |
1972 | ) const BOOST_NOEXCEPT | |
1973 | { | |
1974 | // ...destroy lhs's content... | |
1975 | assigner::lhs_.destroy_content(); // nothrow | |
1976 | ||
1977 | // ...move the rhs_content into lhs's storage... | |
1978 | new(assigner::lhs_.storage_.address()) | |
1979 | RhsT( detail::variant::move(rhs_content) ); // nothrow | |
1980 | ||
1981 | // ...and indicate new content type: | |
1982 | assigner::lhs_.indicate_which(assigner::rhs_which_); // nothrow | |
1983 | } | |
1984 | ||
1985 | template <typename RhsT> | |
1986 | void assign_impl( | |
1987 | RhsT& rhs_content | |
1988 | , mpl::false_ // has_nothrow_copy | |
1989 | , mpl::false_ // is_nothrow_move_constructible | |
1990 | , mpl::true_ // has_fallback_type | |
1991 | ) const | |
1992 | { | |
1993 | // Destroy lhs's content... | |
1994 | assigner::lhs_.destroy_content(); // nothrow | |
1995 | ||
1996 | BOOST_TRY | |
1997 | { | |
1998 | // ...and attempt to copy rhs's content into lhs's storage: | |
1999 | new(assigner::lhs_.storage_.address()) | |
2000 | RhsT( detail::variant::move(rhs_content) ); | |
2001 | } | |
2002 | BOOST_CATCH (...) | |
2003 | { | |
2004 | assigner::construct_fallback(); | |
2005 | ||
2006 | // ...and rethrow: | |
2007 | BOOST_RETHROW; | |
2008 | } | |
2009 | BOOST_CATCH_END | |
2010 | ||
2011 | // In the event of success, indicate new content type: | |
2012 | assigner::lhs_.indicate_which(assigner::rhs_which_); // nothrow | |
2013 | } | |
f67539c2 | 2014 | |
7c673cae FG |
2015 | template <typename RhsT> |
2016 | void assign_impl( | |
2017 | RhsT& rhs_content | |
2018 | , mpl::false_ // has_nothrow_copy | |
2019 | , mpl::false_ // is_nothrow_move_constructible | |
2020 | , mpl::false_ // has_fallback_type | |
2021 | ) const | |
2022 | { | |
2023 | assigner::assign_impl(rhs_content, mpl::false_(), mpl::false_(), mpl::false_()); | |
2024 | } | |
2025 | ||
2026 | public: // internal visitor interfaces | |
2027 | ||
2028 | template <typename RhsT> | |
92f5a8d4 | 2029 | void internal_visit(RhsT& rhs_content, int) const |
7c673cae FG |
2030 | { |
2031 | typedef typename is_nothrow_move_constructible<RhsT>::type | |
2032 | nothrow_move_constructor; | |
2033 | typedef typename mpl::or_< // reduces compile-time | |
2034 | nothrow_move_constructor | |
2035 | , has_nothrow_copy<RhsT> | |
2036 | >::type nothrow_copy; | |
2037 | ||
2038 | assign_impl( | |
2039 | rhs_content | |
2040 | , nothrow_copy() | |
2041 | , nothrow_move_constructor() | |
2042 | , has_fallback_type_() | |
2043 | ); | |
7c673cae FG |
2044 | } |
2045 | ||
2046 | #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600)) | |
2047 | private: | |
2048 | // silence MSVC warning C4512: assignment operator could not be generated | |
2049 | move_assigner& operator= (move_assigner const&); | |
2050 | #endif | |
2051 | }; | |
2052 | ||
2053 | friend class move_assigner; | |
2054 | #endif // BOOST_NO_CXX11_RVALUE_REFERENCES | |
2055 | ||
2056 | void variant_assign(const variant& rhs) | |
2057 | { | |
2058 | // If the contained types are EXACTLY the same... | |
2059 | if (which_ == rhs.which_) | |
2060 | { | |
2061 | // ...then assign rhs's storage to lhs's content: | |
2062 | detail::variant::assign_storage visitor(rhs.storage_.address()); | |
2063 | this->internal_apply_visitor(visitor); | |
2064 | } | |
2065 | else | |
2066 | { | |
2067 | // Otherwise, perform general (copy-based) variant assignment: | |
2068 | assigner visitor(*this, rhs.which()); | |
f67539c2 | 2069 | rhs.internal_apply_visitor(visitor); |
7c673cae FG |
2070 | } |
2071 | } | |
2072 | ||
2073 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
2074 | void variant_assign(variant&& rhs) | |
2075 | { | |
2076 | // If the contained types are EXACTLY the same... | |
2077 | if (which_ == rhs.which_) | |
2078 | { | |
2079 | // ...then move rhs's storage to lhs's content: | |
2080 | detail::variant::move_storage visitor(rhs.storage_.address()); | |
2081 | this->internal_apply_visitor(visitor); | |
2082 | } | |
2083 | else | |
2084 | { | |
2085 | // Otherwise, perform general (move-based) variant assignment: | |
2086 | move_assigner visitor(*this, rhs.which()); | |
f67539c2 | 2087 | rhs.internal_apply_visitor(visitor); |
7c673cae FG |
2088 | } |
2089 | } | |
2090 | #endif // BOOST_NO_CXX11_RVALUE_REFERENCES | |
2091 | ||
2092 | private: // helpers, for modifiers (below) | |
2093 | ||
2094 | template <typename T> | |
2095 | void assign(const T& rhs) | |
2096 | { | |
2097 | // If direct T-to-T assignment is not possible... | |
2098 | detail::variant::direct_assigner<T> direct_assign(rhs); | |
2099 | if (this->apply_visitor(direct_assign) == false) | |
2100 | { | |
2101 | // ...then convert rhs to variant and assign: | |
2102 | // | |
2103 | // While potentially inefficient, the following construction of a | |
2104 | // variant allows T as any type convertible to one of the bounded | |
2105 | // types without excessive code redundancy. | |
2106 | // | |
2107 | variant temp(rhs); | |
2108 | variant_assign( detail::variant::move(temp) ); | |
2109 | } | |
2110 | } | |
2111 | ||
2112 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
2113 | template <typename T> | |
2114 | void move_assign(T&& rhs) | |
2115 | { | |
2116 | // If direct T-to-T move assignment is not possible... | |
2117 | detail::variant::direct_mover<T> direct_move(rhs); | |
2118 | if (this->apply_visitor(direct_move) == false) | |
2119 | { | |
2120 | // ...then convert rhs to variant and assign: | |
2121 | // | |
2122 | // While potentially inefficient, the following construction of a | |
2123 | // variant allows T as any type convertible to one of the bounded | |
2124 | // types without excessive code redundancy. | |
2125 | // | |
2126 | variant temp( detail::variant::move(rhs) ); | |
2127 | variant_assign( detail::variant::move(temp) ); | |
2128 | } | |
2129 | } | |
2130 | #endif // BOOST_NO_CXX11_RVALUE_REFERENCES | |
2131 | ||
2132 | public: // modifiers | |
2133 | ||
2134 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
2135 | template <class T> | |
2136 | typename boost::enable_if< | |
2137 | boost::mpl::and_< | |
2138 | boost::is_rvalue_reference<T&&>, | |
2139 | mpl::not_< boost::is_const<T> >, | |
2140 | boost::detail::variant::is_variant_constructible_from<T&&, internal_types> | |
2141 | >, | |
2142 | variant& | |
f67539c2 | 2143 | >::type operator=(T&& rhs) |
7c673cae FG |
2144 | { |
2145 | move_assign( detail::variant::move(rhs) ); | |
2146 | return *this; | |
2147 | } | |
2148 | #endif // BOOST_NO_CXX11_RVALUE_REFERENCES | |
2149 | ||
2150 | template <typename T> | |
2151 | typename boost::enable_if< | |
2152 | mpl::or_< | |
2153 | boost::is_same<T, variant>, | |
2154 | boost::detail::variant::is_variant_constructible_from<const T&, internal_types> | |
2155 | >, | |
2156 | variant& | |
2157 | >::type operator=(const T& rhs) | |
2158 | { | |
2159 | assign(rhs); | |
2160 | return *this; | |
2161 | } | |
2162 | ||
2163 | // [MSVC6 requires copy assign appear after templated operator=] | |
2164 | variant& operator=(const variant& rhs) | |
2165 | { | |
2166 | variant_assign(rhs); | |
2167 | return *this; | |
2168 | } | |
2169 | ||
2170 | #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES | |
f67539c2 | 2171 | variant& operator=(variant&& rhs) |
7c673cae FG |
2172 | #if !defined(__GNUC__) || (__GNUC__ != 4) || (__GNUC_MINOR__ > 6) || defined(__clang__) |
2173 | BOOST_NOEXCEPT_IF(variant_move_noexcept_constructible::type::value && variant_move_noexcept_assignable::type::value) | |
2174 | #endif | |
2175 | { | |
2176 | variant_assign( detail::variant::move(rhs) ); | |
2177 | return *this; | |
2178 | } | |
2179 | #endif // BOOST_NO_CXX11_RVALUE_REFERENCES | |
2180 | ||
2181 | void swap(variant& rhs) | |
2182 | { | |
2183 | // If the contained types are the same... | |
2184 | if (which() == rhs.which()) | |
2185 | { | |
2186 | // ...then swap the values directly: | |
2187 | detail::variant::swap_with<variant> visitor(rhs); | |
2188 | this->apply_visitor(visitor); | |
2189 | } | |
2190 | else | |
2191 | { | |
2192 | // ...otherwise, perform general variant swap: | |
2193 | variant tmp( detail::variant::move(rhs) ); | |
2194 | rhs = detail::variant::move(*this); | |
2195 | *this = detail::variant::move(tmp); | |
2196 | } | |
2197 | } | |
2198 | ||
2199 | public: // queries | |
2200 | ||
2201 | // | |
2202 | // NOTE: member which() defined above. | |
2203 | // | |
2204 | ||
2205 | bool empty() const BOOST_NOEXCEPT | |
2206 | { | |
2207 | return false; | |
2208 | } | |
2209 | ||
2210 | const boost::typeindex::type_info& type() const | |
2211 | { | |
2212 | detail::variant::reflect visitor; | |
2213 | return this->apply_visitor(visitor); | |
2214 | } | |
2215 | ||
2216 | public: // prevent comparison with foreign types | |
2217 | ||
2218 | template <typename U> | |
2219 | void operator==(const U&) const | |
2220 | { | |
2221 | BOOST_STATIC_ASSERT( false && sizeof(U) ); | |
2222 | } | |
2223 | ||
2224 | template <typename U> | |
2225 | void operator<(const U&) const | |
2226 | { | |
2227 | BOOST_STATIC_ASSERT( false && sizeof(U) ); | |
2228 | } | |
2229 | ||
2230 | template <typename U> | |
2231 | void operator!=(const U&) const | |
2232 | { | |
2233 | BOOST_STATIC_ASSERT( false && sizeof(U) ); | |
2234 | } | |
2235 | ||
2236 | template <typename U> | |
2237 | void operator>(const U&) const | |
2238 | { | |
2239 | BOOST_STATIC_ASSERT( false && sizeof(U) ); | |
2240 | } | |
2241 | ||
2242 | template <typename U> | |
2243 | void operator<=(const U&) const | |
2244 | { | |
2245 | BOOST_STATIC_ASSERT( false && sizeof(U) ); | |
2246 | } | |
2247 | ||
2248 | template <typename U> | |
2249 | void operator>=(const U&) const | |
2250 | { | |
2251 | BOOST_STATIC_ASSERT( false && sizeof(U) ); | |
2252 | } | |
2253 | ||
2254 | public: // comparison operators | |
2255 | ||
2256 | // [MSVC6 requires these operators appear after template operators] | |
2257 | ||
2258 | bool operator==(const variant& rhs) const | |
2259 | { | |
2260 | if (this->which() != rhs.which()) | |
2261 | return false; | |
2262 | ||
2263 | detail::variant::comparer< | |
2264 | variant, detail::variant::equal_comp | |
2265 | > visitor(*this); | |
2266 | return rhs.apply_visitor(visitor); | |
2267 | } | |
2268 | ||
2269 | bool operator<(const variant& rhs) const | |
2270 | { | |
2271 | // | |
2272 | // Dirk Schreib suggested this collating order. | |
2273 | // | |
2274 | ||
2275 | if (this->which() != rhs.which()) | |
2276 | return this->which() < rhs.which(); | |
2277 | ||
2278 | detail::variant::comparer< | |
2279 | variant, detail::variant::less_comp | |
2280 | > visitor(*this); | |
2281 | return rhs.apply_visitor(visitor); | |
2282 | } | |
2283 | ||
2284 | /////////////////////////////////////////////////////////////////////////////// | |
2285 | // comparison operators != > <= >= | |
2286 | inline bool operator!=(const variant& rhs) const | |
2287 | { | |
2288 | return !(*this == rhs); | |
2289 | } | |
2290 | ||
2291 | inline bool operator>(const variant& rhs) const | |
2292 | { | |
2293 | return rhs < *this; | |
2294 | } | |
2295 | ||
2296 | inline bool operator<=(const variant& rhs) const | |
2297 | { | |
2298 | return !(*this > rhs); | |
2299 | } | |
2300 | ||
2301 | inline bool operator>=(const variant& rhs) const | |
2302 | { | |
2303 | return !(*this < rhs); | |
2304 | } | |
2305 | ||
2306 | // helpers, for visitation support (below) -- private when possible | |
2307 | #if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) | |
2308 | ||
2309 | template < BOOST_VARIANT_ENUM_PARAMS(typename U) > | |
2310 | friend class variant; | |
2311 | ||
2312 | private: | |
2313 | ||
2314 | #else// defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) | |
2315 | ||
2316 | public: | |
2317 | ||
2318 | #endif// !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) | |
2319 | ||
2320 | template <typename Visitor, typename VoidPtrCV> | |
92f5a8d4 | 2321 | BOOST_FORCEINLINE static typename Visitor::result_type |
7c673cae FG |
2322 | internal_apply_visitor_impl( |
2323 | int internal_which | |
2324 | , int logical_which | |
2325 | , Visitor& visitor | |
2326 | , VoidPtrCV storage | |
2327 | ) | |
2328 | { | |
2329 | typedef mpl::int_<0> first_which; | |
2330 | typedef typename mpl::begin<internal_types>::type first_it; | |
2331 | typedef typename mpl::end<internal_types>::type last_it; | |
2332 | ||
2333 | typedef detail::variant::visitation_impl_step< | |
2334 | first_it, last_it | |
2335 | > first_step; | |
2336 | ||
2337 | return detail::variant::visitation_impl( | |
2338 | internal_which, logical_which | |
2339 | , visitor, storage, mpl::false_() | |
2340 | , never_uses_backup_flag() | |
2341 | , static_cast<first_which*>(0), static_cast<first_step*>(0) | |
2342 | ); | |
2343 | } | |
2344 | ||
2345 | template <typename Visitor> | |
92f5a8d4 | 2346 | BOOST_FORCEINLINE typename Visitor::result_type |
7c673cae FG |
2347 | internal_apply_visitor(Visitor& visitor) |
2348 | { | |
2349 | return internal_apply_visitor_impl( | |
2350 | which_, which(), visitor, storage_.address() | |
2351 | ); | |
2352 | } | |
2353 | ||
2354 | template <typename Visitor> | |
92f5a8d4 | 2355 | BOOST_FORCEINLINE typename Visitor::result_type |
7c673cae FG |
2356 | internal_apply_visitor(Visitor& visitor) const |
2357 | { | |
2358 | return internal_apply_visitor_impl( | |
2359 | which_, which(), visitor, storage_.address() | |
2360 | ); | |
2361 | } | |
2362 | ||
2363 | public: // visitation support | |
2364 | ||
b32b8144 FG |
2365 | #ifndef BOOST_NO_CXX11_REF_QUALIFIERS |
2366 | ||
2367 | template <typename Visitor> | |
92f5a8d4 | 2368 | typename Visitor::result_type |
b32b8144 FG |
2369 | apply_visitor(Visitor& visitor) && |
2370 | { | |
2371 | detail::variant::invoke_visitor<Visitor, true> invoker(visitor); | |
2372 | return this->internal_apply_visitor(invoker); | |
2373 | } | |
2374 | ||
2375 | template <typename Visitor> | |
92f5a8d4 | 2376 | typename Visitor::result_type |
b32b8144 FG |
2377 | apply_visitor(Visitor& visitor) const&& |
2378 | { | |
2379 | detail::variant::invoke_visitor<Visitor, true> invoker(visitor); | |
2380 | return this->internal_apply_visitor(invoker); | |
2381 | } | |
2382 | ||
2383 | #endif | |
2384 | ||
7c673cae | 2385 | template <typename Visitor> |
92f5a8d4 | 2386 | typename Visitor::result_type |
7c673cae | 2387 | apply_visitor(Visitor& visitor) |
b32b8144 FG |
2388 | #ifndef BOOST_NO_CXX11_REF_QUALIFIERS |
2389 | & | |
2390 | #endif | |
7c673cae | 2391 | { |
b32b8144 | 2392 | detail::variant::invoke_visitor<Visitor, false> invoker(visitor); |
7c673cae FG |
2393 | return this->internal_apply_visitor(invoker); |
2394 | } | |
2395 | ||
2396 | template <typename Visitor> | |
92f5a8d4 | 2397 | typename Visitor::result_type |
7c673cae | 2398 | apply_visitor(Visitor& visitor) const |
b32b8144 FG |
2399 | #ifndef BOOST_NO_CXX11_REF_QUALIFIERS |
2400 | & | |
2401 | #endif | |
7c673cae | 2402 | { |
b32b8144 | 2403 | detail::variant::invoke_visitor<Visitor, false> invoker(visitor); |
7c673cae FG |
2404 | return this->internal_apply_visitor(invoker); |
2405 | } | |
2406 | ||
2407 | }; // class variant | |
2408 | ||
2409 | /////////////////////////////////////////////////////////////////////////////// | |
2410 | // metafunction make_variant_over | |
2411 | // | |
2412 | // See docs and boost/variant/variant_fwd.hpp for more information. | |
2413 | // | |
2414 | template <typename Types> | |
2415 | struct make_variant_over | |
2416 | { | |
2417 | private: // precondition assertions | |
2418 | ||
2419 | BOOST_STATIC_ASSERT(( ::boost::mpl::is_sequence<Types>::value )); | |
b32b8144 FG |
2420 | typedef typename boost::mpl::insert_range< |
2421 | boost::mpl::list<> | |
2422 | , boost::mpl::end< boost::mpl::list<> >::type | |
2423 | , Types | |
2424 | >::type copied_sequence_t; | |
7c673cae FG |
2425 | |
2426 | public: // metafunction result | |
2427 | ||
2428 | typedef variant< | |
b32b8144 | 2429 | detail::variant::over_sequence<copied_sequence_t> |
7c673cae FG |
2430 | > type; |
2431 | ||
2432 | }; | |
2433 | ||
7c673cae FG |
2434 | /////////////////////////////////////////////////////////////////////////////// |
2435 | // function template swap | |
2436 | // | |
2437 | // Swaps two variants of the same type (i.e., identical specification). | |
2438 | // | |
2439 | template < BOOST_VARIANT_ENUM_PARAMS(typename T) > | |
2440 | inline void swap( | |
2441 | variant< BOOST_VARIANT_ENUM_PARAMS(T) >& lhs | |
2442 | , variant< BOOST_VARIANT_ENUM_PARAMS(T) >& rhs | |
2443 | ) | |
2444 | { | |
2445 | lhs.swap(rhs); | |
2446 | } | |
2447 | ||
2448 | } // namespace boost | |
2449 | ||
2450 | // implementation additions | |
2451 | ||
2452 | #if !defined(BOOST_NO_IOSTREAM) | |
2453 | #include <boost/variant/detail/variant_io.hpp> | |
2454 | #endif // BOOST_NO_IOSTREAM | |
2455 | ||
2456 | #endif // BOOST_VARIANT_VARIANT_HPP |