1 // C++0x type_traits -*- C++ -*-
2
3 // Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24
25 /** @file include/type_traits
26 * This is a Standard C++ Library header.
27 */
28
29 #ifndef _GLIBCXX_TYPE_TRAITS
30 #define _GLIBCXX_TYPE_TRAITS 1
31
32 #pragma GCC system_header
33
34 #ifndef __GXX_EXPERIMENTAL_CXX0X__
35 # include <bits/c++0x_warning.h>
36 #else
37
38 #include <bits/c++config.h>
39
40 namespace std _GLIBCXX_VISIBILITY(default)
41 {
42 _GLIBCXX_BEGIN_NAMESPACE_VERSION
43
44 /**
45 * @addtogroup metaprogramming
46 * @{
47 */
48 struct __sfinae_types
49 {
50 typedef char __one;
51 typedef struct { char __arr[2]; } __two;
52 };
53
54 #define _DEFINE_SPEC_0_HELPER \
55 template<>
56
57 #define _DEFINE_SPEC_1_HELPER \
58 template<typename _Tp>
59
60 #define _DEFINE_SPEC_2_HELPER \
61 template<typename _Tp, typename _Cp>
62
63 #define _DEFINE_SPEC(_Order, _Trait, _Type, _Value) \
64 _DEFINE_SPEC_##_Order##_HELPER \
65 struct _Trait<_Type> \
66 : public integral_constant<bool, _Value> { };
67
68 // helper classes.
69
70 /// integral_constant
71 template<typename _Tp, _Tp __v>
72 struct integral_constant
73 {
74 static constexpr _Tp value = __v;
CID 10646 - PARSE_ERROR
member "std::integral_constant<_Tp, __v>::_Tp" is not a type name
During compilation of file '/tmp/buildd/unity-5.6.0/UnityCore/Indicator.cpp'
member "std::integral_constant<_Tp, __v>::_Tp" is not a type name
During compilation of file '/tmp/buildd/unity-5.6.0/UnityCore/Indicators.cpp'
75 typedef _Tp value_type;
76 typedef integral_constant<_Tp, __v> type;
77 constexpr operator value_type() { return value; }
78 };
79
80 /// typedef for true_type
81 typedef integral_constant<bool, true> true_type;
82
83 /// typedef for false_type
84 typedef integral_constant<bool, false> false_type;
85
86 template<typename _Tp, _Tp __v>
87 constexpr _Tp integral_constant<_Tp, __v>::value;
88
89 /// remove_cv
90 template<typename>
91 struct remove_cv;
92
93 template<typename>
94 struct __is_void_helper
95 : public false_type { };
96 _DEFINE_SPEC(0, __is_void_helper, void, true)
97
98 // primary type categories.
99
100 /// is_void
101 template<typename _Tp>
102 struct is_void
103 : public integral_constant<bool, (__is_void_helper<typename
104 remove_cv<_Tp>::type>::value)>
105 { };
106
107 template<typename>
108 struct __is_integral_helper
109 : public false_type { };
110 _DEFINE_SPEC(0, __is_integral_helper, bool, true)
111 _DEFINE_SPEC(0, __is_integral_helper, char, true)
112 _DEFINE_SPEC(0, __is_integral_helper, signed char, true)
113 _DEFINE_SPEC(0, __is_integral_helper, unsigned char, true)
114 #ifdef _GLIBCXX_USE_WCHAR_T
115 _DEFINE_SPEC(0, __is_integral_helper, wchar_t, true)
116 #endif
117 _DEFINE_SPEC(0, __is_integral_helper, char16_t, true)
118 _DEFINE_SPEC(0, __is_integral_helper, char32_t, true)
119 _DEFINE_SPEC(0, __is_integral_helper, short, true)
120 _DEFINE_SPEC(0, __is_integral_helper, unsigned short, true)
121 _DEFINE_SPEC(0, __is_integral_helper, int, true)
122 _DEFINE_SPEC(0, __is_integral_helper, unsigned int, true)
123 _DEFINE_SPEC(0, __is_integral_helper, long, true)
124 _DEFINE_SPEC(0, __is_integral_helper, unsigned long, true)
125 _DEFINE_SPEC(0, __is_integral_helper, long long, true)
126 _DEFINE_SPEC(0, __is_integral_helper, unsigned long long, true)
127
128 /// is_integral
129 template<typename _Tp>
130 struct is_integral
131 : public integral_constant<bool, (__is_integral_helper<typename
132 remove_cv<_Tp>::type>::value)>
133 { };
134
135 template<typename>
136 struct __is_floating_point_helper
137 : public false_type { };
138 _DEFINE_SPEC(0, __is_floating_point_helper, float, true)
139 _DEFINE_SPEC(0, __is_floating_point_helper, double, true)
140 _DEFINE_SPEC(0, __is_floating_point_helper, long double, true)
141
142 /// is_floating_point
143 template<typename _Tp>
144 struct is_floating_point
145 : public integral_constant<bool, (__is_floating_point_helper<typename
146 remove_cv<_Tp>::type>::value)>
147 { };
148
149 /// is_array
150 template<typename>
151 struct is_array
152 : public false_type { };
153
154 template<typename _Tp, std::size_t _Size>
155 struct is_array<_Tp[_Size]>
156 : public true_type { };
157
158 template<typename _Tp>
159 struct is_array<_Tp[]>
160 : public true_type { };
161
162 template<typename>
163 struct __is_pointer_helper
164 : public false_type { };
165 _DEFINE_SPEC(1, __is_pointer_helper, _Tp*, true)
166
167 /// is_pointer
168 template<typename _Tp>
169 struct is_pointer
170 : public integral_constant<bool, (__is_pointer_helper<typename
171 remove_cv<_Tp>::type>::value)>
172 { };
173
174 /// is_reference
175 template<typename _Tp>
176 struct is_reference;
177
178 /// is_function
179 template<typename _Tp>
180 struct is_function;
181
182 template<typename>
183 struct __is_member_object_pointer_helper
184 : public false_type { };
185 _DEFINE_SPEC(2, __is_member_object_pointer_helper, _Tp _Cp::*,
186 !is_function<_Tp>::value)
187
188 /// is_member_object_pointer
189 template<typename _Tp>
190 struct is_member_object_pointer
191 : public integral_constant<bool, (__is_member_object_pointer_helper<
192 typename remove_cv<_Tp>::type>::value)>
193 { };
194
195 template<typename>
196 struct __is_member_function_pointer_helper
197 : public false_type { };
198 _DEFINE_SPEC(2, __is_member_function_pointer_helper, _Tp _Cp::*,
199 is_function<_Tp>::value)
200
201 /// is_member_function_pointer
202 template<typename _Tp>
203 struct is_member_function_pointer
204 : public integral_constant<bool, (__is_member_function_pointer_helper<
205 typename remove_cv<_Tp>::type>::value)>
206 { };
207
208 /// is_enum
209 template<typename _Tp>
210 struct is_enum
211 : public integral_constant<bool, __is_enum(_Tp)>
212 { };
213
214 /// is_union
215 template<typename _Tp>
216 struct is_union
217 : public integral_constant<bool, __is_union(_Tp)>
218 { };
219
220 /// is_class
221 template<typename _Tp>
222 struct is_class
223 : public integral_constant<bool, __is_class(_Tp)>
224 { };
225
226 /// is_function
227 template<typename>
228 struct is_function
229 : public false_type { };
230 template<typename _Res, typename... _ArgTypes>
231 struct is_function<_Res(_ArgTypes...)>
232 : public true_type { };
233 template<typename _Res, typename... _ArgTypes>
234 struct is_function<_Res(_ArgTypes......)>
235 : public true_type { };
236 template<typename _Res, typename... _ArgTypes>
237 struct is_function<_Res(_ArgTypes...) const>
238 : public true_type { };
239 template<typename _Res, typename... _ArgTypes>
240 struct is_function<_Res(_ArgTypes......) const>
241 : public true_type { };
242 template<typename _Res, typename... _ArgTypes>
243 struct is_function<_Res(_ArgTypes...) volatile>
244 : public true_type { };
245 template<typename _Res, typename... _ArgTypes>
246 struct is_function<_Res(_ArgTypes......) volatile>
247 : public true_type { };
248 template<typename _Res, typename... _ArgTypes>
249 struct is_function<_Res(_ArgTypes...) const volatile>
250 : public true_type { };
251 template<typename _Res, typename... _ArgTypes>
252 struct is_function<_Res(_ArgTypes......) const volatile>
253 : public true_type { };
254
255 template<typename>
256 struct __is_nullptr_t_helper
257 : public false_type { };
258 _DEFINE_SPEC(0, __is_nullptr_t_helper, std::nullptr_t, true)
259
260 // __is_nullptr_t (extension).
261 template<typename _Tp>
262 struct __is_nullptr_t
263 : public integral_constant<bool, (__is_nullptr_t_helper<typename
264 remove_cv<_Tp>::type>::value)>
265 { };
266
267 // composite type traits.
268
269 /// is_arithmetic
270 template<typename _Tp>
271 struct is_arithmetic
272 : public integral_constant<bool, (is_integral<_Tp>::value
273 || is_floating_point<_Tp>::value)>
274 { };
275
276 /// is_fundamental
277 template<typename _Tp>
278 struct is_fundamental
279 : public integral_constant<bool, (is_arithmetic<_Tp>::value
280 || is_void<_Tp>::value)>
281 { };
282
283 /// is_object
284 template<typename _Tp>
285 struct is_object
286 : public integral_constant<bool, !(is_function<_Tp>::value
287 || is_reference<_Tp>::value
288 || is_void<_Tp>::value)>
289 { };
290
291 /// is_member_pointer
292 template<typename _Tp>
293 struct is_member_pointer;
294
295 /// is_scalar
296 template<typename _Tp>
297 struct is_scalar
298 : public integral_constant<bool, (is_arithmetic<_Tp>::value
299 || is_enum<_Tp>::value
300 || is_pointer<_Tp>::value
301 || is_member_pointer<_Tp>::value
302 || __is_nullptr_t<_Tp>::value)>
303 { };
304
305 /// is_compound
306 template<typename _Tp>
307 struct is_compound
308 : public integral_constant<bool, !is_fundamental<_Tp>::value> { };
309
310 /// is_member_pointer
311 template<typename _Tp>
312 struct __is_member_pointer_helper
313 : public false_type { };
314 _DEFINE_SPEC(2, __is_member_pointer_helper, _Tp _Cp::*, true)
315
316 template<typename _Tp>
317 struct is_member_pointer
318 : public integral_constant<bool, (__is_member_pointer_helper<
319 typename remove_cv<_Tp>::type>::value)>
320 { };
321
322 // type properties.
323 /// is_const
324 template<typename>
325 struct is_const
326 : public false_type { };
327
328 template<typename _Tp>
329 struct is_const<_Tp const>
330 : public true_type { };
331
332 /// is_volatile
333 template<typename>
334 struct is_volatile
335 : public false_type { };
336
337 template<typename _Tp>
338 struct is_volatile<_Tp volatile>
339 : public true_type { };
340
341 /// is_empty
342 template<typename _Tp>
343 struct is_empty
344 : public integral_constant<bool, __is_empty(_Tp)>
345 { };
346
347 /// is_polymorphic
348 template<typename _Tp>
349 struct is_polymorphic
350 : public integral_constant<bool, __is_polymorphic(_Tp)>
351 { };
352
353 /// is_abstract
354 template<typename _Tp>
355 struct is_abstract
356 : public integral_constant<bool, __is_abstract(_Tp)>
357 { };
358
359 /// has_virtual_destructor
360 template<typename _Tp>
361 struct has_virtual_destructor
362 : public integral_constant<bool, __has_virtual_destructor(_Tp)>
363 { };
364
365 /// alignment_of
366 template<typename _Tp>
367 struct alignment_of
368 : public integral_constant<std::size_t, __alignof__(_Tp)> { };
369
370 /// rank
371 template<typename>
372 struct rank
373 : public integral_constant<std::size_t, 0> { };
374
375 template<typename _Tp, std::size_t _Size>
376 struct rank<_Tp[_Size]>
377 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
378
379 template<typename _Tp>
380 struct rank<_Tp[]>
381 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
382
383 /// extent
384 template<typename, unsigned _Uint = 0>
385 struct extent
386 : public integral_constant<std::size_t, 0> { };
387
388 template<typename _Tp, unsigned _Uint, std::size_t _Size>
389 struct extent<_Tp[_Size], _Uint>
390 : public integral_constant<std::size_t,
391 _Uint == 0 ? _Size : extent<_Tp,
392 _Uint - 1>::value>
393 { };
394
395 template<typename _Tp, unsigned _Uint>
396 struct extent<_Tp[], _Uint>
397 : public integral_constant<std::size_t,
398 _Uint == 0 ? 0 : extent<_Tp,
399 _Uint - 1>::value>
400 { };
401
402 // relationships between types [4.6].
403
404 /// is_same
405 template<typename, typename>
406 struct is_same
407 : public false_type { };
408
409 template<typename _Tp>
410 struct is_same<_Tp, _Tp>
411 : public true_type { };
412
413 // const-volatile modifications [4.7.1].
414
415 /// remove_const
416 template<typename _Tp>
417 struct remove_const
418 { typedef _Tp type; };
419
420 template<typename _Tp>
421 struct remove_const<_Tp const>
422 { typedef _Tp type; };
423
424 /// remove_volatile
425 template<typename _Tp>
426 struct remove_volatile
427 { typedef _Tp type; };
428
429 template<typename _Tp>
430 struct remove_volatile<_Tp volatile>
431 { typedef _Tp type; };
432
433 /// remove_cv
434 template<typename _Tp>
435 struct remove_cv
436 {
437 typedef typename
438 remove_const<typename remove_volatile<_Tp>::type>::type type;
439 };
440
441 /// add_const
442 template<typename _Tp>
443 struct add_const
444 { typedef _Tp const type; };
445
446 /// add_volatile
447 template<typename _Tp>
448 struct add_volatile
449 { typedef _Tp volatile type; };
450
451 /// add_cv
452 template<typename _Tp>
453 struct add_cv
454 {
455 typedef typename
456 add_const<typename add_volatile<_Tp>::type>::type type;
457 };
458
459 // array modifications.
460
461 /// remove_extent
462 template<typename _Tp>
463 struct remove_extent
464 { typedef _Tp type; };
465
466 template<typename _Tp, std::size_t _Size>
467 struct remove_extent<_Tp[_Size]>
468 { typedef _Tp type; };
469
470 template<typename _Tp>
471 struct remove_extent<_Tp[]>
472 { typedef _Tp type; };
473
474 /// remove_all_extents
475 template<typename _Tp>
476 struct remove_all_extents
477 { typedef _Tp type; };
478
479 template<typename _Tp, std::size_t _Size>
480 struct remove_all_extents<_Tp[_Size]>
481 { typedef typename remove_all_extents<_Tp>::type type; };
482
483 template<typename _Tp>
484 struct remove_all_extents<_Tp[]>
485 { typedef typename remove_all_extents<_Tp>::type type; };
486
487 // pointer modifications.
488
489 template<typename _Tp, typename>
490 struct __remove_pointer_helper
491 { typedef _Tp type; };
492
493 template<typename _Tp, typename _Up>
494 struct __remove_pointer_helper<_Tp, _Up*>
495 { typedef _Up type; };
496
497 /// remove_pointer
498 template<typename _Tp>
499 struct remove_pointer
500 : public __remove_pointer_helper<_Tp, typename remove_cv<_Tp>::type>
501 { };
502
503 template<typename>
504 struct remove_reference;
505
506 /// add_pointer
507 template<typename _Tp>
508 struct add_pointer
509 { typedef typename remove_reference<_Tp>::type* type; };
510
511 // Primary classification traits.
512
513 /// is_lvalue_reference
514 template<typename>
515 struct is_lvalue_reference
516 : public false_type { };
517
518 template<typename _Tp>
519 struct is_lvalue_reference<_Tp&>
520 : public true_type { };
521
522 /// is_rvalue_reference
523 template<typename>
524 struct is_rvalue_reference
525 : public false_type { };
526
527 template<typename _Tp>
528 struct is_rvalue_reference<_Tp&&>
529 : public true_type { };
530
531 // Secondary classification traits.
532
533 /// is_reference
534 template<typename _Tp>
535 struct is_reference
536 : public integral_constant<bool, (is_lvalue_reference<_Tp>::value
537 || is_rvalue_reference<_Tp>::value)>
538 { };
539
540 // Reference transformations.
541
542 /// remove_reference
543 template<typename _Tp>
544 struct remove_reference
545 { typedef _Tp type; };
546
547 template<typename _Tp>
548 struct remove_reference<_Tp&>
549 { typedef _Tp type; };
550
551 template<typename _Tp>
552 struct remove_reference<_Tp&&>
553 { typedef _Tp type; };
554
555 template<typename _Tp,
556 bool = !is_reference<_Tp>::value && !is_void<_Tp>::value,
557 bool = is_rvalue_reference<_Tp>::value>
558 struct __add_lvalue_reference_helper
559 { typedef _Tp type; };
560
561 template<typename _Tp>
562 struct __add_lvalue_reference_helper<_Tp, true, false>
563 { typedef _Tp& type; };
564
565 template<typename _Tp>
566 struct __add_lvalue_reference_helper<_Tp, false, true>
567 { typedef typename remove_reference<_Tp>::type& type; };
568
569 /// add_lvalue_reference
570 template<typename _Tp>
571 struct add_lvalue_reference
572 : public __add_lvalue_reference_helper<_Tp>
573 { };
574
575 template<typename _Tp,
576 bool = !is_reference<_Tp>::value && !is_void<_Tp>::value>
577 struct __add_rvalue_reference_helper
578 { typedef _Tp type; };
579
580 template<typename _Tp>
581 struct __add_rvalue_reference_helper<_Tp, true>
582 { typedef _Tp&& type; };
583
584 /// add_rvalue_reference
585 template<typename _Tp>
586 struct add_rvalue_reference
587 : public __add_rvalue_reference_helper<_Tp>
588 { };
589
590 // Scalar properties and transformations.
591
592 template<typename _Tp,
593 bool = is_integral<_Tp>::value,
594 bool = is_floating_point<_Tp>::value>
595 struct __is_signed_helper
596 : public false_type { };
597
598 template<typename _Tp>
599 struct __is_signed_helper<_Tp, false, true>
600 : public true_type { };
601
602 template<typename _Tp>
603 struct __is_signed_helper<_Tp, true, false>
604 : public integral_constant<bool, static_cast<bool>(_Tp(-1) < _Tp(0))>
605 { };
606
607 /// is_signed
608 template<typename _Tp>
609 struct is_signed
610 : public integral_constant<bool, __is_signed_helper<_Tp>::value>
611 { };
612
613 /// is_unsigned
614 template<typename _Tp>
615 struct is_unsigned
616 : public integral_constant<bool, (is_arithmetic<_Tp>::value
617 && !is_signed<_Tp>::value)>
618 { };
619
620 // Member introspection.
621
622 /// is_trivial
623 template<typename _Tp>
624 struct is_trivial
625 : public integral_constant<bool, __is_trivial(_Tp)>
626 { };
627
628 /// is_standard_layout
629 template<typename _Tp>
630 struct is_standard_layout
631 : public integral_constant<bool, __is_standard_layout(_Tp)>
632 { };
633
634 /// is_pod
635 // Could use is_standard_layout && is_trivial instead of the builtin.
636 template<typename _Tp>
637 struct is_pod
638 : public integral_constant<bool, __is_pod(_Tp)>
639 { };
640
641 /// is_literal_type
642 template<typename _Tp>
643 struct is_literal_type
644 : public integral_constant<bool, __is_literal_type(_Tp)>
645 { };
646
647 template<typename _Tp>
648 typename add_rvalue_reference<_Tp>::type declval() noexcept;
649
650 template<typename _Tp, typename... _Args>
651 class __is_constructible_helper
652 : public __sfinae_types
653 {
654 template<typename _Tp1, typename... _Args1>
655 static decltype(_Tp1(declval<_Args1>()...), __one()) __test(int);
656
657 template<typename, typename...>
658 static __two __test(...);
659
660 public:
661 static const bool __value = sizeof(__test<_Tp, _Args...>(0)) == 1;
662 };
663
664 template<typename _Tp, typename _Arg>
665 class __is_constructible_helper<_Tp, _Arg>
666 : public __sfinae_types
667 {
668 template<typename _Tp1, typename _Arg1>
669 static decltype(static_cast<_Tp1>(declval<_Arg1>()), __one())
670 __test(int);
671
672 template<typename, typename>
673 static __two __test(...);
674
675 public:
676 static const bool __value = sizeof(__test<_Tp, _Arg>(0)) == 1;
677 };
678
679 /// is_constructible
680 // XXX FIXME
681 // The C++0x specifications require front-end support, see N2255.
682 template<typename _Tp, typename... _Args>
683 struct is_constructible
684 : public integral_constant<bool,
685 __is_constructible_helper<_Tp,
686 _Args...>::__value>
687 { };
688
689 template<bool, typename _Tp, typename... _Args>
690 struct __is_nt_constructible_helper
691 { static const bool __value = false; };
692
693 template<typename _Tp, typename... _Args>
694 struct __is_nt_constructible_helper<true, _Tp, _Args...>
695 { static const bool __value = noexcept(_Tp(declval<_Args>()...)); };
696
697 template<typename _Tp, typename _Arg>
698 struct __is_nt_constructible_helper<true, _Tp, _Arg>
699 {
700 static const bool __value = noexcept(static_cast<_Tp>(declval<_Arg>()));
701 };
702
703 /// is_nothrow_constructible
704 template<typename _Tp, typename... _Args>
705 struct is_nothrow_constructible
706 : public integral_constant<bool,
707 __is_nt_constructible_helper<is_constructible<_Tp, _Args...>::value,
708 _Tp, _Args...>::__value>
709 { };
710
711 /// has_trivial_default_constructor
712 template<typename _Tp>
713 struct has_trivial_default_constructor
714 : public integral_constant<bool, __has_trivial_constructor(_Tp)>
715 { };
716
717 /// has_trivial_copy_constructor
718 template<typename _Tp>
719 struct has_trivial_copy_constructor
720 : public integral_constant<bool, __has_trivial_copy(_Tp)>
721 { };
722
723 /// has_trivial_copy_assign
724 template<typename _Tp>
725 struct has_trivial_copy_assign
726 : public integral_constant<bool, __has_trivial_assign(_Tp)>
727 { };
728
729 /// has_trivial_destructor
730 template<typename _Tp>
731 struct has_trivial_destructor
732 : public integral_constant<bool, __has_trivial_destructor(_Tp)>
733 { };
734
735 /// has_nothrow_default_constructor
736 template<typename _Tp>
737 struct has_nothrow_default_constructor
738 : public integral_constant<bool, __has_nothrow_constructor(_Tp)>
739 { };
740
741 /// has_nothrow_copy_constructor
742 template<typename _Tp>
743 struct has_nothrow_copy_constructor
744 : public integral_constant<bool, __has_nothrow_copy(_Tp)>
745 { };
746
747 /// has_nothrow_copy_assign
748 template<typename _Tp>
749 struct has_nothrow_copy_assign
750 : public integral_constant<bool, __has_nothrow_assign(_Tp)>
751 { };
752
753 // Relationships between types.
754
755 /// is_base_of
756 template<typename _Base, typename _Derived>
757 struct is_base_of
758 : public integral_constant<bool, __is_base_of(_Base, _Derived)>
759 { };
760
761 template<typename _From, typename _To,
762 bool = (is_void<_From>::value || is_function<_To>::value
763 || is_array<_To>::value)>
764 struct __is_convertible_helper
765 { static const bool __value = is_void<_To>::value; };
766
767 template<typename _From, typename _To>
768 class __is_convertible_helper<_From, _To, false>
769 : public __sfinae_types
770 {
771 template<typename _To1>
772 static void __test_aux(_To1);
773
774 template<typename _From1, typename _To1>
775 static decltype(__test_aux<_To1>(std::declval<_From1>()), __one())
776 __test(int);
777
778 template<typename, typename>
779 static __two __test(...);
780
781 public:
782 static const bool __value = sizeof(__test<_From, _To>(0)) == 1;
783 };
784
785 /// is_convertible
786 // XXX FIXME
787 // The C++0x specifications require front-end support, see N2255.
788 template<typename _From, typename _To>
789 struct is_convertible
790 : public integral_constant<bool,
791 __is_convertible_helper<_From, _To>::__value>
792 { };
793
794 /// is_explicitly_convertible
795 template<typename _From, typename _To>
796 struct is_explicitly_convertible
797 : public is_constructible<_To, _From>
798 { };
799
800 template<std::size_t _Len>
801 struct __aligned_storage_msa
802 {
803 union __type
804 {
805 unsigned char __data[_Len];
806 struct __attribute__((__aligned__)) { } __align;
807 };
808 };
809
810 /**
811 * @brief Alignment type.
812 *
813 * The value of _Align is a default-alignment which shall be the
814 * most stringent alignment requirement for any C++ object type
815 * whose size is no greater than _Len (3.9). The member typedef
816 * type shall be a POD type suitable for use as uninitialized
817 * storage for any object whose size is at most _Len and whose
818 * alignment is a divisor of _Align.
819 */
820 template<std::size_t _Len, std::size_t _Align =
821 __alignof__(typename __aligned_storage_msa<_Len>::__type)>
822 struct aligned_storage
823 {
824 union type
825 {
826 unsigned char __data[_Len];
827 struct __attribute__((__aligned__((_Align)))) { } __align;
828 };
829 };
830
831
832 // Define a nested type if some predicate holds.
833 // Primary template.
834 /// enable_if
835 template<bool, typename _Tp = void>
836 struct enable_if
837 { };
838
839 // Partial specialization for true.
840 template<typename _Tp>
841 struct enable_if<true, _Tp>
842 { typedef _Tp type; };
843
844
845 // A conditional expression, but for types. If true, first, if false, second.
846 // Primary template.
847 /// conditional
848 template<bool _Cond, typename _Iftrue, typename _Iffalse>
849 struct conditional
850 { typedef _Iftrue type; };
851
852 // Partial specialization for false.
853 template<typename _Iftrue, typename _Iffalse>
854 struct conditional<false, _Iftrue, _Iffalse>
855 { typedef _Iffalse type; };
856
857
858 // Decay trait for arrays and functions, used for perfect forwarding
859 // in make_pair, make_tuple, etc.
860 template<typename _Up,
861 bool _IsArray = is_array<_Up>::value,
862 bool _IsFunction = is_function<_Up>::value>
863 struct __decay_selector;
864
865 // NB: DR 705.
866 template<typename _Up>
867 struct __decay_selector<_Up, false, false>
868 { typedef typename remove_cv<_Up>::type __type; };
869
870 template<typename _Up>
871 struct __decay_selector<_Up, true, false>
872 { typedef typename remove_extent<_Up>::type* __type; };
873
874 template<typename _Up>
875 struct __decay_selector<_Up, false, true>
876 { typedef typename add_pointer<_Up>::type __type; };
877
878 /// decay
879 template<typename _Tp>
880 class decay
881 {
882 typedef typename remove_reference<_Tp>::type __remove_type;
883
884 public:
885 typedef typename __decay_selector<__remove_type>::__type type;
886 };
887
888 template<typename _Tp>
889 class reference_wrapper;
890
891 // Helper which adds a reference to a type when given a reference_wrapper
892 template<typename _Tp>
893 struct __strip_reference_wrapper
894 {
895 typedef _Tp __type;
896 };
897
898 template<typename _Tp>
899 struct __strip_reference_wrapper<reference_wrapper<_Tp> >
900 {
901 typedef _Tp& __type;
902 };
903
904 template<typename _Tp>
905 struct __strip_reference_wrapper<const reference_wrapper<_Tp> >
906 {
907 typedef _Tp& __type;
908 };
909
910 template<typename _Tp>
911 struct __decay_and_strip
912 {
913 typedef typename __strip_reference_wrapper<
914 typename decay<_Tp>::type>::__type __type;
915 };
916
917
918 // Utility for constructing identically cv-qualified types.
919 template<typename _Unqualified, bool _IsConst, bool _IsVol>
920 struct __cv_selector;
921
922 template<typename _Unqualified>
923 struct __cv_selector<_Unqualified, false, false>
924 { typedef _Unqualified __type; };
925
926 template<typename _Unqualified>
927 struct __cv_selector<_Unqualified, false, true>
928 { typedef volatile _Unqualified __type; };
929
930 template<typename _Unqualified>
931 struct __cv_selector<_Unqualified, true, false>
932 { typedef const _Unqualified __type; };
933
934 template<typename _Unqualified>
935 struct __cv_selector<_Unqualified, true, true>
936 { typedef const volatile _Unqualified __type; };
937
938 template<typename _Qualified, typename _Unqualified,
939 bool _IsConst = is_const<_Qualified>::value,
940 bool _IsVol = is_volatile<_Qualified>::value>
941 class __match_cv_qualifiers
942 {
943 typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
944
945 public:
946 typedef typename __match::__type __type;
947 };
948
949
950 // Utility for finding the unsigned versions of signed integral types.
951 template<typename _Tp>
952 struct __make_unsigned
953 { typedef _Tp __type; };
954
955 template<>
956 struct __make_unsigned<char>
957 { typedef unsigned char __type; };
958
959 template<>
960 struct __make_unsigned<signed char>
961 { typedef unsigned char __type; };
962
963 template<>
964 struct __make_unsigned<short>
965 { typedef unsigned short __type; };
966
967 template<>
968 struct __make_unsigned<int>
969 { typedef unsigned int __type; };
970
971 template<>
972 struct __make_unsigned<long>
973 { typedef unsigned long __type; };
974
975 template<>
976 struct __make_unsigned<long long>
977 { typedef unsigned long long __type; };
978
979
980 // Select between integral and enum: not possible to be both.
981 template<typename _Tp,
982 bool _IsInt = is_integral<_Tp>::value,
983 bool _IsEnum = is_enum<_Tp>::value>
984 class __make_unsigned_selector;
985
986 template<typename _Tp>
987 class __make_unsigned_selector<_Tp, true, false>
988 {
989 typedef __make_unsigned<typename remove_cv<_Tp>::type> __unsignedt;
990 typedef typename __unsignedt::__type __unsigned_type;
991 typedef __match_cv_qualifiers<_Tp, __unsigned_type> __cv_unsigned;
992
993 public:
994 typedef typename __cv_unsigned::__type __type;
995 };
996
997 template<typename _Tp>
998 class __make_unsigned_selector<_Tp, false, true>
999 {
1000 // With -fshort-enums, an enum may be as small as a char.
1001 typedef unsigned char __smallest;
1002 static const bool __b0 = sizeof(_Tp) <= sizeof(__smallest);
1003 static const bool __b1 = sizeof(_Tp) <= sizeof(unsigned short);
1004 static const bool __b2 = sizeof(_Tp) <= sizeof(unsigned int);
1005 typedef conditional<__b2, unsigned int, unsigned long> __cond2;
1006 typedef typename __cond2::type __cond2_type;
1007 typedef conditional<__b1, unsigned short, __cond2_type> __cond1;
1008 typedef typename __cond1::type __cond1_type;
1009
1010 public:
1011 typedef typename conditional<__b0, __smallest, __cond1_type>::type __type;
1012 };
1013
1014 // Given an integral/enum type, return the corresponding unsigned
1015 // integer type.
1016 // Primary template.
1017 /// make_unsigned
1018 template<typename _Tp>
1019 struct make_unsigned
1020 { typedef typename __make_unsigned_selector<_Tp>::__type type; };
1021
1022 // Integral, but don't define.
1023 template<>
1024 struct make_unsigned<bool>;
1025
1026
1027 // Utility for finding the signed versions of unsigned integral types.
1028 template<typename _Tp>
1029 struct __make_signed
1030 { typedef _Tp __type; };
1031
1032 template<>
1033 struct __make_signed<char>
1034 { typedef signed char __type; };
1035
1036 template<>
1037 struct __make_signed<unsigned char>
1038 { typedef signed char __type; };
1039
1040 template<>
1041 struct __make_signed<unsigned short>
1042 { typedef signed short __type; };
1043
1044 template<>
1045 struct __make_signed<unsigned int>
1046 { typedef signed int __type; };
1047
1048 template<>
1049 struct __make_signed<unsigned long>
1050 { typedef signed long __type; };
1051
1052 template<>
1053 struct __make_signed<unsigned long long>
1054 { typedef signed long long __type; };
1055
1056
1057 // Select between integral and enum: not possible to be both.
1058 template<typename _Tp,
1059 bool _IsInt = is_integral<_Tp>::value,
1060 bool _IsEnum = is_enum<_Tp>::value>
1061 class __make_signed_selector;
1062
1063 template<typename _Tp>
1064 class __make_signed_selector<_Tp, true, false>
1065 {
1066 typedef __make_signed<typename remove_cv<_Tp>::type> __signedt;
1067 typedef typename __signedt::__type __signed_type;
1068 typedef __match_cv_qualifiers<_Tp, __signed_type> __cv_signed;
1069
1070 public:
1071 typedef typename __cv_signed::__type __type;
1072 };
1073
1074 template<typename _Tp>
1075 class __make_signed_selector<_Tp, false, true>
1076 {
1077 // With -fshort-enums, an enum may be as small as a char.
1078 typedef signed char __smallest;
1079 static const bool __b0 = sizeof(_Tp) <= sizeof(__smallest);
1080 static const bool __b1 = sizeof(_Tp) <= sizeof(signed short);
1081 static const bool __b2 = sizeof(_Tp) <= sizeof(signed int);
1082 typedef conditional<__b2, signed int, signed long> __cond2;
1083 typedef typename __cond2::type __cond2_type;
1084 typedef conditional<__b1, signed short, __cond2_type> __cond1;
1085 typedef typename __cond1::type __cond1_type;
1086
1087 public:
1088 typedef typename conditional<__b0, __smallest, __cond1_type>::type __type;
1089 };
1090
1091 // Given an integral/enum type, return the corresponding signed
1092 // integer type.
1093 // Primary template.
1094 /// make_signed
1095 template<typename _Tp>
1096 struct make_signed
1097 { typedef typename __make_signed_selector<_Tp>::__type type; };
1098
1099 // Integral, but don't define.
1100 template<>
1101 struct make_signed<bool>;
1102
1103 /// common_type
1104 template<typename... _Tp>
1105 struct common_type;
1106
1107 template<typename _Tp>
1108 struct common_type<_Tp>
1109 { typedef _Tp type; };
1110
1111 template<typename _Tp, typename _Up>
1112 struct common_type<_Tp, _Up>
1113 { typedef decltype(true ? declval<_Tp>() : declval<_Up>()) type; };
1114
1115 template<typename _Tp, typename _Up, typename... _Vp>
1116 struct common_type<_Tp, _Up, _Vp...>
1117 {
1118 typedef typename
1119 common_type<typename common_type<_Tp, _Up>::type, _Vp...>::type type;
1120 };
1121
1122 /// declval
1123 template<typename _Tp>
1124 struct __declval_protector
1125 {
1126 static const bool __stop = false;
1127 static typename add_rvalue_reference<_Tp>::type __delegate();
1128 };
1129
1130 template<typename _Tp>
1131 inline typename add_rvalue_reference<_Tp>::type
1132 declval() noexcept
1133 {
1134 static_assert(__declval_protector<_Tp>::__stop,
1135 "declval() must not be used!");
1136 return __declval_protector<_Tp>::__delegate();
1137 }
1138
1139 /// result_of
1140 template<typename _Signature>
1141 class result_of;
1142
1143 template<typename _MemPtr, typename _Arg>
1144 struct _Result_of_memobj;
1145
1146 template<typename _Res, typename _Class, typename _Arg>
1147 struct _Result_of_memobj<_Res _Class::*, _Arg>
1148 {
1149 private:
1150 typedef _Res _Class::* _Func;
1151
1152 template<typename _Tp>
1153 static _Tp _S_get(const _Class&);
1154 template<typename _Tp>
1155 static decltype(*std::declval<_Tp>()) _S_get(...);
1156
1157 public:
1158 typedef
1159 decltype(_S_get<_Arg>(std::declval<_Arg>()).*std::declval<_Func>())
1160 __type;
1161 };
1162
1163 template<typename _MemPtr, typename _Arg, typename... _ArgTypes>
1164 struct _Result_of_memfun;
1165
1166 template<typename _Res, typename _Class, typename _Arg, typename... _Args>
1167 struct _Result_of_memfun<_Res _Class::*, _Arg, _Args...>
1168 {
1169 private:
1170 typedef _Res _Class::* _Func;
1171
1172 template<typename _Tp>
1173 static _Tp _S_get(const _Class&);
1174 template<typename _Tp>
1175 static decltype(*std::declval<_Tp>()) _S_get(...);
1176
1177 public:
1178 typedef
1179 decltype((_S_get<_Arg>(std::declval<_Arg>()).*std::declval<_Func>())
1180 (std::declval<_Args>()...) )
1181 __type;
1182 };
1183
1184 template<bool, bool, typename _Functor, typename... _ArgTypes>
1185 struct _Result_of_impl;
1186
1187 template<typename _Functor, typename... _ArgTypes>
1188 struct _Result_of_impl<false, false, _Functor, _ArgTypes...>
1189 {
1190 typedef
1191 decltype( std::declval<_Functor>()(std::declval<_ArgTypes>()...) )
1192 __type;
1193 };
1194
1195 template<typename _MemPtr, typename _Arg>
1196 struct _Result_of_impl<true, false, _MemPtr, _Arg>
1197 : _Result_of_memobj<typename remove_reference<_MemPtr>::type, _Arg>
1198 {
1199 typedef typename _Result_of_memobj<
1200 typename remove_reference<_MemPtr>::type, _Arg>::__type
1201 __type;
1202 };
1203
1204 template<typename _MemPtr, typename _Arg, typename... _ArgTypes>
1205 struct _Result_of_impl<false, true, _MemPtr, _Arg, _ArgTypes...>
1206 : _Result_of_memfun<typename remove_reference<_MemPtr>::type, _Arg,
1207 _ArgTypes...>
1208 {
1209 typedef typename _Result_of_memfun<
1210 typename remove_reference<_MemPtr>::type, _Arg, _ArgTypes...>::__type
1211 __type;
1212 };
1213
1214 template<typename _Functor, typename... _ArgTypes>
1215 struct result_of<_Functor(_ArgTypes...)>
1216 : _Result_of_impl<is_member_object_pointer<
1217 typename remove_reference<_Functor>::type >::value,
1218 is_member_function_pointer<
1219 typename remove_reference<_Functor>::type >::value,
1220 _Functor, _ArgTypes...>
1221 {
1222 typedef typename _Result_of_impl<
1223 is_member_object_pointer<
1224 typename remove_reference<_Functor>::type >::value,
1225 is_member_function_pointer<
1226 typename remove_reference<_Functor>::type >::value,
1227 _Functor, _ArgTypes...>::__type
1228 type;
1229 };
1230
1231 /**
1232 * Use SFINAE to determine if the type _Tp has a publicly-accessible
1233 * member type _NTYPE.
1234 */
1235 #define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \
1236 template<typename _Tp> \
1237 class __has_##_NTYPE##_helper \
1238 : __sfinae_types \
1239 { \
1240 template<typename _Up> \
1241 struct _Wrap_type \
1242 { }; \
1243 \
1244 template<typename _Up> \
1245 static __one __test(_Wrap_type<typename _Up::_NTYPE>*); \
1246 \
1247 template<typename _Up> \
1248 static __two __test(...); \
1249 \
1250 public: \
1251 static const bool value = sizeof(__test<_Tp>(0)) == 1; \
1252 }; \
1253 \
1254 template<typename _Tp> \
1255 struct __has_##_NTYPE \
1256 : integral_constant<bool, __has_##_NTYPE##_helper \
1257 <typename remove_cv<_Tp>::type>::value> \
1258 { };
1259
1260 #undef _DEFINE_SPEC_0_HELPER
1261 #undef _DEFINE_SPEC_1_HELPER
1262 #undef _DEFINE_SPEC_2_HELPER
1263 #undef _DEFINE_SPEC
1264
1265 // @} group metaprogramming
1266 _GLIBCXX_END_NAMESPACE_VERSION
1267 } // namespace
1268
1269 #endif // __GXX_EXPERIMENTAL_CXX0X__
1270
1271 #endif // _GLIBCXX_TYPE_TRAITS