libstdc++
type_traits
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1 // C++11 <type_traits> -*- C++ -*-
2 
3 // Copyright (C) 2007-2019 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 #if __cplusplus < 201103L
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  * @defgroup metaprogramming Metaprogramming
46  * @ingroup utilities
47  *
48  * Template utilities for compile-time introspection and modification,
49  * including type classification traits, type property inspection traits
50  * and type transformation traits.
51  *
52  * @{
53  */
54 
55  /// integral_constant
56  template<typename _Tp, _Tp __v>
57  struct integral_constant
58  {
59  static constexpr _Tp value = __v;
60  typedef _Tp value_type;
61  typedef integral_constant<_Tp, __v> type;
62  constexpr operator value_type() const noexcept { return value; }
63 #if __cplusplus > 201103L
64 
65 #define __cpp_lib_integral_constant_callable 201304
66 
67  constexpr value_type operator()() const noexcept { return value; }
68 #endif
69  };
70 
71  template<typename _Tp, _Tp __v>
72  constexpr _Tp integral_constant<_Tp, __v>::value;
73 
74  /// The type used as a compile-time boolean with true value.
75  typedef integral_constant<bool, true> true_type;
76 
77  /// The type used as a compile-time boolean with false value.
78  typedef integral_constant<bool, false> false_type;
79 
80  template<bool __v>
81  using __bool_constant = integral_constant<bool, __v>;
82 
83 #if __cplusplus > 201402L
84 # define __cpp_lib_bool_constant 201505
85  template<bool __v>
86  using bool_constant = integral_constant<bool, __v>;
87 #endif
88 
89  // Meta programming helper types.
90 
91  template<bool, typename, typename>
92  struct conditional;
93 
94  template<typename...>
95  struct __or_;
96 
97  template<>
98  struct __or_<>
99  : public false_type
100  { };
101 
102  template<typename _B1>
103  struct __or_<_B1>
104  : public _B1
105  { };
106 
107  template<typename _B1, typename _B2>
108  struct __or_<_B1, _B2>
109  : public conditional<_B1::value, _B1, _B2>::type
110  { };
111 
112  template<typename _B1, typename _B2, typename _B3, typename... _Bn>
113  struct __or_<_B1, _B2, _B3, _Bn...>
114  : public conditional<_B1::value, _B1, __or_<_B2, _B3, _Bn...>>::type
115  { };
116 
117  template<typename...>
118  struct __and_;
119 
120  template<>
121  struct __and_<>
122  : public true_type
123  { };
124 
125  template<typename _B1>
126  struct __and_<_B1>
127  : public _B1
128  { };
129 
130  template<typename _B1, typename _B2>
131  struct __and_<_B1, _B2>
132  : public conditional<_B1::value, _B2, _B1>::type
133  { };
134 
135  template<typename _B1, typename _B2, typename _B3, typename... _Bn>
136  struct __and_<_B1, _B2, _B3, _Bn...>
137  : public conditional<_B1::value, __and_<_B2, _B3, _Bn...>, _B1>::type
138  { };
139 
140  template<typename _Pp>
141  struct __not_
142  : public __bool_constant<!bool(_Pp::value)>
143  { };
144 
145 #if __cplusplus >= 201703L
146 
147  template<typename... _Bn>
148  inline constexpr bool __or_v = __or_<_Bn...>::value;
149  template<typename... _Bn>
150  inline constexpr bool __and_v = __and_<_Bn...>::value;
151 
152 #define __cpp_lib_logical_traits 201510
153 
154  template<typename... _Bn>
155  struct conjunction
156  : __and_<_Bn...>
157  { };
158 
159  template<typename... _Bn>
160  struct disjunction
161  : __or_<_Bn...>
162  { };
163 
164  template<typename _Pp>
165  struct negation
166  : __not_<_Pp>
167  { };
168 
169  template<typename... _Bn>
170  inline constexpr bool conjunction_v = conjunction<_Bn...>::value;
171 
172  template<typename... _Bn>
173  inline constexpr bool disjunction_v = disjunction<_Bn...>::value;
174 
175  template<typename _Pp>
176  inline constexpr bool negation_v = negation<_Pp>::value;
177 
178 #endif // C++17
179 
180  // For several sfinae-friendly trait implementations we transport both the
181  // result information (as the member type) and the failure information (no
182  // member type). This is very similar to std::enable_if, but we cannot use
183  // them, because we need to derive from them as an implementation detail.
184 
185  template<typename _Tp>
186  struct __success_type
187  { typedef _Tp type; };
188 
189  struct __failure_type
190  { };
191 
192  // Primary type categories.
193 
194  template<typename>
195  struct remove_cv;
196 
197  template<typename>
198  struct __is_void_helper
199  : public false_type { };
200 
201  template<>
202  struct __is_void_helper<void>
203  : public true_type { };
204 
205  /// is_void
206  template<typename _Tp>
207  struct is_void
208  : public __is_void_helper<typename remove_cv<_Tp>::type>::type
209  { };
210 
211  template<typename>
212  struct __is_integral_helper
213  : public false_type { };
214 
215  template<>
216  struct __is_integral_helper<bool>
217  : public true_type { };
218 
219  template<>
220  struct __is_integral_helper<char>
221  : public true_type { };
222 
223  template<>
224  struct __is_integral_helper<signed char>
225  : public true_type { };
226 
227  template<>
228  struct __is_integral_helper<unsigned char>
229  : public true_type { };
230 
231 #ifdef _GLIBCXX_USE_WCHAR_T
232  template<>
233  struct __is_integral_helper<wchar_t>
234  : public true_type { };
235 #endif
236 
237  template<>
238  struct __is_integral_helper<char16_t>
239  : public true_type { };
240 
241  template<>
242  struct __is_integral_helper<char32_t>
243  : public true_type { };
244 
245  template<>
246  struct __is_integral_helper<short>
247  : public true_type { };
248 
249  template<>
250  struct __is_integral_helper<unsigned short>
251  : public true_type { };
252 
253  template<>
254  struct __is_integral_helper<int>
255  : public true_type { };
256 
257  template<>
258  struct __is_integral_helper<unsigned int>
259  : public true_type { };
260 
261  template<>
262  struct __is_integral_helper<long>
263  : public true_type { };
264 
265  template<>
266  struct __is_integral_helper<unsigned long>
267  : public true_type { };
268 
269  template<>
270  struct __is_integral_helper<long long>
271  : public true_type { };
272 
273  template<>
274  struct __is_integral_helper<unsigned long long>
275  : public true_type { };
276 
277  // Conditionalizing on __STRICT_ANSI__ here will break any port that
278  // uses one of these types for size_t.
279 #if defined(__GLIBCXX_TYPE_INT_N_0)
280  template<>
281  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_0>
282  : public true_type { };
283 
284  template<>
285  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_0>
286  : public true_type { };
287 #endif
288 #if defined(__GLIBCXX_TYPE_INT_N_1)
289  template<>
290  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_1>
291  : public true_type { };
292 
293  template<>
294  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_1>
295  : public true_type { };
296 #endif
297 #if defined(__GLIBCXX_TYPE_INT_N_2)
298  template<>
299  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_2>
300  : public true_type { };
301 
302  template<>
303  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_2>
304  : public true_type { };
305 #endif
306 #if defined(__GLIBCXX_TYPE_INT_N_3)
307  template<>
308  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_3>
309  : public true_type { };
310 
311  template<>
312  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_3>
313  : public true_type { };
314 #endif
315 
316  /// is_integral
317  template<typename _Tp>
318  struct is_integral
319  : public __is_integral_helper<typename remove_cv<_Tp>::type>::type
320  { };
321 
322  template<typename>
323  struct __is_floating_point_helper
324  : public false_type { };
325 
326  template<>
327  struct __is_floating_point_helper<float>
328  : public true_type { };
329 
330  template<>
331  struct __is_floating_point_helper<double>
332  : public true_type { };
333 
334  template<>
335  struct __is_floating_point_helper<long double>
336  : public true_type { };
337 
338 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
339  template<>
340  struct __is_floating_point_helper<__float128>
341  : public true_type { };
342 #endif
343 
344  /// is_floating_point
345  template<typename _Tp>
346  struct is_floating_point
347  : public __is_floating_point_helper<typename remove_cv<_Tp>::type>::type
348  { };
349 
350  /// is_array
351  template<typename>
352  struct is_array
353  : public false_type { };
354 
355  template<typename _Tp, std::size_t _Size>
356  struct is_array<_Tp[_Size]>
357  : public true_type { };
358 
359  template<typename _Tp>
360  struct is_array<_Tp[]>
361  : public true_type { };
362 
363  template<typename>
364  struct __is_pointer_helper
365  : public false_type { };
366 
367  template<typename _Tp>
368  struct __is_pointer_helper<_Tp*>
369  : public true_type { };
370 
371  /// is_pointer
372  template<typename _Tp>
373  struct is_pointer
374  : public __is_pointer_helper<typename remove_cv<_Tp>::type>::type
375  { };
376 
377  /// is_lvalue_reference
378  template<typename>
379  struct is_lvalue_reference
380  : public false_type { };
381 
382  template<typename _Tp>
383  struct is_lvalue_reference<_Tp&>
384  : public true_type { };
385 
386  /// is_rvalue_reference
387  template<typename>
388  struct is_rvalue_reference
389  : public false_type { };
390 
391  template<typename _Tp>
392  struct is_rvalue_reference<_Tp&&>
393  : public true_type { };
394 
395  template<typename>
396  struct is_function;
397 
398  template<typename>
399  struct __is_member_object_pointer_helper
400  : public false_type { };
401 
402  template<typename _Tp, typename _Cp>
403  struct __is_member_object_pointer_helper<_Tp _Cp::*>
404  : public __not_<is_function<_Tp>>::type { };
405 
406  /// is_member_object_pointer
407  template<typename _Tp>
408  struct is_member_object_pointer
409  : public __is_member_object_pointer_helper<
410  typename remove_cv<_Tp>::type>::type
411  { };
412 
413  template<typename>
414  struct __is_member_function_pointer_helper
415  : public false_type { };
416 
417  template<typename _Tp, typename _Cp>
418  struct __is_member_function_pointer_helper<_Tp _Cp::*>
419  : public is_function<_Tp>::type { };
420 
421  /// is_member_function_pointer
422  template<typename _Tp>
423  struct is_member_function_pointer
424  : public __is_member_function_pointer_helper<
425  typename remove_cv<_Tp>::type>::type
426  { };
427 
428  /// is_enum
429  template<typename _Tp>
430  struct is_enum
431  : public integral_constant<bool, __is_enum(_Tp)>
432  { };
433 
434  /// is_union
435  template<typename _Tp>
436  struct is_union
437  : public integral_constant<bool, __is_union(_Tp)>
438  { };
439 
440  /// is_class
441  template<typename _Tp>
442  struct is_class
443  : public integral_constant<bool, __is_class(_Tp)>
444  { };
445 
446  /// is_function
447  template<typename>
448  struct is_function
449  : public false_type { };
450 
451  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
452  struct is_function<_Res(_ArgTypes...) _GLIBCXX_NOEXCEPT_QUAL>
453  : public true_type { };
454 
455  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
456  struct is_function<_Res(_ArgTypes...) & _GLIBCXX_NOEXCEPT_QUAL>
457  : public true_type { };
458 
459  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
460  struct is_function<_Res(_ArgTypes...) && _GLIBCXX_NOEXCEPT_QUAL>
461  : public true_type { };
462 
463  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
464  struct is_function<_Res(_ArgTypes......) _GLIBCXX_NOEXCEPT_QUAL>
465  : public true_type { };
466 
467  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
468  struct is_function<_Res(_ArgTypes......) & _GLIBCXX_NOEXCEPT_QUAL>
469  : public true_type { };
470 
471  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
472  struct is_function<_Res(_ArgTypes......) && _GLIBCXX_NOEXCEPT_QUAL>
473  : public true_type { };
474 
475  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
476  struct is_function<_Res(_ArgTypes...) const _GLIBCXX_NOEXCEPT_QUAL>
477  : public true_type { };
478 
479  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
480  struct is_function<_Res(_ArgTypes...) const & _GLIBCXX_NOEXCEPT_QUAL>
481  : public true_type { };
482 
483  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
484  struct is_function<_Res(_ArgTypes...) const && _GLIBCXX_NOEXCEPT_QUAL>
485  : public true_type { };
486 
487  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
488  struct is_function<_Res(_ArgTypes......) const _GLIBCXX_NOEXCEPT_QUAL>
489  : public true_type { };
490 
491  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
492  struct is_function<_Res(_ArgTypes......) const & _GLIBCXX_NOEXCEPT_QUAL>
493  : public true_type { };
494 
495  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
496  struct is_function<_Res(_ArgTypes......) const && _GLIBCXX_NOEXCEPT_QUAL>
497  : public true_type { };
498 
499  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
500  struct is_function<_Res(_ArgTypes...) volatile _GLIBCXX_NOEXCEPT_QUAL>
501  : public true_type { };
502 
503  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
504  struct is_function<_Res(_ArgTypes...) volatile & _GLIBCXX_NOEXCEPT_QUAL>
505  : public true_type { };
506 
507  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
508  struct is_function<_Res(_ArgTypes...) volatile && _GLIBCXX_NOEXCEPT_QUAL>
509  : public true_type { };
510 
511  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
512  struct is_function<_Res(_ArgTypes......) volatile _GLIBCXX_NOEXCEPT_QUAL>
513  : public true_type { };
514 
515  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
516  struct is_function<_Res(_ArgTypes......) volatile & _GLIBCXX_NOEXCEPT_QUAL>
517  : public true_type { };
518 
519  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
520  struct is_function<_Res(_ArgTypes......) volatile && _GLIBCXX_NOEXCEPT_QUAL>
521  : public true_type { };
522 
523  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
524  struct is_function<_Res(_ArgTypes...) const volatile _GLIBCXX_NOEXCEPT_QUAL>
525  : public true_type { };
526 
527  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
528  struct is_function<_Res(_ArgTypes...) const volatile & _GLIBCXX_NOEXCEPT_QUAL>
529  : public true_type { };
530 
531  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
532  struct is_function<_Res(_ArgTypes...) const volatile && _GLIBCXX_NOEXCEPT_QUAL>
533  : public true_type { };
534 
535  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
536  struct is_function<_Res(_ArgTypes......) const volatile _GLIBCXX_NOEXCEPT_QUAL>
537  : public true_type { };
538 
539  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
540  struct is_function<_Res(_ArgTypes......) const volatile & _GLIBCXX_NOEXCEPT_QUAL>
541  : public true_type { };
542 
543  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
544  struct is_function<_Res(_ArgTypes......) const volatile && _GLIBCXX_NOEXCEPT_QUAL>
545  : public true_type { };
546 
547 #define __cpp_lib_is_null_pointer 201309
548 
549  template<typename>
550  struct __is_null_pointer_helper
551  : public false_type { };
552 
553  template<>
554  struct __is_null_pointer_helper<std::nullptr_t>
555  : public true_type { };
556 
557  /// is_null_pointer (LWG 2247).
558  template<typename _Tp>
559  struct is_null_pointer
560  : public __is_null_pointer_helper<typename remove_cv<_Tp>::type>::type
561  { };
562 
563  /// __is_nullptr_t (extension).
564  template<typename _Tp>
565  struct __is_nullptr_t
566  : public is_null_pointer<_Tp>
567  { };
568 
569  // Composite type categories.
570 
571  /// is_reference
572  template<typename _Tp>
573  struct is_reference
574  : public __or_<is_lvalue_reference<_Tp>,
575  is_rvalue_reference<_Tp>>::type
576  { };
577 
578  /// is_arithmetic
579  template<typename _Tp>
580  struct is_arithmetic
581  : public __or_<is_integral<_Tp>, is_floating_point<_Tp>>::type
582  { };
583 
584  /// is_fundamental
585  template<typename _Tp>
586  struct is_fundamental
587  : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
588  is_null_pointer<_Tp>>::type
589  { };
590 
591  /// is_object
592  template<typename _Tp>
593  struct is_object
594  : public __not_<__or_<is_function<_Tp>, is_reference<_Tp>,
595  is_void<_Tp>>>::type
596  { };
597 
598  template<typename>
599  struct is_member_pointer;
600 
601  /// is_scalar
602  template<typename _Tp>
603  struct is_scalar
604  : public __or_<is_arithmetic<_Tp>, is_enum<_Tp>, is_pointer<_Tp>,
605  is_member_pointer<_Tp>, is_null_pointer<_Tp>>::type
606  { };
607 
608  /// is_compound
609  template<typename _Tp>
610  struct is_compound
611  : public __not_<is_fundamental<_Tp>>::type { };
612 
613  template<typename _Tp>
614  struct __is_member_pointer_helper
615  : public false_type { };
616 
617  template<typename _Tp, typename _Cp>
618  struct __is_member_pointer_helper<_Tp _Cp::*>
619  : public true_type { };
620 
621  /// is_member_pointer
622  template<typename _Tp>
623  struct is_member_pointer
624  : public __is_member_pointer_helper<typename remove_cv<_Tp>::type>::type
625  { };
626 
627  // Utility to detect referenceable types ([defns.referenceable]).
628 
629  template<typename _Tp>
630  struct __is_referenceable
631  : public __or_<is_object<_Tp>, is_reference<_Tp>>::type
632  { };
633 
634  template<typename _Res, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
635  struct __is_referenceable<_Res(_Args...) _GLIBCXX_NOEXCEPT_QUAL>
636  : public true_type
637  { };
638 
639  template<typename _Res, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
640  struct __is_referenceable<_Res(_Args......) _GLIBCXX_NOEXCEPT_QUAL>
641  : public true_type
642  { };
643 
644  // Type properties.
645 
646  /// is_const
647  template<typename>
648  struct is_const
649  : public false_type { };
650 
651  template<typename _Tp>
652  struct is_const<_Tp const>
653  : public true_type { };
654 
655  /// is_volatile
656  template<typename>
657  struct is_volatile
658  : public false_type { };
659 
660  template<typename _Tp>
661  struct is_volatile<_Tp volatile>
662  : public true_type { };
663 
664  /// is_trivial
665  template<typename _Tp>
666  struct is_trivial
667  : public integral_constant<bool, __is_trivial(_Tp)>
668  { };
669 
670  // is_trivially_copyable
671  template<typename _Tp>
672  struct is_trivially_copyable
673  : public integral_constant<bool, __is_trivially_copyable(_Tp)>
674  { };
675 
676  /// is_standard_layout
677  template<typename _Tp>
678  struct is_standard_layout
679  : public integral_constant<bool, __is_standard_layout(_Tp)>
680  { };
681 
682  /// is_pod
683  // Could use is_standard_layout && is_trivial instead of the builtin.
684  template<typename _Tp>
685  struct is_pod
686  : public integral_constant<bool, __is_pod(_Tp)>
687  { };
688 
689  /// is_literal_type
690  template<typename _Tp>
691  struct is_literal_type
692  : public integral_constant<bool, __is_literal_type(_Tp)>
693  { };
694 
695  /// is_empty
696  template<typename _Tp>
697  struct is_empty
698  : public integral_constant<bool, __is_empty(_Tp)>
699  { };
700 
701  /// is_polymorphic
702  template<typename _Tp>
703  struct is_polymorphic
704  : public integral_constant<bool, __is_polymorphic(_Tp)>
705  { };
706 
707 #if __cplusplus >= 201402L
708 #define __cpp_lib_is_final 201402L
709  /// is_final
710  template<typename _Tp>
711  struct is_final
712  : public integral_constant<bool, __is_final(_Tp)>
713  { };
714 #endif
715 
716  /// is_abstract
717  template<typename _Tp>
718  struct is_abstract
719  : public integral_constant<bool, __is_abstract(_Tp)>
720  { };
721 
722  template<typename _Tp,
723  bool = is_arithmetic<_Tp>::value>
724  struct __is_signed_helper
725  : public false_type { };
726 
727  template<typename _Tp>
728  struct __is_signed_helper<_Tp, true>
729  : public integral_constant<bool, _Tp(-1) < _Tp(0)>
730  { };
731 
732  /// is_signed
733  template<typename _Tp>
734  struct is_signed
735  : public __is_signed_helper<_Tp>::type
736  { };
737 
738  /// is_unsigned
739  template<typename _Tp>
740  struct is_unsigned
741  : public __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>
742  { };
743 
744 
745  // Destructible and constructible type properties.
746 
747  /**
748  * @brief Utility to simplify expressions used in unevaluated operands
749  * @ingroup utilities
750  */
751 
752  template<typename _Tp, typename _Up = _Tp&&>
753  _Up
754  __declval(int);
755 
756  template<typename _Tp>
757  _Tp
758  __declval(long);
759 
760  template<typename _Tp>
761  auto declval() noexcept -> decltype(__declval<_Tp>(0));
762 
763  template<typename, unsigned = 0>
764  struct extent;
765 
766  template<typename>
767  struct remove_all_extents;
768 
769  template<typename _Tp>
770  struct __is_array_known_bounds
771  : public integral_constant<bool, (extent<_Tp>::value > 0)>
772  { };
773 
774  template<typename _Tp>
775  struct __is_array_unknown_bounds
776  : public __and_<is_array<_Tp>, __not_<extent<_Tp>>>
777  { };
778 
779  // In N3290 is_destructible does not say anything about function
780  // types and abstract types, see LWG 2049. This implementation
781  // describes function types as non-destructible and all complete
782  // object types as destructible, iff the explicit destructor
783  // call expression is wellformed.
784  struct __do_is_destructible_impl
785  {
786  template<typename _Tp, typename = decltype(declval<_Tp&>().~_Tp())>
787  static true_type __test(int);
788 
789  template<typename>
790  static false_type __test(...);
791  };
792 
793  template<typename _Tp>
794  struct __is_destructible_impl
795  : public __do_is_destructible_impl
796  {
797  typedef decltype(__test<_Tp>(0)) type;
798  };
799 
800  template<typename _Tp,
801  bool = __or_<is_void<_Tp>,
802  __is_array_unknown_bounds<_Tp>,
803  is_function<_Tp>>::value,
804  bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
805  struct __is_destructible_safe;
806 
807  template<typename _Tp>
808  struct __is_destructible_safe<_Tp, false, false>
809  : public __is_destructible_impl<typename
810  remove_all_extents<_Tp>::type>::type
811  { };
812 
813  template<typename _Tp>
814  struct __is_destructible_safe<_Tp, true, false>
815  : public false_type { };
816 
817  template<typename _Tp>
818  struct __is_destructible_safe<_Tp, false, true>
819  : public true_type { };
820 
821  /// is_destructible
822  template<typename _Tp>
823  struct is_destructible
824  : public __is_destructible_safe<_Tp>::type
825  { };
826 
827  // is_nothrow_destructible requires that is_destructible is
828  // satisfied as well. We realize that by mimicing the
829  // implementation of is_destructible but refer to noexcept(expr)
830  // instead of decltype(expr).
831  struct __do_is_nt_destructible_impl
832  {
833  template<typename _Tp>
834  static __bool_constant<noexcept(declval<_Tp&>().~_Tp())>
835  __test(int);
836 
837  template<typename>
838  static false_type __test(...);
839  };
840 
841  template<typename _Tp>
842  struct __is_nt_destructible_impl
843  : public __do_is_nt_destructible_impl
844  {
845  typedef decltype(__test<_Tp>(0)) type;
846  };
847 
848  template<typename _Tp,
849  bool = __or_<is_void<_Tp>,
850  __is_array_unknown_bounds<_Tp>,
851  is_function<_Tp>>::value,
852  bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
853  struct __is_nt_destructible_safe;
854 
855  template<typename _Tp>
856  struct __is_nt_destructible_safe<_Tp, false, false>
857  : public __is_nt_destructible_impl<typename
858  remove_all_extents<_Tp>::type>::type
859  { };
860 
861  template<typename _Tp>
862  struct __is_nt_destructible_safe<_Tp, true, false>
863  : public false_type { };
864 
865  template<typename _Tp>
866  struct __is_nt_destructible_safe<_Tp, false, true>
867  : public true_type { };
868 
869  /// is_nothrow_destructible
870  template<typename _Tp>
871  struct is_nothrow_destructible
872  : public __is_nt_destructible_safe<_Tp>::type
873  { };
874 
875  struct __do_is_default_constructible_impl
876  {
877  template<typename _Tp, typename = decltype(_Tp())>
878  static true_type __test(int);
879 
880  template<typename>
881  static false_type __test(...);
882  };
883 
884  template<typename _Tp>
885  struct __is_default_constructible_impl
886  : public __do_is_default_constructible_impl
887  {
888  typedef decltype(__test<_Tp>(0)) type;
889  };
890 
891  template<typename _Tp>
892  struct __is_default_constructible_atom
893  : public __and_<__not_<is_void<_Tp>>,
894  __is_default_constructible_impl<_Tp>>
895  { };
896 
897  template<typename _Tp, bool = is_array<_Tp>::value>
898  struct __is_default_constructible_safe;
899 
900  // The following technique is a workaround for a current core language
901  // restriction, which does not allow for array types to occur in
902  // functional casts of the form T(). Complete arrays can be default-
903  // constructed, if the element type is default-constructible, but
904  // arrays with unknown bounds are not.
905  template<typename _Tp>
906  struct __is_default_constructible_safe<_Tp, true>
907  : public __and_<__is_array_known_bounds<_Tp>,
908  __is_default_constructible_atom<typename
909  remove_all_extents<_Tp>::type>>
910  { };
911 
912  template<typename _Tp>
913  struct __is_default_constructible_safe<_Tp, false>
914  : public __is_default_constructible_atom<_Tp>::type
915  { };
916 
917  /// is_default_constructible
918  template<typename _Tp>
919  struct is_default_constructible
920  : public __is_default_constructible_safe<_Tp>::type
921  { };
922 
923  /// is_constructible
924  template<typename _Tp, typename... _Args>
925  struct is_constructible
926  : public __bool_constant<__is_constructible(_Tp, _Args...)>
927  { };
928 
929  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
930  struct __is_copy_constructible_impl;
931 
932  template<typename _Tp>
933  struct __is_copy_constructible_impl<_Tp, false>
934  : public false_type { };
935 
936  template<typename _Tp>
937  struct __is_copy_constructible_impl<_Tp, true>
938  : public is_constructible<_Tp, const _Tp&>
939  { };
940 
941  /// is_copy_constructible
942  template<typename _Tp>
943  struct is_copy_constructible
944  : public __is_copy_constructible_impl<_Tp>
945  { };
946 
947  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
948  struct __is_move_constructible_impl;
949 
950  template<typename _Tp>
951  struct __is_move_constructible_impl<_Tp, false>
952  : public false_type { };
953 
954  template<typename _Tp>
955  struct __is_move_constructible_impl<_Tp, true>
956  : public is_constructible<_Tp, _Tp&&>
957  { };
958 
959  /// is_move_constructible
960  template<typename _Tp>
961  struct is_move_constructible
962  : public __is_move_constructible_impl<_Tp>
963  { };
964 
965  template<typename _Tp>
966  struct __is_nt_default_constructible_atom
967  : public integral_constant<bool, noexcept(_Tp())>
968  { };
969 
970  template<typename _Tp, bool = is_array<_Tp>::value>
971  struct __is_nt_default_constructible_impl;
972 
973  template<typename _Tp>
974  struct __is_nt_default_constructible_impl<_Tp, true>
975  : public __and_<__is_array_known_bounds<_Tp>,
976  __is_nt_default_constructible_atom<typename
977  remove_all_extents<_Tp>::type>>
978  { };
979 
980  template<typename _Tp>
981  struct __is_nt_default_constructible_impl<_Tp, false>
982  : public __is_nt_default_constructible_atom<_Tp>
983  { };
984 
985  /// is_nothrow_default_constructible
986  template<typename _Tp>
987  struct is_nothrow_default_constructible
988  : public __and_<is_default_constructible<_Tp>,
989  __is_nt_default_constructible_impl<_Tp>>
990  { };
991 
992  template<typename _Tp, typename... _Args>
993  struct __is_nt_constructible_impl
994  : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))>
995  { };
996 
997  template<typename _Tp, typename _Arg>
998  struct __is_nt_constructible_impl<_Tp, _Arg>
999  : public integral_constant<bool,
1000  noexcept(static_cast<_Tp>(declval<_Arg>()))>
1001  { };
1002 
1003  template<typename _Tp>
1004  struct __is_nt_constructible_impl<_Tp>
1005  : public is_nothrow_default_constructible<_Tp>
1006  { };
1007 
1008  /// is_nothrow_constructible
1009  template<typename _Tp, typename... _Args>
1010  struct is_nothrow_constructible
1011  : public __and_<is_constructible<_Tp, _Args...>,
1012  __is_nt_constructible_impl<_Tp, _Args...>>
1013  { };
1014 
1015  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1016  struct __is_nothrow_copy_constructible_impl;
1017 
1018  template<typename _Tp>
1019  struct __is_nothrow_copy_constructible_impl<_Tp, false>
1020  : public false_type { };
1021 
1022  template<typename _Tp>
1023  struct __is_nothrow_copy_constructible_impl<_Tp, true>
1024  : public is_nothrow_constructible<_Tp, const _Tp&>
1025  { };
1026 
1027  /// is_nothrow_copy_constructible
1028  template<typename _Tp>
1029  struct is_nothrow_copy_constructible
1030  : public __is_nothrow_copy_constructible_impl<_Tp>
1031  { };
1032 
1033  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1034  struct __is_nothrow_move_constructible_impl;
1035 
1036  template<typename _Tp>
1037  struct __is_nothrow_move_constructible_impl<_Tp, false>
1038  : public false_type { };
1039 
1040  template<typename _Tp>
1041  struct __is_nothrow_move_constructible_impl<_Tp, true>
1042  : public is_nothrow_constructible<_Tp, _Tp&&>
1043  { };
1044 
1045  /// is_nothrow_move_constructible
1046  template<typename _Tp>
1047  struct is_nothrow_move_constructible
1048  : public __is_nothrow_move_constructible_impl<_Tp>
1049  { };
1050 
1051  /// is_assignable
1052  template<typename _Tp, typename _Up>
1053  struct is_assignable
1054  : public __bool_constant<__is_assignable(_Tp, _Up)>
1055  { };
1056 
1057  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1058  struct __is_copy_assignable_impl;
1059 
1060  template<typename _Tp>
1061  struct __is_copy_assignable_impl<_Tp, false>
1062  : public false_type { };
1063 
1064  template<typename _Tp>
1065  struct __is_copy_assignable_impl<_Tp, true>
1066  : public is_assignable<_Tp&, const _Tp&>
1067  { };
1068 
1069  /// is_copy_assignable
1070  template<typename _Tp>
1071  struct is_copy_assignable
1072  : public __is_copy_assignable_impl<_Tp>
1073  { };
1074 
1075  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1076  struct __is_move_assignable_impl;
1077 
1078  template<typename _Tp>
1079  struct __is_move_assignable_impl<_Tp, false>
1080  : public false_type { };
1081 
1082  template<typename _Tp>
1083  struct __is_move_assignable_impl<_Tp, true>
1084  : public is_assignable<_Tp&, _Tp&&>
1085  { };
1086 
1087  /// is_move_assignable
1088  template<typename _Tp>
1089  struct is_move_assignable
1090  : public __is_move_assignable_impl<_Tp>
1091  { };
1092 
1093  template<typename _Tp, typename _Up>
1094  struct __is_nt_assignable_impl
1095  : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Up>())>
1096  { };
1097 
1098  /// is_nothrow_assignable
1099  template<typename _Tp, typename _Up>
1100  struct is_nothrow_assignable
1101  : public __and_<is_assignable<_Tp, _Up>,
1102  __is_nt_assignable_impl<_Tp, _Up>>
1103  { };
1104 
1105  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1106  struct __is_nt_copy_assignable_impl;
1107 
1108  template<typename _Tp>
1109  struct __is_nt_copy_assignable_impl<_Tp, false>
1110  : public false_type { };
1111 
1112  template<typename _Tp>
1113  struct __is_nt_copy_assignable_impl<_Tp, true>
1114  : public is_nothrow_assignable<_Tp&, const _Tp&>
1115  { };
1116 
1117  /// is_nothrow_copy_assignable
1118  template<typename _Tp>
1119  struct is_nothrow_copy_assignable
1120  : public __is_nt_copy_assignable_impl<_Tp>
1121  { };
1122 
1123  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1124  struct __is_nt_move_assignable_impl;
1125 
1126  template<typename _Tp>
1127  struct __is_nt_move_assignable_impl<_Tp, false>
1128  : public false_type { };
1129 
1130  template<typename _Tp>
1131  struct __is_nt_move_assignable_impl<_Tp, true>
1132  : public is_nothrow_assignable<_Tp&, _Tp&&>
1133  { };
1134 
1135  /// is_nothrow_move_assignable
1136  template<typename _Tp>
1137  struct is_nothrow_move_assignable
1138  : public __is_nt_move_assignable_impl<_Tp>
1139  { };
1140 
1141  /// is_trivially_constructible
1142  template<typename _Tp, typename... _Args>
1143  struct is_trivially_constructible
1144  : public __bool_constant<__is_trivially_constructible(_Tp, _Args...)>
1145  { };
1146 
1147  /// is_trivially_default_constructible
1148  template<typename _Tp>
1149  struct is_trivially_default_constructible
1150  : public is_trivially_constructible<_Tp>::type
1151  { };
1152 
1153  struct __do_is_implicitly_default_constructible_impl
1154  {
1155  template <typename _Tp>
1156  static void __helper(const _Tp&);
1157 
1158  template <typename _Tp>
1159  static true_type __test(const _Tp&,
1160  decltype(__helper<const _Tp&>({}))* = 0);
1161 
1162  static false_type __test(...);
1163  };
1164 
1165  template<typename _Tp>
1166  struct __is_implicitly_default_constructible_impl
1167  : public __do_is_implicitly_default_constructible_impl
1168  {
1169  typedef decltype(__test(declval<_Tp>())) type;
1170  };
1171 
1172  template<typename _Tp>
1173  struct __is_implicitly_default_constructible_safe
1174  : public __is_implicitly_default_constructible_impl<_Tp>::type
1175  { };
1176 
1177  template <typename _Tp>
1178  struct __is_implicitly_default_constructible
1179  : public __and_<is_default_constructible<_Tp>,
1180  __is_implicitly_default_constructible_safe<_Tp>>
1181  { };
1182 
1183  /// is_trivially_copy_constructible
1184 
1185  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1186  struct __is_trivially_copy_constructible_impl;
1187 
1188  template<typename _Tp>
1189  struct __is_trivially_copy_constructible_impl<_Tp, false>
1190  : public false_type { };
1191 
1192  template<typename _Tp>
1193  struct __is_trivially_copy_constructible_impl<_Tp, true>
1194  : public __and_<is_copy_constructible<_Tp>,
1195  integral_constant<bool,
1196  __is_trivially_constructible(_Tp, const _Tp&)>>
1197  { };
1198 
1199  template<typename _Tp>
1200  struct is_trivially_copy_constructible
1201  : public __is_trivially_copy_constructible_impl<_Tp>
1202  { };
1203 
1204  /// is_trivially_move_constructible
1205 
1206  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1207  struct __is_trivially_move_constructible_impl;
1208 
1209  template<typename _Tp>
1210  struct __is_trivially_move_constructible_impl<_Tp, false>
1211  : public false_type { };
1212 
1213  template<typename _Tp>
1214  struct __is_trivially_move_constructible_impl<_Tp, true>
1215  : public __and_<is_move_constructible<_Tp>,
1216  integral_constant<bool,
1217  __is_trivially_constructible(_Tp, _Tp&&)>>
1218  { };
1219 
1220  template<typename _Tp>
1221  struct is_trivially_move_constructible
1222  : public __is_trivially_move_constructible_impl<_Tp>
1223  { };
1224 
1225  /// is_trivially_assignable
1226  template<typename _Tp, typename _Up>
1227  struct is_trivially_assignable
1228  : public __bool_constant<__is_trivially_assignable(_Tp, _Up)>
1229  { };
1230 
1231  /// is_trivially_copy_assignable
1232 
1233  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1234  struct __is_trivially_copy_assignable_impl;
1235 
1236  template<typename _Tp>
1237  struct __is_trivially_copy_assignable_impl<_Tp, false>
1238  : public false_type { };
1239 
1240  template<typename _Tp>
1241  struct __is_trivially_copy_assignable_impl<_Tp, true>
1242  : public __bool_constant<__is_trivially_assignable(_Tp&, const _Tp&)>
1243  { };
1244 
1245  template<typename _Tp>
1246  struct is_trivially_copy_assignable
1247  : public __is_trivially_copy_assignable_impl<_Tp>
1248  { };
1249 
1250  /// is_trivially_move_assignable
1251 
1252  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1253  struct __is_trivially_move_assignable_impl;
1254 
1255  template<typename _Tp>
1256  struct __is_trivially_move_assignable_impl<_Tp, false>
1257  : public false_type { };
1258 
1259  template<typename _Tp>
1260  struct __is_trivially_move_assignable_impl<_Tp, true>
1261  : public __bool_constant<__is_trivially_assignable(_Tp&, _Tp&&)>
1262  { };
1263 
1264  template<typename _Tp>
1265  struct is_trivially_move_assignable
1266  : public __is_trivially_move_assignable_impl<_Tp>
1267  { };
1268 
1269  /// is_trivially_destructible
1270  template<typename _Tp>
1271  struct is_trivially_destructible
1272  : public __and_<is_destructible<_Tp>,
1273  __bool_constant<__has_trivial_destructor(_Tp)>>
1274  { };
1275 
1276 
1277  /// has_virtual_destructor
1278  template<typename _Tp>
1279  struct has_virtual_destructor
1280  : public integral_constant<bool, __has_virtual_destructor(_Tp)>
1281  { };
1282 
1283 
1284  // type property queries.
1285 
1286  /// alignment_of
1287  template<typename _Tp>
1288  struct alignment_of
1289  : public integral_constant<std::size_t, alignof(_Tp)> { };
1290 
1291  /// rank
1292  template<typename>
1293  struct rank
1294  : public integral_constant<std::size_t, 0> { };
1295 
1296  template<typename _Tp, std::size_t _Size>
1297  struct rank<_Tp[_Size]>
1298  : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1299 
1300  template<typename _Tp>
1301  struct rank<_Tp[]>
1302  : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1303 
1304  /// extent
1305  template<typename, unsigned _Uint>
1306  struct extent
1307  : public integral_constant<std::size_t, 0> { };
1308 
1309  template<typename _Tp, unsigned _Uint, std::size_t _Size>
1310  struct extent<_Tp[_Size], _Uint>
1311  : public integral_constant<std::size_t,
1312  _Uint == 0 ? _Size : extent<_Tp,
1313  _Uint - 1>::value>
1314  { };
1315 
1316  template<typename _Tp, unsigned _Uint>
1317  struct extent<_Tp[], _Uint>
1318  : public integral_constant<std::size_t,
1319  _Uint == 0 ? 0 : extent<_Tp,
1320  _Uint - 1>::value>
1321  { };
1322 
1323 
1324  // Type relations.
1325 
1326  /// is_same
1327  template<typename, typename>
1328  struct is_same
1329  : public false_type { };
1330 
1331  template<typename _Tp>
1332  struct is_same<_Tp, _Tp>
1333  : public true_type { };
1334 
1335  /// is_base_of
1336  template<typename _Base, typename _Derived>
1337  struct is_base_of
1338  : public integral_constant<bool, __is_base_of(_Base, _Derived)>
1339  { };
1340 
1341  template<typename _From, typename _To,
1342  bool = __or_<is_void<_From>, is_function<_To>,
1343  is_array<_To>>::value>
1344  struct __is_convertible_helper
1345  {
1346  typedef typename is_void<_To>::type type;
1347  };
1348 
1349  template<typename _From, typename _To>
1350  class __is_convertible_helper<_From, _To, false>
1351  {
1352  template<typename _To1>
1353  static void __test_aux(_To1) noexcept;
1354 
1355  template<typename _From1, typename _To1,
1356  typename = decltype(__test_aux<_To1>(std::declval<_From1>()))>
1357  static true_type
1358  __test(int);
1359 
1360  template<typename, typename>
1361  static false_type
1362  __test(...);
1363 
1364  public:
1365  typedef decltype(__test<_From, _To>(0)) type;
1366  };
1367 
1368 
1369  /// is_convertible
1370  template<typename _From, typename _To>
1371  struct is_convertible
1372  : public __is_convertible_helper<_From, _To>::type
1373  { };
1374 
1375 #if __cplusplus > 201703L
1376  template<typename _From, typename _To,
1377  bool = __or_<is_void<_From>, is_function<_To>,
1378  is_array<_To>>::value>
1379  struct __is_nt_convertible_helper
1380  : is_void<_To>
1381  { };
1382 
1383  template<typename _From, typename _To>
1384  class __is_nt_convertible_helper<_From, _To, false>
1385  {
1386  template<typename _To1>
1387  static void __test_aux(_To1) noexcept;
1388 
1389  template<typename _From1, typename _To1>
1390  static bool_constant<noexcept(__test_aux<_To1>(std::declval<_From1>()))>
1391  __test(int);
1392 
1393  template<typename, typename>
1394  static false_type
1395  __test(...);
1396 
1397  public:
1398  using type = decltype(__test<_From, _To>(0));
1399  };
1400 
1401  /// is_nothrow_convertible
1402  template<typename _From, typename _To>
1403  struct is_nothrow_convertible
1404  : public __is_nt_convertible_helper<_From, _To>::type
1405  { };
1406 
1407  /// is_nothrow_convertible_v
1408  template<typename _From, typename _To>
1409  inline constexpr bool is_nothrow_convertible_v
1410  = is_nothrow_convertible<_From, _To>::value;
1411 #endif // C++2a
1412 
1413  // Const-volatile modifications.
1414 
1415  /// remove_const
1416  template<typename _Tp>
1417  struct remove_const
1418  { typedef _Tp type; };
1419 
1420  template<typename _Tp>
1421  struct remove_const<_Tp const>
1422  { typedef _Tp type; };
1423 
1424  /// remove_volatile
1425  template<typename _Tp>
1426  struct remove_volatile
1427  { typedef _Tp type; };
1428 
1429  template<typename _Tp>
1430  struct remove_volatile<_Tp volatile>
1431  { typedef _Tp type; };
1432 
1433  /// remove_cv
1434  template<typename _Tp>
1435  struct remove_cv
1436  {
1437  typedef typename
1438  remove_const<typename remove_volatile<_Tp>::type>::type type;
1439  };
1440 
1441  /// add_const
1442  template<typename _Tp>
1443  struct add_const
1444  { typedef _Tp const type; };
1445 
1446  /// add_volatile
1447  template<typename _Tp>
1448  struct add_volatile
1449  { typedef _Tp volatile type; };
1450 
1451  /// add_cv
1452  template<typename _Tp>
1453  struct add_cv
1454  {
1455  typedef typename
1456  add_const<typename add_volatile<_Tp>::type>::type type;
1457  };
1458 
1459 #if __cplusplus > 201103L
1460 
1461 #define __cpp_lib_transformation_trait_aliases 201304
1462 
1463  /// Alias template for remove_const
1464  template<typename _Tp>
1465  using remove_const_t = typename remove_const<_Tp>::type;
1466 
1467  /// Alias template for remove_volatile
1468  template<typename _Tp>
1469  using remove_volatile_t = typename remove_volatile<_Tp>::type;
1470 
1471  /// Alias template for remove_cv
1472  template<typename _Tp>
1473  using remove_cv_t = typename remove_cv<_Tp>::type;
1474 
1475  /// Alias template for add_const
1476  template<typename _Tp>
1477  using add_const_t = typename add_const<_Tp>::type;
1478 
1479  /// Alias template for add_volatile
1480  template<typename _Tp>
1481  using add_volatile_t = typename add_volatile<_Tp>::type;
1482 
1483  /// Alias template for add_cv
1484  template<typename _Tp>
1485  using add_cv_t = typename add_cv<_Tp>::type;
1486 #endif
1487 
1488  // Reference transformations.
1489 
1490  /// remove_reference
1491  template<typename _Tp>
1492  struct remove_reference
1493  { typedef _Tp type; };
1494 
1495  template<typename _Tp>
1496  struct remove_reference<_Tp&>
1497  { typedef _Tp type; };
1498 
1499  template<typename _Tp>
1500  struct remove_reference<_Tp&&>
1501  { typedef _Tp type; };
1502 
1503  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1504  struct __add_lvalue_reference_helper
1505  { typedef _Tp type; };
1506 
1507  template<typename _Tp>
1508  struct __add_lvalue_reference_helper<_Tp, true>
1509  { typedef _Tp& type; };
1510 
1511  /// add_lvalue_reference
1512  template<typename _Tp>
1513  struct add_lvalue_reference
1514  : public __add_lvalue_reference_helper<_Tp>
1515  { };
1516 
1517  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1518  struct __add_rvalue_reference_helper
1519  { typedef _Tp type; };
1520 
1521  template<typename _Tp>
1522  struct __add_rvalue_reference_helper<_Tp, true>
1523  { typedef _Tp&& type; };
1524 
1525  /// add_rvalue_reference
1526  template<typename _Tp>
1527  struct add_rvalue_reference
1528  : public __add_rvalue_reference_helper<_Tp>
1529  { };
1530 
1531 #if __cplusplus > 201103L
1532  /// Alias template for remove_reference
1533  template<typename _Tp>
1534  using remove_reference_t = typename remove_reference<_Tp>::type;
1535 
1536  /// Alias template for add_lvalue_reference
1537  template<typename _Tp>
1538  using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
1539 
1540  /// Alias template for add_rvalue_reference
1541  template<typename _Tp>
1542  using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
1543 #endif
1544 
1545  // Sign modifications.
1546 
1547  // Utility for constructing identically cv-qualified types.
1548  template<typename _Unqualified, bool _IsConst, bool _IsVol>
1549  struct __cv_selector;
1550 
1551  template<typename _Unqualified>
1552  struct __cv_selector<_Unqualified, false, false>
1553  { typedef _Unqualified __type; };
1554 
1555  template<typename _Unqualified>
1556  struct __cv_selector<_Unqualified, false, true>
1557  { typedef volatile _Unqualified __type; };
1558 
1559  template<typename _Unqualified>
1560  struct __cv_selector<_Unqualified, true, false>
1561  { typedef const _Unqualified __type; };
1562 
1563  template<typename _Unqualified>
1564  struct __cv_selector<_Unqualified, true, true>
1565  { typedef const volatile _Unqualified __type; };
1566 
1567  template<typename _Qualified, typename _Unqualified,
1568  bool _IsConst = is_const<_Qualified>::value,
1569  bool _IsVol = is_volatile<_Qualified>::value>
1570  class __match_cv_qualifiers
1571  {
1572  typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
1573 
1574  public:
1575  typedef typename __match::__type __type;
1576  };
1577 
1578  // Utility for finding the unsigned versions of signed integral types.
1579  template<typename _Tp>
1580  struct __make_unsigned
1581  { typedef _Tp __type; };
1582 
1583  template<>
1584  struct __make_unsigned<char>
1585  { typedef unsigned char __type; };
1586 
1587  template<>
1588  struct __make_unsigned<signed char>
1589  { typedef unsigned char __type; };
1590 
1591  template<>
1592  struct __make_unsigned<short>
1593  { typedef unsigned short __type; };
1594 
1595  template<>
1596  struct __make_unsigned<int>
1597  { typedef unsigned int __type; };
1598 
1599  template<>
1600  struct __make_unsigned<long>
1601  { typedef unsigned long __type; };
1602 
1603  template<>
1604  struct __make_unsigned<long long>
1605  { typedef unsigned long long __type; };
1606 
1607 #if defined(__GLIBCXX_TYPE_INT_N_0)
1608  template<>
1609  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_0>
1610  { typedef unsigned __GLIBCXX_TYPE_INT_N_0 __type; };
1611 #endif
1612 #if defined(__GLIBCXX_TYPE_INT_N_1)
1613  template<>
1614  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_1>
1615  { typedef unsigned __GLIBCXX_TYPE_INT_N_1 __type; };
1616 #endif
1617 #if defined(__GLIBCXX_TYPE_INT_N_2)
1618  template<>
1619  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_2>
1620  { typedef unsigned __GLIBCXX_TYPE_INT_N_2 __type; };
1621 #endif
1622 #if defined(__GLIBCXX_TYPE_INT_N_3)
1623  template<>
1624  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_3>
1625  { typedef unsigned __GLIBCXX_TYPE_INT_N_3 __type; };
1626 #endif
1627 
1628  // Select between integral and enum: not possible to be both.
1629  template<typename _Tp,
1630  bool _IsInt = is_integral<_Tp>::value,
1631  bool _IsEnum = is_enum<_Tp>::value>
1632  class __make_unsigned_selector;
1633 
1634  template<typename _Tp>
1635  class __make_unsigned_selector<_Tp, true, false>
1636  {
1637  using __unsigned_type
1638  = typename __make_unsigned<typename remove_cv<_Tp>::type>::__type;
1639 
1640  public:
1641  using __type
1642  = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1643  };
1644 
1645  class __make_unsigned_selector_base
1646  {
1647  protected:
1648  template<typename...> struct _List { };
1649 
1650  template<typename _Tp, typename... _Up>
1651  struct _List<_Tp, _Up...> : _List<_Up...>
1652  { static constexpr size_t __size = sizeof(_Tp); };
1653 
1654  template<size_t _Sz, typename _Tp, bool = (_Sz <= _Tp::__size)>
1655  struct __select;
1656 
1657  template<size_t _Sz, typename _Uint, typename... _UInts>
1658  struct __select<_Sz, _List<_Uint, _UInts...>, true>
1659  { using __type = _Uint; };
1660 
1661  template<size_t _Sz, typename _Uint, typename... _UInts>
1662  struct __select<_Sz, _List<_Uint, _UInts...>, false>
1663  : __select<_Sz, _List<_UInts...>>
1664  { };
1665  };
1666 
1667  // Choose unsigned integer type with the smallest rank and same size as _Tp
1668  template<typename _Tp>
1669  class __make_unsigned_selector<_Tp, false, true>
1670  : __make_unsigned_selector_base
1671  {
1672  // With -fshort-enums, an enum may be as small as a char.
1673  using _UInts = _List<unsigned char, unsigned short, unsigned int,
1674  unsigned long, unsigned long long>;
1675 
1676  using __unsigned_type = typename __select<sizeof(_Tp), _UInts>::__type;
1677 
1678  public:
1679  using __type
1680  = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1681  };
1682 
1683  // wchar_t, char16_t and char32_t are integral types but are neither
1684  // signed integer types nor unsigned integer types, so must be
1685  // transformed to the unsigned integer type with the smallest rank.
1686  // Use the partial specialization for enumeration types to do that.
1687 #if defined(_GLIBCXX_USE_WCHAR_T)
1688  template<>
1689  struct __make_unsigned<wchar_t>
1690  {
1691  using __type
1692  = typename __make_unsigned_selector<wchar_t, false, true>::__type;
1693  };
1694 #endif
1695 
1696  template<>
1697  struct __make_unsigned<char16_t>
1698  {
1699  using __type
1700  = typename __make_unsigned_selector<char16_t, false, true>::__type;
1701  };
1702 
1703  template<>
1704  struct __make_unsigned<char32_t>
1705  {
1706  using __type
1707  = typename __make_unsigned_selector<char32_t, false, true>::__type;
1708  };
1709 
1710  // Given an integral/enum type, return the corresponding unsigned
1711  // integer type.
1712  // Primary template.
1713  /// make_unsigned
1714  template<typename _Tp>
1715  struct make_unsigned
1716  { typedef typename __make_unsigned_selector<_Tp>::__type type; };
1717 
1718  // Integral, but don't define.
1719  template<>
1720  struct make_unsigned<bool>;
1721 
1722 
1723  // Utility for finding the signed versions of unsigned integral types.
1724  template<typename _Tp>
1725  struct __make_signed
1726  { typedef _Tp __type; };
1727 
1728  template<>
1729  struct __make_signed<char>
1730  { typedef signed char __type; };
1731 
1732  template<>
1733  struct __make_signed<unsigned char>
1734  { typedef signed char __type; };
1735 
1736  template<>
1737  struct __make_signed<unsigned short>
1738  { typedef signed short __type; };
1739 
1740  template<>
1741  struct __make_signed<unsigned int>
1742  { typedef signed int __type; };
1743 
1744  template<>
1745  struct __make_signed<unsigned long>
1746  { typedef signed long __type; };
1747 
1748  template<>
1749  struct __make_signed<unsigned long long>
1750  { typedef signed long long __type; };
1751 
1752 #if defined(__GLIBCXX_TYPE_INT_N_0)
1753  template<>
1754  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_0>
1755  { typedef __GLIBCXX_TYPE_INT_N_0 __type; };
1756 #endif
1757 #if defined(__GLIBCXX_TYPE_INT_N_1)
1758  template<>
1759  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_1>
1760  { typedef __GLIBCXX_TYPE_INT_N_1 __type; };
1761 #endif
1762 #if defined(__GLIBCXX_TYPE_INT_N_2)
1763  template<>
1764  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_2>
1765  { typedef __GLIBCXX_TYPE_INT_N_2 __type; };
1766 #endif
1767 #if defined(__GLIBCXX_TYPE_INT_N_3)
1768  template<>
1769  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_3>
1770  { typedef __GLIBCXX_TYPE_INT_N_3 __type; };
1771 #endif
1772 
1773  // Select between integral and enum: not possible to be both.
1774  template<typename _Tp,
1775  bool _IsInt = is_integral<_Tp>::value,
1776  bool _IsEnum = is_enum<_Tp>::value>
1777  class __make_signed_selector;
1778 
1779  template<typename _Tp>
1780  class __make_signed_selector<_Tp, true, false>
1781  {
1782  using __signed_type
1783  = typename __make_signed<typename remove_cv<_Tp>::type>::__type;
1784 
1785  public:
1786  using __type
1787  = typename __match_cv_qualifiers<_Tp, __signed_type>::__type;
1788  };
1789 
1790  // Choose signed integer type with the smallest rank and same size as _Tp
1791  template<typename _Tp>
1792  class __make_signed_selector<_Tp, false, true>
1793  {
1794  typedef typename __make_unsigned_selector<_Tp>::__type __unsigned_type;
1795 
1796  public:
1797  typedef typename __make_signed_selector<__unsigned_type>::__type __type;
1798  };
1799 
1800  // wchar_t, char16_t and char32_t are integral types but are neither
1801  // signed integer types nor unsigned integer types, so must be
1802  // transformed to the signed integer type with the smallest rank.
1803  // Use the partial specialization for enumeration types to do that.
1804 #if defined(_GLIBCXX_USE_WCHAR_T)
1805  template<>
1806  struct __make_signed<wchar_t>
1807  {
1808  using __type
1809  = typename __make_signed_selector<wchar_t, false, true>::__type;
1810  };
1811 #endif
1812 
1813  template<>
1814  struct __make_signed<char16_t>
1815  {
1816  using __type
1817  = typename __make_signed_selector<char16_t, false, true>::__type;
1818  };
1819 
1820  template<>
1821  struct __make_signed<char32_t>
1822  {
1823  using __type
1824  = typename __make_signed_selector<char32_t, false, true>::__type;
1825  };
1826 
1827  // Given an integral/enum type, return the corresponding signed
1828  // integer type.
1829  // Primary template.
1830  /// make_signed
1831  template<typename _Tp>
1832  struct make_signed
1833  { typedef typename __make_signed_selector<_Tp>::__type type; };
1834 
1835  // Integral, but don't define.
1836  template<>
1837  struct make_signed<bool>;
1838 
1839 #if __cplusplus > 201103L
1840  /// Alias template for make_signed
1841  template<typename _Tp>
1842  using make_signed_t = typename make_signed<_Tp>::type;
1843 
1844  /// Alias template for make_unsigned
1845  template<typename _Tp>
1846  using make_unsigned_t = typename make_unsigned<_Tp>::type;
1847 #endif
1848 
1849  // Array modifications.
1850 
1851  /// remove_extent
1852  template<typename _Tp>
1853  struct remove_extent
1854  { typedef _Tp type; };
1855 
1856  template<typename _Tp, std::size_t _Size>
1857  struct remove_extent<_Tp[_Size]>
1858  { typedef _Tp type; };
1859 
1860  template<typename _Tp>
1861  struct remove_extent<_Tp[]>
1862  { typedef _Tp type; };
1863 
1864  /// remove_all_extents
1865  template<typename _Tp>
1866  struct remove_all_extents
1867  { typedef _Tp type; };
1868 
1869  template<typename _Tp, std::size_t _Size>
1870  struct remove_all_extents<_Tp[_Size]>
1871  { typedef typename remove_all_extents<_Tp>::type type; };
1872 
1873  template<typename _Tp>
1874  struct remove_all_extents<_Tp[]>
1875  { typedef typename remove_all_extents<_Tp>::type type; };
1876 
1877 #if __cplusplus > 201103L
1878  /// Alias template for remove_extent
1879  template<typename _Tp>
1880  using remove_extent_t = typename remove_extent<_Tp>::type;
1881 
1882  /// Alias template for remove_all_extents
1883  template<typename _Tp>
1884  using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
1885 #endif
1886 
1887  // Pointer modifications.
1888 
1889  template<typename _Tp, typename>
1890  struct __remove_pointer_helper
1891  { typedef _Tp type; };
1892 
1893  template<typename _Tp, typename _Up>
1894  struct __remove_pointer_helper<_Tp, _Up*>
1895  { typedef _Up type; };
1896 
1897  /// remove_pointer
1898  template<typename _Tp>
1899  struct remove_pointer
1900  : public __remove_pointer_helper<_Tp, typename remove_cv<_Tp>::type>
1901  { };
1902 
1903  /// add_pointer
1904  template<typename _Tp, bool = __or_<__is_referenceable<_Tp>,
1905  is_void<_Tp>>::value>
1906  struct __add_pointer_helper
1907  { typedef _Tp type; };
1908 
1909  template<typename _Tp>
1910  struct __add_pointer_helper<_Tp, true>
1911  { typedef typename remove_reference<_Tp>::type* type; };
1912 
1913  template<typename _Tp>
1914  struct add_pointer
1915  : public __add_pointer_helper<_Tp>
1916  { };
1917 
1918 #if __cplusplus > 201103L
1919  /// Alias template for remove_pointer
1920  template<typename _Tp>
1921  using remove_pointer_t = typename remove_pointer<_Tp>::type;
1922 
1923  /// Alias template for add_pointer
1924  template<typename _Tp>
1925  using add_pointer_t = typename add_pointer<_Tp>::type;
1926 #endif
1927 
1928  template<std::size_t _Len>
1929  struct __aligned_storage_msa
1930  {
1931  union __type
1932  {
1933  unsigned char __data[_Len];
1934  struct __attribute__((__aligned__)) { } __align;
1935  };
1936  };
1937 
1938  /**
1939  * @brief Alignment type.
1940  *
1941  * The value of _Align is a default-alignment which shall be the
1942  * most stringent alignment requirement for any C++ object type
1943  * whose size is no greater than _Len (3.9). The member typedef
1944  * type shall be a POD type suitable for use as uninitialized
1945  * storage for any object whose size is at most _Len and whose
1946  * alignment is a divisor of _Align.
1947  */
1948  template<std::size_t _Len, std::size_t _Align =
1949  __alignof__(typename __aligned_storage_msa<_Len>::__type)>
1950  struct aligned_storage
1951  {
1952  union type
1953  {
1954  unsigned char __data[_Len];
1955  struct __attribute__((__aligned__((_Align)))) { } __align;
1956  };
1957  };
1958 
1959  template <typename... _Types>
1960  struct __strictest_alignment
1961  {
1962  static const size_t _S_alignment = 0;
1963  static const size_t _S_size = 0;
1964  };
1965 
1966  template <typename _Tp, typename... _Types>
1967  struct __strictest_alignment<_Tp, _Types...>
1968  {
1969  static const size_t _S_alignment =
1970  alignof(_Tp) > __strictest_alignment<_Types...>::_S_alignment
1971  ? alignof(_Tp) : __strictest_alignment<_Types...>::_S_alignment;
1972  static const size_t _S_size =
1973  sizeof(_Tp) > __strictest_alignment<_Types...>::_S_size
1974  ? sizeof(_Tp) : __strictest_alignment<_Types...>::_S_size;
1975  };
1976 
1977  /**
1978  * @brief Provide aligned storage for types.
1979  *
1980  * [meta.trans.other]
1981  *
1982  * Provides aligned storage for any of the provided types of at
1983  * least size _Len.
1984  *
1985  * @see aligned_storage
1986  */
1987  template <size_t _Len, typename... _Types>
1988  struct aligned_union
1989  {
1990  private:
1991  static_assert(sizeof...(_Types) != 0, "At least one type is required");
1992 
1993  using __strictest = __strictest_alignment<_Types...>;
1994  static const size_t _S_len = _Len > __strictest::_S_size
1995  ? _Len : __strictest::_S_size;
1996  public:
1997  /// The value of the strictest alignment of _Types.
1998  static const size_t alignment_value = __strictest::_S_alignment;
1999  /// The storage.
2000  typedef typename aligned_storage<_S_len, alignment_value>::type type;
2001  };
2002 
2003  template <size_t _Len, typename... _Types>
2004  const size_t aligned_union<_Len, _Types...>::alignment_value;
2005 
2006  // Decay trait for arrays and functions, used for perfect forwarding
2007  // in make_pair, make_tuple, etc.
2008  template<typename _Up,
2009  bool _IsArray = is_array<_Up>::value,
2010  bool _IsFunction = is_function<_Up>::value>
2011  struct __decay_selector;
2012 
2013  // NB: DR 705.
2014  template<typename _Up>
2015  struct __decay_selector<_Up, false, false>
2016  { typedef typename remove_cv<_Up>::type __type; };
2017 
2018  template<typename _Up>
2019  struct __decay_selector<_Up, true, false>
2020  { typedef typename remove_extent<_Up>::type* __type; };
2021 
2022  template<typename _Up>
2023  struct __decay_selector<_Up, false, true>
2024  { typedef typename add_pointer<_Up>::type __type; };
2025 
2026  /// decay
2027  template<typename _Tp>
2028  class decay
2029  {
2030  typedef typename remove_reference<_Tp>::type __remove_type;
2031 
2032  public:
2033  typedef typename __decay_selector<__remove_type>::__type type;
2034  };
2035 
2036  template<typename _Tp>
2037  class reference_wrapper;
2038 
2039  // Helper which adds a reference to a type when given a reference_wrapper
2040  template<typename _Tp>
2041  struct __strip_reference_wrapper
2042  {
2043  typedef _Tp __type;
2044  };
2045 
2046  template<typename _Tp>
2047  struct __strip_reference_wrapper<reference_wrapper<_Tp> >
2048  {
2049  typedef _Tp& __type;
2050  };
2051 
2052  template<typename _Tp>
2053  struct __decay_and_strip
2054  {
2055  typedef typename __strip_reference_wrapper<
2056  typename decay<_Tp>::type>::__type __type;
2057  };
2058 
2059 
2060  // Primary template.
2061  /// Define a member typedef @c type only if a boolean constant is true.
2062  template<bool, typename _Tp = void>
2063  struct enable_if
2064  { };
2065 
2066  // Partial specialization for true.
2067  template<typename _Tp>
2068  struct enable_if<true, _Tp>
2069  { typedef _Tp type; };
2070 
2071  template<typename... _Cond>
2072  using _Require = typename enable_if<__and_<_Cond...>::value>::type;
2073 
2074  // Primary template.
2075  /// Define a member typedef @c type to one of two argument types.
2076  template<bool _Cond, typename _Iftrue, typename _Iffalse>
2077  struct conditional
2078  { typedef _Iftrue type; };
2079 
2080  // Partial specialization for false.
2081  template<typename _Iftrue, typename _Iffalse>
2082  struct conditional<false, _Iftrue, _Iffalse>
2083  { typedef _Iffalse type; };
2084 
2085  /// common_type
2086  template<typename... _Tp>
2087  struct common_type;
2088 
2089  // Sfinae-friendly common_type implementation:
2090 
2091  struct __do_common_type_impl
2092  {
2093  template<typename _Tp, typename _Up>
2094  static __success_type<typename decay<decltype
2095  (true ? std::declval<_Tp>()
2096  : std::declval<_Up>())>::type> _S_test(int);
2097 
2098  template<typename, typename>
2099  static __failure_type _S_test(...);
2100  };
2101 
2102  template<typename _Tp, typename _Up>
2103  struct __common_type_impl
2104  : private __do_common_type_impl
2105  {
2106  typedef decltype(_S_test<_Tp, _Up>(0)) type;
2107  };
2108 
2109  struct __do_member_type_wrapper
2110  {
2111  template<typename _Tp>
2112  static __success_type<typename _Tp::type> _S_test(int);
2113 
2114  template<typename>
2115  static __failure_type _S_test(...);
2116  };
2117 
2118  template<typename _Tp>
2119  struct __member_type_wrapper
2120  : private __do_member_type_wrapper
2121  {
2122  typedef decltype(_S_test<_Tp>(0)) type;
2123  };
2124 
2125  template<typename _CTp, typename... _Args>
2126  struct __expanded_common_type_wrapper
2127  {
2128  typedef common_type<typename _CTp::type, _Args...> type;
2129  };
2130 
2131  template<typename... _Args>
2132  struct __expanded_common_type_wrapper<__failure_type, _Args...>
2133  { typedef __failure_type type; };
2134 
2135  template<>
2136  struct common_type<>
2137  { };
2138 
2139  template<typename _Tp>
2140  struct common_type<_Tp>
2141  : common_type<_Tp, _Tp>
2142  { };
2143 
2144  template<typename _Tp, typename _Up>
2145  struct common_type<_Tp, _Up>
2146  : public __common_type_impl<_Tp, _Up>::type
2147  { };
2148 
2149  template<typename _Tp, typename _Up, typename... _Vp>
2150  struct common_type<_Tp, _Up, _Vp...>
2151  : public __expanded_common_type_wrapper<typename __member_type_wrapper<
2152  common_type<_Tp, _Up>>::type, _Vp...>::type
2153  { };
2154 
2155  /// The underlying type of an enum.
2156  template<typename _Tp>
2157  struct underlying_type
2158  {
2159  typedef __underlying_type(_Tp) type;
2160  };
2161 
2162  template<typename _Tp>
2163  struct __declval_protector
2164  {
2165  static const bool __stop = false;
2166  };
2167 
2168  template<typename _Tp>
2169  auto declval() noexcept -> decltype(__declval<_Tp>(0))
2170  {
2171  static_assert(__declval_protector<_Tp>::__stop,
2172  "declval() must not be used!");
2173  return __declval<_Tp>(0);
2174  }
2175 
2176  // __remove_cvref_t (std::remove_cvref_t for C++11).
2177  template<typename _Tp>
2178  using __remove_cvref_t
2179  = typename remove_cv<typename remove_reference<_Tp>::type>::type;
2180 
2181  /// result_of
2182  template<typename _Signature>
2183  class result_of;
2184 
2185  // Sfinae-friendly result_of implementation:
2186 
2187 #define __cpp_lib_result_of_sfinae 201210
2188 
2189  struct __invoke_memfun_ref { };
2190  struct __invoke_memfun_deref { };
2191  struct __invoke_memobj_ref { };
2192  struct __invoke_memobj_deref { };
2193  struct __invoke_other { };
2194 
2195  // Associate a tag type with a specialization of __success_type.
2196  template<typename _Tp, typename _Tag>
2197  struct __result_of_success : __success_type<_Tp>
2198  { using __invoke_type = _Tag; };
2199 
2200  // [func.require] paragraph 1 bullet 1:
2201  struct __result_of_memfun_ref_impl
2202  {
2203  template<typename _Fp, typename _Tp1, typename... _Args>
2204  static __result_of_success<decltype(
2205  (std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...)
2206  ), __invoke_memfun_ref> _S_test(int);
2207 
2208  template<typename...>
2209  static __failure_type _S_test(...);
2210  };
2211 
2212  template<typename _MemPtr, typename _Arg, typename... _Args>
2213  struct __result_of_memfun_ref
2214  : private __result_of_memfun_ref_impl
2215  {
2216  typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2217  };
2218 
2219  // [func.require] paragraph 1 bullet 2:
2220  struct __result_of_memfun_deref_impl
2221  {
2222  template<typename _Fp, typename _Tp1, typename... _Args>
2223  static __result_of_success<decltype(
2224  ((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...)
2225  ), __invoke_memfun_deref> _S_test(int);
2226 
2227  template<typename...>
2228  static __failure_type _S_test(...);
2229  };
2230 
2231  template<typename _MemPtr, typename _Arg, typename... _Args>
2232  struct __result_of_memfun_deref
2233  : private __result_of_memfun_deref_impl
2234  {
2235  typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2236  };
2237 
2238  // [func.require] paragraph 1 bullet 3:
2239  struct __result_of_memobj_ref_impl
2240  {
2241  template<typename _Fp, typename _Tp1>
2242  static __result_of_success<decltype(
2243  std::declval<_Tp1>().*std::declval<_Fp>()
2244  ), __invoke_memobj_ref> _S_test(int);
2245 
2246  template<typename, typename>
2247  static __failure_type _S_test(...);
2248  };
2249 
2250  template<typename _MemPtr, typename _Arg>
2251  struct __result_of_memobj_ref
2252  : private __result_of_memobj_ref_impl
2253  {
2254  typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2255  };
2256 
2257  // [func.require] paragraph 1 bullet 4:
2258  struct __result_of_memobj_deref_impl
2259  {
2260  template<typename _Fp, typename _Tp1>
2261  static __result_of_success<decltype(
2262  (*std::declval<_Tp1>()).*std::declval<_Fp>()
2263  ), __invoke_memobj_deref> _S_test(int);
2264 
2265  template<typename, typename>
2266  static __failure_type _S_test(...);
2267  };
2268 
2269  template<typename _MemPtr, typename _Arg>
2270  struct __result_of_memobj_deref
2271  : private __result_of_memobj_deref_impl
2272  {
2273  typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2274  };
2275 
2276  template<typename _MemPtr, typename _Arg>
2277  struct __result_of_memobj;
2278 
2279  template<typename _Res, typename _Class, typename _Arg>
2280  struct __result_of_memobj<_Res _Class::*, _Arg>
2281  {
2282  typedef __remove_cvref_t<_Arg> _Argval;
2283  typedef _Res _Class::* _MemPtr;
2284  typedef typename conditional<__or_<is_same<_Argval, _Class>,
2285  is_base_of<_Class, _Argval>>::value,
2286  __result_of_memobj_ref<_MemPtr, _Arg>,
2287  __result_of_memobj_deref<_MemPtr, _Arg>
2288  >::type::type type;
2289  };
2290 
2291  template<typename _MemPtr, typename _Arg, typename... _Args>
2292  struct __result_of_memfun;
2293 
2294  template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2295  struct __result_of_memfun<_Res _Class::*, _Arg, _Args...>
2296  {
2297  typedef __remove_cvref_t<_Arg> _Argval;
2298  typedef _Res _Class::* _MemPtr;
2299  typedef typename conditional<__or_<is_same<_Argval, _Class>,
2300  is_base_of<_Class, _Argval>>::value,
2301  __result_of_memfun_ref<_MemPtr, _Arg, _Args...>,
2302  __result_of_memfun_deref<_MemPtr, _Arg, _Args...>
2303  >::type::type type;
2304  };
2305 
2306  // _GLIBCXX_RESOLVE_LIB_DEFECTS
2307  // 2219. INVOKE-ing a pointer to member with a reference_wrapper
2308  // as the object expression
2309 
2310  // Used by result_of, invoke etc. to unwrap a reference_wrapper.
2311  template<typename _Tp, typename _Up = typename decay<_Tp>::type>
2312  struct __inv_unwrap
2313  {
2314  using type = _Tp;
2315  };
2316 
2317  template<typename _Tp, typename _Up>
2318  struct __inv_unwrap<_Tp, reference_wrapper<_Up>>
2319  {
2320  using type = _Up&;
2321  };
2322 
2323  template<bool, bool, typename _Functor, typename... _ArgTypes>
2324  struct __result_of_impl
2325  {
2326  typedef __failure_type type;
2327  };
2328 
2329  template<typename _MemPtr, typename _Arg>
2330  struct __result_of_impl<true, false, _MemPtr, _Arg>
2331  : public __result_of_memobj<typename decay<_MemPtr>::type,
2332  typename __inv_unwrap<_Arg>::type>
2333  { };
2334 
2335  template<typename _MemPtr, typename _Arg, typename... _Args>
2336  struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...>
2337  : public __result_of_memfun<typename decay<_MemPtr>::type,
2338  typename __inv_unwrap<_Arg>::type, _Args...>
2339  { };
2340 
2341  // [func.require] paragraph 1 bullet 5:
2342  struct __result_of_other_impl
2343  {
2344  template<typename _Fn, typename... _Args>
2345  static __result_of_success<decltype(
2346  std::declval<_Fn>()(std::declval<_Args>()...)
2347  ), __invoke_other> _S_test(int);
2348 
2349  template<typename...>
2350  static __failure_type _S_test(...);
2351  };
2352 
2353  template<typename _Functor, typename... _ArgTypes>
2354  struct __result_of_impl<false, false, _Functor, _ArgTypes...>
2355  : private __result_of_other_impl
2356  {
2357  typedef decltype(_S_test<_Functor, _ArgTypes...>(0)) type;
2358  };
2359 
2360  // __invoke_result (std::invoke_result for C++11)
2361  template<typename _Functor, typename... _ArgTypes>
2362  struct __invoke_result
2363  : public __result_of_impl<
2364  is_member_object_pointer<
2365  typename remove_reference<_Functor>::type
2366  >::value,
2367  is_member_function_pointer<
2368  typename remove_reference<_Functor>::type
2369  >::value,
2370  _Functor, _ArgTypes...
2371  >::type
2372  { };
2373 
2374  template<typename _Functor, typename... _ArgTypes>
2375  struct result_of<_Functor(_ArgTypes...)>
2376  : public __invoke_result<_Functor, _ArgTypes...>
2377  { };
2378 
2379 #if __cplusplus >= 201402L
2380  /// Alias template for aligned_storage
2381  template<size_t _Len, size_t _Align =
2382  __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2383  using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
2384 
2385  template <size_t _Len, typename... _Types>
2386  using aligned_union_t = typename aligned_union<_Len, _Types...>::type;
2387 
2388  /// Alias template for decay
2389  template<typename _Tp>
2390  using decay_t = typename decay<_Tp>::type;
2391 
2392  /// Alias template for enable_if
2393  template<bool _Cond, typename _Tp = void>
2394  using enable_if_t = typename enable_if<_Cond, _Tp>::type;
2395 
2396  /// Alias template for conditional
2397  template<bool _Cond, typename _Iftrue, typename _Iffalse>
2398  using conditional_t = typename conditional<_Cond, _Iftrue, _Iffalse>::type;
2399 
2400  /// Alias template for common_type
2401  template<typename... _Tp>
2402  using common_type_t = typename common_type<_Tp...>::type;
2403 
2404  /// Alias template for underlying_type
2405  template<typename _Tp>
2406  using underlying_type_t = typename underlying_type<_Tp>::type;
2407 
2408  /// Alias template for result_of
2409  template<typename _Tp>
2410  using result_of_t = typename result_of<_Tp>::type;
2411 #endif // C++14
2412 
2413  // __enable_if_t (std::enable_if_t for C++11)
2414  template<bool _Cond, typename _Tp = void>
2415  using __enable_if_t = typename enable_if<_Cond, _Tp>::type;
2416 
2417  // __void_t (std::void_t for C++11)
2418  template<typename...> using __void_t = void;
2419 
2420 #if __cplusplus >= 201703L || !defined(__STRICT_ANSI__) // c++17 or gnu++11
2421 #define __cpp_lib_void_t 201411
2422  /// A metafunction that always yields void, used for detecting valid types.
2423  template<typename...> using void_t = void;
2424 #endif
2425 
2426  /// Implementation of the detection idiom (negative case).
2427  template<typename _Default, typename _AlwaysVoid,
2428  template<typename...> class _Op, typename... _Args>
2429  struct __detector
2430  {
2431  using value_t = false_type;
2432  using type = _Default;
2433  };
2434 
2435  /// Implementation of the detection idiom (positive case).
2436  template<typename _Default, template<typename...> class _Op,
2437  typename... _Args>
2438  struct __detector<_Default, __void_t<_Op<_Args...>>, _Op, _Args...>
2439  {
2440  using value_t = true_type;
2441  using type = _Op<_Args...>;
2442  };
2443 
2444  // Detect whether _Op<_Args...> is a valid type, use _Default if not.
2445  template<typename _Default, template<typename...> class _Op,
2446  typename... _Args>
2447  using __detected_or = __detector<_Default, void, _Op, _Args...>;
2448 
2449  // _Op<_Args...> if that is a valid type, otherwise _Default.
2450  template<typename _Default, template<typename...> class _Op,
2451  typename... _Args>
2452  using __detected_or_t
2453  = typename __detected_or<_Default, _Op, _Args...>::type;
2454 
2455  /// @} group metaprogramming
2456 
2457  /**
2458  * Use SFINAE to determine if the type _Tp has a publicly-accessible
2459  * member type _NTYPE.
2460  */
2461 #define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \
2462  template<typename _Tp, typename = __void_t<>> \
2463  struct __has_##_NTYPE \
2464  : false_type \
2465  { }; \
2466  template<typename _Tp> \
2467  struct __has_##_NTYPE<_Tp, __void_t<typename _Tp::_NTYPE>> \
2468  : true_type \
2469  { };
2470 
2471  template <typename _Tp>
2472  struct __is_swappable;
2473 
2474  template <typename _Tp>
2475  struct __is_nothrow_swappable;
2476 
2477  template<typename... _Elements>
2478  class tuple;
2479 
2480  template<typename>
2481  struct __is_tuple_like_impl : false_type
2482  { };
2483 
2484  template<typename... _Tps>
2485  struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
2486  { };
2487 
2488  // Internal type trait that allows us to sfinae-protect tuple_cat.
2489  template<typename _Tp>
2490  struct __is_tuple_like
2491  : public __is_tuple_like_impl<__remove_cvref_t<_Tp>>::type
2492  { };
2493 
2494  template<typename _Tp>
2495  inline
2496  typename enable_if<__and_<__not_<__is_tuple_like<_Tp>>,
2497  is_move_constructible<_Tp>,
2498  is_move_assignable<_Tp>>::value>::type
2499  swap(_Tp&, _Tp&)
2500  noexcept(__and_<is_nothrow_move_constructible<_Tp>,
2501  is_nothrow_move_assignable<_Tp>>::value);
2502 
2503  template<typename _Tp, size_t _Nm>
2504  inline
2505  typename enable_if<__is_swappable<_Tp>::value>::type
2506  swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
2507  noexcept(__is_nothrow_swappable<_Tp>::value);
2508 
2509  namespace __swappable_details {
2510  using std::swap;
2511 
2512  struct __do_is_swappable_impl
2513  {
2514  template<typename _Tp, typename
2515  = decltype(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))>
2516  static true_type __test(int);
2517 
2518  template<typename>
2519  static false_type __test(...);
2520  };
2521 
2522  struct __do_is_nothrow_swappable_impl
2523  {
2524  template<typename _Tp>
2525  static __bool_constant<
2526  noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))
2527  > __test(int);
2528 
2529  template<typename>
2530  static false_type __test(...);
2531  };
2532 
2533  } // namespace __swappable_details
2534 
2535  template<typename _Tp>
2536  struct __is_swappable_impl
2537  : public __swappable_details::__do_is_swappable_impl
2538  {
2539  typedef decltype(__test<_Tp>(0)) type;
2540  };
2541 
2542  template<typename _Tp>
2543  struct __is_nothrow_swappable_impl
2544  : public __swappable_details::__do_is_nothrow_swappable_impl
2545  {
2546  typedef decltype(__test<_Tp>(0)) type;
2547  };
2548 
2549  template<typename _Tp>
2550  struct __is_swappable
2551  : public __is_swappable_impl<_Tp>::type
2552  { };
2553 
2554  template<typename _Tp>
2555  struct __is_nothrow_swappable
2556  : public __is_nothrow_swappable_impl<_Tp>::type
2557  { };
2558 
2559 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
2560 #define __cpp_lib_is_swappable 201603
2561  /// Metafunctions used for detecting swappable types: p0185r1
2562 
2563  /// is_swappable
2564  template<typename _Tp>
2565  struct is_swappable
2566  : public __is_swappable_impl<_Tp>::type
2567  { };
2568 
2569  /// is_nothrow_swappable
2570  template<typename _Tp>
2571  struct is_nothrow_swappable
2572  : public __is_nothrow_swappable_impl<_Tp>::type
2573  { };
2574 
2575 #if __cplusplus >= 201402L
2576  /// is_swappable_v
2577  template<typename _Tp>
2578  _GLIBCXX17_INLINE constexpr bool is_swappable_v =
2579  is_swappable<_Tp>::value;
2580 
2581  /// is_nothrow_swappable_v
2582  template<typename _Tp>
2583  _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_v =
2584  is_nothrow_swappable<_Tp>::value;
2585 #endif // __cplusplus >= 201402L
2586 
2587  namespace __swappable_with_details {
2588  using std::swap;
2589 
2590  struct __do_is_swappable_with_impl
2591  {
2592  template<typename _Tp, typename _Up, typename
2593  = decltype(swap(std::declval<_Tp>(), std::declval<_Up>())),
2594  typename
2595  = decltype(swap(std::declval<_Up>(), std::declval<_Tp>()))>
2596  static true_type __test(int);
2597 
2598  template<typename, typename>
2599  static false_type __test(...);
2600  };
2601 
2602  struct __do_is_nothrow_swappable_with_impl
2603  {
2604  template<typename _Tp, typename _Up>
2605  static __bool_constant<
2606  noexcept(swap(std::declval<_Tp>(), std::declval<_Up>()))
2607  &&
2608  noexcept(swap(std::declval<_Up>(), std::declval<_Tp>()))
2609  > __test(int);
2610 
2611  template<typename, typename>
2612  static false_type __test(...);
2613  };
2614 
2615  } // namespace __swappable_with_details
2616 
2617  template<typename _Tp, typename _Up>
2618  struct __is_swappable_with_impl
2619  : public __swappable_with_details::__do_is_swappable_with_impl
2620  {
2621  typedef decltype(__test<_Tp, _Up>(0)) type;
2622  };
2623 
2624  // Optimization for the homogenous lvalue case, not required:
2625  template<typename _Tp>
2626  struct __is_swappable_with_impl<_Tp&, _Tp&>
2627  : public __swappable_details::__do_is_swappable_impl
2628  {
2629  typedef decltype(__test<_Tp&>(0)) type;
2630  };
2631 
2632  template<typename _Tp, typename _Up>
2633  struct __is_nothrow_swappable_with_impl
2634  : public __swappable_with_details::__do_is_nothrow_swappable_with_impl
2635  {
2636  typedef decltype(__test<_Tp, _Up>(0)) type;
2637  };
2638 
2639  // Optimization for the homogenous lvalue case, not required:
2640  template<typename _Tp>
2641  struct __is_nothrow_swappable_with_impl<_Tp&, _Tp&>
2642  : public __swappable_details::__do_is_nothrow_swappable_impl
2643  {
2644  typedef decltype(__test<_Tp&>(0)) type;
2645  };
2646 
2647  /// is_swappable_with
2648  template<typename _Tp, typename _Up>
2649  struct is_swappable_with
2650  : public __is_swappable_with_impl<_Tp, _Up>::type
2651  { };
2652 
2653  /// is_nothrow_swappable_with
2654  template<typename _Tp, typename _Up>
2655  struct is_nothrow_swappable_with
2656  : public __is_nothrow_swappable_with_impl<_Tp, _Up>::type
2657  { };
2658 
2659 #if __cplusplus >= 201402L
2660  /// is_swappable_with_v
2661  template<typename _Tp, typename _Up>
2662  _GLIBCXX17_INLINE constexpr bool is_swappable_with_v =
2663  is_swappable_with<_Tp, _Up>::value;
2664 
2665  /// is_nothrow_swappable_with_v
2666  template<typename _Tp, typename _Up>
2667  _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_with_v =
2668  is_nothrow_swappable_with<_Tp, _Up>::value;
2669 #endif // __cplusplus >= 201402L
2670 
2671 #endif// c++1z or gnu++11
2672 
2673  // __is_invocable (std::is_invocable for C++11)
2674 
2675  template<typename _Result, typename _Ret, typename = void>
2676  struct __is_invocable_impl : false_type { };
2677 
2678  template<typename _Result, typename _Ret>
2679  struct __is_invocable_impl<_Result, _Ret, __void_t<typename _Result::type>>
2680  : __or_<is_void<_Ret>, is_convertible<typename _Result::type, _Ret>>::type
2681  { };
2682 
2683  template<typename _Fn, typename... _ArgTypes>
2684  struct __is_invocable
2685  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2686  { };
2687 
2688  template<typename _Fn, typename _Tp, typename... _Args>
2689  constexpr bool __call_is_nt(__invoke_memfun_ref)
2690  {
2691  using _Up = typename __inv_unwrap<_Tp>::type;
2692  return noexcept((std::declval<_Up>().*std::declval<_Fn>())(
2693  std::declval<_Args>()...));
2694  }
2695 
2696  template<typename _Fn, typename _Tp, typename... _Args>
2697  constexpr bool __call_is_nt(__invoke_memfun_deref)
2698  {
2699  return noexcept(((*std::declval<_Tp>()).*std::declval<_Fn>())(
2700  std::declval<_Args>()...));
2701  }
2702 
2703  template<typename _Fn, typename _Tp>
2704  constexpr bool __call_is_nt(__invoke_memobj_ref)
2705  {
2706  using _Up = typename __inv_unwrap<_Tp>::type;
2707  return noexcept(std::declval<_Up>().*std::declval<_Fn>());
2708  }
2709 
2710  template<typename _Fn, typename _Tp>
2711  constexpr bool __call_is_nt(__invoke_memobj_deref)
2712  {
2713  return noexcept((*std::declval<_Tp>()).*std::declval<_Fn>());
2714  }
2715 
2716  template<typename _Fn, typename... _Args>
2717  constexpr bool __call_is_nt(__invoke_other)
2718  {
2719  return noexcept(std::declval<_Fn>()(std::declval<_Args>()...));
2720  }
2721 
2722  template<typename _Result, typename _Fn, typename... _Args>
2723  struct __call_is_nothrow
2724  : __bool_constant<
2725  std::__call_is_nt<_Fn, _Args...>(typename _Result::__invoke_type{})
2726  >
2727  { };
2728 
2729  template<typename _Fn, typename... _Args>
2730  using __call_is_nothrow_
2731  = __call_is_nothrow<__invoke_result<_Fn, _Args...>, _Fn, _Args...>;
2732 
2733  // __is_nothrow_invocable (std::is_nothrow_invocable for C++11)
2734  template<typename _Fn, typename... _Args>
2735  struct __is_nothrow_invocable
2736  : __and_<__is_invocable<_Fn, _Args...>,
2737  __call_is_nothrow_<_Fn, _Args...>>::type
2738  { };
2739 
2740  struct __nonesuch {
2741  __nonesuch() = delete;
2742  ~__nonesuch() = delete;
2743  __nonesuch(__nonesuch const&) = delete;
2744  void operator=(__nonesuch const&) = delete;
2745  };
2746 
2747 #if __cplusplus >= 201703L
2748 # define __cpp_lib_is_invocable 201703
2749 
2750  /// std::invoke_result
2751  template<typename _Functor, typename... _ArgTypes>
2752  struct invoke_result
2753  : public __invoke_result<_Functor, _ArgTypes...>
2754  { };
2755 
2756  /// std::invoke_result_t
2757  template<typename _Fn, typename... _Args>
2758  using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
2759 
2760  /// std::is_invocable
2761  template<typename _Fn, typename... _ArgTypes>
2762  struct is_invocable
2763  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2764  { };
2765 
2766  /// std::is_invocable_r
2767  template<typename _Ret, typename _Fn, typename... _ArgTypes>
2768  struct is_invocable_r
2769  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>::type
2770  { };
2771 
2772  /// std::is_nothrow_invocable
2773  template<typename _Fn, typename... _ArgTypes>
2774  struct is_nothrow_invocable
2775  : __and_<__is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>,
2776  __call_is_nothrow_<_Fn, _ArgTypes...>>::type
2777  { };
2778 
2779  template<typename _Result, typename _Ret, typename = void>
2780  struct __is_nt_invocable_impl : false_type { };
2781 
2782  template<typename _Result, typename _Ret>
2783  struct __is_nt_invocable_impl<_Result, _Ret,
2784  __void_t<typename _Result::type>>
2785  : __or_<is_void<_Ret>,
2786  __and_<is_convertible<typename _Result::type, _Ret>,
2787  is_nothrow_constructible<_Ret, typename _Result::type>>>
2788  { };
2789 
2790  /// std::is_nothrow_invocable_r
2791  template<typename _Ret, typename _Fn, typename... _ArgTypes>
2792  struct is_nothrow_invocable_r
2793  : __and_<__is_nt_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>,
2794  __call_is_nothrow_<_Fn, _ArgTypes...>>::type
2795  { };
2796 
2797  /// std::is_invocable_v
2798  template<typename _Fn, typename... _Args>
2799  inline constexpr bool is_invocable_v = is_invocable<_Fn, _Args...>::value;
2800 
2801  /// std::is_nothrow_invocable_v
2802  template<typename _Fn, typename... _Args>
2803  inline constexpr bool is_nothrow_invocable_v
2804  = is_nothrow_invocable<_Fn, _Args...>::value;
2805 
2806  /// std::is_invocable_r_v
2807  template<typename _Fn, typename... _Args>
2808  inline constexpr bool is_invocable_r_v
2809  = is_invocable_r<_Fn, _Args...>::value;
2810 
2811  /// std::is_nothrow_invocable_r_v
2812  template<typename _Fn, typename... _Args>
2813  inline constexpr bool is_nothrow_invocable_r_v
2814  = is_nothrow_invocable_r<_Fn, _Args...>::value;
2815 #endif // C++17
2816 
2817 #if __cplusplus >= 201703L
2818 # define __cpp_lib_type_trait_variable_templates 201510L
2819 template <typename _Tp>
2820  inline constexpr bool is_void_v = is_void<_Tp>::value;
2821 template <typename _Tp>
2822  inline constexpr bool is_null_pointer_v = is_null_pointer<_Tp>::value;
2823 template <typename _Tp>
2824  inline constexpr bool is_integral_v = is_integral<_Tp>::value;
2825 template <typename _Tp>
2826  inline constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
2827 template <typename _Tp>
2828  inline constexpr bool is_array_v = is_array<_Tp>::value;
2829 template <typename _Tp>
2830  inline constexpr bool is_pointer_v = is_pointer<_Tp>::value;
2831 template <typename _Tp>
2832  inline constexpr bool is_lvalue_reference_v =
2833  is_lvalue_reference<_Tp>::value;
2834 template <typename _Tp>
2835  inline constexpr bool is_rvalue_reference_v =
2836  is_rvalue_reference<_Tp>::value;
2837 template <typename _Tp>
2838  inline constexpr bool is_member_object_pointer_v =
2839  is_member_object_pointer<_Tp>::value;
2840 template <typename _Tp>
2841  inline constexpr bool is_member_function_pointer_v =
2842  is_member_function_pointer<_Tp>::value;
2843 template <typename _Tp>
2844  inline constexpr bool is_enum_v = is_enum<_Tp>::value;
2845 template <typename _Tp>
2846  inline constexpr bool is_union_v = is_union<_Tp>::value;
2847 template <typename _Tp>
2848  inline constexpr bool is_class_v = is_class<_Tp>::value;
2849 template <typename _Tp>
2850  inline constexpr bool is_function_v = is_function<_Tp>::value;
2851 template <typename _Tp>
2852  inline constexpr bool is_reference_v = is_reference<_Tp>::value;
2853 template <typename _Tp>
2854  inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
2855 template <typename _Tp>
2856  inline constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
2857 template <typename _Tp>
2858  inline constexpr bool is_object_v = is_object<_Tp>::value;
2859 template <typename _Tp>
2860  inline constexpr bool is_scalar_v = is_scalar<_Tp>::value;
2861 template <typename _Tp>
2862  inline constexpr bool is_compound_v = is_compound<_Tp>::value;
2863 template <typename _Tp>
2864  inline constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value;
2865 template <typename _Tp>
2866  inline constexpr bool is_const_v = is_const<_Tp>::value;
2867 template <typename _Tp>
2868  inline constexpr bool is_volatile_v = is_volatile<_Tp>::value;
2869 template <typename _Tp>
2870  inline constexpr bool is_trivial_v = is_trivial<_Tp>::value;
2871 template <typename _Tp>
2872  inline constexpr bool is_trivially_copyable_v =
2873  is_trivially_copyable<_Tp>::value;
2874 template <typename _Tp>
2875  inline constexpr bool is_standard_layout_v = is_standard_layout<_Tp>::value;
2876 template <typename _Tp>
2877  inline constexpr bool is_pod_v = is_pod<_Tp>::value;
2878 template <typename _Tp>
2879  inline constexpr bool is_literal_type_v = is_literal_type<_Tp>::value;
2880 template <typename _Tp>
2881  inline constexpr bool is_empty_v = is_empty<_Tp>::value;
2882 template <typename _Tp>
2883  inline constexpr bool is_polymorphic_v = is_polymorphic<_Tp>::value;
2884 template <typename _Tp>
2885  inline constexpr bool is_abstract_v = is_abstract<_Tp>::value;
2886 template <typename _Tp>
2887  inline constexpr bool is_final_v = is_final<_Tp>::value;
2888 template <typename _Tp>
2889  inline constexpr bool is_signed_v = is_signed<_Tp>::value;
2890 template <typename _Tp>
2891  inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
2892 template <typename _Tp, typename... _Args>
2893  inline constexpr bool is_constructible_v =
2894  is_constructible<_Tp, _Args...>::value;
2895 template <typename _Tp>
2896  inline constexpr bool is_default_constructible_v =
2897  is_default_constructible<_Tp>::value;
2898 template <typename _Tp>
2899  inline constexpr bool is_copy_constructible_v =
2900  is_copy_constructible<_Tp>::value;
2901 template <typename _Tp>
2902  inline constexpr bool is_move_constructible_v =
2903  is_move_constructible<_Tp>::value;
2904 template <typename _Tp, typename _Up>
2905  inline constexpr bool is_assignable_v = is_assignable<_Tp, _Up>::value;
2906 template <typename _Tp>
2907  inline constexpr bool is_copy_assignable_v = is_copy_assignable<_Tp>::value;
2908 template <typename _Tp>
2909  inline constexpr bool is_move_assignable_v = is_move_assignable<_Tp>::value;
2910 template <typename _Tp>
2911  inline constexpr bool is_destructible_v = is_destructible<_Tp>::value;
2912 template <typename _Tp, typename... _Args>
2913  inline constexpr bool is_trivially_constructible_v =
2914  is_trivially_constructible<_Tp, _Args...>::value;
2915 template <typename _Tp>
2916  inline constexpr bool is_trivially_default_constructible_v =
2917  is_trivially_default_constructible<_Tp>::value;
2918 template <typename _Tp>
2919  inline constexpr bool is_trivially_copy_constructible_v =
2920  is_trivially_copy_constructible<_Tp>::value;
2921 template <typename _Tp>
2922  inline constexpr bool is_trivially_move_constructible_v =
2923  is_trivially_move_constructible<_Tp>::value;
2924 template <typename _Tp, typename _Up>
2925  inline constexpr bool is_trivially_assignable_v =
2926  is_trivially_assignable<_Tp, _Up>::value;
2927 template <typename _Tp>
2928  inline constexpr bool is_trivially_copy_assignable_v =
2929  is_trivially_copy_assignable<_Tp>::value;
2930 template <typename _Tp>
2931  inline constexpr bool is_trivially_move_assignable_v =
2932  is_trivially_move_assignable<_Tp>::value;
2933 template <typename _Tp>
2934  inline constexpr bool is_trivially_destructible_v =
2935  is_trivially_destructible<_Tp>::value;
2936 template <typename _Tp, typename... _Args>
2937  inline constexpr bool is_nothrow_constructible_v =
2938  is_nothrow_constructible<_Tp, _Args...>::value;
2939 template <typename _Tp>
2940  inline constexpr bool is_nothrow_default_constructible_v =
2941  is_nothrow_default_constructible<_Tp>::value;
2942 template <typename _Tp>
2943  inline constexpr bool is_nothrow_copy_constructible_v =
2944  is_nothrow_copy_constructible<_Tp>::value;
2945 template <typename _Tp>
2946  inline constexpr bool is_nothrow_move_constructible_v =
2947  is_nothrow_move_constructible<_Tp>::value;
2948 template <typename _Tp, typename _Up>
2949  inline constexpr bool is_nothrow_assignable_v =
2950  is_nothrow_assignable<_Tp, _Up>::value;
2951 template <typename _Tp>
2952  inline constexpr bool is_nothrow_copy_assignable_v =
2953  is_nothrow_copy_assignable<_Tp>::value;
2954 template <typename _Tp>
2955  inline constexpr bool is_nothrow_move_assignable_v =
2956  is_nothrow_move_assignable<_Tp>::value;
2957 template <typename _Tp>
2958  inline constexpr bool is_nothrow_destructible_v =
2959  is_nothrow_destructible<_Tp>::value;
2960 template <typename _Tp>
2961  inline constexpr bool has_virtual_destructor_v =
2962  has_virtual_destructor<_Tp>::value;
2963 template <typename _Tp>
2964  inline constexpr size_t alignment_of_v = alignment_of<_Tp>::value;
2965 template <typename _Tp>
2966  inline constexpr size_t rank_v = rank<_Tp>::value;
2967 template <typename _Tp, unsigned _Idx = 0>
2968  inline constexpr size_t extent_v = extent<_Tp, _Idx>::value;
2969 template <typename _Tp, typename _Up>
2970  inline constexpr bool is_same_v = is_same<_Tp, _Up>::value;
2971 template <typename _Base, typename _Derived>
2972  inline constexpr bool is_base_of_v = is_base_of<_Base, _Derived>::value;
2973 template <typename _From, typename _To>
2974  inline constexpr bool is_convertible_v = is_convertible<_From, _To>::value;
2975 
2976 #ifdef _GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP
2977 # define __cpp_lib_has_unique_object_representations 201606
2978  /// has_unique_object_representations
2979  template<typename _Tp>
2980  struct has_unique_object_representations
2981  : bool_constant<__has_unique_object_representations(
2982  remove_cv_t<remove_all_extents_t<_Tp>>
2983  )>
2984  { };
2985 
2986  template<typename _Tp>
2987  inline constexpr bool has_unique_object_representations_v
2988  = has_unique_object_representations<_Tp>::value;
2989 #endif
2990 
2991 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE
2992 # define __cpp_lib_is_aggregate 201703
2993  /// is_aggregate
2994  template<typename _Tp>
2995  struct is_aggregate
2996  : bool_constant<__is_aggregate(remove_cv_t<_Tp>)> { };
2997 
2998  /// is_aggregate_v
2999  template<typename _Tp>
3000  inline constexpr bool is_aggregate_v = is_aggregate<_Tp>::value;
3001 #endif
3002 #endif // C++17
3003 
3004 #if __cplusplus > 201703L
3005  /// Byte order
3006  enum class endian
3007  {
3008  little = __ORDER_LITTLE_ENDIAN__,
3009  big = __ORDER_BIG_ENDIAN__,
3010  native = __BYTE_ORDER__
3011  };
3012 
3013  /// Remove references and cv-qualifiers.
3014  template<typename _Tp>
3015  struct remove_cvref
3016  {
3017  using type = __remove_cvref_t<_Tp>;
3018  };
3019 
3020  template<typename _Tp>
3021  using remove_cvref_t = __remove_cvref_t<_Tp>;
3022 
3023  /// Identity metafunction.
3024  template<typename _Tp>
3025  struct type_identity { using type = _Tp; };
3026 
3027  template<typename _Tp>
3028  using type_identity_t = typename type_identity<_Tp>::type;
3029 
3030  /// Unwrap a reference_wrapper
3031  template<typename _Tp>
3032  struct unwrap_reference { using type = _Tp; };
3033 
3034  template<typename _Tp>
3035  struct unwrap_reference<reference_wrapper<_Tp>> { using type = _Tp&; };
3036 
3037  /// Decay type and if it's a reference_wrapper, unwrap it
3038  template<typename _Tp>
3039  struct unwrap_ref_decay : unwrap_reference<decay_t<_Tp>> { };
3040 
3041  template<typename _Tp>
3042  using unwrap_ref_decay_t = typename unwrap_ref_decay<_Tp>::type;
3043 
3044 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
3045 
3046 #define __cpp_lib_is_constant_evaluated 201811L
3047 
3048  constexpr inline bool
3049  is_constant_evaluated() noexcept
3050  { return __builtin_is_constant_evaluated(); }
3051 #endif
3052 
3053 #endif // C++2a
3054 
3055 _GLIBCXX_END_NAMESPACE_VERSION
3056 } // namespace std
3057 
3058 #endif // C++11
3059 
3060 #endif // _GLIBCXX_TYPE_TRAITS