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 #ifdef _GLIBCXX_USE_CHAR8_T
238  template<>
239  struct __is_integral_helper<char8_t>
240  : public true_type { };
241 #endif
242 
243  template<>
244  struct __is_integral_helper<char16_t>
245  : public true_type { };
246 
247  template<>
248  struct __is_integral_helper<char32_t>
249  : public true_type { };
250 
251  template<>
252  struct __is_integral_helper<short>
253  : public true_type { };
254 
255  template<>
256  struct __is_integral_helper<unsigned short>
257  : public true_type { };
258 
259  template<>
260  struct __is_integral_helper<int>
261  : public true_type { };
262 
263  template<>
264  struct __is_integral_helper<unsigned int>
265  : public true_type { };
266 
267  template<>
268  struct __is_integral_helper<long>
269  : public true_type { };
270 
271  template<>
272  struct __is_integral_helper<unsigned long>
273  : public true_type { };
274 
275  template<>
276  struct __is_integral_helper<long long>
277  : public true_type { };
278 
279  template<>
280  struct __is_integral_helper<unsigned long long>
281  : public true_type { };
282 
283  // Conditionalizing on __STRICT_ANSI__ here will break any port that
284  // uses one of these types for size_t.
285 #if defined(__GLIBCXX_TYPE_INT_N_0)
286  template<>
287  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_0>
288  : public true_type { };
289 
290  template<>
291  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_0>
292  : public true_type { };
293 #endif
294 #if defined(__GLIBCXX_TYPE_INT_N_1)
295  template<>
296  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_1>
297  : public true_type { };
298 
299  template<>
300  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_1>
301  : public true_type { };
302 #endif
303 #if defined(__GLIBCXX_TYPE_INT_N_2)
304  template<>
305  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_2>
306  : public true_type { };
307 
308  template<>
309  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_2>
310  : public true_type { };
311 #endif
312 #if defined(__GLIBCXX_TYPE_INT_N_3)
313  template<>
314  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_3>
315  : public true_type { };
316 
317  template<>
318  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_3>
319  : public true_type { };
320 #endif
321 
322  /// is_integral
323  template<typename _Tp>
324  struct is_integral
325  : public __is_integral_helper<typename remove_cv<_Tp>::type>::type
326  { };
327 
328  template<typename>
329  struct __is_floating_point_helper
330  : public false_type { };
331 
332  template<>
333  struct __is_floating_point_helper<float>
334  : public true_type { };
335 
336  template<>
337  struct __is_floating_point_helper<double>
338  : public true_type { };
339 
340  template<>
341  struct __is_floating_point_helper<long double>
342  : public true_type { };
343 
344 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128) && !defined(__CUDACC__)
345  template<>
346  struct __is_floating_point_helper<__float128>
347  : public true_type { };
348 #endif
349 
350  /// is_floating_point
351  template<typename _Tp>
352  struct is_floating_point
353  : public __is_floating_point_helper<typename remove_cv<_Tp>::type>::type
354  { };
355 
356  /// is_array
357  template<typename>
358  struct is_array
359  : public false_type { };
360 
361  template<typename _Tp, std::size_t _Size>
362  struct is_array<_Tp[_Size]>
363  : public true_type { };
364 
365  template<typename _Tp>
366  struct is_array<_Tp[]>
367  : public true_type { };
368 
369  template<typename>
370  struct __is_pointer_helper
371  : public false_type { };
372 
373  template<typename _Tp>
374  struct __is_pointer_helper<_Tp*>
375  : public true_type { };
376 
377  /// is_pointer
378  template<typename _Tp>
379  struct is_pointer
380  : public __is_pointer_helper<typename remove_cv<_Tp>::type>::type
381  { };
382 
383  /// is_lvalue_reference
384  template<typename>
385  struct is_lvalue_reference
386  : public false_type { };
387 
388  template<typename _Tp>
389  struct is_lvalue_reference<_Tp&>
390  : public true_type { };
391 
392  /// is_rvalue_reference
393  template<typename>
394  struct is_rvalue_reference
395  : public false_type { };
396 
397  template<typename _Tp>
398  struct is_rvalue_reference<_Tp&&>
399  : public true_type { };
400 
401  template<typename>
402  struct is_function;
403 
404  template<typename>
405  struct __is_member_object_pointer_helper
406  : public false_type { };
407 
408  template<typename _Tp, typename _Cp>
409  struct __is_member_object_pointer_helper<_Tp _Cp::*>
410  : public __not_<is_function<_Tp>>::type { };
411 
412  /// is_member_object_pointer
413  template<typename _Tp>
414  struct is_member_object_pointer
415  : public __is_member_object_pointer_helper<
416  typename remove_cv<_Tp>::type>::type
417  { };
418 
419  template<typename>
420  struct __is_member_function_pointer_helper
421  : public false_type { };
422 
423  template<typename _Tp, typename _Cp>
424  struct __is_member_function_pointer_helper<_Tp _Cp::*>
425  : public is_function<_Tp>::type { };
426 
427  /// is_member_function_pointer
428  template<typename _Tp>
429  struct is_member_function_pointer
430  : public __is_member_function_pointer_helper<
431  typename remove_cv<_Tp>::type>::type
432  { };
433 
434  /// is_enum
435  template<typename _Tp>
436  struct is_enum
437  : public integral_constant<bool, __is_enum(_Tp)>
438  { };
439 
440  /// is_union
441  template<typename _Tp>
442  struct is_union
443  : public integral_constant<bool, __is_union(_Tp)>
444  { };
445 
446  /// is_class
447  template<typename _Tp>
448  struct is_class
449  : public integral_constant<bool, __is_class(_Tp)>
450  { };
451 
452  /// is_function
453  template<typename>
454  struct is_function
455  : public false_type { };
456 
457  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
458  struct is_function<_Res(_ArgTypes...) _GLIBCXX_NOEXCEPT_QUAL>
459  : public true_type { };
460 
461  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
462  struct is_function<_Res(_ArgTypes...) & _GLIBCXX_NOEXCEPT_QUAL>
463  : public true_type { };
464 
465  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
466  struct is_function<_Res(_ArgTypes...) && _GLIBCXX_NOEXCEPT_QUAL>
467  : public true_type { };
468 
469  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
470  struct is_function<_Res(_ArgTypes......) _GLIBCXX_NOEXCEPT_QUAL>
471  : public true_type { };
472 
473  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
474  struct is_function<_Res(_ArgTypes......) & _GLIBCXX_NOEXCEPT_QUAL>
475  : public true_type { };
476 
477  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
478  struct is_function<_Res(_ArgTypes......) && _GLIBCXX_NOEXCEPT_QUAL>
479  : public true_type { };
480 
481  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
482  struct is_function<_Res(_ArgTypes...) const _GLIBCXX_NOEXCEPT_QUAL>
483  : public true_type { };
484 
485  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
486  struct is_function<_Res(_ArgTypes...) const & _GLIBCXX_NOEXCEPT_QUAL>
487  : public true_type { };
488 
489  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
490  struct is_function<_Res(_ArgTypes...) const && _GLIBCXX_NOEXCEPT_QUAL>
491  : public true_type { };
492 
493  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
494  struct is_function<_Res(_ArgTypes......) const _GLIBCXX_NOEXCEPT_QUAL>
495  : public true_type { };
496 
497  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
498  struct is_function<_Res(_ArgTypes......) const & _GLIBCXX_NOEXCEPT_QUAL>
499  : public true_type { };
500 
501  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
502  struct is_function<_Res(_ArgTypes......) const && _GLIBCXX_NOEXCEPT_QUAL>
503  : public true_type { };
504 
505  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
506  struct is_function<_Res(_ArgTypes...) volatile _GLIBCXX_NOEXCEPT_QUAL>
507  : public true_type { };
508 
509  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
510  struct is_function<_Res(_ArgTypes...) volatile & _GLIBCXX_NOEXCEPT_QUAL>
511  : public true_type { };
512 
513  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
514  struct is_function<_Res(_ArgTypes...) volatile && _GLIBCXX_NOEXCEPT_QUAL>
515  : public true_type { };
516 
517  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
518  struct is_function<_Res(_ArgTypes......) volatile _GLIBCXX_NOEXCEPT_QUAL>
519  : public true_type { };
520 
521  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
522  struct is_function<_Res(_ArgTypes......) volatile & _GLIBCXX_NOEXCEPT_QUAL>
523  : public true_type { };
524 
525  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
526  struct is_function<_Res(_ArgTypes......) volatile && _GLIBCXX_NOEXCEPT_QUAL>
527  : public true_type { };
528 
529  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
530  struct is_function<_Res(_ArgTypes...) const volatile _GLIBCXX_NOEXCEPT_QUAL>
531  : public true_type { };
532 
533  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
534  struct is_function<_Res(_ArgTypes...) const volatile & _GLIBCXX_NOEXCEPT_QUAL>
535  : public true_type { };
536 
537  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
538  struct is_function<_Res(_ArgTypes...) const volatile && _GLIBCXX_NOEXCEPT_QUAL>
539  : public true_type { };
540 
541  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
542  struct is_function<_Res(_ArgTypes......) const volatile _GLIBCXX_NOEXCEPT_QUAL>
543  : public true_type { };
544 
545  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
546  struct is_function<_Res(_ArgTypes......) const volatile & _GLIBCXX_NOEXCEPT_QUAL>
547  : public true_type { };
548 
549  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
550  struct is_function<_Res(_ArgTypes......) const volatile && _GLIBCXX_NOEXCEPT_QUAL>
551  : public true_type { };
552 
553 #define __cpp_lib_is_null_pointer 201309
554 
555  template<typename>
556  struct __is_null_pointer_helper
557  : public false_type { };
558 
559  template<>
560  struct __is_null_pointer_helper<std::nullptr_t>
561  : public true_type { };
562 
563  /// is_null_pointer (LWG 2247).
564  template<typename _Tp>
565  struct is_null_pointer
566  : public __is_null_pointer_helper<typename remove_cv<_Tp>::type>::type
567  { };
568 
569  /// __is_nullptr_t (extension).
570  template<typename _Tp>
571  struct __is_nullptr_t
572  : public is_null_pointer<_Tp>
573  { };
574 
575  // Composite type categories.
576 
577  /// is_reference
578  template<typename _Tp>
579  struct is_reference
580  : public __or_<is_lvalue_reference<_Tp>,
581  is_rvalue_reference<_Tp>>::type
582  { };
583 
584  /// is_arithmetic
585  template<typename _Tp>
586  struct is_arithmetic
587  : public __or_<is_integral<_Tp>, is_floating_point<_Tp>>::type
588  { };
589 
590  /// is_fundamental
591  template<typename _Tp>
592  struct is_fundamental
593  : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
594  is_null_pointer<_Tp>>::type
595  { };
596 
597  /// is_object
598  template<typename _Tp>
599  struct is_object
600  : public __not_<__or_<is_function<_Tp>, is_reference<_Tp>,
601  is_void<_Tp>>>::type
602  { };
603 
604  template<typename>
605  struct is_member_pointer;
606 
607  /// is_scalar
608  template<typename _Tp>
609  struct is_scalar
610  : public __or_<is_arithmetic<_Tp>, is_enum<_Tp>, is_pointer<_Tp>,
611  is_member_pointer<_Tp>, is_null_pointer<_Tp>>::type
612  { };
613 
614  /// is_compound
615  template<typename _Tp>
616  struct is_compound
617  : public __not_<is_fundamental<_Tp>>::type { };
618 
619  template<typename _Tp>
620  struct __is_member_pointer_helper
621  : public false_type { };
622 
623  template<typename _Tp, typename _Cp>
624  struct __is_member_pointer_helper<_Tp _Cp::*>
625  : public true_type { };
626 
627  /// is_member_pointer
628  template<typename _Tp>
629  struct is_member_pointer
630  : public __is_member_pointer_helper<typename remove_cv<_Tp>::type>::type
631  { };
632 
633  // Utility to detect referenceable types ([defns.referenceable]).
634 
635  template<typename _Tp>
636  struct __is_referenceable
637  : public __or_<is_object<_Tp>, is_reference<_Tp>>::type
638  { };
639 
640  template<typename _Res, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
641  struct __is_referenceable<_Res(_Args...) _GLIBCXX_NOEXCEPT_QUAL>
642  : public true_type
643  { };
644 
645  template<typename _Res, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
646  struct __is_referenceable<_Res(_Args......) _GLIBCXX_NOEXCEPT_QUAL>
647  : public true_type
648  { };
649 
650  // Type properties.
651 
652  /// is_const
653  template<typename>
654  struct is_const
655  : public false_type { };
656 
657  template<typename _Tp>
658  struct is_const<_Tp const>
659  : public true_type { };
660 
661  /// is_volatile
662  template<typename>
663  struct is_volatile
664  : public false_type { };
665 
666  template<typename _Tp>
667  struct is_volatile<_Tp volatile>
668  : public true_type { };
669 
670  /// is_trivial
671  template<typename _Tp>
672  struct is_trivial
673  : public integral_constant<bool, __is_trivial(_Tp)>
674  { };
675 
676  // is_trivially_copyable
677  template<typename _Tp>
678  struct is_trivially_copyable
679  : public integral_constant<bool, __is_trivially_copyable(_Tp)>
680  { };
681 
682  /// is_standard_layout
683  template<typename _Tp>
684  struct is_standard_layout
685  : public integral_constant<bool, __is_standard_layout(_Tp)>
686  { };
687 
688  /// is_pod
689  // Could use is_standard_layout && is_trivial instead of the builtin.
690  template<typename _Tp>
691  struct is_pod
692  : public integral_constant<bool, __is_pod(_Tp)>
693  { };
694 
695  /// is_literal_type
696  template<typename _Tp>
697  struct is_literal_type
698  : public integral_constant<bool, __is_literal_type(_Tp)>
699  { };
700 
701  /// is_empty
702  template<typename _Tp>
703  struct is_empty
704  : public integral_constant<bool, __is_empty(_Tp)>
705  { };
706 
707  /// is_polymorphic
708  template<typename _Tp>
709  struct is_polymorphic
710  : public integral_constant<bool, __is_polymorphic(_Tp)>
711  { };
712 
713 #if __cplusplus >= 201402L
714 #define __cpp_lib_is_final 201402L
715  /// is_final
716  template<typename _Tp>
717  struct is_final
718  : public integral_constant<bool, __is_final(_Tp)>
719  { };
720 #endif
721 
722  /// is_abstract
723  template<typename _Tp>
724  struct is_abstract
725  : public integral_constant<bool, __is_abstract(_Tp)>
726  { };
727 
728  template<typename _Tp,
729  bool = is_arithmetic<_Tp>::value>
730  struct __is_signed_helper
731  : public false_type { };
732 
733  template<typename _Tp>
734  struct __is_signed_helper<_Tp, true>
735  : public integral_constant<bool, _Tp(-1) < _Tp(0)>
736  { };
737 
738  /// is_signed
739  template<typename _Tp>
740  struct is_signed
741  : public __is_signed_helper<_Tp>::type
742  { };
743 
744  /// is_unsigned
745  template<typename _Tp>
746  struct is_unsigned
747  : public __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>
748  { };
749 
750 
751  // Destructible and constructible type properties.
752 
753  /**
754  * @brief Utility to simplify expressions used in unevaluated operands
755  * @ingroup utilities
756  */
757 
758  template<typename _Tp, typename _Up = _Tp&&>
759  _Up
760  __declval(int);
761 
762  template<typename _Tp>
763  _Tp
764  __declval(long);
765 
766  template<typename _Tp>
767  auto declval() noexcept -> decltype(__declval<_Tp>(0));
768 
769  template<typename, unsigned = 0>
770  struct extent;
771 
772  template<typename>
773  struct remove_all_extents;
774 
775  template<typename _Tp>
776  struct __is_array_known_bounds
777  : public integral_constant<bool, (extent<_Tp>::value > 0)>
778  { };
779 
780  template<typename _Tp>
781  struct __is_array_unknown_bounds
782  : public __and_<is_array<_Tp>, __not_<extent<_Tp>>>
783  { };
784 
785  // In N3290 is_destructible does not say anything about function
786  // types and abstract types, see LWG 2049. This implementation
787  // describes function types as non-destructible and all complete
788  // object types as destructible, iff the explicit destructor
789  // call expression is wellformed.
790  struct __do_is_destructible_impl
791  {
792  template<typename _Tp, typename = decltype(declval<_Tp&>().~_Tp())>
793  static true_type __test(int);
794 
795  template<typename>
796  static false_type __test(...);
797  };
798 
799  template<typename _Tp>
800  struct __is_destructible_impl
801  : public __do_is_destructible_impl
802  {
803  typedef decltype(__test<_Tp>(0)) type;
804  };
805 
806  template<typename _Tp,
807  bool = __or_<is_void<_Tp>,
808  __is_array_unknown_bounds<_Tp>,
809  is_function<_Tp>>::value,
810  bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
811  struct __is_destructible_safe;
812 
813  template<typename _Tp>
814  struct __is_destructible_safe<_Tp, false, false>
815  : public __is_destructible_impl<typename
816  remove_all_extents<_Tp>::type>::type
817  { };
818 
819  template<typename _Tp>
820  struct __is_destructible_safe<_Tp, true, false>
821  : public false_type { };
822 
823  template<typename _Tp>
824  struct __is_destructible_safe<_Tp, false, true>
825  : public true_type { };
826 
827  /// is_destructible
828  template<typename _Tp>
829  struct is_destructible
830  : public __is_destructible_safe<_Tp>::type
831  { };
832 
833  // is_nothrow_destructible requires that is_destructible is
834  // satisfied as well. We realize that by mimicing the
835  // implementation of is_destructible but refer to noexcept(expr)
836  // instead of decltype(expr).
837  struct __do_is_nt_destructible_impl
838  {
839  template<typename _Tp>
840  static __bool_constant<noexcept(declval<_Tp&>().~_Tp())>
841  __test(int);
842 
843  template<typename>
844  static false_type __test(...);
845  };
846 
847  template<typename _Tp>
848  struct __is_nt_destructible_impl
849  : public __do_is_nt_destructible_impl
850  {
851  typedef decltype(__test<_Tp>(0)) type;
852  };
853 
854  template<typename _Tp,
855  bool = __or_<is_void<_Tp>,
856  __is_array_unknown_bounds<_Tp>,
857  is_function<_Tp>>::value,
858  bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
859  struct __is_nt_destructible_safe;
860 
861  template<typename _Tp>
862  struct __is_nt_destructible_safe<_Tp, false, false>
863  : public __is_nt_destructible_impl<typename
864  remove_all_extents<_Tp>::type>::type
865  { };
866 
867  template<typename _Tp>
868  struct __is_nt_destructible_safe<_Tp, true, false>
869  : public false_type { };
870 
871  template<typename _Tp>
872  struct __is_nt_destructible_safe<_Tp, false, true>
873  : public true_type { };
874 
875  /// is_nothrow_destructible
876  template<typename _Tp>
877  struct is_nothrow_destructible
878  : public __is_nt_destructible_safe<_Tp>::type
879  { };
880 
881  /// is_constructible
882  template<typename _Tp, typename... _Args>
883  struct is_constructible
884  : public __bool_constant<__is_constructible(_Tp, _Args...)>
885  { };
886 
887  /// is_default_constructible
888  template<typename _Tp>
889  struct is_default_constructible
890  : public is_constructible<_Tp>::type
891  { };
892 
893  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
894  struct __is_copy_constructible_impl;
895 
896  template<typename _Tp>
897  struct __is_copy_constructible_impl<_Tp, false>
898  : public false_type { };
899 
900  template<typename _Tp>
901  struct __is_copy_constructible_impl<_Tp, true>
902  : public is_constructible<_Tp, const _Tp&>
903  { };
904 
905  /// is_copy_constructible
906  template<typename _Tp>
907  struct is_copy_constructible
908  : public __is_copy_constructible_impl<_Tp>
909  { };
910 
911  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
912  struct __is_move_constructible_impl;
913 
914  template<typename _Tp>
915  struct __is_move_constructible_impl<_Tp, false>
916  : public false_type { };
917 
918  template<typename _Tp>
919  struct __is_move_constructible_impl<_Tp, true>
920  : public is_constructible<_Tp, _Tp&&>
921  { };
922 
923  /// is_move_constructible
924  template<typename _Tp>
925  struct is_move_constructible
926  : public __is_move_constructible_impl<_Tp>
927  { };
928 
929  template<bool, typename _Tp, typename... _Args>
930  struct __is_nt_constructible_impl
931  : public false_type
932  { };
933 
934  template<typename _Tp, typename... _Args>
935  struct __is_nt_constructible_impl<true, _Tp, _Args...>
936  : public __bool_constant<noexcept(_Tp(std::declval<_Args>()...))>
937  { };
938 
939  template<typename _Tp, typename _Arg>
940  struct __is_nt_constructible_impl<true, _Tp, _Arg>
941  : public __bool_constant<noexcept(static_cast<_Tp>(std::declval<_Arg>()))>
942  { };
943 
944  template<typename _Tp>
945  struct __is_nt_constructible_impl<true, _Tp>
946  : public __bool_constant<noexcept(_Tp())>
947  { };
948 
949  template<typename _Tp, size_t _Num>
950  struct __is_nt_constructible_impl<true, _Tp[_Num]>
951  : public __bool_constant<noexcept(typename remove_all_extents<_Tp>::type())>
952  { };
953 
954  template<typename _Tp, typename... _Args>
955  using __is_nothrow_constructible_impl
956  = __is_nt_constructible_impl<__is_constructible(_Tp, _Args...),
957  _Tp, _Args...>;
958 
959  /// is_nothrow_constructible
960  template<typename _Tp, typename... _Args>
961  struct is_nothrow_constructible
962  : public __is_nothrow_constructible_impl<_Tp, _Args...>::type
963  { };
964 
965  /// is_nothrow_default_constructible
966  template<typename _Tp>
967  struct is_nothrow_default_constructible
968  : public __is_nothrow_constructible_impl<_Tp>::type
969  { };
970 
971 
972  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
973  struct __is_nothrow_copy_constructible_impl;
974 
975  template<typename _Tp>
976  struct __is_nothrow_copy_constructible_impl<_Tp, false>
977  : public false_type { };
978 
979  template<typename _Tp>
980  struct __is_nothrow_copy_constructible_impl<_Tp, true>
981  : public is_nothrow_constructible<_Tp, const _Tp&>
982  { };
983 
984  /// is_nothrow_copy_constructible
985  template<typename _Tp>
986  struct is_nothrow_copy_constructible
987  : public __is_nothrow_copy_constructible_impl<_Tp>
988  { };
989 
990  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
991  struct __is_nothrow_move_constructible_impl;
992 
993  template<typename _Tp>
994  struct __is_nothrow_move_constructible_impl<_Tp, false>
995  : public false_type { };
996 
997  template<typename _Tp>
998  struct __is_nothrow_move_constructible_impl<_Tp, true>
999  : public is_nothrow_constructible<_Tp, _Tp&&>
1000  { };
1001 
1002  /// is_nothrow_move_constructible
1003  template<typename _Tp>
1004  struct is_nothrow_move_constructible
1005  : public __is_nothrow_move_constructible_impl<_Tp>
1006  { };
1007 
1008  /// is_assignable
1009  template<typename _Tp, typename _Up>
1010  struct is_assignable
1011  : public __bool_constant<__is_assignable(_Tp, _Up)>
1012  { };
1013 
1014  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1015  struct __is_copy_assignable_impl;
1016 
1017  template<typename _Tp>
1018  struct __is_copy_assignable_impl<_Tp, false>
1019  : public false_type { };
1020 
1021  template<typename _Tp>
1022  struct __is_copy_assignable_impl<_Tp, true>
1023  : public is_assignable<_Tp&, const _Tp&>
1024  { };
1025 
1026  /// is_copy_assignable
1027  template<typename _Tp>
1028  struct is_copy_assignable
1029  : public __is_copy_assignable_impl<_Tp>
1030  { };
1031 
1032  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1033  struct __is_move_assignable_impl;
1034 
1035  template<typename _Tp>
1036  struct __is_move_assignable_impl<_Tp, false>
1037  : public false_type { };
1038 
1039  template<typename _Tp>
1040  struct __is_move_assignable_impl<_Tp, true>
1041  : public is_assignable<_Tp&, _Tp&&>
1042  { };
1043 
1044  /// is_move_assignable
1045  template<typename _Tp>
1046  struct is_move_assignable
1047  : public __is_move_assignable_impl<_Tp>
1048  { };
1049 
1050  template<typename _Tp, typename _Up>
1051  struct __is_nt_assignable_impl
1052  : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Up>())>
1053  { };
1054 
1055  /// is_nothrow_assignable
1056  template<typename _Tp, typename _Up>
1057  struct is_nothrow_assignable
1058  : public __and_<is_assignable<_Tp, _Up>,
1059  __is_nt_assignable_impl<_Tp, _Up>>
1060  { };
1061 
1062  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1063  struct __is_nt_copy_assignable_impl;
1064 
1065  template<typename _Tp>
1066  struct __is_nt_copy_assignable_impl<_Tp, false>
1067  : public false_type { };
1068 
1069  template<typename _Tp>
1070  struct __is_nt_copy_assignable_impl<_Tp, true>
1071  : public is_nothrow_assignable<_Tp&, const _Tp&>
1072  { };
1073 
1074  /// is_nothrow_copy_assignable
1075  template<typename _Tp>
1076  struct is_nothrow_copy_assignable
1077  : public __is_nt_copy_assignable_impl<_Tp>
1078  { };
1079 
1080  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1081  struct __is_nt_move_assignable_impl;
1082 
1083  template<typename _Tp>
1084  struct __is_nt_move_assignable_impl<_Tp, false>
1085  : public false_type { };
1086 
1087  template<typename _Tp>
1088  struct __is_nt_move_assignable_impl<_Tp, true>
1089  : public is_nothrow_assignable<_Tp&, _Tp&&>
1090  { };
1091 
1092  /// is_nothrow_move_assignable
1093  template<typename _Tp>
1094  struct is_nothrow_move_assignable
1095  : public __is_nt_move_assignable_impl<_Tp>
1096  { };
1097 
1098  /// is_trivially_constructible
1099  template<typename _Tp, typename... _Args>
1100  struct is_trivially_constructible
1101  : public __bool_constant<__is_trivially_constructible(_Tp, _Args...)>
1102  { };
1103 
1104  /// is_trivially_default_constructible
1105  template<typename _Tp>
1106  struct is_trivially_default_constructible
1107  : public is_trivially_constructible<_Tp>::type
1108  { };
1109 
1110  struct __do_is_implicitly_default_constructible_impl
1111  {
1112  template <typename _Tp>
1113  static void __helper(const _Tp&);
1114 
1115  template <typename _Tp>
1116  static true_type __test(const _Tp&,
1117  decltype(__helper<const _Tp&>({}))* = 0);
1118 
1119  static false_type __test(...);
1120  };
1121 
1122  template<typename _Tp>
1123  struct __is_implicitly_default_constructible_impl
1124  : public __do_is_implicitly_default_constructible_impl
1125  {
1126  typedef decltype(__test(declval<_Tp>())) type;
1127  };
1128 
1129  template<typename _Tp>
1130  struct __is_implicitly_default_constructible_safe
1131  : public __is_implicitly_default_constructible_impl<_Tp>::type
1132  { };
1133 
1134  template <typename _Tp>
1135  struct __is_implicitly_default_constructible
1136  : public __and_<is_default_constructible<_Tp>,
1137  __is_implicitly_default_constructible_safe<_Tp>>
1138  { };
1139 
1140  /// is_trivially_copy_constructible
1141 
1142  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1143  struct __is_trivially_copy_constructible_impl;
1144 
1145  template<typename _Tp>
1146  struct __is_trivially_copy_constructible_impl<_Tp, false>
1147  : public false_type { };
1148 
1149  template<typename _Tp>
1150  struct __is_trivially_copy_constructible_impl<_Tp, true>
1151  : public __and_<is_copy_constructible<_Tp>,
1152  integral_constant<bool,
1153  __is_trivially_constructible(_Tp, const _Tp&)>>
1154  { };
1155 
1156  template<typename _Tp>
1157  struct is_trivially_copy_constructible
1158  : public __is_trivially_copy_constructible_impl<_Tp>
1159  { };
1160 
1161  /// is_trivially_move_constructible
1162 
1163  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1164  struct __is_trivially_move_constructible_impl;
1165 
1166  template<typename _Tp>
1167  struct __is_trivially_move_constructible_impl<_Tp, false>
1168  : public false_type { };
1169 
1170  template<typename _Tp>
1171  struct __is_trivially_move_constructible_impl<_Tp, true>
1172  : public __and_<is_move_constructible<_Tp>,
1173  integral_constant<bool,
1174  __is_trivially_constructible(_Tp, _Tp&&)>>
1175  { };
1176 
1177  template<typename _Tp>
1178  struct is_trivially_move_constructible
1179  : public __is_trivially_move_constructible_impl<_Tp>
1180  { };
1181 
1182  /// is_trivially_assignable
1183  template<typename _Tp, typename _Up>
1184  struct is_trivially_assignable
1185  : public __bool_constant<__is_trivially_assignable(_Tp, _Up)>
1186  { };
1187 
1188  /// is_trivially_copy_assignable
1189 
1190  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1191  struct __is_trivially_copy_assignable_impl;
1192 
1193  template<typename _Tp>
1194  struct __is_trivially_copy_assignable_impl<_Tp, false>
1195  : public false_type { };
1196 
1197  template<typename _Tp>
1198  struct __is_trivially_copy_assignable_impl<_Tp, true>
1199  : public __bool_constant<__is_trivially_assignable(_Tp&, const _Tp&)>
1200  { };
1201 
1202  template<typename _Tp>
1203  struct is_trivially_copy_assignable
1204  : public __is_trivially_copy_assignable_impl<_Tp>
1205  { };
1206 
1207  /// is_trivially_move_assignable
1208 
1209  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1210  struct __is_trivially_move_assignable_impl;
1211 
1212  template<typename _Tp>
1213  struct __is_trivially_move_assignable_impl<_Tp, false>
1214  : public false_type { };
1215 
1216  template<typename _Tp>
1217  struct __is_trivially_move_assignable_impl<_Tp, true>
1218  : public __bool_constant<__is_trivially_assignable(_Tp&, _Tp&&)>
1219  { };
1220 
1221  template<typename _Tp>
1222  struct is_trivially_move_assignable
1223  : public __is_trivially_move_assignable_impl<_Tp>
1224  { };
1225 
1226  /// is_trivially_destructible
1227  template<typename _Tp>
1228  struct is_trivially_destructible
1229  : public __and_<is_destructible<_Tp>,
1230  __bool_constant<__has_trivial_destructor(_Tp)>>
1231  { };
1232 
1233 
1234  /// has_virtual_destructor
1235  template<typename _Tp>
1236  struct has_virtual_destructor
1237  : public integral_constant<bool, __has_virtual_destructor(_Tp)>
1238  { };
1239 
1240 
1241  // type property queries.
1242 
1243  /// alignment_of
1244  template<typename _Tp>
1245  struct alignment_of
1246  : public integral_constant<std::size_t, alignof(_Tp)> { };
1247 
1248  /// rank
1249  template<typename>
1250  struct rank
1251  : public integral_constant<std::size_t, 0> { };
1252 
1253  template<typename _Tp, std::size_t _Size>
1254  struct rank<_Tp[_Size]>
1255  : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1256 
1257  template<typename _Tp>
1258  struct rank<_Tp[]>
1259  : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1260 
1261  /// extent
1262  template<typename, unsigned _Uint>
1263  struct extent
1264  : public integral_constant<std::size_t, 0> { };
1265 
1266  template<typename _Tp, unsigned _Uint, std::size_t _Size>
1267  struct extent<_Tp[_Size], _Uint>
1268  : public integral_constant<std::size_t,
1269  _Uint == 0 ? _Size : extent<_Tp,
1270  _Uint - 1>::value>
1271  { };
1272 
1273  template<typename _Tp, unsigned _Uint>
1274  struct extent<_Tp[], _Uint>
1275  : public integral_constant<std::size_t,
1276  _Uint == 0 ? 0 : extent<_Tp,
1277  _Uint - 1>::value>
1278  { };
1279 
1280 
1281  // Type relations.
1282 
1283  /// is_same
1284  template<typename, typename>
1285  struct is_same
1286  : public false_type { };
1287 
1288  template<typename _Tp>
1289  struct is_same<_Tp, _Tp>
1290  : public true_type { };
1291 
1292  /// is_base_of
1293  template<typename _Base, typename _Derived>
1294  struct is_base_of
1295  : public integral_constant<bool, __is_base_of(_Base, _Derived)>
1296  { };
1297 
1298  template<typename _From, typename _To,
1299  bool = __or_<is_void<_From>, is_function<_To>,
1300  is_array<_To>>::value>
1301  struct __is_convertible_helper
1302  {
1303  typedef typename is_void<_To>::type type;
1304  };
1305 
1306  template<typename _From, typename _To>
1307  class __is_convertible_helper<_From, _To, false>
1308  {
1309  template<typename _To1>
1310  static void __test_aux(_To1) noexcept;
1311 
1312  template<typename _From1, typename _To1,
1313  typename = decltype(__test_aux<_To1>(std::declval<_From1>()))>
1314  static true_type
1315  __test(int);
1316 
1317  template<typename, typename>
1318  static false_type
1319  __test(...);
1320 
1321  public:
1322  typedef decltype(__test<_From, _To>(0)) type;
1323  };
1324 
1325 
1326  /// is_convertible
1327  template<typename _From, typename _To>
1328  struct is_convertible
1329  : public __is_convertible_helper<_From, _To>::type
1330  { };
1331 
1332 #if __cplusplus > 201703L
1333  template<typename _From, typename _To,
1334  bool = __or_<is_void<_From>, is_function<_To>,
1335  is_array<_To>>::value>
1336  struct __is_nt_convertible_helper
1337  : is_void<_To>
1338  { };
1339 
1340  template<typename _From, typename _To>
1341  class __is_nt_convertible_helper<_From, _To, false>
1342  {
1343  template<typename _To1>
1344  static void __test_aux(_To1) noexcept;
1345 
1346  template<typename _From1, typename _To1>
1347  static bool_constant<noexcept(__test_aux<_To1>(std::declval<_From1>()))>
1348  __test(int);
1349 
1350  template<typename, typename>
1351  static false_type
1352  __test(...);
1353 
1354  public:
1355  using type = decltype(__test<_From, _To>(0));
1356  };
1357 
1358 #define __cpp_lib_is_nothrow_convertible 201806L
1359  /// is_nothrow_convertible
1360  template<typename _From, typename _To>
1361  struct is_nothrow_convertible
1362  : public __is_nt_convertible_helper<_From, _To>::type
1363  { };
1364 
1365  /// is_nothrow_convertible_v
1366  template<typename _From, typename _To>
1367  inline constexpr bool is_nothrow_convertible_v
1368  = is_nothrow_convertible<_From, _To>::value;
1369 #endif // C++2a
1370 
1371  // Const-volatile modifications.
1372 
1373  /// remove_const
1374  template<typename _Tp>
1375  struct remove_const
1376  { typedef _Tp type; };
1377 
1378  template<typename _Tp>
1379  struct remove_const<_Tp const>
1380  { typedef _Tp type; };
1381 
1382  /// remove_volatile
1383  template<typename _Tp>
1384  struct remove_volatile
1385  { typedef _Tp type; };
1386 
1387  template<typename _Tp>
1388  struct remove_volatile<_Tp volatile>
1389  { typedef _Tp type; };
1390 
1391  /// remove_cv
1392  template<typename _Tp>
1393  struct remove_cv
1394  {
1395  typedef typename
1396  remove_const<typename remove_volatile<_Tp>::type>::type type;
1397  };
1398 
1399  /// add_const
1400  template<typename _Tp>
1401  struct add_const
1402  { typedef _Tp const type; };
1403 
1404  /// add_volatile
1405  template<typename _Tp>
1406  struct add_volatile
1407  { typedef _Tp volatile type; };
1408 
1409  /// add_cv
1410  template<typename _Tp>
1411  struct add_cv
1412  {
1413  typedef typename
1414  add_const<typename add_volatile<_Tp>::type>::type type;
1415  };
1416 
1417 #if __cplusplus > 201103L
1418 
1419 #define __cpp_lib_transformation_trait_aliases 201304
1420 
1421  /// Alias template for remove_const
1422  template<typename _Tp>
1423  using remove_const_t = typename remove_const<_Tp>::type;
1424 
1425  /// Alias template for remove_volatile
1426  template<typename _Tp>
1427  using remove_volatile_t = typename remove_volatile<_Tp>::type;
1428 
1429  /// Alias template for remove_cv
1430  template<typename _Tp>
1431  using remove_cv_t = typename remove_cv<_Tp>::type;
1432 
1433  /// Alias template for add_const
1434  template<typename _Tp>
1435  using add_const_t = typename add_const<_Tp>::type;
1436 
1437  /// Alias template for add_volatile
1438  template<typename _Tp>
1439  using add_volatile_t = typename add_volatile<_Tp>::type;
1440 
1441  /// Alias template for add_cv
1442  template<typename _Tp>
1443  using add_cv_t = typename add_cv<_Tp>::type;
1444 #endif
1445 
1446  // Reference transformations.
1447 
1448  /// remove_reference
1449  template<typename _Tp>
1450  struct remove_reference
1451  { typedef _Tp type; };
1452 
1453  template<typename _Tp>
1454  struct remove_reference<_Tp&>
1455  { typedef _Tp type; };
1456 
1457  template<typename _Tp>
1458  struct remove_reference<_Tp&&>
1459  { typedef _Tp type; };
1460 
1461  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1462  struct __add_lvalue_reference_helper
1463  { typedef _Tp type; };
1464 
1465  template<typename _Tp>
1466  struct __add_lvalue_reference_helper<_Tp, true>
1467  { typedef _Tp& type; };
1468 
1469  /// add_lvalue_reference
1470  template<typename _Tp>
1471  struct add_lvalue_reference
1472  : public __add_lvalue_reference_helper<_Tp>
1473  { };
1474 
1475  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1476  struct __add_rvalue_reference_helper
1477  { typedef _Tp type; };
1478 
1479  template<typename _Tp>
1480  struct __add_rvalue_reference_helper<_Tp, true>
1481  { typedef _Tp&& type; };
1482 
1483  /// add_rvalue_reference
1484  template<typename _Tp>
1485  struct add_rvalue_reference
1486  : public __add_rvalue_reference_helper<_Tp>
1487  { };
1488 
1489 #if __cplusplus > 201103L
1490  /// Alias template for remove_reference
1491  template<typename _Tp>
1492  using remove_reference_t = typename remove_reference<_Tp>::type;
1493 
1494  /// Alias template for add_lvalue_reference
1495  template<typename _Tp>
1496  using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
1497 
1498  /// Alias template for add_rvalue_reference
1499  template<typename _Tp>
1500  using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
1501 #endif
1502 
1503  // Sign modifications.
1504 
1505  // Utility for constructing identically cv-qualified types.
1506  template<typename _Unqualified, bool _IsConst, bool _IsVol>
1507  struct __cv_selector;
1508 
1509  template<typename _Unqualified>
1510  struct __cv_selector<_Unqualified, false, false>
1511  { typedef _Unqualified __type; };
1512 
1513  template<typename _Unqualified>
1514  struct __cv_selector<_Unqualified, false, true>
1515  { typedef volatile _Unqualified __type; };
1516 
1517  template<typename _Unqualified>
1518  struct __cv_selector<_Unqualified, true, false>
1519  { typedef const _Unqualified __type; };
1520 
1521  template<typename _Unqualified>
1522  struct __cv_selector<_Unqualified, true, true>
1523  { typedef const volatile _Unqualified __type; };
1524 
1525  template<typename _Qualified, typename _Unqualified,
1526  bool _IsConst = is_const<_Qualified>::value,
1527  bool _IsVol = is_volatile<_Qualified>::value>
1528  class __match_cv_qualifiers
1529  {
1530  typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
1531 
1532  public:
1533  typedef typename __match::__type __type;
1534  };
1535 
1536  // Utility for finding the unsigned versions of signed integral types.
1537  template<typename _Tp>
1538  struct __make_unsigned
1539  { typedef _Tp __type; };
1540 
1541  template<>
1542  struct __make_unsigned<char>
1543  { typedef unsigned char __type; };
1544 
1545  template<>
1546  struct __make_unsigned<signed char>
1547  { typedef unsigned char __type; };
1548 
1549  template<>
1550  struct __make_unsigned<short>
1551  { typedef unsigned short __type; };
1552 
1553  template<>
1554  struct __make_unsigned<int>
1555  { typedef unsigned int __type; };
1556 
1557  template<>
1558  struct __make_unsigned<long>
1559  { typedef unsigned long __type; };
1560 
1561  template<>
1562  struct __make_unsigned<long long>
1563  { typedef unsigned long long __type; };
1564 
1565 #if defined(__GLIBCXX_TYPE_INT_N_0)
1566  template<>
1567  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_0>
1568  { typedef unsigned __GLIBCXX_TYPE_INT_N_0 __type; };
1569 #endif
1570 #if defined(__GLIBCXX_TYPE_INT_N_1)
1571  template<>
1572  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_1>
1573  { typedef unsigned __GLIBCXX_TYPE_INT_N_1 __type; };
1574 #endif
1575 #if defined(__GLIBCXX_TYPE_INT_N_2)
1576  template<>
1577  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_2>
1578  { typedef unsigned __GLIBCXX_TYPE_INT_N_2 __type; };
1579 #endif
1580 #if defined(__GLIBCXX_TYPE_INT_N_3)
1581  template<>
1582  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_3>
1583  { typedef unsigned __GLIBCXX_TYPE_INT_N_3 __type; };
1584 #endif
1585 
1586  // Select between integral and enum: not possible to be both.
1587  template<typename _Tp,
1588  bool _IsInt = is_integral<_Tp>::value,
1589  bool _IsEnum = is_enum<_Tp>::value>
1590  class __make_unsigned_selector;
1591 
1592  template<typename _Tp>
1593  class __make_unsigned_selector<_Tp, true, false>
1594  {
1595  using __unsigned_type
1596  = typename __make_unsigned<typename remove_cv<_Tp>::type>::__type;
1597 
1598  public:
1599  using __type
1600  = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1601  };
1602 
1603  class __make_unsigned_selector_base
1604  {
1605  protected:
1606  template<typename...> struct _List { };
1607 
1608  template<typename _Tp, typename... _Up>
1609  struct _List<_Tp, _Up...> : _List<_Up...>
1610  { static constexpr size_t __size = sizeof(_Tp); };
1611 
1612  template<size_t _Sz, typename _Tp, bool = (_Sz <= _Tp::__size)>
1613  struct __select;
1614 
1615  template<size_t _Sz, typename _Uint, typename... _UInts>
1616  struct __select<_Sz, _List<_Uint, _UInts...>, true>
1617  { using __type = _Uint; };
1618 
1619  template<size_t _Sz, typename _Uint, typename... _UInts>
1620  struct __select<_Sz, _List<_Uint, _UInts...>, false>
1621  : __select<_Sz, _List<_UInts...>>
1622  { };
1623  };
1624 
1625  // Choose unsigned integer type with the smallest rank and same size as _Tp
1626  template<typename _Tp>
1627  class __make_unsigned_selector<_Tp, false, true>
1628  : __make_unsigned_selector_base
1629  {
1630  // With -fshort-enums, an enum may be as small as a char.
1631  using _UInts = _List<unsigned char, unsigned short, unsigned int,
1632  unsigned long, unsigned long long>;
1633 
1634  using __unsigned_type = typename __select<sizeof(_Tp), _UInts>::__type;
1635 
1636  public:
1637  using __type
1638  = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1639  };
1640 
1641  // wchar_t, char8_t, char16_t and char32_t are integral types but are
1642  // neither signed integer types nor unsigned integer types, so must be
1643  // transformed to the unsigned integer type with the smallest rank.
1644  // Use the partial specialization for enumeration types to do that.
1645 #if defined(_GLIBCXX_USE_WCHAR_T)
1646  template<>
1647  struct __make_unsigned<wchar_t>
1648  {
1649  using __type
1650  = typename __make_unsigned_selector<wchar_t, false, true>::__type;
1651  };
1652 #endif
1653 
1654 #ifdef _GLIBCXX_USE_CHAR8_T
1655  template<>
1656  struct __make_unsigned<char8_t>
1657  {
1658  using __type
1659  = typename __make_unsigned_selector<char8_t, false, true>::__type;
1660  };
1661 #endif
1662 
1663  template<>
1664  struct __make_unsigned<char16_t>
1665  {
1666  using __type
1667  = typename __make_unsigned_selector<char16_t, false, true>::__type;
1668  };
1669 
1670  template<>
1671  struct __make_unsigned<char32_t>
1672  {
1673  using __type
1674  = typename __make_unsigned_selector<char32_t, false, true>::__type;
1675  };
1676 
1677  // Given an integral/enum type, return the corresponding unsigned
1678  // integer type.
1679  // Primary template.
1680  /// make_unsigned
1681  template<typename _Tp>
1682  struct make_unsigned
1683  { typedef typename __make_unsigned_selector<_Tp>::__type type; };
1684 
1685  // Integral, but don't define.
1686  template<>
1687  struct make_unsigned<bool>;
1688 
1689 
1690  // Utility for finding the signed versions of unsigned integral types.
1691  template<typename _Tp>
1692  struct __make_signed
1693  { typedef _Tp __type; };
1694 
1695  template<>
1696  struct __make_signed<char>
1697  { typedef signed char __type; };
1698 
1699  template<>
1700  struct __make_signed<unsigned char>
1701  { typedef signed char __type; };
1702 
1703  template<>
1704  struct __make_signed<unsigned short>
1705  { typedef signed short __type; };
1706 
1707  template<>
1708  struct __make_signed<unsigned int>
1709  { typedef signed int __type; };
1710 
1711  template<>
1712  struct __make_signed<unsigned long>
1713  { typedef signed long __type; };
1714 
1715  template<>
1716  struct __make_signed<unsigned long long>
1717  { typedef signed long long __type; };
1718 
1719 #if defined(__GLIBCXX_TYPE_INT_N_0)
1720  template<>
1721  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_0>
1722  { typedef __GLIBCXX_TYPE_INT_N_0 __type; };
1723 #endif
1724 #if defined(__GLIBCXX_TYPE_INT_N_1)
1725  template<>
1726  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_1>
1727  { typedef __GLIBCXX_TYPE_INT_N_1 __type; };
1728 #endif
1729 #if defined(__GLIBCXX_TYPE_INT_N_2)
1730  template<>
1731  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_2>
1732  { typedef __GLIBCXX_TYPE_INT_N_2 __type; };
1733 #endif
1734 #if defined(__GLIBCXX_TYPE_INT_N_3)
1735  template<>
1736  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_3>
1737  { typedef __GLIBCXX_TYPE_INT_N_3 __type; };
1738 #endif
1739 
1740  // Select between integral and enum: not possible to be both.
1741  template<typename _Tp,
1742  bool _IsInt = is_integral<_Tp>::value,
1743  bool _IsEnum = is_enum<_Tp>::value>
1744  class __make_signed_selector;
1745 
1746  template<typename _Tp>
1747  class __make_signed_selector<_Tp, true, false>
1748  {
1749  using __signed_type
1750  = typename __make_signed<typename remove_cv<_Tp>::type>::__type;
1751 
1752  public:
1753  using __type
1754  = typename __match_cv_qualifiers<_Tp, __signed_type>::__type;
1755  };
1756 
1757  // Choose signed integer type with the smallest rank and same size as _Tp
1758  template<typename _Tp>
1759  class __make_signed_selector<_Tp, false, true>
1760  {
1761  typedef typename __make_unsigned_selector<_Tp>::__type __unsigned_type;
1762 
1763  public:
1764  typedef typename __make_signed_selector<__unsigned_type>::__type __type;
1765  };
1766 
1767  // wchar_t, char16_t and char32_t are integral types but are neither
1768  // signed integer types nor unsigned integer types, so must be
1769  // transformed to the signed integer type with the smallest rank.
1770  // Use the partial specialization for enumeration types to do that.
1771 #if defined(_GLIBCXX_USE_WCHAR_T)
1772  template<>
1773  struct __make_signed<wchar_t>
1774  {
1775  using __type
1776  = typename __make_signed_selector<wchar_t, false, true>::__type;
1777  };
1778 #endif
1779 
1780 #if defined(_GLIBCXX_USE_CHAR8_T)
1781  template<>
1782  struct __make_signed<char8_t>
1783  {
1784  using __type
1785  = typename __make_signed_selector<char8_t, false, true>::__type;
1786  };
1787 #endif
1788 
1789  template<>
1790  struct __make_signed<char16_t>
1791  {
1792  using __type
1793  = typename __make_signed_selector<char16_t, false, true>::__type;
1794  };
1795 
1796  template<>
1797  struct __make_signed<char32_t>
1798  {
1799  using __type
1800  = typename __make_signed_selector<char32_t, false, true>::__type;
1801  };
1802 
1803  // Given an integral/enum type, return the corresponding signed
1804  // integer type.
1805  // Primary template.
1806  /// make_signed
1807  template<typename _Tp>
1808  struct make_signed
1809  { typedef typename __make_signed_selector<_Tp>::__type type; };
1810 
1811  // Integral, but don't define.
1812  template<>
1813  struct make_signed<bool>;
1814 
1815 #if __cplusplus > 201103L
1816  /// Alias template for make_signed
1817  template<typename _Tp>
1818  using make_signed_t = typename make_signed<_Tp>::type;
1819 
1820  /// Alias template for make_unsigned
1821  template<typename _Tp>
1822  using make_unsigned_t = typename make_unsigned<_Tp>::type;
1823 #endif
1824 
1825  // Array modifications.
1826 
1827  /// remove_extent
1828  template<typename _Tp>
1829  struct remove_extent
1830  { typedef _Tp type; };
1831 
1832  template<typename _Tp, std::size_t _Size>
1833  struct remove_extent<_Tp[_Size]>
1834  { typedef _Tp type; };
1835 
1836  template<typename _Tp>
1837  struct remove_extent<_Tp[]>
1838  { typedef _Tp type; };
1839 
1840  /// remove_all_extents
1841  template<typename _Tp>
1842  struct remove_all_extents
1843  { typedef _Tp type; };
1844 
1845  template<typename _Tp, std::size_t _Size>
1846  struct remove_all_extents<_Tp[_Size]>
1847  { typedef typename remove_all_extents<_Tp>::type type; };
1848 
1849  template<typename _Tp>
1850  struct remove_all_extents<_Tp[]>
1851  { typedef typename remove_all_extents<_Tp>::type type; };
1852 
1853 #if __cplusplus > 201103L
1854  /// Alias template for remove_extent
1855  template<typename _Tp>
1856  using remove_extent_t = typename remove_extent<_Tp>::type;
1857 
1858  /// Alias template for remove_all_extents
1859  template<typename _Tp>
1860  using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
1861 #endif
1862 
1863  // Pointer modifications.
1864 
1865  template<typename _Tp, typename>
1866  struct __remove_pointer_helper
1867  { typedef _Tp type; };
1868 
1869  template<typename _Tp, typename _Up>
1870  struct __remove_pointer_helper<_Tp, _Up*>
1871  { typedef _Up type; };
1872 
1873  /// remove_pointer
1874  template<typename _Tp>
1875  struct remove_pointer
1876  : public __remove_pointer_helper<_Tp, typename remove_cv<_Tp>::type>
1877  { };
1878 
1879  /// add_pointer
1880  template<typename _Tp, bool = __or_<__is_referenceable<_Tp>,
1881  is_void<_Tp>>::value>
1882  struct __add_pointer_helper
1883  { typedef _Tp type; };
1884 
1885  template<typename _Tp>
1886  struct __add_pointer_helper<_Tp, true>
1887  { typedef typename remove_reference<_Tp>::type* type; };
1888 
1889  template<typename _Tp>
1890  struct add_pointer
1891  : public __add_pointer_helper<_Tp>
1892  { };
1893 
1894 #if __cplusplus > 201103L
1895  /// Alias template for remove_pointer
1896  template<typename _Tp>
1897  using remove_pointer_t = typename remove_pointer<_Tp>::type;
1898 
1899  /// Alias template for add_pointer
1900  template<typename _Tp>
1901  using add_pointer_t = typename add_pointer<_Tp>::type;
1902 #endif
1903 
1904  template<std::size_t _Len>
1905  struct __aligned_storage_msa
1906  {
1907  union __type
1908  {
1909  unsigned char __data[_Len];
1910  struct __attribute__((__aligned__)) { } __align;
1911  };
1912  };
1913 
1914  /**
1915  * @brief Alignment type.
1916  *
1917  * The value of _Align is a default-alignment which shall be the
1918  * most stringent alignment requirement for any C++ object type
1919  * whose size is no greater than _Len (3.9). The member typedef
1920  * type shall be a POD type suitable for use as uninitialized
1921  * storage for any object whose size is at most _Len and whose
1922  * alignment is a divisor of _Align.
1923  */
1924  template<std::size_t _Len, std::size_t _Align =
1925  __alignof__(typename __aligned_storage_msa<_Len>::__type)>
1926  struct aligned_storage
1927  {
1928  union type
1929  {
1930  unsigned char __data[_Len];
1931  struct __attribute__((__aligned__((_Align)))) { } __align;
1932  };
1933  };
1934 
1935  template <typename... _Types>
1936  struct __strictest_alignment
1937  {
1938  static const size_t _S_alignment = 0;
1939  static const size_t _S_size = 0;
1940  };
1941 
1942  template <typename _Tp, typename... _Types>
1943  struct __strictest_alignment<_Tp, _Types...>
1944  {
1945  static const size_t _S_alignment =
1946  alignof(_Tp) > __strictest_alignment<_Types...>::_S_alignment
1947  ? alignof(_Tp) : __strictest_alignment<_Types...>::_S_alignment;
1948  static const size_t _S_size =
1949  sizeof(_Tp) > __strictest_alignment<_Types...>::_S_size
1950  ? sizeof(_Tp) : __strictest_alignment<_Types...>::_S_size;
1951  };
1952 
1953  /**
1954  * @brief Provide aligned storage for types.
1955  *
1956  * [meta.trans.other]
1957  *
1958  * Provides aligned storage for any of the provided types of at
1959  * least size _Len.
1960  *
1961  * @see aligned_storage
1962  */
1963  template <size_t _Len, typename... _Types>
1964  struct aligned_union
1965  {
1966  private:
1967  static_assert(sizeof...(_Types) != 0, "At least one type is required");
1968 
1969  using __strictest = __strictest_alignment<_Types...>;
1970  static const size_t _S_len = _Len > __strictest::_S_size
1971  ? _Len : __strictest::_S_size;
1972  public:
1973  /// The value of the strictest alignment of _Types.
1974  static const size_t alignment_value = __strictest::_S_alignment;
1975  /// The storage.
1976  typedef typename aligned_storage<_S_len, alignment_value>::type type;
1977  };
1978 
1979  template <size_t _Len, typename... _Types>
1980  const size_t aligned_union<_Len, _Types...>::alignment_value;
1981 
1982  // Decay trait for arrays and functions, used for perfect forwarding
1983  // in make_pair, make_tuple, etc.
1984  template<typename _Up,
1985  bool _IsArray = is_array<_Up>::value,
1986  bool _IsFunction = is_function<_Up>::value>
1987  struct __decay_selector;
1988 
1989  // NB: DR 705.
1990  template<typename _Up>
1991  struct __decay_selector<_Up, false, false>
1992  { typedef typename remove_cv<_Up>::type __type; };
1993 
1994  template<typename _Up>
1995  struct __decay_selector<_Up, true, false>
1996  { typedef typename remove_extent<_Up>::type* __type; };
1997 
1998  template<typename _Up>
1999  struct __decay_selector<_Up, false, true>
2000  { typedef typename add_pointer<_Up>::type __type; };
2001 
2002  /// decay
2003  template<typename _Tp>
2004  class decay
2005  {
2006  typedef typename remove_reference<_Tp>::type __remove_type;
2007 
2008  public:
2009  typedef typename __decay_selector<__remove_type>::__type type;
2010  };
2011 
2012  template<typename _Tp>
2013  class reference_wrapper;
2014 
2015  // Helper which adds a reference to a type when given a reference_wrapper
2016  template<typename _Tp>
2017  struct __strip_reference_wrapper
2018  {
2019  typedef _Tp __type;
2020  };
2021 
2022  template<typename _Tp>
2023  struct __strip_reference_wrapper<reference_wrapper<_Tp> >
2024  {
2025  typedef _Tp& __type;
2026  };
2027 
2028  template<typename _Tp>
2029  struct __decay_and_strip
2030  {
2031  typedef typename __strip_reference_wrapper<
2032  typename decay<_Tp>::type>::__type __type;
2033  };
2034 
2035 
2036  // Primary template.
2037  /// Define a member typedef @c type only if a boolean constant is true.
2038  template<bool, typename _Tp = void>
2039  struct enable_if
2040  { };
2041 
2042  // Partial specialization for true.
2043  template<typename _Tp>
2044  struct enable_if<true, _Tp>
2045  { typedef _Tp type; };
2046 
2047  template<typename... _Cond>
2048  using _Require = typename enable_if<__and_<_Cond...>::value>::type;
2049 
2050  // Primary template.
2051  /// Define a member typedef @c type to one of two argument types.
2052  template<bool _Cond, typename _Iftrue, typename _Iffalse>
2053  struct conditional
2054  { typedef _Iftrue type; };
2055 
2056  // Partial specialization for false.
2057  template<typename _Iftrue, typename _Iffalse>
2058  struct conditional<false, _Iftrue, _Iffalse>
2059  { typedef _Iffalse type; };
2060 
2061  /// common_type
2062  template<typename... _Tp>
2063  struct common_type;
2064 
2065  // Sfinae-friendly common_type implementation:
2066 
2067  struct __do_common_type_impl
2068  {
2069  template<typename _Tp, typename _Up>
2070  static __success_type<typename decay<decltype
2071  (true ? std::declval<_Tp>()
2072  : std::declval<_Up>())>::type> _S_test(int);
2073 
2074  template<typename, typename>
2075  static __failure_type _S_test(...);
2076  };
2077 
2078  template<typename _Tp, typename _Up>
2079  struct __common_type_impl
2080  : private __do_common_type_impl
2081  {
2082  typedef decltype(_S_test<_Tp, _Up>(0)) type;
2083  };
2084 
2085  struct __do_member_type_wrapper
2086  {
2087  template<typename _Tp>
2088  static __success_type<typename _Tp::type> _S_test(int);
2089 
2090  template<typename>
2091  static __failure_type _S_test(...);
2092  };
2093 
2094  template<typename _Tp>
2095  struct __member_type_wrapper
2096  : private __do_member_type_wrapper
2097  {
2098  typedef decltype(_S_test<_Tp>(0)) type;
2099  };
2100 
2101  template<typename _CTp, typename... _Args>
2102  struct __expanded_common_type_wrapper
2103  {
2104  typedef common_type<typename _CTp::type, _Args...> type;
2105  };
2106 
2107  template<typename... _Args>
2108  struct __expanded_common_type_wrapper<__failure_type, _Args...>
2109  { typedef __failure_type type; };
2110 
2111  template<>
2112  struct common_type<>
2113  { };
2114 
2115  template<typename _Tp>
2116  struct common_type<_Tp>
2117  : common_type<_Tp, _Tp>
2118  { };
2119 
2120  template<typename _Tp, typename _Up>
2121  struct common_type<_Tp, _Up>
2122  : public __common_type_impl<_Tp, _Up>::type
2123  { };
2124 
2125  template<typename _Tp, typename _Up, typename... _Vp>
2126  struct common_type<_Tp, _Up, _Vp...>
2127  : public __expanded_common_type_wrapper<typename __member_type_wrapper<
2128  common_type<_Tp, _Up>>::type, _Vp...>::type
2129  { };
2130 
2131  template<typename _Tp, bool = is_enum<_Tp>::value>
2132  struct __underlying_type_impl
2133  {
2134  using type = __underlying_type(_Tp);
2135  };
2136 
2137  template<typename _Tp>
2138  struct __underlying_type_impl<_Tp, false>
2139  { };
2140 
2141  /// The underlying type of an enum.
2142  template<typename _Tp>
2143  struct underlying_type
2144  : public __underlying_type_impl<_Tp>
2145  { };
2146 
2147  template<typename _Tp>
2148  struct __declval_protector
2149  {
2150  static const bool __stop = false;
2151  };
2152 
2153  template<typename _Tp>
2154  auto declval() noexcept -> decltype(__declval<_Tp>(0))
2155  {
2156  static_assert(__declval_protector<_Tp>::__stop,
2157  "declval() must not be used!");
2158  return __declval<_Tp>(0);
2159  }
2160 
2161  // __remove_cvref_t (std::remove_cvref_t for C++11).
2162  template<typename _Tp>
2163  using __remove_cvref_t
2164  = typename remove_cv<typename remove_reference<_Tp>::type>::type;
2165 
2166  /// result_of
2167  template<typename _Signature>
2168  class result_of;
2169 
2170  // Sfinae-friendly result_of implementation:
2171 
2172 #define __cpp_lib_result_of_sfinae 201210
2173 
2174  struct __invoke_memfun_ref { };
2175  struct __invoke_memfun_deref { };
2176  struct __invoke_memobj_ref { };
2177  struct __invoke_memobj_deref { };
2178  struct __invoke_other { };
2179 
2180  // Associate a tag type with a specialization of __success_type.
2181  template<typename _Tp, typename _Tag>
2182  struct __result_of_success : __success_type<_Tp>
2183  { using __invoke_type = _Tag; };
2184 
2185  // [func.require] paragraph 1 bullet 1:
2186  struct __result_of_memfun_ref_impl
2187  {
2188  template<typename _Fp, typename _Tp1, typename... _Args>
2189  static __result_of_success<decltype(
2190  (std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...)
2191  ), __invoke_memfun_ref> _S_test(int);
2192 
2193  template<typename...>
2194  static __failure_type _S_test(...);
2195  };
2196 
2197  template<typename _MemPtr, typename _Arg, typename... _Args>
2198  struct __result_of_memfun_ref
2199  : private __result_of_memfun_ref_impl
2200  {
2201  typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2202  };
2203 
2204  // [func.require] paragraph 1 bullet 2:
2205  struct __result_of_memfun_deref_impl
2206  {
2207  template<typename _Fp, typename _Tp1, typename... _Args>
2208  static __result_of_success<decltype(
2209  ((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...)
2210  ), __invoke_memfun_deref> _S_test(int);
2211 
2212  template<typename...>
2213  static __failure_type _S_test(...);
2214  };
2215 
2216  template<typename _MemPtr, typename _Arg, typename... _Args>
2217  struct __result_of_memfun_deref
2218  : private __result_of_memfun_deref_impl
2219  {
2220  typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2221  };
2222 
2223  // [func.require] paragraph 1 bullet 3:
2224  struct __result_of_memobj_ref_impl
2225  {
2226  template<typename _Fp, typename _Tp1>
2227  static __result_of_success<decltype(
2228  std::declval<_Tp1>().*std::declval<_Fp>()
2229  ), __invoke_memobj_ref> _S_test(int);
2230 
2231  template<typename, typename>
2232  static __failure_type _S_test(...);
2233  };
2234 
2235  template<typename _MemPtr, typename _Arg>
2236  struct __result_of_memobj_ref
2237  : private __result_of_memobj_ref_impl
2238  {
2239  typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2240  };
2241 
2242  // [func.require] paragraph 1 bullet 4:
2243  struct __result_of_memobj_deref_impl
2244  {
2245  template<typename _Fp, typename _Tp1>
2246  static __result_of_success<decltype(
2247  (*std::declval<_Tp1>()).*std::declval<_Fp>()
2248  ), __invoke_memobj_deref> _S_test(int);
2249 
2250  template<typename, typename>
2251  static __failure_type _S_test(...);
2252  };
2253 
2254  template<typename _MemPtr, typename _Arg>
2255  struct __result_of_memobj_deref
2256  : private __result_of_memobj_deref_impl
2257  {
2258  typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2259  };
2260 
2261  template<typename _MemPtr, typename _Arg>
2262  struct __result_of_memobj;
2263 
2264  template<typename _Res, typename _Class, typename _Arg>
2265  struct __result_of_memobj<_Res _Class::*, _Arg>
2266  {
2267  typedef __remove_cvref_t<_Arg> _Argval;
2268  typedef _Res _Class::* _MemPtr;
2269  typedef typename conditional<__or_<is_same<_Argval, _Class>,
2270  is_base_of<_Class, _Argval>>::value,
2271  __result_of_memobj_ref<_MemPtr, _Arg>,
2272  __result_of_memobj_deref<_MemPtr, _Arg>
2273  >::type::type type;
2274  };
2275 
2276  template<typename _MemPtr, typename _Arg, typename... _Args>
2277  struct __result_of_memfun;
2278 
2279  template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2280  struct __result_of_memfun<_Res _Class::*, _Arg, _Args...>
2281  {
2282  typedef typename remove_reference<_Arg>::type _Argval;
2283  typedef _Res _Class::* _MemPtr;
2284  typedef typename conditional<is_base_of<_Class, _Argval>::value,
2285  __result_of_memfun_ref<_MemPtr, _Arg, _Args...>,
2286  __result_of_memfun_deref<_MemPtr, _Arg, _Args...>
2287  >::type::type type;
2288  };
2289 
2290  // _GLIBCXX_RESOLVE_LIB_DEFECTS
2291  // 2219. INVOKE-ing a pointer to member with a reference_wrapper
2292  // as the object expression
2293 
2294  // Used by result_of, invoke etc. to unwrap a reference_wrapper.
2295  template<typename _Tp, typename _Up = __remove_cvref_t<_Tp>>
2296  struct __inv_unwrap
2297  {
2298  using type = _Tp;
2299  };
2300 
2301  template<typename _Tp, typename _Up>
2302  struct __inv_unwrap<_Tp, reference_wrapper<_Up>>
2303  {
2304  using type = _Up&;
2305  };
2306 
2307  template<bool, bool, typename _Functor, typename... _ArgTypes>
2308  struct __result_of_impl
2309  {
2310  typedef __failure_type type;
2311  };
2312 
2313  template<typename _MemPtr, typename _Arg>
2314  struct __result_of_impl<true, false, _MemPtr, _Arg>
2315  : public __result_of_memobj<typename decay<_MemPtr>::type,
2316  typename __inv_unwrap<_Arg>::type>
2317  { };
2318 
2319  template<typename _MemPtr, typename _Arg, typename... _Args>
2320  struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...>
2321  : public __result_of_memfun<typename decay<_MemPtr>::type,
2322  typename __inv_unwrap<_Arg>::type, _Args...>
2323  { };
2324 
2325  // [func.require] paragraph 1 bullet 5:
2326  struct __result_of_other_impl
2327  {
2328  template<typename _Fn, typename... _Args>
2329  static __result_of_success<decltype(
2330  std::declval<_Fn>()(std::declval<_Args>()...)
2331  ), __invoke_other> _S_test(int);
2332 
2333  template<typename...>
2334  static __failure_type _S_test(...);
2335  };
2336 
2337  template<typename _Functor, typename... _ArgTypes>
2338  struct __result_of_impl<false, false, _Functor, _ArgTypes...>
2339  : private __result_of_other_impl
2340  {
2341  typedef decltype(_S_test<_Functor, _ArgTypes...>(0)) type;
2342  };
2343 
2344  // __invoke_result (std::invoke_result for C++11)
2345  template<typename _Functor, typename... _ArgTypes>
2346  struct __invoke_result
2347  : public __result_of_impl<
2348  is_member_object_pointer<
2349  typename remove_reference<_Functor>::type
2350  >::value,
2351  is_member_function_pointer<
2352  typename remove_reference<_Functor>::type
2353  >::value,
2354  _Functor, _ArgTypes...
2355  >::type
2356  { };
2357 
2358  template<typename _Functor, typename... _ArgTypes>
2359  struct result_of<_Functor(_ArgTypes...)>
2360  : public __invoke_result<_Functor, _ArgTypes...>
2361  { };
2362 
2363 #if __cplusplus >= 201402L
2364  /// Alias template for aligned_storage
2365  template<size_t _Len, size_t _Align =
2366  __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2367  using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
2368 
2369  template <size_t _Len, typename... _Types>
2370  using aligned_union_t = typename aligned_union<_Len, _Types...>::type;
2371 
2372  /// Alias template for decay
2373  template<typename _Tp>
2374  using decay_t = typename decay<_Tp>::type;
2375 
2376  /// Alias template for enable_if
2377  template<bool _Cond, typename _Tp = void>
2378  using enable_if_t = typename enable_if<_Cond, _Tp>::type;
2379 
2380  /// Alias template for conditional
2381  template<bool _Cond, typename _Iftrue, typename _Iffalse>
2382  using conditional_t = typename conditional<_Cond, _Iftrue, _Iffalse>::type;
2383 
2384  /// Alias template for common_type
2385  template<typename... _Tp>
2386  using common_type_t = typename common_type<_Tp...>::type;
2387 
2388  /// Alias template for underlying_type
2389  template<typename _Tp>
2390  using underlying_type_t = typename underlying_type<_Tp>::type;
2391 
2392  /// Alias template for result_of
2393  template<typename _Tp>
2394  using result_of_t = typename result_of<_Tp>::type;
2395 #endif // C++14
2396 
2397  // __enable_if_t (std::enable_if_t for C++11)
2398  template<bool _Cond, typename _Tp = void>
2399  using __enable_if_t = typename enable_if<_Cond, _Tp>::type;
2400 
2401  // __void_t (std::void_t for C++11)
2402  template<typename...> using __void_t = void;
2403 
2404 #if __cplusplus >= 201703L || !defined(__STRICT_ANSI__) // c++17 or gnu++11
2405 #define __cpp_lib_void_t 201411
2406  /// A metafunction that always yields void, used for detecting valid types.
2407  template<typename...> using void_t = void;
2408 #endif
2409 
2410  /// Implementation of the detection idiom (negative case).
2411  template<typename _Default, typename _AlwaysVoid,
2412  template<typename...> class _Op, typename... _Args>
2413  struct __detector
2414  {
2415  using value_t = false_type;
2416  using type = _Default;
2417  };
2418 
2419  /// Implementation of the detection idiom (positive case).
2420  template<typename _Default, template<typename...> class _Op,
2421  typename... _Args>
2422  struct __detector<_Default, __void_t<_Op<_Args...>>, _Op, _Args...>
2423  {
2424  using value_t = true_type;
2425  using type = _Op<_Args...>;
2426  };
2427 
2428  // Detect whether _Op<_Args...> is a valid type, use _Default if not.
2429  template<typename _Default, template<typename...> class _Op,
2430  typename... _Args>
2431  using __detected_or = __detector<_Default, void, _Op, _Args...>;
2432 
2433  // _Op<_Args...> if that is a valid type, otherwise _Default.
2434  template<typename _Default, template<typename...> class _Op,
2435  typename... _Args>
2436  using __detected_or_t
2437  = typename __detected_or<_Default, _Op, _Args...>::type;
2438 
2439  /// @} group metaprogramming
2440 
2441  /**
2442  * Use SFINAE to determine if the type _Tp has a publicly-accessible
2443  * member type _NTYPE.
2444  */
2445 #define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \
2446  template<typename _Tp, typename = __void_t<>> \
2447  struct __has_##_NTYPE \
2448  : false_type \
2449  { }; \
2450  template<typename _Tp> \
2451  struct __has_##_NTYPE<_Tp, __void_t<typename _Tp::_NTYPE>> \
2452  : true_type \
2453  { };
2454 
2455  template <typename _Tp>
2456  struct __is_swappable;
2457 
2458  template <typename _Tp>
2459  struct __is_nothrow_swappable;
2460 
2461  template<typename... _Elements>
2462  class tuple;
2463 
2464  template<typename>
2465  struct __is_tuple_like_impl : false_type
2466  { };
2467 
2468  template<typename... _Tps>
2469  struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
2470  { };
2471 
2472  // Internal type trait that allows us to sfinae-protect tuple_cat.
2473  template<typename _Tp>
2474  struct __is_tuple_like
2475  : public __is_tuple_like_impl<__remove_cvref_t<_Tp>>::type
2476  { };
2477 
2478  template<typename _Tp>
2479  inline
2480  typename enable_if<__and_<__not_<__is_tuple_like<_Tp>>,
2481  is_move_constructible<_Tp>,
2482  is_move_assignable<_Tp>>::value>::type
2483  swap(_Tp&, _Tp&)
2484  noexcept(__and_<is_nothrow_move_constructible<_Tp>,
2485  is_nothrow_move_assignable<_Tp>>::value);
2486 
2487  template<typename _Tp, size_t _Nm>
2488  inline
2489  typename enable_if<__is_swappable<_Tp>::value>::type
2490  swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
2491  noexcept(__is_nothrow_swappable<_Tp>::value);
2492 
2493  namespace __swappable_details {
2494  using std::swap;
2495 
2496  struct __do_is_swappable_impl
2497  {
2498  template<typename _Tp, typename
2499  = decltype(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))>
2500  static true_type __test(int);
2501 
2502  template<typename>
2503  static false_type __test(...);
2504  };
2505 
2506  struct __do_is_nothrow_swappable_impl
2507  {
2508  template<typename _Tp>
2509  static __bool_constant<
2510  noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))
2511  > __test(int);
2512 
2513  template<typename>
2514  static false_type __test(...);
2515  };
2516 
2517  } // namespace __swappable_details
2518 
2519  template<typename _Tp>
2520  struct __is_swappable_impl
2521  : public __swappable_details::__do_is_swappable_impl
2522  {
2523  typedef decltype(__test<_Tp>(0)) type;
2524  };
2525 
2526  template<typename _Tp>
2527  struct __is_nothrow_swappable_impl
2528  : public __swappable_details::__do_is_nothrow_swappable_impl
2529  {
2530  typedef decltype(__test<_Tp>(0)) type;
2531  };
2532 
2533  template<typename _Tp>
2534  struct __is_swappable
2535  : public __is_swappable_impl<_Tp>::type
2536  { };
2537 
2538  template<typename _Tp>
2539  struct __is_nothrow_swappable
2540  : public __is_nothrow_swappable_impl<_Tp>::type
2541  { };
2542 
2543 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
2544 #define __cpp_lib_is_swappable 201603
2545  /// Metafunctions used for detecting swappable types: p0185r1
2546 
2547  /// is_swappable
2548  template<typename _Tp>
2549  struct is_swappable
2550  : public __is_swappable_impl<_Tp>::type
2551  { };
2552 
2553  /// is_nothrow_swappable
2554  template<typename _Tp>
2555  struct is_nothrow_swappable
2556  : public __is_nothrow_swappable_impl<_Tp>::type
2557  { };
2558 
2559 #if __cplusplus >= 201402L
2560  /// is_swappable_v
2561  template<typename _Tp>
2562  _GLIBCXX17_INLINE constexpr bool is_swappable_v =
2563  is_swappable<_Tp>::value;
2564 
2565  /// is_nothrow_swappable_v
2566  template<typename _Tp>
2567  _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_v =
2568  is_nothrow_swappable<_Tp>::value;
2569 #endif // __cplusplus >= 201402L
2570 
2571  namespace __swappable_with_details {
2572  using std::swap;
2573 
2574  struct __do_is_swappable_with_impl
2575  {
2576  template<typename _Tp, typename _Up, typename
2577  = decltype(swap(std::declval<_Tp>(), std::declval<_Up>())),
2578  typename
2579  = decltype(swap(std::declval<_Up>(), std::declval<_Tp>()))>
2580  static true_type __test(int);
2581 
2582  template<typename, typename>
2583  static false_type __test(...);
2584  };
2585 
2586  struct __do_is_nothrow_swappable_with_impl
2587  {
2588  template<typename _Tp, typename _Up>
2589  static __bool_constant<
2590  noexcept(swap(std::declval<_Tp>(), std::declval<_Up>()))
2591  &&
2592  noexcept(swap(std::declval<_Up>(), std::declval<_Tp>()))
2593  > __test(int);
2594 
2595  template<typename, typename>
2596  static false_type __test(...);
2597  };
2598 
2599  } // namespace __swappable_with_details
2600 
2601  template<typename _Tp, typename _Up>
2602  struct __is_swappable_with_impl
2603  : public __swappable_with_details::__do_is_swappable_with_impl
2604  {
2605  typedef decltype(__test<_Tp, _Up>(0)) type;
2606  };
2607 
2608  // Optimization for the homogenous lvalue case, not required:
2609  template<typename _Tp>
2610  struct __is_swappable_with_impl<_Tp&, _Tp&>
2611  : public __swappable_details::__do_is_swappable_impl
2612  {
2613  typedef decltype(__test<_Tp&>(0)) type;
2614  };
2615 
2616  template<typename _Tp, typename _Up>
2617  struct __is_nothrow_swappable_with_impl
2618  : public __swappable_with_details::__do_is_nothrow_swappable_with_impl
2619  {
2620  typedef decltype(__test<_Tp, _Up>(0)) type;
2621  };
2622 
2623  // Optimization for the homogenous lvalue case, not required:
2624  template<typename _Tp>
2625  struct __is_nothrow_swappable_with_impl<_Tp&, _Tp&>
2626  : public __swappable_details::__do_is_nothrow_swappable_impl
2627  {
2628  typedef decltype(__test<_Tp&>(0)) type;
2629  };
2630 
2631  /// is_swappable_with
2632  template<typename _Tp, typename _Up>
2633  struct is_swappable_with
2634  : public __is_swappable_with_impl<_Tp, _Up>::type
2635  { };
2636 
2637  /// is_nothrow_swappable_with
2638  template<typename _Tp, typename _Up>
2639  struct is_nothrow_swappable_with
2640  : public __is_nothrow_swappable_with_impl<_Tp, _Up>::type
2641  { };
2642 
2643 #if __cplusplus >= 201402L
2644  /// is_swappable_with_v
2645  template<typename _Tp, typename _Up>
2646  _GLIBCXX17_INLINE constexpr bool is_swappable_with_v =
2647  is_swappable_with<_Tp, _Up>::value;
2648 
2649  /// is_nothrow_swappable_with_v
2650  template<typename _Tp, typename _Up>
2651  _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_with_v =
2652  is_nothrow_swappable_with<_Tp, _Up>::value;
2653 #endif // __cplusplus >= 201402L
2654 
2655 #endif// c++1z or gnu++11
2656 
2657  // __is_invocable (std::is_invocable for C++11)
2658 
2659  // The primary template is used for invalid INVOKE expressions.
2660  template<typename _Result, typename _Ret,
2661  bool = is_void<_Ret>::value, typename = void>
2662  struct __is_invocable_impl : false_type { };
2663 
2664  // Used for valid INVOKE and INVOKE<void> expressions.
2665  template<typename _Result, typename _Ret>
2666  struct __is_invocable_impl<_Result, _Ret,
2667  /* is_void<_Ret> = */ true,
2668  __void_t<typename _Result::type>>
2669  : true_type
2670  { };
2671 
2672 #pragma GCC diagnostic push
2673 #pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
2674  // Used for INVOKE<R> expressions to check the implicit conversion to R.
2675  template<typename _Result, typename _Ret>
2676  struct __is_invocable_impl<_Result, _Ret,
2677  /* is_void<_Ret> = */ false,
2678  __void_t<typename _Result::type>>
2679  {
2680  private:
2681  // The type of the INVOKE expression.
2682  // Unlike declval, this doesn't add_rvalue_reference.
2683  static typename _Result::type _S_get();
2684 
2685  template<typename _Tp>
2686  static void _S_conv(_Tp);
2687 
2688  // This overload is viable if INVOKE(f, args...) can convert to _Tp.
2689  template<typename _Tp, typename = decltype(_S_conv<_Tp>(_S_get()))>
2690  static true_type
2691  _S_test(int);
2692 
2693  template<typename _Tp>
2694  static false_type
2695  _S_test(...);
2696 
2697  public:
2698  using type = decltype(_S_test<_Ret>(1));
2699  };
2700 #pragma GCC diagnostic pop
2701 
2702  template<typename _Fn, typename... _ArgTypes>
2703  struct __is_invocable
2704  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2705  { };
2706 
2707  template<typename _Fn, typename _Tp, typename... _Args>
2708  constexpr bool __call_is_nt(__invoke_memfun_ref)
2709  {
2710  using _Up = typename __inv_unwrap<_Tp>::type;
2711  return noexcept((std::declval<_Up>().*std::declval<_Fn>())(
2712  std::declval<_Args>()...));
2713  }
2714 
2715  template<typename _Fn, typename _Tp, typename... _Args>
2716  constexpr bool __call_is_nt(__invoke_memfun_deref)
2717  {
2718  return noexcept(((*std::declval<_Tp>()).*std::declval<_Fn>())(
2719  std::declval<_Args>()...));
2720  }
2721 
2722  template<typename _Fn, typename _Tp>
2723  constexpr bool __call_is_nt(__invoke_memobj_ref)
2724  {
2725  using _Up = typename __inv_unwrap<_Tp>::type;
2726  return noexcept(std::declval<_Up>().*std::declval<_Fn>());
2727  }
2728 
2729  template<typename _Fn, typename _Tp>
2730  constexpr bool __call_is_nt(__invoke_memobj_deref)
2731  {
2732  return noexcept((*std::declval<_Tp>()).*std::declval<_Fn>());
2733  }
2734 
2735  template<typename _Fn, typename... _Args>
2736  constexpr bool __call_is_nt(__invoke_other)
2737  {
2738  return noexcept(std::declval<_Fn>()(std::declval<_Args>()...));
2739  }
2740 
2741  template<typename _Result, typename _Fn, typename... _Args>
2742  struct __call_is_nothrow
2743  : __bool_constant<
2744  std::__call_is_nt<_Fn, _Args...>(typename _Result::__invoke_type{})
2745  >
2746  { };
2747 
2748  template<typename _Fn, typename... _Args>
2749  using __call_is_nothrow_
2750  = __call_is_nothrow<__invoke_result<_Fn, _Args...>, _Fn, _Args...>;
2751 
2752  // __is_nothrow_invocable (std::is_nothrow_invocable for C++11)
2753  template<typename _Fn, typename... _Args>
2754  struct __is_nothrow_invocable
2755  : __and_<__is_invocable<_Fn, _Args...>,
2756  __call_is_nothrow_<_Fn, _Args...>>::type
2757  { };
2758 
2759  struct __nonesuch {
2760  __nonesuch() = delete;
2761  ~__nonesuch() = delete;
2762  __nonesuch(__nonesuch const&) = delete;
2763  void operator=(__nonesuch const&) = delete;
2764  };
2765 
2766 #if __cplusplus >= 201703L
2767 # define __cpp_lib_is_invocable 201703
2768 
2769  /// std::invoke_result
2770  template<typename _Functor, typename... _ArgTypes>
2771  struct invoke_result
2772  : public __invoke_result<_Functor, _ArgTypes...>
2773  { };
2774 
2775  /// std::invoke_result_t
2776  template<typename _Fn, typename... _Args>
2777  using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
2778 
2779  /// std::is_invocable
2780  template<typename _Fn, typename... _ArgTypes>
2781  struct is_invocable
2782  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2783  { };
2784 
2785  /// std::is_invocable_r
2786  template<typename _Ret, typename _Fn, typename... _ArgTypes>
2787  struct is_invocable_r
2788  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>::type
2789  { };
2790 
2791  /// std::is_nothrow_invocable
2792  template<typename _Fn, typename... _ArgTypes>
2793  struct is_nothrow_invocable
2794  : __and_<__is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>,
2795  __call_is_nothrow_<_Fn, _ArgTypes...>>::type
2796  { };
2797 
2798  template<typename _Result, typename _Ret, typename = void>
2799  struct __is_nt_invocable_impl : false_type { };
2800 
2801  template<typename _Result, typename _Ret>
2802  struct __is_nt_invocable_impl<_Result, _Ret,
2803  __void_t<typename _Result::type>>
2804  : __or_<is_void<_Ret>,
2805  __and_<is_convertible<typename _Result::type, _Ret>,
2806  is_nothrow_constructible<_Ret, typename _Result::type>>>
2807  { };
2808 
2809  /// std::is_nothrow_invocable_r
2810  template<typename _Ret, typename _Fn, typename... _ArgTypes>
2811  struct is_nothrow_invocable_r
2812  : __and_<__is_nt_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>,
2813  __call_is_nothrow_<_Fn, _ArgTypes...>>::type
2814  { };
2815 
2816  /// std::is_invocable_v
2817  template<typename _Fn, typename... _Args>
2818  inline constexpr bool is_invocable_v = is_invocable<_Fn, _Args...>::value;
2819 
2820  /// std::is_nothrow_invocable_v
2821  template<typename _Fn, typename... _Args>
2822  inline constexpr bool is_nothrow_invocable_v
2823  = is_nothrow_invocable<_Fn, _Args...>::value;
2824 
2825  /// std::is_invocable_r_v
2826  template<typename _Fn, typename... _Args>
2827  inline constexpr bool is_invocable_r_v
2828  = is_invocable_r<_Fn, _Args...>::value;
2829 
2830  /// std::is_nothrow_invocable_r_v
2831  template<typename _Fn, typename... _Args>
2832  inline constexpr bool is_nothrow_invocable_r_v
2833  = is_nothrow_invocable_r<_Fn, _Args...>::value;
2834 #endif // C++17
2835 
2836 #if __cplusplus >= 201703L
2837 # define __cpp_lib_type_trait_variable_templates 201510L
2838 template <typename _Tp>
2839  inline constexpr bool is_void_v = is_void<_Tp>::value;
2840 template <typename _Tp>
2841  inline constexpr bool is_null_pointer_v = is_null_pointer<_Tp>::value;
2842 template <typename _Tp>
2843  inline constexpr bool is_integral_v = is_integral<_Tp>::value;
2844 template <typename _Tp>
2845  inline constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
2846 template <typename _Tp>
2847  inline constexpr bool is_array_v = is_array<_Tp>::value;
2848 template <typename _Tp>
2849  inline constexpr bool is_pointer_v = is_pointer<_Tp>::value;
2850 template <typename _Tp>
2851  inline constexpr bool is_lvalue_reference_v =
2852  is_lvalue_reference<_Tp>::value;
2853 template <typename _Tp>
2854  inline constexpr bool is_rvalue_reference_v =
2855  is_rvalue_reference<_Tp>::value;
2856 template <typename _Tp>
2857  inline constexpr bool is_member_object_pointer_v =
2858  is_member_object_pointer<_Tp>::value;
2859 template <typename _Tp>
2860  inline constexpr bool is_member_function_pointer_v =
2861  is_member_function_pointer<_Tp>::value;
2862 template <typename _Tp>
2863  inline constexpr bool is_enum_v = is_enum<_Tp>::value;
2864 template <typename _Tp>
2865  inline constexpr bool is_union_v = is_union<_Tp>::value;
2866 template <typename _Tp>
2867  inline constexpr bool is_class_v = is_class<_Tp>::value;
2868 template <typename _Tp>
2869  inline constexpr bool is_function_v = is_function<_Tp>::value;
2870 template <typename _Tp>
2871  inline constexpr bool is_reference_v = is_reference<_Tp>::value;
2872 template <typename _Tp>
2873  inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
2874 template <typename _Tp>
2875  inline constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
2876 template <typename _Tp>
2877  inline constexpr bool is_object_v = is_object<_Tp>::value;
2878 template <typename _Tp>
2879  inline constexpr bool is_scalar_v = is_scalar<_Tp>::value;
2880 template <typename _Tp>
2881  inline constexpr bool is_compound_v = is_compound<_Tp>::value;
2882 template <typename _Tp>
2883  inline constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value;
2884 template <typename _Tp>
2885  inline constexpr bool is_const_v = is_const<_Tp>::value;
2886 template <typename _Tp>
2887  inline constexpr bool is_volatile_v = is_volatile<_Tp>::value;
2888 template <typename _Tp>
2889  inline constexpr bool is_trivial_v = is_trivial<_Tp>::value;
2890 template <typename _Tp>
2891  inline constexpr bool is_trivially_copyable_v =
2892  is_trivially_copyable<_Tp>::value;
2893 template <typename _Tp>
2894  inline constexpr bool is_standard_layout_v = is_standard_layout<_Tp>::value;
2895 template <typename _Tp>
2896  inline constexpr bool is_pod_v = is_pod<_Tp>::value;
2897 template <typename _Tp>
2898  inline constexpr bool is_literal_type_v = is_literal_type<_Tp>::value;
2899 template <typename _Tp>
2900  inline constexpr bool is_empty_v = is_empty<_Tp>::value;
2901 template <typename _Tp>
2902  inline constexpr bool is_polymorphic_v = is_polymorphic<_Tp>::value;
2903 template <typename _Tp>
2904  inline constexpr bool is_abstract_v = is_abstract<_Tp>::value;
2905 template <typename _Tp>
2906  inline constexpr bool is_final_v = is_final<_Tp>::value;
2907 template <typename _Tp>
2908  inline constexpr bool is_signed_v = is_signed<_Tp>::value;
2909 template <typename _Tp>
2910  inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
2911 template <typename _Tp, typename... _Args>
2912  inline constexpr bool is_constructible_v =
2913  is_constructible<_Tp, _Args...>::value;
2914 template <typename _Tp>
2915  inline constexpr bool is_default_constructible_v =
2916  is_default_constructible<_Tp>::value;
2917 template <typename _Tp>
2918  inline constexpr bool is_copy_constructible_v =
2919  is_copy_constructible<_Tp>::value;
2920 template <typename _Tp>
2921  inline constexpr bool is_move_constructible_v =
2922  is_move_constructible<_Tp>::value;
2923 template <typename _Tp, typename _Up>
2924  inline constexpr bool is_assignable_v = is_assignable<_Tp, _Up>::value;
2925 template <typename _Tp>
2926  inline constexpr bool is_copy_assignable_v = is_copy_assignable<_Tp>::value;
2927 template <typename _Tp>
2928  inline constexpr bool is_move_assignable_v = is_move_assignable<_Tp>::value;
2929 template <typename _Tp>
2930  inline constexpr bool is_destructible_v = is_destructible<_Tp>::value;
2931 template <typename _Tp, typename... _Args>
2932  inline constexpr bool is_trivially_constructible_v =
2933  is_trivially_constructible<_Tp, _Args...>::value;
2934 template <typename _Tp>
2935  inline constexpr bool is_trivially_default_constructible_v =
2936  is_trivially_default_constructible<_Tp>::value;
2937 template <typename _Tp>
2938  inline constexpr bool is_trivially_copy_constructible_v =
2939  is_trivially_copy_constructible<_Tp>::value;
2940 template <typename _Tp>
2941  inline constexpr bool is_trivially_move_constructible_v =
2942  is_trivially_move_constructible<_Tp>::value;
2943 template <typename _Tp, typename _Up>
2944  inline constexpr bool is_trivially_assignable_v =
2945  is_trivially_assignable<_Tp, _Up>::value;
2946 template <typename _Tp>
2947  inline constexpr bool is_trivially_copy_assignable_v =
2948  is_trivially_copy_assignable<_Tp>::value;
2949 template <typename _Tp>
2950  inline constexpr bool is_trivially_move_assignable_v =
2951  is_trivially_move_assignable<_Tp>::value;
2952 template <typename _Tp>
2953  inline constexpr bool is_trivially_destructible_v =
2954  is_trivially_destructible<_Tp>::value;
2955 template <typename _Tp, typename... _Args>
2956  inline constexpr bool is_nothrow_constructible_v =
2957  is_nothrow_constructible<_Tp, _Args...>::value;
2958 template <typename _Tp>
2959  inline constexpr bool is_nothrow_default_constructible_v =
2960  is_nothrow_default_constructible<_Tp>::value;
2961 template <typename _Tp>
2962  inline constexpr bool is_nothrow_copy_constructible_v =
2963  is_nothrow_copy_constructible<_Tp>::value;
2964 template <typename _Tp>
2965  inline constexpr bool is_nothrow_move_constructible_v =
2966  is_nothrow_move_constructible<_Tp>::value;
2967 template <typename _Tp, typename _Up>
2968  inline constexpr bool is_nothrow_assignable_v =
2969  is_nothrow_assignable<_Tp, _Up>::value;
2970 template <typename _Tp>
2971  inline constexpr bool is_nothrow_copy_assignable_v =
2972  is_nothrow_copy_assignable<_Tp>::value;
2973 template <typename _Tp>
2974  inline constexpr bool is_nothrow_move_assignable_v =
2975  is_nothrow_move_assignable<_Tp>::value;
2976 template <typename _Tp>
2977  inline constexpr bool is_nothrow_destructible_v =
2978  is_nothrow_destructible<_Tp>::value;
2979 template <typename _Tp>
2980  inline constexpr bool has_virtual_destructor_v =
2981  has_virtual_destructor<_Tp>::value;
2982 template <typename _Tp>
2983  inline constexpr size_t alignment_of_v = alignment_of<_Tp>::value;
2984 template <typename _Tp>
2985  inline constexpr size_t rank_v = rank<_Tp>::value;
2986 template <typename _Tp, unsigned _Idx = 0>
2987  inline constexpr size_t extent_v = extent<_Tp, _Idx>::value;
2988 template <typename _Tp, typename _Up>
2989  inline constexpr bool is_same_v = is_same<_Tp, _Up>::value;
2990 template <typename _Base, typename _Derived>
2991  inline constexpr bool is_base_of_v = is_base_of<_Base, _Derived>::value;
2992 template <typename _From, typename _To>
2993  inline constexpr bool is_convertible_v = is_convertible<_From, _To>::value;
2994 
2995 #ifdef _GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP
2996 # define __cpp_lib_has_unique_object_representations 201606
2997  /// has_unique_object_representations
2998  template<typename _Tp>
2999  struct has_unique_object_representations
3000  : bool_constant<__has_unique_object_representations(
3001  remove_cv_t<remove_all_extents_t<_Tp>>
3002  )>
3003  { };
3004 
3005  template<typename _Tp>
3006  inline constexpr bool has_unique_object_representations_v
3007  = has_unique_object_representations<_Tp>::value;
3008 #endif
3009 
3010 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE
3011 # define __cpp_lib_is_aggregate 201703
3012  /// is_aggregate
3013  template<typename _Tp>
3014  struct is_aggregate
3015  : bool_constant<__is_aggregate(remove_cv_t<_Tp>)> { };
3016 
3017  /// is_aggregate_v
3018  template<typename _Tp>
3019  inline constexpr bool is_aggregate_v = is_aggregate<_Tp>::value;
3020 #endif
3021 #endif // C++17
3022 
3023 #if __cplusplus > 201703L
3024 #define __cpp_lib_remove_cvref 201711L
3025 
3026  /// Remove references and cv-qualifiers.
3027  template<typename _Tp>
3028  struct remove_cvref
3029  {
3030  using type = __remove_cvref_t<_Tp>;
3031  };
3032 
3033  template<typename _Tp>
3034  using remove_cvref_t = __remove_cvref_t<_Tp>;
3035 
3036 #define __cpp_lib_type_identity 201806L
3037  /// Identity metafunction.
3038  template<typename _Tp>
3039  struct type_identity { using type = _Tp; };
3040 
3041  template<typename _Tp>
3042  using type_identity_t = typename type_identity<_Tp>::type;
3043 
3044 #define __cpp_lib_unwrap_ref 201811L
3045 
3046  /// Unwrap a reference_wrapper
3047  template<typename _Tp>
3048  struct unwrap_reference { using type = _Tp; };
3049 
3050  template<typename _Tp>
3051  struct unwrap_reference<reference_wrapper<_Tp>> { using type = _Tp&; };
3052 
3053  template<typename _Tp>
3054  using unwrap_reference_t = typename unwrap_reference<_Tp>::type;
3055 
3056  /// Decay type and if it's a reference_wrapper, unwrap it
3057  template<typename _Tp>
3058  struct unwrap_ref_decay { using type = unwrap_reference_t<decay_t<_Tp>>; };
3059 
3060  template<typename _Tp>
3061  using unwrap_ref_decay_t = typename unwrap_ref_decay<_Tp>::type;
3062 
3063 #define __cpp_lib_bounded_array_traits 201902L
3064 
3065  /// True for a type that is an array of known bound.
3066  template<typename _Tp>
3067  struct is_bounded_array
3068  : public __is_array_known_bounds<_Tp>
3069  { };
3070 
3071  /// True for a type that is an array of unknown bound.
3072  template<typename _Tp>
3073  struct is_unbounded_array
3074  : public __is_array_unknown_bounds<_Tp>
3075  { };
3076 
3077  template<typename _Tp>
3078  inline constexpr bool is_bounded_array_v
3079  = is_bounded_array<_Tp>::value;
3080 
3081  template<typename _Tp>
3082  inline constexpr bool is_unbounded_array_v
3083  = is_unbounded_array<_Tp>::value;
3084 
3085 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
3086 
3087 #define __cpp_lib_is_constant_evaluated 201811L
3088 
3089  constexpr inline bool
3090  is_constant_evaluated() noexcept
3091  { return __builtin_is_constant_evaluated(); }
3092 #endif
3093 
3094 #endif // C++2a
3095 
3096 _GLIBCXX_END_NAMESPACE_VERSION
3097 } // namespace std
3098 
3099 #endif // C++11
3100 
3101 #endif // _GLIBCXX_TYPE_TRAITS