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<typename _Tp>
930  struct __is_nt_default_constructible_atom
931  : public integral_constant<bool, noexcept(_Tp())>
932  { };
933 
934  template<typename _Tp, bool = is_array<_Tp>::value>
935  struct __is_nt_default_constructible_impl;
936 
937  template<typename _Tp>
938  struct __is_nt_default_constructible_impl<_Tp, true>
939  : public __and_<__is_array_known_bounds<_Tp>,
940  __is_nt_default_constructible_atom<typename
941  remove_all_extents<_Tp>::type>>
942  { };
943 
944  template<typename _Tp>
945  struct __is_nt_default_constructible_impl<_Tp, false>
946  : public __is_nt_default_constructible_atom<_Tp>
947  { };
948 
949  /// is_nothrow_default_constructible
950  template<typename _Tp>
951  struct is_nothrow_default_constructible
952  : public __and_<is_default_constructible<_Tp>,
953  __is_nt_default_constructible_impl<_Tp>>
954  { };
955 
956  template<typename _Tp, typename... _Args>
957  struct __is_nt_constructible_impl
958  : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))>
959  { };
960 
961  template<typename _Tp, typename _Arg>
962  struct __is_nt_constructible_impl<_Tp, _Arg>
963  : public integral_constant<bool,
964  noexcept(static_cast<_Tp>(declval<_Arg>()))>
965  { };
966 
967  template<typename _Tp>
968  struct __is_nt_constructible_impl<_Tp>
969  : public is_nothrow_default_constructible<_Tp>
970  { };
971 
972  /// is_nothrow_constructible
973  template<typename _Tp, typename... _Args>
974  struct is_nothrow_constructible
975  : public __and_<is_constructible<_Tp, _Args...>,
976  __is_nt_constructible_impl<_Tp, _Args...>>
977  { };
978 
979  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
980  struct __is_nothrow_copy_constructible_impl;
981 
982  template<typename _Tp>
983  struct __is_nothrow_copy_constructible_impl<_Tp, false>
984  : public false_type { };
985 
986  template<typename _Tp>
987  struct __is_nothrow_copy_constructible_impl<_Tp, true>
988  : public is_nothrow_constructible<_Tp, const _Tp&>
989  { };
990 
991  /// is_nothrow_copy_constructible
992  template<typename _Tp>
993  struct is_nothrow_copy_constructible
994  : public __is_nothrow_copy_constructible_impl<_Tp>
995  { };
996 
997  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
998  struct __is_nothrow_move_constructible_impl;
999 
1000  template<typename _Tp>
1001  struct __is_nothrow_move_constructible_impl<_Tp, false>
1002  : public false_type { };
1003 
1004  template<typename _Tp>
1005  struct __is_nothrow_move_constructible_impl<_Tp, true>
1006  : public is_nothrow_constructible<_Tp, _Tp&&>
1007  { };
1008 
1009  /// is_nothrow_move_constructible
1010  template<typename _Tp>
1011  struct is_nothrow_move_constructible
1012  : public __is_nothrow_move_constructible_impl<_Tp>
1013  { };
1014 
1015  /// is_assignable
1016  template<typename _Tp, typename _Up>
1017  struct is_assignable
1018  : public __bool_constant<__is_assignable(_Tp, _Up)>
1019  { };
1020 
1021  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1022  struct __is_copy_assignable_impl;
1023 
1024  template<typename _Tp>
1025  struct __is_copy_assignable_impl<_Tp, false>
1026  : public false_type { };
1027 
1028  template<typename _Tp>
1029  struct __is_copy_assignable_impl<_Tp, true>
1030  : public is_assignable<_Tp&, const _Tp&>
1031  { };
1032 
1033  /// is_copy_assignable
1034  template<typename _Tp>
1035  struct is_copy_assignable
1036  : public __is_copy_assignable_impl<_Tp>
1037  { };
1038 
1039  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1040  struct __is_move_assignable_impl;
1041 
1042  template<typename _Tp>
1043  struct __is_move_assignable_impl<_Tp, false>
1044  : public false_type { };
1045 
1046  template<typename _Tp>
1047  struct __is_move_assignable_impl<_Tp, true>
1048  : public is_assignable<_Tp&, _Tp&&>
1049  { };
1050 
1051  /// is_move_assignable
1052  template<typename _Tp>
1053  struct is_move_assignable
1054  : public __is_move_assignable_impl<_Tp>
1055  { };
1056 
1057  template<typename _Tp, typename _Up>
1058  struct __is_nt_assignable_impl
1059  : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Up>())>
1060  { };
1061 
1062  /// is_nothrow_assignable
1063  template<typename _Tp, typename _Up>
1064  struct is_nothrow_assignable
1065  : public __and_<is_assignable<_Tp, _Up>,
1066  __is_nt_assignable_impl<_Tp, _Up>>
1067  { };
1068 
1069  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1070  struct __is_nt_copy_assignable_impl;
1071 
1072  template<typename _Tp>
1073  struct __is_nt_copy_assignable_impl<_Tp, false>
1074  : public false_type { };
1075 
1076  template<typename _Tp>
1077  struct __is_nt_copy_assignable_impl<_Tp, true>
1078  : public is_nothrow_assignable<_Tp&, const _Tp&>
1079  { };
1080 
1081  /// is_nothrow_copy_assignable
1082  template<typename _Tp>
1083  struct is_nothrow_copy_assignable
1084  : public __is_nt_copy_assignable_impl<_Tp>
1085  { };
1086 
1087  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1088  struct __is_nt_move_assignable_impl;
1089 
1090  template<typename _Tp>
1091  struct __is_nt_move_assignable_impl<_Tp, false>
1092  : public false_type { };
1093 
1094  template<typename _Tp>
1095  struct __is_nt_move_assignable_impl<_Tp, true>
1096  : public is_nothrow_assignable<_Tp&, _Tp&&>
1097  { };
1098 
1099  /// is_nothrow_move_assignable
1100  template<typename _Tp>
1101  struct is_nothrow_move_assignable
1102  : public __is_nt_move_assignable_impl<_Tp>
1103  { };
1104 
1105  /// is_trivially_constructible
1106  template<typename _Tp, typename... _Args>
1107  struct is_trivially_constructible
1108  : public __bool_constant<__is_trivially_constructible(_Tp, _Args...)>
1109  { };
1110 
1111  /// is_trivially_default_constructible
1112  template<typename _Tp>
1113  struct is_trivially_default_constructible
1114  : public is_trivially_constructible<_Tp>::type
1115  { };
1116 
1117  struct __do_is_implicitly_default_constructible_impl
1118  {
1119  template <typename _Tp>
1120  static void __helper(const _Tp&);
1121 
1122  template <typename _Tp>
1123  static true_type __test(const _Tp&,
1124  decltype(__helper<const _Tp&>({}))* = 0);
1125 
1126  static false_type __test(...);
1127  };
1128 
1129  template<typename _Tp>
1130  struct __is_implicitly_default_constructible_impl
1131  : public __do_is_implicitly_default_constructible_impl
1132  {
1133  typedef decltype(__test(declval<_Tp>())) type;
1134  };
1135 
1136  template<typename _Tp>
1137  struct __is_implicitly_default_constructible_safe
1138  : public __is_implicitly_default_constructible_impl<_Tp>::type
1139  { };
1140 
1141  template <typename _Tp>
1142  struct __is_implicitly_default_constructible
1143  : public __and_<is_default_constructible<_Tp>,
1144  __is_implicitly_default_constructible_safe<_Tp>>
1145  { };
1146 
1147  /// is_trivially_copy_constructible
1148 
1149  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1150  struct __is_trivially_copy_constructible_impl;
1151 
1152  template<typename _Tp>
1153  struct __is_trivially_copy_constructible_impl<_Tp, false>
1154  : public false_type { };
1155 
1156  template<typename _Tp>
1157  struct __is_trivially_copy_constructible_impl<_Tp, true>
1158  : public __and_<is_copy_constructible<_Tp>,
1159  integral_constant<bool,
1160  __is_trivially_constructible(_Tp, const _Tp&)>>
1161  { };
1162 
1163  template<typename _Tp>
1164  struct is_trivially_copy_constructible
1165  : public __is_trivially_copy_constructible_impl<_Tp>
1166  { };
1167 
1168  /// is_trivially_move_constructible
1169 
1170  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1171  struct __is_trivially_move_constructible_impl;
1172 
1173  template<typename _Tp>
1174  struct __is_trivially_move_constructible_impl<_Tp, false>
1175  : public false_type { };
1176 
1177  template<typename _Tp>
1178  struct __is_trivially_move_constructible_impl<_Tp, true>
1179  : public __and_<is_move_constructible<_Tp>,
1180  integral_constant<bool,
1181  __is_trivially_constructible(_Tp, _Tp&&)>>
1182  { };
1183 
1184  template<typename _Tp>
1185  struct is_trivially_move_constructible
1186  : public __is_trivially_move_constructible_impl<_Tp>
1187  { };
1188 
1189  /// is_trivially_assignable
1190  template<typename _Tp, typename _Up>
1191  struct is_trivially_assignable
1192  : public __bool_constant<__is_trivially_assignable(_Tp, _Up)>
1193  { };
1194 
1195  /// is_trivially_copy_assignable
1196 
1197  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1198  struct __is_trivially_copy_assignable_impl;
1199 
1200  template<typename _Tp>
1201  struct __is_trivially_copy_assignable_impl<_Tp, false>
1202  : public false_type { };
1203 
1204  template<typename _Tp>
1205  struct __is_trivially_copy_assignable_impl<_Tp, true>
1206  : public __bool_constant<__is_trivially_assignable(_Tp&, const _Tp&)>
1207  { };
1208 
1209  template<typename _Tp>
1210  struct is_trivially_copy_assignable
1211  : public __is_trivially_copy_assignable_impl<_Tp>
1212  { };
1213 
1214  /// is_trivially_move_assignable
1215 
1216  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1217  struct __is_trivially_move_assignable_impl;
1218 
1219  template<typename _Tp>
1220  struct __is_trivially_move_assignable_impl<_Tp, false>
1221  : public false_type { };
1222 
1223  template<typename _Tp>
1224  struct __is_trivially_move_assignable_impl<_Tp, true>
1225  : public __bool_constant<__is_trivially_assignable(_Tp&, _Tp&&)>
1226  { };
1227 
1228  template<typename _Tp>
1229  struct is_trivially_move_assignable
1230  : public __is_trivially_move_assignable_impl<_Tp>
1231  { };
1232 
1233  /// is_trivially_destructible
1234  template<typename _Tp>
1235  struct is_trivially_destructible
1236  : public __and_<is_destructible<_Tp>,
1237  __bool_constant<__has_trivial_destructor(_Tp)>>
1238  { };
1239 
1240 
1241  /// has_virtual_destructor
1242  template<typename _Tp>
1243  struct has_virtual_destructor
1244  : public integral_constant<bool, __has_virtual_destructor(_Tp)>
1245  { };
1246 
1247 
1248  // type property queries.
1249 
1250  /// alignment_of
1251  template<typename _Tp>
1252  struct alignment_of
1253  : public integral_constant<std::size_t, alignof(_Tp)> { };
1254 
1255  /// rank
1256  template<typename>
1257  struct rank
1258  : public integral_constant<std::size_t, 0> { };
1259 
1260  template<typename _Tp, std::size_t _Size>
1261  struct rank<_Tp[_Size]>
1262  : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1263 
1264  template<typename _Tp>
1265  struct rank<_Tp[]>
1266  : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1267 
1268  /// extent
1269  template<typename, unsigned _Uint>
1270  struct extent
1271  : public integral_constant<std::size_t, 0> { };
1272 
1273  template<typename _Tp, unsigned _Uint, std::size_t _Size>
1274  struct extent<_Tp[_Size], _Uint>
1275  : public integral_constant<std::size_t,
1276  _Uint == 0 ? _Size : extent<_Tp,
1277  _Uint - 1>::value>
1278  { };
1279 
1280  template<typename _Tp, unsigned _Uint>
1281  struct extent<_Tp[], _Uint>
1282  : public integral_constant<std::size_t,
1283  _Uint == 0 ? 0 : extent<_Tp,
1284  _Uint - 1>::value>
1285  { };
1286 
1287 
1288  // Type relations.
1289 
1290  /// is_same
1291  template<typename, typename>
1292  struct is_same
1293  : public false_type { };
1294 
1295  template<typename _Tp>
1296  struct is_same<_Tp, _Tp>
1297  : public true_type { };
1298 
1299  /// is_base_of
1300  template<typename _Base, typename _Derived>
1301  struct is_base_of
1302  : public integral_constant<bool, __is_base_of(_Base, _Derived)>
1303  { };
1304 
1305  template<typename _From, typename _To,
1306  bool = __or_<is_void<_From>, is_function<_To>,
1307  is_array<_To>>::value>
1308  struct __is_convertible_helper
1309  {
1310  typedef typename is_void<_To>::type type;
1311  };
1312 
1313  template<typename _From, typename _To>
1314  class __is_convertible_helper<_From, _To, false>
1315  {
1316  template<typename _To1>
1317  static void __test_aux(_To1) noexcept;
1318 
1319  template<typename _From1, typename _To1,
1320  typename = decltype(__test_aux<_To1>(std::declval<_From1>()))>
1321  static true_type
1322  __test(int);
1323 
1324  template<typename, typename>
1325  static false_type
1326  __test(...);
1327 
1328  public:
1329  typedef decltype(__test<_From, _To>(0)) type;
1330  };
1331 
1332 
1333  /// is_convertible
1334  template<typename _From, typename _To>
1335  struct is_convertible
1336  : public __is_convertible_helper<_From, _To>::type
1337  { };
1338 
1339 #if __cplusplus > 201703L
1340  template<typename _From, typename _To,
1341  bool = __or_<is_void<_From>, is_function<_To>,
1342  is_array<_To>>::value>
1343  struct __is_nt_convertible_helper
1344  : is_void<_To>
1345  { };
1346 
1347  template<typename _From, typename _To>
1348  class __is_nt_convertible_helper<_From, _To, false>
1349  {
1350  template<typename _To1>
1351  static void __test_aux(_To1) noexcept;
1352 
1353  template<typename _From1, typename _To1>
1354  static bool_constant<noexcept(__test_aux<_To1>(std::declval<_From1>()))>
1355  __test(int);
1356 
1357  template<typename, typename>
1358  static false_type
1359  __test(...);
1360 
1361  public:
1362  using type = decltype(__test<_From, _To>(0));
1363  };
1364 
1365 #define __cpp_lib_is_nothrow_convertible 201806L
1366  /// is_nothrow_convertible
1367  template<typename _From, typename _To>
1368  struct is_nothrow_convertible
1369  : public __is_nt_convertible_helper<_From, _To>::type
1370  { };
1371 
1372  /// is_nothrow_convertible_v
1373  template<typename _From, typename _To>
1374  inline constexpr bool is_nothrow_convertible_v
1375  = is_nothrow_convertible<_From, _To>::value;
1376 #endif // C++2a
1377 
1378  // Const-volatile modifications.
1379 
1380  /// remove_const
1381  template<typename _Tp>
1382  struct remove_const
1383  { typedef _Tp type; };
1384 
1385  template<typename _Tp>
1386  struct remove_const<_Tp const>
1387  { typedef _Tp type; };
1388 
1389  /// remove_volatile
1390  template<typename _Tp>
1391  struct remove_volatile
1392  { typedef _Tp type; };
1393 
1394  template<typename _Tp>
1395  struct remove_volatile<_Tp volatile>
1396  { typedef _Tp type; };
1397 
1398  /// remove_cv
1399  template<typename _Tp>
1400  struct remove_cv
1401  {
1402  typedef typename
1403  remove_const<typename remove_volatile<_Tp>::type>::type type;
1404  };
1405 
1406  /// add_const
1407  template<typename _Tp>
1408  struct add_const
1409  { typedef _Tp const type; };
1410 
1411  /// add_volatile
1412  template<typename _Tp>
1413  struct add_volatile
1414  { typedef _Tp volatile type; };
1415 
1416  /// add_cv
1417  template<typename _Tp>
1418  struct add_cv
1419  {
1420  typedef typename
1421  add_const<typename add_volatile<_Tp>::type>::type type;
1422  };
1423 
1424 #if __cplusplus > 201103L
1425 
1426 #define __cpp_lib_transformation_trait_aliases 201304
1427 
1428  /// Alias template for remove_const
1429  template<typename _Tp>
1430  using remove_const_t = typename remove_const<_Tp>::type;
1431 
1432  /// Alias template for remove_volatile
1433  template<typename _Tp>
1434  using remove_volatile_t = typename remove_volatile<_Tp>::type;
1435 
1436  /// Alias template for remove_cv
1437  template<typename _Tp>
1438  using remove_cv_t = typename remove_cv<_Tp>::type;
1439 
1440  /// Alias template for add_const
1441  template<typename _Tp>
1442  using add_const_t = typename add_const<_Tp>::type;
1443 
1444  /// Alias template for add_volatile
1445  template<typename _Tp>
1446  using add_volatile_t = typename add_volatile<_Tp>::type;
1447 
1448  /// Alias template for add_cv
1449  template<typename _Tp>
1450  using add_cv_t = typename add_cv<_Tp>::type;
1451 #endif
1452 
1453  // Reference transformations.
1454 
1455  /// remove_reference
1456  template<typename _Tp>
1457  struct remove_reference
1458  { typedef _Tp type; };
1459 
1460  template<typename _Tp>
1461  struct remove_reference<_Tp&>
1462  { typedef _Tp type; };
1463 
1464  template<typename _Tp>
1465  struct remove_reference<_Tp&&>
1466  { typedef _Tp type; };
1467 
1468  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1469  struct __add_lvalue_reference_helper
1470  { typedef _Tp type; };
1471 
1472  template<typename _Tp>
1473  struct __add_lvalue_reference_helper<_Tp, true>
1474  { typedef _Tp& type; };
1475 
1476  /// add_lvalue_reference
1477  template<typename _Tp>
1478  struct add_lvalue_reference
1479  : public __add_lvalue_reference_helper<_Tp>
1480  { };
1481 
1482  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1483  struct __add_rvalue_reference_helper
1484  { typedef _Tp type; };
1485 
1486  template<typename _Tp>
1487  struct __add_rvalue_reference_helper<_Tp, true>
1488  { typedef _Tp&& type; };
1489 
1490  /// add_rvalue_reference
1491  template<typename _Tp>
1492  struct add_rvalue_reference
1493  : public __add_rvalue_reference_helper<_Tp>
1494  { };
1495 
1496 #if __cplusplus > 201103L
1497  /// Alias template for remove_reference
1498  template<typename _Tp>
1499  using remove_reference_t = typename remove_reference<_Tp>::type;
1500 
1501  /// Alias template for add_lvalue_reference
1502  template<typename _Tp>
1503  using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
1504 
1505  /// Alias template for add_rvalue_reference
1506  template<typename _Tp>
1507  using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
1508 #endif
1509 
1510  // Sign modifications.
1511 
1512  // Utility for constructing identically cv-qualified types.
1513  template<typename _Unqualified, bool _IsConst, bool _IsVol>
1514  struct __cv_selector;
1515 
1516  template<typename _Unqualified>
1517  struct __cv_selector<_Unqualified, false, false>
1518  { typedef _Unqualified __type; };
1519 
1520  template<typename _Unqualified>
1521  struct __cv_selector<_Unqualified, false, true>
1522  { typedef volatile _Unqualified __type; };
1523 
1524  template<typename _Unqualified>
1525  struct __cv_selector<_Unqualified, true, false>
1526  { typedef const _Unqualified __type; };
1527 
1528  template<typename _Unqualified>
1529  struct __cv_selector<_Unqualified, true, true>
1530  { typedef const volatile _Unqualified __type; };
1531 
1532  template<typename _Qualified, typename _Unqualified,
1533  bool _IsConst = is_const<_Qualified>::value,
1534  bool _IsVol = is_volatile<_Qualified>::value>
1535  class __match_cv_qualifiers
1536  {
1537  typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
1538 
1539  public:
1540  typedef typename __match::__type __type;
1541  };
1542 
1543  // Utility for finding the unsigned versions of signed integral types.
1544  template<typename _Tp>
1545  struct __make_unsigned
1546  { typedef _Tp __type; };
1547 
1548  template<>
1549  struct __make_unsigned<char>
1550  { typedef unsigned char __type; };
1551 
1552  template<>
1553  struct __make_unsigned<signed char>
1554  { typedef unsigned char __type; };
1555 
1556  template<>
1557  struct __make_unsigned<short>
1558  { typedef unsigned short __type; };
1559 
1560  template<>
1561  struct __make_unsigned<int>
1562  { typedef unsigned int __type; };
1563 
1564  template<>
1565  struct __make_unsigned<long>
1566  { typedef unsigned long __type; };
1567 
1568  template<>
1569  struct __make_unsigned<long long>
1570  { typedef unsigned long long __type; };
1571 
1572 #if defined(__GLIBCXX_TYPE_INT_N_0)
1573  template<>
1574  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_0>
1575  { typedef unsigned __GLIBCXX_TYPE_INT_N_0 __type; };
1576 #endif
1577 #if defined(__GLIBCXX_TYPE_INT_N_1)
1578  template<>
1579  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_1>
1580  { typedef unsigned __GLIBCXX_TYPE_INT_N_1 __type; };
1581 #endif
1582 #if defined(__GLIBCXX_TYPE_INT_N_2)
1583  template<>
1584  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_2>
1585  { typedef unsigned __GLIBCXX_TYPE_INT_N_2 __type; };
1586 #endif
1587 #if defined(__GLIBCXX_TYPE_INT_N_3)
1588  template<>
1589  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_3>
1590  { typedef unsigned __GLIBCXX_TYPE_INT_N_3 __type; };
1591 #endif
1592 
1593  // Select between integral and enum: not possible to be both.
1594  template<typename _Tp,
1595  bool _IsInt = is_integral<_Tp>::value,
1596  bool _IsEnum = is_enum<_Tp>::value>
1597  class __make_unsigned_selector;
1598 
1599  template<typename _Tp>
1600  class __make_unsigned_selector<_Tp, true, false>
1601  {
1602  using __unsigned_type
1603  = typename __make_unsigned<typename remove_cv<_Tp>::type>::__type;
1604 
1605  public:
1606  using __type
1607  = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1608  };
1609 
1610  class __make_unsigned_selector_base
1611  {
1612  protected:
1613  template<typename...> struct _List { };
1614 
1615  template<typename _Tp, typename... _Up>
1616  struct _List<_Tp, _Up...> : _List<_Up...>
1617  { static constexpr size_t __size = sizeof(_Tp); };
1618 
1619  template<size_t _Sz, typename _Tp, bool = (_Sz <= _Tp::__size)>
1620  struct __select;
1621 
1622  template<size_t _Sz, typename _Uint, typename... _UInts>
1623  struct __select<_Sz, _List<_Uint, _UInts...>, true>
1624  { using __type = _Uint; };
1625 
1626  template<size_t _Sz, typename _Uint, typename... _UInts>
1627  struct __select<_Sz, _List<_Uint, _UInts...>, false>
1628  : __select<_Sz, _List<_UInts...>>
1629  { };
1630  };
1631 
1632  // Choose unsigned integer type with the smallest rank and same size as _Tp
1633  template<typename _Tp>
1634  class __make_unsigned_selector<_Tp, false, true>
1635  : __make_unsigned_selector_base
1636  {
1637  // With -fshort-enums, an enum may be as small as a char.
1638  using _UInts = _List<unsigned char, unsigned short, unsigned int,
1639  unsigned long, unsigned long long>;
1640 
1641  using __unsigned_type = typename __select<sizeof(_Tp), _UInts>::__type;
1642 
1643  public:
1644  using __type
1645  = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1646  };
1647 
1648  // wchar_t, char8_t, char16_t and char32_t are integral types but are
1649  // neither signed integer types nor unsigned integer types, so must be
1650  // transformed to the unsigned integer type with the smallest rank.
1651  // Use the partial specialization for enumeration types to do that.
1652 #if defined(_GLIBCXX_USE_WCHAR_T)
1653  template<>
1654  struct __make_unsigned<wchar_t>
1655  {
1656  using __type
1657  = typename __make_unsigned_selector<wchar_t, false, true>::__type;
1658  };
1659 #endif
1660 
1661 #ifdef _GLIBCXX_USE_CHAR8_T
1662  template<>
1663  struct __make_unsigned<char8_t>
1664  {
1665  using __type
1666  = typename __make_unsigned_selector<char8_t, false, true>::__type;
1667  };
1668 #endif
1669 
1670  template<>
1671  struct __make_unsigned<char16_t>
1672  {
1673  using __type
1674  = typename __make_unsigned_selector<char16_t, false, true>::__type;
1675  };
1676 
1677  template<>
1678  struct __make_unsigned<char32_t>
1679  {
1680  using __type
1681  = typename __make_unsigned_selector<char32_t, false, true>::__type;
1682  };
1683 
1684  // Given an integral/enum type, return the corresponding unsigned
1685  // integer type.
1686  // Primary template.
1687  /// make_unsigned
1688  template<typename _Tp>
1689  struct make_unsigned
1690  { typedef typename __make_unsigned_selector<_Tp>::__type type; };
1691 
1692  // Integral, but don't define.
1693  template<>
1694  struct make_unsigned<bool>;
1695 
1696 
1697  // Utility for finding the signed versions of unsigned integral types.
1698  template<typename _Tp>
1699  struct __make_signed
1700  { typedef _Tp __type; };
1701 
1702  template<>
1703  struct __make_signed<char>
1704  { typedef signed char __type; };
1705 
1706  template<>
1707  struct __make_signed<unsigned char>
1708  { typedef signed char __type; };
1709 
1710  template<>
1711  struct __make_signed<unsigned short>
1712  { typedef signed short __type; };
1713 
1714  template<>
1715  struct __make_signed<unsigned int>
1716  { typedef signed int __type; };
1717 
1718  template<>
1719  struct __make_signed<unsigned long>
1720  { typedef signed long __type; };
1721 
1722  template<>
1723  struct __make_signed<unsigned long long>
1724  { typedef signed long long __type; };
1725 
1726 #if defined(__GLIBCXX_TYPE_INT_N_0)
1727  template<>
1728  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_0>
1729  { typedef __GLIBCXX_TYPE_INT_N_0 __type; };
1730 #endif
1731 #if defined(__GLIBCXX_TYPE_INT_N_1)
1732  template<>
1733  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_1>
1734  { typedef __GLIBCXX_TYPE_INT_N_1 __type; };
1735 #endif
1736 #if defined(__GLIBCXX_TYPE_INT_N_2)
1737  template<>
1738  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_2>
1739  { typedef __GLIBCXX_TYPE_INT_N_2 __type; };
1740 #endif
1741 #if defined(__GLIBCXX_TYPE_INT_N_3)
1742  template<>
1743  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_3>
1744  { typedef __GLIBCXX_TYPE_INT_N_3 __type; };
1745 #endif
1746 
1747  // Select between integral and enum: not possible to be both.
1748  template<typename _Tp,
1749  bool _IsInt = is_integral<_Tp>::value,
1750  bool _IsEnum = is_enum<_Tp>::value>
1751  class __make_signed_selector;
1752 
1753  template<typename _Tp>
1754  class __make_signed_selector<_Tp, true, false>
1755  {
1756  using __signed_type
1757  = typename __make_signed<typename remove_cv<_Tp>::type>::__type;
1758 
1759  public:
1760  using __type
1761  = typename __match_cv_qualifiers<_Tp, __signed_type>::__type;
1762  };
1763 
1764  // Choose signed integer type with the smallest rank and same size as _Tp
1765  template<typename _Tp>
1766  class __make_signed_selector<_Tp, false, true>
1767  {
1768  typedef typename __make_unsigned_selector<_Tp>::__type __unsigned_type;
1769 
1770  public:
1771  typedef typename __make_signed_selector<__unsigned_type>::__type __type;
1772  };
1773 
1774  // wchar_t, char16_t and char32_t are integral types but are neither
1775  // signed integer types nor unsigned integer types, so must be
1776  // transformed to the signed integer type with the smallest rank.
1777  // Use the partial specialization for enumeration types to do that.
1778 #if defined(_GLIBCXX_USE_WCHAR_T)
1779  template<>
1780  struct __make_signed<wchar_t>
1781  {
1782  using __type
1783  = typename __make_signed_selector<wchar_t, false, true>::__type;
1784  };
1785 #endif
1786 
1787 #if defined(_GLIBCXX_USE_CHAR8_T)
1788  template<>
1789  struct __make_signed<char8_t>
1790  {
1791  using __type
1792  = typename __make_signed_selector<char8_t, false, true>::__type;
1793  };
1794 #endif
1795 
1796  template<>
1797  struct __make_signed<char16_t>
1798  {
1799  using __type
1800  = typename __make_signed_selector<char16_t, false, true>::__type;
1801  };
1802 
1803  template<>
1804  struct __make_signed<char32_t>
1805  {
1806  using __type
1807  = typename __make_signed_selector<char32_t, false, true>::__type;
1808  };
1809 
1810  // Given an integral/enum type, return the corresponding signed
1811  // integer type.
1812  // Primary template.
1813  /// make_signed
1814  template<typename _Tp>
1815  struct make_signed
1816  { typedef typename __make_signed_selector<_Tp>::__type type; };
1817 
1818  // Integral, but don't define.
1819  template<>
1820  struct make_signed<bool>;
1821 
1822 #if __cplusplus > 201103L
1823  /// Alias template for make_signed
1824  template<typename _Tp>
1825  using make_signed_t = typename make_signed<_Tp>::type;
1826 
1827  /// Alias template for make_unsigned
1828  template<typename _Tp>
1829  using make_unsigned_t = typename make_unsigned<_Tp>::type;
1830 #endif
1831 
1832  // Array modifications.
1833 
1834  /// remove_extent
1835  template<typename _Tp>
1836  struct remove_extent
1837  { typedef _Tp type; };
1838 
1839  template<typename _Tp, std::size_t _Size>
1840  struct remove_extent<_Tp[_Size]>
1841  { typedef _Tp type; };
1842 
1843  template<typename _Tp>
1844  struct remove_extent<_Tp[]>
1845  { typedef _Tp type; };
1846 
1847  /// remove_all_extents
1848  template<typename _Tp>
1849  struct remove_all_extents
1850  { typedef _Tp type; };
1851 
1852  template<typename _Tp, std::size_t _Size>
1853  struct remove_all_extents<_Tp[_Size]>
1854  { typedef typename remove_all_extents<_Tp>::type type; };
1855 
1856  template<typename _Tp>
1857  struct remove_all_extents<_Tp[]>
1858  { typedef typename remove_all_extents<_Tp>::type type; };
1859 
1860 #if __cplusplus > 201103L
1861  /// Alias template for remove_extent
1862  template<typename _Tp>
1863  using remove_extent_t = typename remove_extent<_Tp>::type;
1864 
1865  /// Alias template for remove_all_extents
1866  template<typename _Tp>
1867  using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
1868 #endif
1869 
1870  // Pointer modifications.
1871 
1872  template<typename _Tp, typename>
1873  struct __remove_pointer_helper
1874  { typedef _Tp type; };
1875 
1876  template<typename _Tp, typename _Up>
1877  struct __remove_pointer_helper<_Tp, _Up*>
1878  { typedef _Up type; };
1879 
1880  /// remove_pointer
1881  template<typename _Tp>
1882  struct remove_pointer
1883  : public __remove_pointer_helper<_Tp, typename remove_cv<_Tp>::type>
1884  { };
1885 
1886  /// add_pointer
1887  template<typename _Tp, bool = __or_<__is_referenceable<_Tp>,
1888  is_void<_Tp>>::value>
1889  struct __add_pointer_helper
1890  { typedef _Tp type; };
1891 
1892  template<typename _Tp>
1893  struct __add_pointer_helper<_Tp, true>
1894  { typedef typename remove_reference<_Tp>::type* type; };
1895 
1896  template<typename _Tp>
1897  struct add_pointer
1898  : public __add_pointer_helper<_Tp>
1899  { };
1900 
1901 #if __cplusplus > 201103L
1902  /// Alias template for remove_pointer
1903  template<typename _Tp>
1904  using remove_pointer_t = typename remove_pointer<_Tp>::type;
1905 
1906  /// Alias template for add_pointer
1907  template<typename _Tp>
1908  using add_pointer_t = typename add_pointer<_Tp>::type;
1909 #endif
1910 
1911  template<std::size_t _Len>
1912  struct __aligned_storage_msa
1913  {
1914  union __type
1915  {
1916  unsigned char __data[_Len];
1917  struct __attribute__((__aligned__)) { } __align;
1918  };
1919  };
1920 
1921  /**
1922  * @brief Alignment type.
1923  *
1924  * The value of _Align is a default-alignment which shall be the
1925  * most stringent alignment requirement for any C++ object type
1926  * whose size is no greater than _Len (3.9). The member typedef
1927  * type shall be a POD type suitable for use as uninitialized
1928  * storage for any object whose size is at most _Len and whose
1929  * alignment is a divisor of _Align.
1930  */
1931  template<std::size_t _Len, std::size_t _Align =
1932  __alignof__(typename __aligned_storage_msa<_Len>::__type)>
1933  struct aligned_storage
1934  {
1935  union type
1936  {
1937  unsigned char __data[_Len];
1938  struct __attribute__((__aligned__((_Align)))) { } __align;
1939  };
1940  };
1941 
1942  template <typename... _Types>
1943  struct __strictest_alignment
1944  {
1945  static const size_t _S_alignment = 0;
1946  static const size_t _S_size = 0;
1947  };
1948 
1949  template <typename _Tp, typename... _Types>
1950  struct __strictest_alignment<_Tp, _Types...>
1951  {
1952  static const size_t _S_alignment =
1953  alignof(_Tp) > __strictest_alignment<_Types...>::_S_alignment
1954  ? alignof(_Tp) : __strictest_alignment<_Types...>::_S_alignment;
1955  static const size_t _S_size =
1956  sizeof(_Tp) > __strictest_alignment<_Types...>::_S_size
1957  ? sizeof(_Tp) : __strictest_alignment<_Types...>::_S_size;
1958  };
1959 
1960  /**
1961  * @brief Provide aligned storage for types.
1962  *
1963  * [meta.trans.other]
1964  *
1965  * Provides aligned storage for any of the provided types of at
1966  * least size _Len.
1967  *
1968  * @see aligned_storage
1969  */
1970  template <size_t _Len, typename... _Types>
1971  struct aligned_union
1972  {
1973  private:
1974  static_assert(sizeof...(_Types) != 0, "At least one type is required");
1975 
1976  using __strictest = __strictest_alignment<_Types...>;
1977  static const size_t _S_len = _Len > __strictest::_S_size
1978  ? _Len : __strictest::_S_size;
1979  public:
1980  /// The value of the strictest alignment of _Types.
1981  static const size_t alignment_value = __strictest::_S_alignment;
1982  /// The storage.
1983  typedef typename aligned_storage<_S_len, alignment_value>::type type;
1984  };
1985 
1986  template <size_t _Len, typename... _Types>
1987  const size_t aligned_union<_Len, _Types...>::alignment_value;
1988 
1989  // Decay trait for arrays and functions, used for perfect forwarding
1990  // in make_pair, make_tuple, etc.
1991  template<typename _Up,
1992  bool _IsArray = is_array<_Up>::value,
1993  bool _IsFunction = is_function<_Up>::value>
1994  struct __decay_selector;
1995 
1996  // NB: DR 705.
1997  template<typename _Up>
1998  struct __decay_selector<_Up, false, false>
1999  { typedef typename remove_cv<_Up>::type __type; };
2000 
2001  template<typename _Up>
2002  struct __decay_selector<_Up, true, false>
2003  { typedef typename remove_extent<_Up>::type* __type; };
2004 
2005  template<typename _Up>
2006  struct __decay_selector<_Up, false, true>
2007  { typedef typename add_pointer<_Up>::type __type; };
2008 
2009  /// decay
2010  template<typename _Tp>
2011  class decay
2012  {
2013  typedef typename remove_reference<_Tp>::type __remove_type;
2014 
2015  public:
2016  typedef typename __decay_selector<__remove_type>::__type type;
2017  };
2018 
2019  template<typename _Tp>
2020  class reference_wrapper;
2021 
2022  // Helper which adds a reference to a type when given a reference_wrapper
2023  template<typename _Tp>
2024  struct __strip_reference_wrapper
2025  {
2026  typedef _Tp __type;
2027  };
2028 
2029  template<typename _Tp>
2030  struct __strip_reference_wrapper<reference_wrapper<_Tp> >
2031  {
2032  typedef _Tp& __type;
2033  };
2034 
2035  template<typename _Tp>
2036  struct __decay_and_strip
2037  {
2038  typedef typename __strip_reference_wrapper<
2039  typename decay<_Tp>::type>::__type __type;
2040  };
2041 
2042 
2043  // Primary template.
2044  /// Define a member typedef @c type only if a boolean constant is true.
2045  template<bool, typename _Tp = void>
2046  struct enable_if
2047  { };
2048 
2049  // Partial specialization for true.
2050  template<typename _Tp>
2051  struct enable_if<true, _Tp>
2052  { typedef _Tp type; };
2053 
2054  template<typename... _Cond>
2055  using _Require = typename enable_if<__and_<_Cond...>::value>::type;
2056 
2057  // Primary template.
2058  /// Define a member typedef @c type to one of two argument types.
2059  template<bool _Cond, typename _Iftrue, typename _Iffalse>
2060  struct conditional
2061  { typedef _Iftrue type; };
2062 
2063  // Partial specialization for false.
2064  template<typename _Iftrue, typename _Iffalse>
2065  struct conditional<false, _Iftrue, _Iffalse>
2066  { typedef _Iffalse type; };
2067 
2068  /// common_type
2069  template<typename... _Tp>
2070  struct common_type;
2071 
2072  // Sfinae-friendly common_type implementation:
2073 
2074  struct __do_common_type_impl
2075  {
2076  template<typename _Tp, typename _Up>
2077  static __success_type<typename decay<decltype
2078  (true ? std::declval<_Tp>()
2079  : std::declval<_Up>())>::type> _S_test(int);
2080 
2081  template<typename, typename>
2082  static __failure_type _S_test(...);
2083  };
2084 
2085  template<typename _Tp, typename _Up>
2086  struct __common_type_impl
2087  : private __do_common_type_impl
2088  {
2089  typedef decltype(_S_test<_Tp, _Up>(0)) type;
2090  };
2091 
2092  struct __do_member_type_wrapper
2093  {
2094  template<typename _Tp>
2095  static __success_type<typename _Tp::type> _S_test(int);
2096 
2097  template<typename>
2098  static __failure_type _S_test(...);
2099  };
2100 
2101  template<typename _Tp>
2102  struct __member_type_wrapper
2103  : private __do_member_type_wrapper
2104  {
2105  typedef decltype(_S_test<_Tp>(0)) type;
2106  };
2107 
2108  template<typename _CTp, typename... _Args>
2109  struct __expanded_common_type_wrapper
2110  {
2111  typedef common_type<typename _CTp::type, _Args...> type;
2112  };
2113 
2114  template<typename... _Args>
2115  struct __expanded_common_type_wrapper<__failure_type, _Args...>
2116  { typedef __failure_type type; };
2117 
2118  template<>
2119  struct common_type<>
2120  { };
2121 
2122  template<typename _Tp>
2123  struct common_type<_Tp>
2124  : common_type<_Tp, _Tp>
2125  { };
2126 
2127  template<typename _Tp, typename _Up>
2128  struct common_type<_Tp, _Up>
2129  : public __common_type_impl<_Tp, _Up>::type
2130  { };
2131 
2132  template<typename _Tp, typename _Up, typename... _Vp>
2133  struct common_type<_Tp, _Up, _Vp...>
2134  : public __expanded_common_type_wrapper<typename __member_type_wrapper<
2135  common_type<_Tp, _Up>>::type, _Vp...>::type
2136  { };
2137 
2138  template<typename _Tp, bool = is_enum<_Tp>::value>
2139  struct __underlying_type_impl
2140  {
2141  using type = __underlying_type(_Tp);
2142  };
2143 
2144  template<typename _Tp>
2145  struct __underlying_type_impl<_Tp, false>
2146  { };
2147 
2148  /// The underlying type of an enum.
2149  template<typename _Tp>
2150  struct underlying_type
2151  : public __underlying_type_impl<_Tp>
2152  { };
2153 
2154  template<typename _Tp>
2155  struct __declval_protector
2156  {
2157  static const bool __stop = false;
2158  };
2159 
2160  template<typename _Tp>
2161  auto declval() noexcept -> decltype(__declval<_Tp>(0))
2162  {
2163  static_assert(__declval_protector<_Tp>::__stop,
2164  "declval() must not be used!");
2165  return __declval<_Tp>(0);
2166  }
2167 
2168  // __remove_cvref_t (std::remove_cvref_t for C++11).
2169  template<typename _Tp>
2170  using __remove_cvref_t
2171  = typename remove_cv<typename remove_reference<_Tp>::type>::type;
2172 
2173  /// result_of
2174  template<typename _Signature>
2175  class result_of;
2176 
2177  // Sfinae-friendly result_of implementation:
2178 
2179 #define __cpp_lib_result_of_sfinae 201210
2180 
2181  struct __invoke_memfun_ref { };
2182  struct __invoke_memfun_deref { };
2183  struct __invoke_memobj_ref { };
2184  struct __invoke_memobj_deref { };
2185  struct __invoke_other { };
2186 
2187  // Associate a tag type with a specialization of __success_type.
2188  template<typename _Tp, typename _Tag>
2189  struct __result_of_success : __success_type<_Tp>
2190  { using __invoke_type = _Tag; };
2191 
2192  // [func.require] paragraph 1 bullet 1:
2193  struct __result_of_memfun_ref_impl
2194  {
2195  template<typename _Fp, typename _Tp1, typename... _Args>
2196  static __result_of_success<decltype(
2197  (std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...)
2198  ), __invoke_memfun_ref> _S_test(int);
2199 
2200  template<typename...>
2201  static __failure_type _S_test(...);
2202  };
2203 
2204  template<typename _MemPtr, typename _Arg, typename... _Args>
2205  struct __result_of_memfun_ref
2206  : private __result_of_memfun_ref_impl
2207  {
2208  typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2209  };
2210 
2211  // [func.require] paragraph 1 bullet 2:
2212  struct __result_of_memfun_deref_impl
2213  {
2214  template<typename _Fp, typename _Tp1, typename... _Args>
2215  static __result_of_success<decltype(
2216  ((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...)
2217  ), __invoke_memfun_deref> _S_test(int);
2218 
2219  template<typename...>
2220  static __failure_type _S_test(...);
2221  };
2222 
2223  template<typename _MemPtr, typename _Arg, typename... _Args>
2224  struct __result_of_memfun_deref
2225  : private __result_of_memfun_deref_impl
2226  {
2227  typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2228  };
2229 
2230  // [func.require] paragraph 1 bullet 3:
2231  struct __result_of_memobj_ref_impl
2232  {
2233  template<typename _Fp, typename _Tp1>
2234  static __result_of_success<decltype(
2235  std::declval<_Tp1>().*std::declval<_Fp>()
2236  ), __invoke_memobj_ref> _S_test(int);
2237 
2238  template<typename, typename>
2239  static __failure_type _S_test(...);
2240  };
2241 
2242  template<typename _MemPtr, typename _Arg>
2243  struct __result_of_memobj_ref
2244  : private __result_of_memobj_ref_impl
2245  {
2246  typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2247  };
2248 
2249  // [func.require] paragraph 1 bullet 4:
2250  struct __result_of_memobj_deref_impl
2251  {
2252  template<typename _Fp, typename _Tp1>
2253  static __result_of_success<decltype(
2254  (*std::declval<_Tp1>()).*std::declval<_Fp>()
2255  ), __invoke_memobj_deref> _S_test(int);
2256 
2257  template<typename, typename>
2258  static __failure_type _S_test(...);
2259  };
2260 
2261  template<typename _MemPtr, typename _Arg>
2262  struct __result_of_memobj_deref
2263  : private __result_of_memobj_deref_impl
2264  {
2265  typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2266  };
2267 
2268  template<typename _MemPtr, typename _Arg>
2269  struct __result_of_memobj;
2270 
2271  template<typename _Res, typename _Class, typename _Arg>
2272  struct __result_of_memobj<_Res _Class::*, _Arg>
2273  {
2274  typedef __remove_cvref_t<_Arg> _Argval;
2275  typedef _Res _Class::* _MemPtr;
2276  typedef typename conditional<__or_<is_same<_Argval, _Class>,
2277  is_base_of<_Class, _Argval>>::value,
2278  __result_of_memobj_ref<_MemPtr, _Arg>,
2279  __result_of_memobj_deref<_MemPtr, _Arg>
2280  >::type::type type;
2281  };
2282 
2283  template<typename _MemPtr, typename _Arg, typename... _Args>
2284  struct __result_of_memfun;
2285 
2286  template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2287  struct __result_of_memfun<_Res _Class::*, _Arg, _Args...>
2288  {
2289  typedef typename remove_reference<_Arg>::type _Argval;
2290  typedef _Res _Class::* _MemPtr;
2291  typedef typename conditional<is_base_of<_Class, _Argval>::value,
2292  __result_of_memfun_ref<_MemPtr, _Arg, _Args...>,
2293  __result_of_memfun_deref<_MemPtr, _Arg, _Args...>
2294  >::type::type type;
2295  };
2296 
2297  // _GLIBCXX_RESOLVE_LIB_DEFECTS
2298  // 2219. INVOKE-ing a pointer to member with a reference_wrapper
2299  // as the object expression
2300 
2301  // Used by result_of, invoke etc. to unwrap a reference_wrapper.
2302  template<typename _Tp, typename _Up = __remove_cvref_t<_Tp>>
2303  struct __inv_unwrap
2304  {
2305  using type = _Tp;
2306  };
2307 
2308  template<typename _Tp, typename _Up>
2309  struct __inv_unwrap<_Tp, reference_wrapper<_Up>>
2310  {
2311  using type = _Up&;
2312  };
2313 
2314  template<bool, bool, typename _Functor, typename... _ArgTypes>
2315  struct __result_of_impl
2316  {
2317  typedef __failure_type type;
2318  };
2319 
2320  template<typename _MemPtr, typename _Arg>
2321  struct __result_of_impl<true, false, _MemPtr, _Arg>
2322  : public __result_of_memobj<typename decay<_MemPtr>::type,
2323  typename __inv_unwrap<_Arg>::type>
2324  { };
2325 
2326  template<typename _MemPtr, typename _Arg, typename... _Args>
2327  struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...>
2328  : public __result_of_memfun<typename decay<_MemPtr>::type,
2329  typename __inv_unwrap<_Arg>::type, _Args...>
2330  { };
2331 
2332  // [func.require] paragraph 1 bullet 5:
2333  struct __result_of_other_impl
2334  {
2335  template<typename _Fn, typename... _Args>
2336  static __result_of_success<decltype(
2337  std::declval<_Fn>()(std::declval<_Args>()...)
2338  ), __invoke_other> _S_test(int);
2339 
2340  template<typename...>
2341  static __failure_type _S_test(...);
2342  };
2343 
2344  template<typename _Functor, typename... _ArgTypes>
2345  struct __result_of_impl<false, false, _Functor, _ArgTypes...>
2346  : private __result_of_other_impl
2347  {
2348  typedef decltype(_S_test<_Functor, _ArgTypes...>(0)) type;
2349  };
2350 
2351  // __invoke_result (std::invoke_result for C++11)
2352  template<typename _Functor, typename... _ArgTypes>
2353  struct __invoke_result
2354  : public __result_of_impl<
2355  is_member_object_pointer<
2356  typename remove_reference<_Functor>::type
2357  >::value,
2358  is_member_function_pointer<
2359  typename remove_reference<_Functor>::type
2360  >::value,
2361  _Functor, _ArgTypes...
2362  >::type
2363  { };
2364 
2365  template<typename _Functor, typename... _ArgTypes>
2366  struct result_of<_Functor(_ArgTypes...)>
2367  : public __invoke_result<_Functor, _ArgTypes...>
2368  { };
2369 
2370 #if __cplusplus >= 201402L
2371  /// Alias template for aligned_storage
2372  template<size_t _Len, size_t _Align =
2373  __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2374  using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
2375 
2376  template <size_t _Len, typename... _Types>
2377  using aligned_union_t = typename aligned_union<_Len, _Types...>::type;
2378 
2379  /// Alias template for decay
2380  template<typename _Tp>
2381  using decay_t = typename decay<_Tp>::type;
2382 
2383  /// Alias template for enable_if
2384  template<bool _Cond, typename _Tp = void>
2385  using enable_if_t = typename enable_if<_Cond, _Tp>::type;
2386 
2387  /// Alias template for conditional
2388  template<bool _Cond, typename _Iftrue, typename _Iffalse>
2389  using conditional_t = typename conditional<_Cond, _Iftrue, _Iffalse>::type;
2390 
2391  /// Alias template for common_type
2392  template<typename... _Tp>
2393  using common_type_t = typename common_type<_Tp...>::type;
2394 
2395  /// Alias template for underlying_type
2396  template<typename _Tp>
2397  using underlying_type_t = typename underlying_type<_Tp>::type;
2398 
2399  /// Alias template for result_of
2400  template<typename _Tp>
2401  using result_of_t = typename result_of<_Tp>::type;
2402 #endif // C++14
2403 
2404  // __enable_if_t (std::enable_if_t for C++11)
2405  template<bool _Cond, typename _Tp = void>
2406  using __enable_if_t = typename enable_if<_Cond, _Tp>::type;
2407 
2408  // __void_t (std::void_t for C++11)
2409  template<typename...> using __void_t = void;
2410 
2411 #if __cplusplus >= 201703L || !defined(__STRICT_ANSI__) // c++17 or gnu++11
2412 #define __cpp_lib_void_t 201411
2413  /// A metafunction that always yields void, used for detecting valid types.
2414  template<typename...> using void_t = void;
2415 #endif
2416 
2417  /// Implementation of the detection idiom (negative case).
2418  template<typename _Default, typename _AlwaysVoid,
2419  template<typename...> class _Op, typename... _Args>
2420  struct __detector
2421  {
2422  using value_t = false_type;
2423  using type = _Default;
2424  };
2425 
2426  /// Implementation of the detection idiom (positive case).
2427  template<typename _Default, template<typename...> class _Op,
2428  typename... _Args>
2429  struct __detector<_Default, __void_t<_Op<_Args...>>, _Op, _Args...>
2430  {
2431  using value_t = true_type;
2432  using type = _Op<_Args...>;
2433  };
2434 
2435  // Detect whether _Op<_Args...> is a valid type, use _Default if not.
2436  template<typename _Default, template<typename...> class _Op,
2437  typename... _Args>
2438  using __detected_or = __detector<_Default, void, _Op, _Args...>;
2439 
2440  // _Op<_Args...> if that is a valid type, otherwise _Default.
2441  template<typename _Default, template<typename...> class _Op,
2442  typename... _Args>
2443  using __detected_or_t
2444  = typename __detected_or<_Default, _Op, _Args...>::type;
2445 
2446  /// @} group metaprogramming
2447 
2448  /**
2449  * Use SFINAE to determine if the type _Tp has a publicly-accessible
2450  * member type _NTYPE.
2451  */
2452 #define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \
2453  template<typename _Tp, typename = __void_t<>> \
2454  struct __has_##_NTYPE \
2455  : false_type \
2456  { }; \
2457  template<typename _Tp> \
2458  struct __has_##_NTYPE<_Tp, __void_t<typename _Tp::_NTYPE>> \
2459  : true_type \
2460  { };
2461 
2462  template <typename _Tp>
2463  struct __is_swappable;
2464 
2465  template <typename _Tp>
2466  struct __is_nothrow_swappable;
2467 
2468  template<typename... _Elements>
2469  class tuple;
2470 
2471  template<typename>
2472  struct __is_tuple_like_impl : false_type
2473  { };
2474 
2475  template<typename... _Tps>
2476  struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
2477  { };
2478 
2479  // Internal type trait that allows us to sfinae-protect tuple_cat.
2480  template<typename _Tp>
2481  struct __is_tuple_like
2482  : public __is_tuple_like_impl<__remove_cvref_t<_Tp>>::type
2483  { };
2484 
2485  template<typename _Tp>
2486  inline
2487  typename enable_if<__and_<__not_<__is_tuple_like<_Tp>>,
2488  is_move_constructible<_Tp>,
2489  is_move_assignable<_Tp>>::value>::type
2490  swap(_Tp&, _Tp&)
2491  noexcept(__and_<is_nothrow_move_constructible<_Tp>,
2492  is_nothrow_move_assignable<_Tp>>::value);
2493 
2494  template<typename _Tp, size_t _Nm>
2495  inline
2496  typename enable_if<__is_swappable<_Tp>::value>::type
2497  swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
2498  noexcept(__is_nothrow_swappable<_Tp>::value);
2499 
2500  namespace __swappable_details {
2501  using std::swap;
2502 
2503  struct __do_is_swappable_impl
2504  {
2505  template<typename _Tp, typename
2506  = decltype(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))>
2507  static true_type __test(int);
2508 
2509  template<typename>
2510  static false_type __test(...);
2511  };
2512 
2513  struct __do_is_nothrow_swappable_impl
2514  {
2515  template<typename _Tp>
2516  static __bool_constant<
2517  noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))
2518  > __test(int);
2519 
2520  template<typename>
2521  static false_type __test(...);
2522  };
2523 
2524  } // namespace __swappable_details
2525 
2526  template<typename _Tp>
2527  struct __is_swappable_impl
2528  : public __swappable_details::__do_is_swappable_impl
2529  {
2530  typedef decltype(__test<_Tp>(0)) type;
2531  };
2532 
2533  template<typename _Tp>
2534  struct __is_nothrow_swappable_impl
2535  : public __swappable_details::__do_is_nothrow_swappable_impl
2536  {
2537  typedef decltype(__test<_Tp>(0)) type;
2538  };
2539 
2540  template<typename _Tp>
2541  struct __is_swappable
2542  : public __is_swappable_impl<_Tp>::type
2543  { };
2544 
2545  template<typename _Tp>
2546  struct __is_nothrow_swappable
2547  : public __is_nothrow_swappable_impl<_Tp>::type
2548  { };
2549 
2550 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
2551 #define __cpp_lib_is_swappable 201603
2552  /// Metafunctions used for detecting swappable types: p0185r1
2553 
2554  /// is_swappable
2555  template<typename _Tp>
2556  struct is_swappable
2557  : public __is_swappable_impl<_Tp>::type
2558  { };
2559 
2560  /// is_nothrow_swappable
2561  template<typename _Tp>
2562  struct is_nothrow_swappable
2563  : public __is_nothrow_swappable_impl<_Tp>::type
2564  { };
2565 
2566 #if __cplusplus >= 201402L
2567  /// is_swappable_v
2568  template<typename _Tp>
2569  _GLIBCXX17_INLINE constexpr bool is_swappable_v =
2570  is_swappable<_Tp>::value;
2571 
2572  /// is_nothrow_swappable_v
2573  template<typename _Tp>
2574  _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_v =
2575  is_nothrow_swappable<_Tp>::value;
2576 #endif // __cplusplus >= 201402L
2577 
2578  namespace __swappable_with_details {
2579  using std::swap;
2580 
2581  struct __do_is_swappable_with_impl
2582  {
2583  template<typename _Tp, typename _Up, typename
2584  = decltype(swap(std::declval<_Tp>(), std::declval<_Up>())),
2585  typename
2586  = decltype(swap(std::declval<_Up>(), std::declval<_Tp>()))>
2587  static true_type __test(int);
2588 
2589  template<typename, typename>
2590  static false_type __test(...);
2591  };
2592 
2593  struct __do_is_nothrow_swappable_with_impl
2594  {
2595  template<typename _Tp, typename _Up>
2596  static __bool_constant<
2597  noexcept(swap(std::declval<_Tp>(), std::declval<_Up>()))
2598  &&
2599  noexcept(swap(std::declval<_Up>(), std::declval<_Tp>()))
2600  > __test(int);
2601 
2602  template<typename, typename>
2603  static false_type __test(...);
2604  };
2605 
2606  } // namespace __swappable_with_details
2607 
2608  template<typename _Tp, typename _Up>
2609  struct __is_swappable_with_impl
2610  : public __swappable_with_details::__do_is_swappable_with_impl
2611  {
2612  typedef decltype(__test<_Tp, _Up>(0)) type;
2613  };
2614 
2615  // Optimization for the homogenous lvalue case, not required:
2616  template<typename _Tp>
2617  struct __is_swappable_with_impl<_Tp&, _Tp&>
2618  : public __swappable_details::__do_is_swappable_impl
2619  {
2620  typedef decltype(__test<_Tp&>(0)) type;
2621  };
2622 
2623  template<typename _Tp, typename _Up>
2624  struct __is_nothrow_swappable_with_impl
2625  : public __swappable_with_details::__do_is_nothrow_swappable_with_impl
2626  {
2627  typedef decltype(__test<_Tp, _Up>(0)) type;
2628  };
2629 
2630  // Optimization for the homogenous lvalue case, not required:
2631  template<typename _Tp>
2632  struct __is_nothrow_swappable_with_impl<_Tp&, _Tp&>
2633  : public __swappable_details::__do_is_nothrow_swappable_impl
2634  {
2635  typedef decltype(__test<_Tp&>(0)) type;
2636  };
2637 
2638  /// is_swappable_with
2639  template<typename _Tp, typename _Up>
2640  struct is_swappable_with
2641  : public __is_swappable_with_impl<_Tp, _Up>::type
2642  { };
2643 
2644  /// is_nothrow_swappable_with
2645  template<typename _Tp, typename _Up>
2646  struct is_nothrow_swappable_with
2647  : public __is_nothrow_swappable_with_impl<_Tp, _Up>::type
2648  { };
2649 
2650 #if __cplusplus >= 201402L
2651  /// is_swappable_with_v
2652  template<typename _Tp, typename _Up>
2653  _GLIBCXX17_INLINE constexpr bool is_swappable_with_v =
2654  is_swappable_with<_Tp, _Up>::value;
2655 
2656  /// is_nothrow_swappable_with_v
2657  template<typename _Tp, typename _Up>
2658  _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_with_v =
2659  is_nothrow_swappable_with<_Tp, _Up>::value;
2660 #endif // __cplusplus >= 201402L
2661 
2662 #endif// c++1z or gnu++11
2663 
2664  // __is_invocable (std::is_invocable for C++11)
2665 
2666  // The primary template is used for invalid INVOKE expressions.
2667  template<typename _Result, typename _Ret,
2668  bool = is_void<_Ret>::value, typename = void>
2669  struct __is_invocable_impl : false_type { };
2670 
2671  // Used for valid INVOKE and INVOKE<void> expressions.
2672  template<typename _Result, typename _Ret>
2673  struct __is_invocable_impl<_Result, _Ret,
2674  /* is_void<_Ret> = */ true,
2675  __void_t<typename _Result::type>>
2676  : true_type
2677  { };
2678 
2679 #pragma GCC diagnostic push
2680 #pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
2681  // Used for INVOKE<R> expressions to check the implicit conversion to R.
2682  template<typename _Result, typename _Ret>
2683  struct __is_invocable_impl<_Result, _Ret,
2684  /* is_void<_Ret> = */ false,
2685  __void_t<typename _Result::type>>
2686  {
2687  private:
2688  // The type of the INVOKE expression.
2689  // Unlike declval, this doesn't add_rvalue_reference.
2690  static typename _Result::type _S_get();
2691 
2692  template<typename _Tp>
2693  static void _S_conv(_Tp);
2694 
2695  // This overload is viable if INVOKE(f, args...) can convert to _Tp.
2696  template<typename _Tp, typename = decltype(_S_conv<_Tp>(_S_get()))>
2697  static true_type
2698  _S_test(int);
2699 
2700  template<typename _Tp>
2701  static false_type
2702  _S_test(...);
2703 
2704  public:
2705  using type = decltype(_S_test<_Ret>(1));
2706  };
2707 #pragma GCC diagnostic pop
2708 
2709  template<typename _Fn, typename... _ArgTypes>
2710  struct __is_invocable
2711  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2712  { };
2713 
2714  template<typename _Fn, typename _Tp, typename... _Args>
2715  constexpr bool __call_is_nt(__invoke_memfun_ref)
2716  {
2717  using _Up = typename __inv_unwrap<_Tp>::type;
2718  return noexcept((std::declval<_Up>().*std::declval<_Fn>())(
2719  std::declval<_Args>()...));
2720  }
2721 
2722  template<typename _Fn, typename _Tp, typename... _Args>
2723  constexpr bool __call_is_nt(__invoke_memfun_deref)
2724  {
2725  return noexcept(((*std::declval<_Tp>()).*std::declval<_Fn>())(
2726  std::declval<_Args>()...));
2727  }
2728 
2729  template<typename _Fn, typename _Tp>
2730  constexpr bool __call_is_nt(__invoke_memobj_ref)
2731  {
2732  using _Up = typename __inv_unwrap<_Tp>::type;
2733  return noexcept(std::declval<_Up>().*std::declval<_Fn>());
2734  }
2735 
2736  template<typename _Fn, typename _Tp>
2737  constexpr bool __call_is_nt(__invoke_memobj_deref)
2738  {
2739  return noexcept((*std::declval<_Tp>()).*std::declval<_Fn>());
2740  }
2741 
2742  template<typename _Fn, typename... _Args>
2743  constexpr bool __call_is_nt(__invoke_other)
2744  {
2745  return noexcept(std::declval<_Fn>()(std::declval<_Args>()...));
2746  }
2747 
2748  template<typename _Result, typename _Fn, typename... _Args>
2749  struct __call_is_nothrow
2750  : __bool_constant<
2751  std::__call_is_nt<_Fn, _Args...>(typename _Result::__invoke_type{})
2752  >
2753  { };
2754 
2755  template<typename _Fn, typename... _Args>
2756  using __call_is_nothrow_
2757  = __call_is_nothrow<__invoke_result<_Fn, _Args...>, _Fn, _Args...>;
2758 
2759  // __is_nothrow_invocable (std::is_nothrow_invocable for C++11)
2760  template<typename _Fn, typename... _Args>
2761  struct __is_nothrow_invocable
2762  : __and_<__is_invocable<_Fn, _Args...>,
2763  __call_is_nothrow_<_Fn, _Args...>>::type
2764  { };
2765 
2766  struct __nonesuch {
2767  __nonesuch() = delete;
2768  ~__nonesuch() = delete;
2769  __nonesuch(__nonesuch const&) = delete;
2770  void operator=(__nonesuch const&) = delete;
2771  };
2772 
2773 #if __cplusplus >= 201703L
2774 # define __cpp_lib_is_invocable 201703
2775 
2776  /// std::invoke_result
2777  template<typename _Functor, typename... _ArgTypes>
2778  struct invoke_result
2779  : public __invoke_result<_Functor, _ArgTypes...>
2780  { };
2781 
2782  /// std::invoke_result_t
2783  template<typename _Fn, typename... _Args>
2784  using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
2785 
2786  /// std::is_invocable
2787  template<typename _Fn, typename... _ArgTypes>
2788  struct is_invocable
2789  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2790  { };
2791 
2792  /// std::is_invocable_r
2793  template<typename _Ret, typename _Fn, typename... _ArgTypes>
2794  struct is_invocable_r
2795  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>::type
2796  { };
2797 
2798  /// std::is_nothrow_invocable
2799  template<typename _Fn, typename... _ArgTypes>
2800  struct is_nothrow_invocable
2801  : __and_<__is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>,
2802  __call_is_nothrow_<_Fn, _ArgTypes...>>::type
2803  { };
2804 
2805  template<typename _Result, typename _Ret, typename = void>
2806  struct __is_nt_invocable_impl : false_type { };
2807 
2808  template<typename _Result, typename _Ret>
2809  struct __is_nt_invocable_impl<_Result, _Ret,
2810  __void_t<typename _Result::type>>
2811  : __or_<is_void<_Ret>,
2812  __and_<is_convertible<typename _Result::type, _Ret>,
2813  is_nothrow_constructible<_Ret, typename _Result::type>>>
2814  { };
2815 
2816  /// std::is_nothrow_invocable_r
2817  template<typename _Ret, typename _Fn, typename... _ArgTypes>
2818  struct is_nothrow_invocable_r
2819  : __and_<__is_nt_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>,
2820  __call_is_nothrow_<_Fn, _ArgTypes...>>::type
2821  { };
2822 
2823  /// std::is_invocable_v
2824  template<typename _Fn, typename... _Args>
2825  inline constexpr bool is_invocable_v = is_invocable<_Fn, _Args...>::value;
2826 
2827  /// std::is_nothrow_invocable_v
2828  template<typename _Fn, typename... _Args>
2829  inline constexpr bool is_nothrow_invocable_v
2830  = is_nothrow_invocable<_Fn, _Args...>::value;
2831 
2832  /// std::is_invocable_r_v
2833  template<typename _Fn, typename... _Args>
2834  inline constexpr bool is_invocable_r_v
2835  = is_invocable_r<_Fn, _Args...>::value;
2836 
2837  /// std::is_nothrow_invocable_r_v
2838  template<typename _Fn, typename... _Args>
2839  inline constexpr bool is_nothrow_invocable_r_v
2840  = is_nothrow_invocable_r<_Fn, _Args...>::value;
2841 #endif // C++17
2842 
2843 #if __cplusplus >= 201703L
2844 # define __cpp_lib_type_trait_variable_templates 201510L
2845 template <typename _Tp>
2846  inline constexpr bool is_void_v = is_void<_Tp>::value;
2847 template <typename _Tp>
2848  inline constexpr bool is_null_pointer_v = is_null_pointer<_Tp>::value;
2849 template <typename _Tp>
2850  inline constexpr bool is_integral_v = is_integral<_Tp>::value;
2851 template <typename _Tp>
2852  inline constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
2853 template <typename _Tp>
2854  inline constexpr bool is_array_v = is_array<_Tp>::value;
2855 template <typename _Tp>
2856  inline constexpr bool is_pointer_v = is_pointer<_Tp>::value;
2857 template <typename _Tp>
2858  inline constexpr bool is_lvalue_reference_v =
2859  is_lvalue_reference<_Tp>::value;
2860 template <typename _Tp>
2861  inline constexpr bool is_rvalue_reference_v =
2862  is_rvalue_reference<_Tp>::value;
2863 template <typename _Tp>
2864  inline constexpr bool is_member_object_pointer_v =
2865  is_member_object_pointer<_Tp>::value;
2866 template <typename _Tp>
2867  inline constexpr bool is_member_function_pointer_v =
2868  is_member_function_pointer<_Tp>::value;
2869 template <typename _Tp>
2870  inline constexpr bool is_enum_v = is_enum<_Tp>::value;
2871 template <typename _Tp>
2872  inline constexpr bool is_union_v = is_union<_Tp>::value;
2873 template <typename _Tp>
2874  inline constexpr bool is_class_v = is_class<_Tp>::value;
2875 template <typename _Tp>
2876  inline constexpr bool is_function_v = is_function<_Tp>::value;
2877 template <typename _Tp>
2878  inline constexpr bool is_reference_v = is_reference<_Tp>::value;
2879 template <typename _Tp>
2880  inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
2881 template <typename _Tp>
2882  inline constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
2883 template <typename _Tp>
2884  inline constexpr bool is_object_v = is_object<_Tp>::value;
2885 template <typename _Tp>
2886  inline constexpr bool is_scalar_v = is_scalar<_Tp>::value;
2887 template <typename _Tp>
2888  inline constexpr bool is_compound_v = is_compound<_Tp>::value;
2889 template <typename _Tp>
2890  inline constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value;
2891 template <typename _Tp>
2892  inline constexpr bool is_const_v = is_const<_Tp>::value;
2893 template <typename _Tp>
2894  inline constexpr bool is_volatile_v = is_volatile<_Tp>::value;
2895 template <typename _Tp>
2896  inline constexpr bool is_trivial_v = is_trivial<_Tp>::value;
2897 template <typename _Tp>
2898  inline constexpr bool is_trivially_copyable_v =
2899  is_trivially_copyable<_Tp>::value;
2900 template <typename _Tp>
2901  inline constexpr bool is_standard_layout_v = is_standard_layout<_Tp>::value;
2902 template <typename _Tp>
2903  inline constexpr bool is_pod_v = is_pod<_Tp>::value;
2904 template <typename _Tp>
2905  inline constexpr bool is_literal_type_v = is_literal_type<_Tp>::value;
2906 template <typename _Tp>
2907  inline constexpr bool is_empty_v = is_empty<_Tp>::value;
2908 template <typename _Tp>
2909  inline constexpr bool is_polymorphic_v = is_polymorphic<_Tp>::value;
2910 template <typename _Tp>
2911  inline constexpr bool is_abstract_v = is_abstract<_Tp>::value;
2912 template <typename _Tp>
2913  inline constexpr bool is_final_v = is_final<_Tp>::value;
2914 template <typename _Tp>
2915  inline constexpr bool is_signed_v = is_signed<_Tp>::value;
2916 template <typename _Tp>
2917  inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
2918 template <typename _Tp, typename... _Args>
2919  inline constexpr bool is_constructible_v =
2920  is_constructible<_Tp, _Args...>::value;
2921 template <typename _Tp>
2922  inline constexpr bool is_default_constructible_v =
2923  is_default_constructible<_Tp>::value;
2924 template <typename _Tp>
2925  inline constexpr bool is_copy_constructible_v =
2926  is_copy_constructible<_Tp>::value;
2927 template <typename _Tp>
2928  inline constexpr bool is_move_constructible_v =
2929  is_move_constructible<_Tp>::value;
2930 template <typename _Tp, typename _Up>
2931  inline constexpr bool is_assignable_v = is_assignable<_Tp, _Up>::value;
2932 template <typename _Tp>
2933  inline constexpr bool is_copy_assignable_v = is_copy_assignable<_Tp>::value;
2934 template <typename _Tp>
2935  inline constexpr bool is_move_assignable_v = is_move_assignable<_Tp>::value;
2936 template <typename _Tp>
2937  inline constexpr bool is_destructible_v = is_destructible<_Tp>::value;
2938 template <typename _Tp, typename... _Args>
2939  inline constexpr bool is_trivially_constructible_v =
2940  is_trivially_constructible<_Tp, _Args...>::value;
2941 template <typename _Tp>
2942  inline constexpr bool is_trivially_default_constructible_v =
2943  is_trivially_default_constructible<_Tp>::value;
2944 template <typename _Tp>
2945  inline constexpr bool is_trivially_copy_constructible_v =
2946  is_trivially_copy_constructible<_Tp>::value;
2947 template <typename _Tp>
2948  inline constexpr bool is_trivially_move_constructible_v =
2949  is_trivially_move_constructible<_Tp>::value;
2950 template <typename _Tp, typename _Up>
2951  inline constexpr bool is_trivially_assignable_v =
2952  is_trivially_assignable<_Tp, _Up>::value;
2953 template <typename _Tp>
2954  inline constexpr bool is_trivially_copy_assignable_v =
2955  is_trivially_copy_assignable<_Tp>::value;
2956 template <typename _Tp>
2957  inline constexpr bool is_trivially_move_assignable_v =
2958  is_trivially_move_assignable<_Tp>::value;
2959 template <typename _Tp>
2960  inline constexpr bool is_trivially_destructible_v =
2961  is_trivially_destructible<_Tp>::value;
2962 template <typename _Tp, typename... _Args>
2963  inline constexpr bool is_nothrow_constructible_v =
2964  is_nothrow_constructible<_Tp, _Args...>::value;
2965 template <typename _Tp>
2966  inline constexpr bool is_nothrow_default_constructible_v =
2967  is_nothrow_default_constructible<_Tp>::value;
2968 template <typename _Tp>
2969  inline constexpr bool is_nothrow_copy_constructible_v =
2970  is_nothrow_copy_constructible<_Tp>::value;
2971 template <typename _Tp>
2972  inline constexpr bool is_nothrow_move_constructible_v =
2973  is_nothrow_move_constructible<_Tp>::value;
2974 template <typename _Tp, typename _Up>
2975  inline constexpr bool is_nothrow_assignable_v =
2976  is_nothrow_assignable<_Tp, _Up>::value;
2977 template <typename _Tp>
2978  inline constexpr bool is_nothrow_copy_assignable_v =
2979  is_nothrow_copy_assignable<_Tp>::value;
2980 template <typename _Tp>
2981  inline constexpr bool is_nothrow_move_assignable_v =
2982  is_nothrow_move_assignable<_Tp>::value;
2983 template <typename _Tp>
2984  inline constexpr bool is_nothrow_destructible_v =
2985  is_nothrow_destructible<_Tp>::value;
2986 template <typename _Tp>
2987  inline constexpr bool has_virtual_destructor_v =
2988  has_virtual_destructor<_Tp>::value;
2989 template <typename _Tp>
2990  inline constexpr size_t alignment_of_v = alignment_of<_Tp>::value;
2991 template <typename _Tp>
2992  inline constexpr size_t rank_v = rank<_Tp>::value;
2993 template <typename _Tp, unsigned _Idx = 0>
2994  inline constexpr size_t extent_v = extent<_Tp, _Idx>::value;
2995 template <typename _Tp, typename _Up>
2996  inline constexpr bool is_same_v = is_same<_Tp, _Up>::value;
2997 template <typename _Base, typename _Derived>
2998  inline constexpr bool is_base_of_v = is_base_of<_Base, _Derived>::value;
2999 template <typename _From, typename _To>
3000  inline constexpr bool is_convertible_v = is_convertible<_From, _To>::value;
3001 
3002 #ifdef _GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP
3003 # define __cpp_lib_has_unique_object_representations 201606
3004  /// has_unique_object_representations
3005  template<typename _Tp>
3006  struct has_unique_object_representations
3007  : bool_constant<__has_unique_object_representations(
3008  remove_cv_t<remove_all_extents_t<_Tp>>
3009  )>
3010  { };
3011 
3012  template<typename _Tp>
3013  inline constexpr bool has_unique_object_representations_v
3014  = has_unique_object_representations<_Tp>::value;
3015 #endif
3016 
3017 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE
3018 # define __cpp_lib_is_aggregate 201703
3019  /// is_aggregate
3020  template<typename _Tp>
3021  struct is_aggregate
3022  : bool_constant<__is_aggregate(remove_cv_t<_Tp>)> { };
3023 
3024  /// is_aggregate_v
3025  template<typename _Tp>
3026  inline constexpr bool is_aggregate_v = is_aggregate<_Tp>::value;
3027 #endif
3028 #endif // C++17
3029 
3030 #if __cplusplus > 201703L
3031 #define __cpp_lib_remove_cvref 201711L
3032 
3033  /// Remove references and cv-qualifiers.
3034  template<typename _Tp>
3035  struct remove_cvref
3036  {
3037  using type = __remove_cvref_t<_Tp>;
3038  };
3039 
3040  template<typename _Tp>
3041  using remove_cvref_t = __remove_cvref_t<_Tp>;
3042 
3043 #define __cpp_lib_type_identity 201806L
3044  /// Identity metafunction.
3045  template<typename _Tp>
3046  struct type_identity { using type = _Tp; };
3047 
3048  template<typename _Tp>
3049  using type_identity_t = typename type_identity<_Tp>::type;
3050 
3051 #define __cpp_lib_unwrap_ref 201811L
3052 
3053  /// Unwrap a reference_wrapper
3054  template<typename _Tp>
3055  struct unwrap_reference { using type = _Tp; };
3056 
3057  template<typename _Tp>
3058  struct unwrap_reference<reference_wrapper<_Tp>> { using type = _Tp&; };
3059 
3060  template<typename _Tp>
3061  using unwrap_reference_t = typename unwrap_reference<_Tp>::type;
3062 
3063  /// Decay type and if it's a reference_wrapper, unwrap it
3064  template<typename _Tp>
3065  struct unwrap_ref_decay { using type = unwrap_reference_t<decay_t<_Tp>>; };
3066 
3067  template<typename _Tp>
3068  using unwrap_ref_decay_t = typename unwrap_ref_decay<_Tp>::type;
3069 
3070 #define __cpp_lib_bounded_array_traits 201902L
3071 
3072  /// True for a type that is an array of known bound.
3073  template<typename _Tp>
3074  struct is_bounded_array
3075  : public __is_array_known_bounds<_Tp>
3076  { };
3077 
3078  /// True for a type that is an array of unknown bound.
3079  template<typename _Tp>
3080  struct is_unbounded_array
3081  : public __is_array_unknown_bounds<_Tp>
3082  { };
3083 
3084  template<typename _Tp>
3085  inline constexpr bool is_bounded_array_v
3086  = is_bounded_array<_Tp>::value;
3087 
3088  template<typename _Tp>
3089  inline constexpr bool is_unbounded_array_v
3090  = is_unbounded_array<_Tp>::value;
3091 
3092 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
3093 
3094 #define __cpp_lib_is_constant_evaluated 201811L
3095 
3096  constexpr inline bool
3097  is_constant_evaluated() noexcept
3098  { return __builtin_is_constant_evaluated(); }
3099 #endif
3100 
3101 #endif // C++2a
3102 
3103 _GLIBCXX_END_NAMESPACE_VERSION
3104 } // namespace std
3105 
3106 #endif // C++11
3107 
3108 #endif // _GLIBCXX_TYPE_TRAITS