libstdc++
type_traits
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1 // C++11 <type_traits> -*- C++ -*-
2 
3 // Copyright (C) 2007-2018 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 #define __cpp_lib_logical_traits 201510
148 
149  template<typename... _Bn>
150  struct conjunction
151  : __and_<_Bn...>
152  { };
153 
154  template<typename... _Bn>
155  struct disjunction
156  : __or_<_Bn...>
157  { };
158 
159  template<typename _Pp>
160  struct negation
161  : __not_<_Pp>
162  { };
163 
164  template<typename... _Bn>
165  inline constexpr bool conjunction_v = conjunction<_Bn...>::value;
166 
167  template<typename... _Bn>
168  inline constexpr bool disjunction_v = disjunction<_Bn...>::value;
169 
170  template<typename _Pp>
171  inline constexpr bool negation_v = negation<_Pp>::value;
172 
173 #endif // C++17
174 
175  // For several sfinae-friendly trait implementations we transport both the
176  // result information (as the member type) and the failure information (no
177  // member type). This is very similar to std::enable_if, but we cannot use
178  // them, because we need to derive from them as an implementation detail.
179 
180  template<typename _Tp>
181  struct __success_type
182  { typedef _Tp type; };
183 
184  struct __failure_type
185  { };
186 
187  // Primary type categories.
188 
189  template<typename>
190  struct remove_cv;
191 
192  template<typename>
193  struct __is_void_helper
194  : public false_type { };
195 
196  template<>
197  struct __is_void_helper<void>
198  : public true_type { };
199 
200  /// is_void
201  template<typename _Tp>
202  struct is_void
203  : public __is_void_helper<typename remove_cv<_Tp>::type>::type
204  { };
205 
206  template<typename>
207  struct __is_integral_helper
208  : public false_type { };
209 
210  template<>
211  struct __is_integral_helper<bool>
212  : public true_type { };
213 
214  template<>
215  struct __is_integral_helper<char>
216  : public true_type { };
217 
218  template<>
219  struct __is_integral_helper<signed char>
220  : public true_type { };
221 
222  template<>
223  struct __is_integral_helper<unsigned char>
224  : public true_type { };
225 
226 #ifdef _GLIBCXX_USE_WCHAR_T
227  template<>
228  struct __is_integral_helper<wchar_t>
229  : public true_type { };
230 #endif
231 
232  template<>
233  struct __is_integral_helper<char16_t>
234  : public true_type { };
235 
236  template<>
237  struct __is_integral_helper<char32_t>
238  : public true_type { };
239 
240  template<>
241  struct __is_integral_helper<short>
242  : public true_type { };
243 
244  template<>
245  struct __is_integral_helper<unsigned short>
246  : public true_type { };
247 
248  template<>
249  struct __is_integral_helper<int>
250  : public true_type { };
251 
252  template<>
253  struct __is_integral_helper<unsigned int>
254  : public true_type { };
255 
256  template<>
257  struct __is_integral_helper<long>
258  : public true_type { };
259 
260  template<>
261  struct __is_integral_helper<unsigned long>
262  : public true_type { };
263 
264  template<>
265  struct __is_integral_helper<long long>
266  : public true_type { };
267 
268  template<>
269  struct __is_integral_helper<unsigned long long>
270  : public true_type { };
271 
272  // Conditionalizing on __STRICT_ANSI__ here will break any port that
273  // uses one of these types for size_t.
274 #if defined(__GLIBCXX_TYPE_INT_N_0)
275  template<>
276  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_0>
277  : public true_type { };
278 
279  template<>
280  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_0>
281  : public true_type { };
282 #endif
283 #if defined(__GLIBCXX_TYPE_INT_N_1)
284  template<>
285  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_1>
286  : public true_type { };
287 
288  template<>
289  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_1>
290  : public true_type { };
291 #endif
292 #if defined(__GLIBCXX_TYPE_INT_N_2)
293  template<>
294  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_2>
295  : public true_type { };
296 
297  template<>
298  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_2>
299  : public true_type { };
300 #endif
301 #if defined(__GLIBCXX_TYPE_INT_N_3)
302  template<>
303  struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_3>
304  : public true_type { };
305 
306  template<>
307  struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_3>
308  : public true_type { };
309 #endif
310 
311  /// is_integral
312  template<typename _Tp>
313  struct is_integral
314  : public __is_integral_helper<typename remove_cv<_Tp>::type>::type
315  { };
316 
317  template<typename>
318  struct __is_floating_point_helper
319  : public false_type { };
320 
321  template<>
322  struct __is_floating_point_helper<float>
323  : public true_type { };
324 
325  template<>
326  struct __is_floating_point_helper<double>
327  : public true_type { };
328 
329  template<>
330  struct __is_floating_point_helper<long double>
331  : public true_type { };
332 
333 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
334  template<>
335  struct __is_floating_point_helper<__float128>
336  : public true_type { };
337 #endif
338 
339  /// is_floating_point
340  template<typename _Tp>
341  struct is_floating_point
342  : public __is_floating_point_helper<typename remove_cv<_Tp>::type>::type
343  { };
344 
345  /// is_array
346  template<typename>
347  struct is_array
348  : public false_type { };
349 
350  template<typename _Tp, std::size_t _Size>
351  struct is_array<_Tp[_Size]>
352  : public true_type { };
353 
354  template<typename _Tp>
355  struct is_array<_Tp[]>
356  : public true_type { };
357 
358  template<typename>
359  struct __is_pointer_helper
360  : public false_type { };
361 
362  template<typename _Tp>
363  struct __is_pointer_helper<_Tp*>
364  : public true_type { };
365 
366  /// is_pointer
367  template<typename _Tp>
368  struct is_pointer
369  : public __is_pointer_helper<typename remove_cv<_Tp>::type>::type
370  { };
371 
372  /// is_lvalue_reference
373  template<typename>
374  struct is_lvalue_reference
375  : public false_type { };
376 
377  template<typename _Tp>
378  struct is_lvalue_reference<_Tp&>
379  : public true_type { };
380 
381  /// is_rvalue_reference
382  template<typename>
383  struct is_rvalue_reference
384  : public false_type { };
385 
386  template<typename _Tp>
387  struct is_rvalue_reference<_Tp&&>
388  : public true_type { };
389 
390  template<typename>
391  struct is_function;
392 
393  template<typename>
394  struct __is_member_object_pointer_helper
395  : public false_type { };
396 
397  template<typename _Tp, typename _Cp>
398  struct __is_member_object_pointer_helper<_Tp _Cp::*>
399  : public integral_constant<bool, !is_function<_Tp>::value> { };
400 
401  /// is_member_object_pointer
402  template<typename _Tp>
403  struct is_member_object_pointer
404  : public __is_member_object_pointer_helper<
405  typename remove_cv<_Tp>::type>::type
406  { };
407 
408  template<typename>
409  struct __is_member_function_pointer_helper
410  : public false_type { };
411 
412  template<typename _Tp, typename _Cp>
413  struct __is_member_function_pointer_helper<_Tp _Cp::*>
414  : public integral_constant<bool, is_function<_Tp>::value> { };
415 
416  /// is_member_function_pointer
417  template<typename _Tp>
418  struct is_member_function_pointer
419  : public __is_member_function_pointer_helper<
420  typename remove_cv<_Tp>::type>::type
421  { };
422 
423  /// is_enum
424  template<typename _Tp>
425  struct is_enum
426  : public integral_constant<bool, __is_enum(_Tp)>
427  { };
428 
429  /// is_union
430  template<typename _Tp>
431  struct is_union
432  : public integral_constant<bool, __is_union(_Tp)>
433  { };
434 
435  /// is_class
436  template<typename _Tp>
437  struct is_class
438  : public integral_constant<bool, __is_class(_Tp)>
439  { };
440 
441  /// is_function
442  template<typename>
443  struct is_function
444  : public false_type { };
445 
446  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
447  struct is_function<_Res(_ArgTypes...) _GLIBCXX_NOEXCEPT_QUAL>
448  : public true_type { };
449 
450  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
451  struct is_function<_Res(_ArgTypes...) & _GLIBCXX_NOEXCEPT_QUAL>
452  : public true_type { };
453 
454  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
455  struct is_function<_Res(_ArgTypes...) && _GLIBCXX_NOEXCEPT_QUAL>
456  : public true_type { };
457 
458  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
459  struct is_function<_Res(_ArgTypes......) _GLIBCXX_NOEXCEPT_QUAL>
460  : public true_type { };
461 
462  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
463  struct is_function<_Res(_ArgTypes......) & _GLIBCXX_NOEXCEPT_QUAL>
464  : public true_type { };
465 
466  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
467  struct is_function<_Res(_ArgTypes......) && _GLIBCXX_NOEXCEPT_QUAL>
468  : public true_type { };
469 
470  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
471  struct is_function<_Res(_ArgTypes...) const _GLIBCXX_NOEXCEPT_QUAL>
472  : public true_type { };
473 
474  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
475  struct is_function<_Res(_ArgTypes...) const & _GLIBCXX_NOEXCEPT_QUAL>
476  : public true_type { };
477 
478  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
479  struct is_function<_Res(_ArgTypes...) const && _GLIBCXX_NOEXCEPT_QUAL>
480  : public true_type { };
481 
482  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
483  struct is_function<_Res(_ArgTypes......) const _GLIBCXX_NOEXCEPT_QUAL>
484  : public true_type { };
485 
486  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
487  struct is_function<_Res(_ArgTypes......) const & _GLIBCXX_NOEXCEPT_QUAL>
488  : public true_type { };
489 
490  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
491  struct is_function<_Res(_ArgTypes......) const && _GLIBCXX_NOEXCEPT_QUAL>
492  : public true_type { };
493 
494  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
495  struct is_function<_Res(_ArgTypes...) volatile _GLIBCXX_NOEXCEPT_QUAL>
496  : public true_type { };
497 
498  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
499  struct is_function<_Res(_ArgTypes...) volatile & _GLIBCXX_NOEXCEPT_QUAL>
500  : public true_type { };
501 
502  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
503  struct is_function<_Res(_ArgTypes...) volatile && _GLIBCXX_NOEXCEPT_QUAL>
504  : public true_type { };
505 
506  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
507  struct is_function<_Res(_ArgTypes......) volatile _GLIBCXX_NOEXCEPT_QUAL>
508  : public true_type { };
509 
510  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
511  struct is_function<_Res(_ArgTypes......) volatile & _GLIBCXX_NOEXCEPT_QUAL>
512  : public true_type { };
513 
514  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
515  struct is_function<_Res(_ArgTypes......) volatile && _GLIBCXX_NOEXCEPT_QUAL>
516  : public true_type { };
517 
518  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
519  struct is_function<_Res(_ArgTypes...) const volatile _GLIBCXX_NOEXCEPT_QUAL>
520  : public true_type { };
521 
522  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
523  struct is_function<_Res(_ArgTypes...) const volatile & _GLIBCXX_NOEXCEPT_QUAL>
524  : public true_type { };
525 
526  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
527  struct is_function<_Res(_ArgTypes...) const volatile && _GLIBCXX_NOEXCEPT_QUAL>
528  : public true_type { };
529 
530  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
531  struct is_function<_Res(_ArgTypes......) const volatile _GLIBCXX_NOEXCEPT_QUAL>
532  : public true_type { };
533 
534  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
535  struct is_function<_Res(_ArgTypes......) const volatile & _GLIBCXX_NOEXCEPT_QUAL>
536  : public true_type { };
537 
538  template<typename _Res, typename... _ArgTypes _GLIBCXX_NOEXCEPT_PARM>
539  struct is_function<_Res(_ArgTypes......) const volatile && _GLIBCXX_NOEXCEPT_QUAL>
540  : public true_type { };
541 
542 #define __cpp_lib_is_null_pointer 201309
543 
544  template<typename>
545  struct __is_null_pointer_helper
546  : public false_type { };
547 
548  template<>
549  struct __is_null_pointer_helper<std::nullptr_t>
550  : public true_type { };
551 
552  /// is_null_pointer (LWG 2247).
553  template<typename _Tp>
554  struct is_null_pointer
555  : public __is_null_pointer_helper<typename remove_cv<_Tp>::type>::type
556  { };
557 
558  /// __is_nullptr_t (extension).
559  template<typename _Tp>
560  struct __is_nullptr_t
561  : public is_null_pointer<_Tp>
562  { };
563 
564  // Composite type categories.
565 
566  /// is_reference
567  template<typename _Tp>
568  struct is_reference
569  : public __or_<is_lvalue_reference<_Tp>,
570  is_rvalue_reference<_Tp>>::type
571  { };
572 
573  /// is_arithmetic
574  template<typename _Tp>
575  struct is_arithmetic
576  : public __or_<is_integral<_Tp>, is_floating_point<_Tp>>::type
577  { };
578 
579  /// is_fundamental
580  template<typename _Tp>
581  struct is_fundamental
582  : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
583  is_null_pointer<_Tp>>::type
584  { };
585 
586  /// is_object
587  template<typename _Tp>
588  struct is_object
589  : public __not_<__or_<is_function<_Tp>, is_reference<_Tp>,
590  is_void<_Tp>>>::type
591  { };
592 
593  template<typename>
594  struct is_member_pointer;
595 
596  /// is_scalar
597  template<typename _Tp>
598  struct is_scalar
599  : public __or_<is_arithmetic<_Tp>, is_enum<_Tp>, is_pointer<_Tp>,
600  is_member_pointer<_Tp>, is_null_pointer<_Tp>>::type
601  { };
602 
603  /// is_compound
604  template<typename _Tp>
605  struct is_compound
606  : public integral_constant<bool, !is_fundamental<_Tp>::value> { };
607 
608  template<typename _Tp>
609  struct __is_member_pointer_helper
610  : public false_type { };
611 
612  template<typename _Tp, typename _Cp>
613  struct __is_member_pointer_helper<_Tp _Cp::*>
614  : public true_type { };
615 
616  /// is_member_pointer
617  template<typename _Tp>
618  struct is_member_pointer
619  : public __is_member_pointer_helper<typename remove_cv<_Tp>::type>::type
620  { };
621 
622  // Utility to detect referenceable types ([defns.referenceable]).
623 
624  template<typename _Tp>
625  struct __is_referenceable
626  : public __or_<is_object<_Tp>, is_reference<_Tp>>::type
627  { };
628 
629  template<typename _Res, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
630  struct __is_referenceable<_Res(_Args...) _GLIBCXX_NOEXCEPT_QUAL>
631  : public true_type
632  { };
633 
634  template<typename _Res, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
635  struct __is_referenceable<_Res(_Args......) _GLIBCXX_NOEXCEPT_QUAL>
636  : public true_type
637  { };
638 
639  // Type properties.
640 
641  /// is_const
642  template<typename>
643  struct is_const
644  : public false_type { };
645 
646  template<typename _Tp>
647  struct is_const<_Tp const>
648  : public true_type { };
649 
650  /// is_volatile
651  template<typename>
652  struct is_volatile
653  : public false_type { };
654 
655  template<typename _Tp>
656  struct is_volatile<_Tp volatile>
657  : public true_type { };
658 
659  /// is_trivial
660  template<typename _Tp>
661  struct is_trivial
662  : public integral_constant<bool, __is_trivial(_Tp)>
663  { };
664 
665  // is_trivially_copyable
666  template<typename _Tp>
667  struct is_trivially_copyable
668  : public integral_constant<bool, __is_trivially_copyable(_Tp)>
669  { };
670 
671  /// is_standard_layout
672  template<typename _Tp>
673  struct is_standard_layout
674  : public integral_constant<bool, __is_standard_layout(_Tp)>
675  { };
676 
677  /// is_pod
678  // Could use is_standard_layout && is_trivial instead of the builtin.
679  template<typename _Tp>
680  struct is_pod
681  : public integral_constant<bool, __is_pod(_Tp)>
682  { };
683 
684  /// is_literal_type
685  template<typename _Tp>
686  struct is_literal_type
687  : public integral_constant<bool, __is_literal_type(_Tp)>
688  { };
689 
690  /// is_empty
691  template<typename _Tp>
692  struct is_empty
693  : public integral_constant<bool, __is_empty(_Tp)>
694  { };
695 
696  /// is_polymorphic
697  template<typename _Tp>
698  struct is_polymorphic
699  : public integral_constant<bool, __is_polymorphic(_Tp)>
700  { };
701 
702 #if __cplusplus >= 201402L
703 #define __cpp_lib_is_final 201402L
704  /// is_final
705  template<typename _Tp>
706  struct is_final
707  : public integral_constant<bool, __is_final(_Tp)>
708  { };
709 #endif
710 
711  /// is_abstract
712  template<typename _Tp>
713  struct is_abstract
714  : public integral_constant<bool, __is_abstract(_Tp)>
715  { };
716 
717  template<typename _Tp,
718  bool = is_arithmetic<_Tp>::value>
719  struct __is_signed_helper
720  : public false_type { };
721 
722  template<typename _Tp>
723  struct __is_signed_helper<_Tp, true>
724  : public integral_constant<bool, _Tp(-1) < _Tp(0)>
725  { };
726 
727  /// is_signed
728  template<typename _Tp>
729  struct is_signed
730  : public __is_signed_helper<_Tp>::type
731  { };
732 
733  /// is_unsigned
734  template<typename _Tp>
735  struct is_unsigned
736  : public __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>
737  { };
738 
739 
740  // Destructible and constructible type properties.
741 
742  /**
743  * @brief Utility to simplify expressions used in unevaluated operands
744  * @ingroup utilities
745  */
746 
747  template<typename _Tp, typename _Up = _Tp&&>
748  _Up
749  __declval(int);
750 
751  template<typename _Tp>
752  _Tp
753  __declval(long);
754 
755  template<typename _Tp>
756  auto declval() noexcept -> decltype(__declval<_Tp>(0));
757 
758  template<typename, unsigned = 0>
759  struct extent;
760 
761  template<typename>
762  struct remove_all_extents;
763 
764  template<typename _Tp>
765  struct __is_array_known_bounds
766  : public integral_constant<bool, (extent<_Tp>::value > 0)>
767  { };
768 
769  template<typename _Tp>
770  struct __is_array_unknown_bounds
771  : public __and_<is_array<_Tp>, __not_<extent<_Tp>>>
772  { };
773 
774  // In N3290 is_destructible does not say anything about function
775  // types and abstract types, see LWG 2049. This implementation
776  // describes function types as non-destructible and all complete
777  // object types as destructible, iff the explicit destructor
778  // call expression is wellformed.
779  struct __do_is_destructible_impl
780  {
781  template<typename _Tp, typename = decltype(declval<_Tp&>().~_Tp())>
782  static true_type __test(int);
783 
784  template<typename>
785  static false_type __test(...);
786  };
787 
788  template<typename _Tp>
789  struct __is_destructible_impl
790  : public __do_is_destructible_impl
791  {
792  typedef decltype(__test<_Tp>(0)) type;
793  };
794 
795  template<typename _Tp,
796  bool = __or_<is_void<_Tp>,
797  __is_array_unknown_bounds<_Tp>,
798  is_function<_Tp>>::value,
799  bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
800  struct __is_destructible_safe;
801 
802  template<typename _Tp>
803  struct __is_destructible_safe<_Tp, false, false>
804  : public __is_destructible_impl<typename
805  remove_all_extents<_Tp>::type>::type
806  { };
807 
808  template<typename _Tp>
809  struct __is_destructible_safe<_Tp, true, false>
810  : public false_type { };
811 
812  template<typename _Tp>
813  struct __is_destructible_safe<_Tp, false, true>
814  : public true_type { };
815 
816  /// is_destructible
817  template<typename _Tp>
818  struct is_destructible
819  : public __is_destructible_safe<_Tp>::type
820  { };
821 
822  // is_nothrow_destructible requires that is_destructible is
823  // satisfied as well. We realize that by mimicing the
824  // implementation of is_destructible but refer to noexcept(expr)
825  // instead of decltype(expr).
826  struct __do_is_nt_destructible_impl
827  {
828  template<typename _Tp>
829  static integral_constant<bool, noexcept(declval<_Tp&>().~_Tp())>
830  __test(int);
831 
832  template<typename>
833  static false_type __test(...);
834  };
835 
836  template<typename _Tp>
837  struct __is_nt_destructible_impl
838  : public __do_is_nt_destructible_impl
839  {
840  typedef decltype(__test<_Tp>(0)) type;
841  };
842 
843  template<typename _Tp,
844  bool = __or_<is_void<_Tp>,
845  __is_array_unknown_bounds<_Tp>,
846  is_function<_Tp>>::value,
847  bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
848  struct __is_nt_destructible_safe;
849 
850  template<typename _Tp>
851  struct __is_nt_destructible_safe<_Tp, false, false>
852  : public __is_nt_destructible_impl<typename
853  remove_all_extents<_Tp>::type>::type
854  { };
855 
856  template<typename _Tp>
857  struct __is_nt_destructible_safe<_Tp, true, false>
858  : public false_type { };
859 
860  template<typename _Tp>
861  struct __is_nt_destructible_safe<_Tp, false, true>
862  : public true_type { };
863 
864  /// is_nothrow_destructible
865  template<typename _Tp>
866  struct is_nothrow_destructible
867  : public __is_nt_destructible_safe<_Tp>::type
868  { };
869 
870  /// is_constructible
871  template<typename _Tp, typename... _Args>
872  struct is_constructible
873  : public __bool_constant<__is_constructible(_Tp, _Args...)>
874  { };
875 
876  /// is_default_constructible
877  template<typename _Tp>
878  struct is_default_constructible
879  : public is_constructible<_Tp>::type
880  { };
881 
882  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
883  struct __is_copy_constructible_impl;
884 
885  template<typename _Tp>
886  struct __is_copy_constructible_impl<_Tp, false>
887  : public false_type { };
888 
889  template<typename _Tp>
890  struct __is_copy_constructible_impl<_Tp, true>
891  : public is_constructible<_Tp, const _Tp&>
892  { };
893 
894  /// is_copy_constructible
895  template<typename _Tp>
896  struct is_copy_constructible
897  : public __is_copy_constructible_impl<_Tp>
898  { };
899 
900  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
901  struct __is_move_constructible_impl;
902 
903  template<typename _Tp>
904  struct __is_move_constructible_impl<_Tp, false>
905  : public false_type { };
906 
907  template<typename _Tp>
908  struct __is_move_constructible_impl<_Tp, true>
909  : public is_constructible<_Tp, _Tp&&>
910  { };
911 
912  /// is_move_constructible
913  template<typename _Tp>
914  struct is_move_constructible
915  : public __is_move_constructible_impl<_Tp>
916  { };
917 
918  template<typename _Tp>
919  struct __is_nt_default_constructible_atom
920  : public integral_constant<bool, noexcept(_Tp())>
921  { };
922 
923  template<typename _Tp, bool = is_array<_Tp>::value>
924  struct __is_nt_default_constructible_impl;
925 
926  template<typename _Tp>
927  struct __is_nt_default_constructible_impl<_Tp, true>
928  : public __and_<__is_array_known_bounds<_Tp>,
929  __is_nt_default_constructible_atom<typename
930  remove_all_extents<_Tp>::type>>
931  { };
932 
933  template<typename _Tp>
934  struct __is_nt_default_constructible_impl<_Tp, false>
935  : public __is_nt_default_constructible_atom<_Tp>
936  { };
937 
938  /// is_nothrow_default_constructible
939  template<typename _Tp>
940  struct is_nothrow_default_constructible
941  : public __and_<is_default_constructible<_Tp>,
942  __is_nt_default_constructible_impl<_Tp>>
943  { };
944 
945  template<typename _Tp, typename... _Args>
946  struct __is_nt_constructible_impl
947  : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))>
948  { };
949 
950  template<typename _Tp, typename _Arg>
951  struct __is_nt_constructible_impl<_Tp, _Arg>
952  : public integral_constant<bool,
953  noexcept(static_cast<_Tp>(declval<_Arg>()))>
954  { };
955 
956  template<typename _Tp>
957  struct __is_nt_constructible_impl<_Tp>
958  : public is_nothrow_default_constructible<_Tp>
959  { };
960 
961  /// is_nothrow_constructible
962  template<typename _Tp, typename... _Args>
963  struct is_nothrow_constructible
964  : public __and_<is_constructible<_Tp, _Args...>,
965  __is_nt_constructible_impl<_Tp, _Args...>>
966  { };
967 
968  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
969  struct __is_nothrow_copy_constructible_impl;
970 
971  template<typename _Tp>
972  struct __is_nothrow_copy_constructible_impl<_Tp, false>
973  : public false_type { };
974 
975  template<typename _Tp>
976  struct __is_nothrow_copy_constructible_impl<_Tp, true>
977  : public is_nothrow_constructible<_Tp, const _Tp&>
978  { };
979 
980  /// is_nothrow_copy_constructible
981  template<typename _Tp>
982  struct is_nothrow_copy_constructible
983  : public __is_nothrow_copy_constructible_impl<_Tp>
984  { };
985 
986  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
987  struct __is_nothrow_move_constructible_impl;
988 
989  template<typename _Tp>
990  struct __is_nothrow_move_constructible_impl<_Tp, false>
991  : public false_type { };
992 
993  template<typename _Tp>
994  struct __is_nothrow_move_constructible_impl<_Tp, true>
995  : public is_nothrow_constructible<_Tp, _Tp&&>
996  { };
997 
998  /// is_nothrow_move_constructible
999  template<typename _Tp>
1000  struct is_nothrow_move_constructible
1001  : public __is_nothrow_move_constructible_impl<_Tp>
1002  { };
1003 
1004  /// is_assignable
1005  template<typename _Tp, typename _Up>
1006  struct is_assignable
1007  : public __bool_constant<__is_assignable(_Tp, _Up)>
1008  { };
1009 
1010  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1011  struct __is_copy_assignable_impl;
1012 
1013  template<typename _Tp>
1014  struct __is_copy_assignable_impl<_Tp, false>
1015  : public false_type { };
1016 
1017  template<typename _Tp>
1018  struct __is_copy_assignable_impl<_Tp, true>
1019  : public is_assignable<_Tp&, const _Tp&>
1020  { };
1021 
1022  /// is_copy_assignable
1023  template<typename _Tp>
1024  struct is_copy_assignable
1025  : public __is_copy_assignable_impl<_Tp>
1026  { };
1027 
1028  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1029  struct __is_move_assignable_impl;
1030 
1031  template<typename _Tp>
1032  struct __is_move_assignable_impl<_Tp, false>
1033  : public false_type { };
1034 
1035  template<typename _Tp>
1036  struct __is_move_assignable_impl<_Tp, true>
1037  : public is_assignable<_Tp&, _Tp&&>
1038  { };
1039 
1040  /// is_move_assignable
1041  template<typename _Tp>
1042  struct is_move_assignable
1043  : public __is_move_assignable_impl<_Tp>
1044  { };
1045 
1046  template<typename _Tp, typename _Up>
1047  struct __is_nt_assignable_impl
1048  : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Up>())>
1049  { };
1050 
1051  /// is_nothrow_assignable
1052  template<typename _Tp, typename _Up>
1053  struct is_nothrow_assignable
1054  : public __and_<is_assignable<_Tp, _Up>,
1055  __is_nt_assignable_impl<_Tp, _Up>>
1056  { };
1057 
1058  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1059  struct __is_nt_copy_assignable_impl;
1060 
1061  template<typename _Tp>
1062  struct __is_nt_copy_assignable_impl<_Tp, false>
1063  : public false_type { };
1064 
1065  template<typename _Tp>
1066  struct __is_nt_copy_assignable_impl<_Tp, true>
1067  : public is_nothrow_assignable<_Tp&, const _Tp&>
1068  { };
1069 
1070  /// is_nothrow_copy_assignable
1071  template<typename _Tp>
1072  struct is_nothrow_copy_assignable
1073  : public __is_nt_copy_assignable_impl<_Tp>
1074  { };
1075 
1076  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1077  struct __is_nt_move_assignable_impl;
1078 
1079  template<typename _Tp>
1080  struct __is_nt_move_assignable_impl<_Tp, false>
1081  : public false_type { };
1082 
1083  template<typename _Tp>
1084  struct __is_nt_move_assignable_impl<_Tp, true>
1085  : public is_nothrow_assignable<_Tp&, _Tp&&>
1086  { };
1087 
1088  /// is_nothrow_move_assignable
1089  template<typename _Tp>
1090  struct is_nothrow_move_assignable
1091  : public __is_nt_move_assignable_impl<_Tp>
1092  { };
1093 
1094  /// is_trivially_constructible
1095  template<typename _Tp, typename... _Args>
1096  struct is_trivially_constructible
1097  : public __and_<is_constructible<_Tp, _Args...>, __bool_constant<
1098  __is_trivially_constructible(_Tp, _Args...)>>::type
1099  { };
1100 
1101  /// is_trivially_default_constructible
1102  template<typename _Tp>
1103  struct is_trivially_default_constructible
1104  : public is_trivially_constructible<_Tp>::type
1105  { };
1106 
1107  struct __do_is_implicitly_default_constructible_impl
1108  {
1109  template <typename _Tp>
1110  static void __helper(const _Tp&);
1111 
1112  template <typename _Tp>
1113  static true_type __test(const _Tp&,
1114  decltype(__helper<const _Tp&>({}))* = 0);
1115 
1116  static false_type __test(...);
1117  };
1118 
1119  template<typename _Tp>
1120  struct __is_implicitly_default_constructible_impl
1121  : public __do_is_implicitly_default_constructible_impl
1122  {
1123  typedef decltype(__test(declval<_Tp>())) type;
1124  };
1125 
1126  template<typename _Tp>
1127  struct __is_implicitly_default_constructible_safe
1128  : public __is_implicitly_default_constructible_impl<_Tp>::type
1129  { };
1130 
1131  template <typename _Tp>
1132  struct __is_implicitly_default_constructible
1133  : public __and_<is_default_constructible<_Tp>,
1134  __is_implicitly_default_constructible_safe<_Tp>>
1135  { };
1136 
1137  /// is_trivially_copy_constructible
1138 
1139  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1140  struct __is_trivially_copy_constructible_impl;
1141 
1142  template<typename _Tp>
1143  struct __is_trivially_copy_constructible_impl<_Tp, false>
1144  : public false_type { };
1145 
1146  template<typename _Tp>
1147  struct __is_trivially_copy_constructible_impl<_Tp, true>
1148  : public __and_<is_copy_constructible<_Tp>,
1149  integral_constant<bool,
1150  __is_trivially_constructible(_Tp, const _Tp&)>>
1151  { };
1152 
1153  template<typename _Tp>
1154  struct is_trivially_copy_constructible
1155  : public __is_trivially_copy_constructible_impl<_Tp>
1156  { };
1157 
1158  /// is_trivially_move_constructible
1159 
1160  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1161  struct __is_trivially_move_constructible_impl;
1162 
1163  template<typename _Tp>
1164  struct __is_trivially_move_constructible_impl<_Tp, false>
1165  : public false_type { };
1166 
1167  template<typename _Tp>
1168  struct __is_trivially_move_constructible_impl<_Tp, true>
1169  : public __and_<is_move_constructible<_Tp>,
1170  integral_constant<bool,
1171  __is_trivially_constructible(_Tp, _Tp&&)>>
1172  { };
1173 
1174  template<typename _Tp>
1175  struct is_trivially_move_constructible
1176  : public __is_trivially_move_constructible_impl<_Tp>
1177  { };
1178 
1179  /// is_trivially_assignable
1180  template<typename _Tp, typename _Up>
1181  struct is_trivially_assignable
1182  : public __bool_constant<__is_trivially_assignable(_Tp, _Up)>
1183  { };
1184 
1185  /// is_trivially_copy_assignable
1186 
1187  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1188  struct __is_trivially_copy_assignable_impl;
1189 
1190  template<typename _Tp>
1191  struct __is_trivially_copy_assignable_impl<_Tp, false>
1192  : public false_type { };
1193 
1194  template<typename _Tp>
1195  struct __is_trivially_copy_assignable_impl<_Tp, true>
1196  : public __and_<is_copy_assignable<_Tp>,
1197  integral_constant<bool,
1198  __is_trivially_assignable(_Tp&, const _Tp&)>>
1199  { };
1200 
1201  template<typename _Tp>
1202  struct is_trivially_copy_assignable
1203  : public __is_trivially_copy_assignable_impl<_Tp>
1204  { };
1205 
1206  /// is_trivially_move_assignable
1207 
1208  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1209  struct __is_trivially_move_assignable_impl;
1210 
1211  template<typename _Tp>
1212  struct __is_trivially_move_assignable_impl<_Tp, false>
1213  : public false_type { };
1214 
1215  template<typename _Tp>
1216  struct __is_trivially_move_assignable_impl<_Tp, true>
1217  : public __and_<is_move_assignable<_Tp>,
1218  integral_constant<bool,
1219  __is_trivially_assignable(_Tp&, _Tp&&)>>
1220  { };
1221 
1222  template<typename _Tp>
1223  struct is_trivially_move_assignable
1224  : public __is_trivially_move_assignable_impl<_Tp>
1225  { };
1226 
1227  /// is_trivially_destructible
1228  template<typename _Tp>
1229  struct is_trivially_destructible
1230  : public __and_<is_destructible<_Tp>, integral_constant<bool,
1231  __has_trivial_destructor(_Tp)>>
1232  { };
1233 
1234 
1235  /// has_virtual_destructor
1236  template<typename _Tp>
1237  struct has_virtual_destructor
1238  : public integral_constant<bool, __has_virtual_destructor(_Tp)>
1239  { };
1240 
1241 
1242  // type property queries.
1243 
1244  /// alignment_of
1245  template<typename _Tp>
1246  struct alignment_of
1247  : public integral_constant<std::size_t, alignof(_Tp)> { };
1248 
1249  /// rank
1250  template<typename>
1251  struct rank
1252  : public integral_constant<std::size_t, 0> { };
1253 
1254  template<typename _Tp, std::size_t _Size>
1255  struct rank<_Tp[_Size]>
1256  : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1257 
1258  template<typename _Tp>
1259  struct rank<_Tp[]>
1260  : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1261 
1262  /// extent
1263  template<typename, unsigned _Uint>
1264  struct extent
1265  : public integral_constant<std::size_t, 0> { };
1266 
1267  template<typename _Tp, unsigned _Uint, std::size_t _Size>
1268  struct extent<_Tp[_Size], _Uint>
1269  : public integral_constant<std::size_t,
1270  _Uint == 0 ? _Size : extent<_Tp,
1271  _Uint - 1>::value>
1272  { };
1273 
1274  template<typename _Tp, unsigned _Uint>
1275  struct extent<_Tp[], _Uint>
1276  : public integral_constant<std::size_t,
1277  _Uint == 0 ? 0 : extent<_Tp,
1278  _Uint - 1>::value>
1279  { };
1280 
1281 
1282  // Type relations.
1283 
1284  /// is_same
1285  template<typename, typename>
1286  struct is_same
1287  : public false_type { };
1288 
1289  template<typename _Tp>
1290  struct is_same<_Tp, _Tp>
1291  : public true_type { };
1292 
1293  /// is_base_of
1294  template<typename _Base, typename _Derived>
1295  struct is_base_of
1296  : public integral_constant<bool, __is_base_of(_Base, _Derived)>
1297  { };
1298 
1299  template<typename _From, typename _To,
1300  bool = __or_<is_void<_From>, is_function<_To>,
1301  is_array<_To>>::value>
1302  struct __is_convertible_helper
1303  { typedef typename is_void<_To>::type type; };
1304 
1305  template<typename _From, typename _To>
1306  class __is_convertible_helper<_From, _To, false>
1307  {
1308  template<typename _To1>
1309  static void __test_aux(_To1);
1310 
1311  template<typename _From1, typename _To1,
1312  typename = decltype(__test_aux<_To1>(std::declval<_From1>()))>
1313  static true_type
1314  __test(int);
1315 
1316  template<typename, typename>
1317  static false_type
1318  __test(...);
1319 
1320  public:
1321  typedef decltype(__test<_From, _To>(0)) type;
1322  };
1323 
1324 
1325  /// is_convertible
1326  template<typename _From, typename _To>
1327  struct is_convertible
1328  : public __is_convertible_helper<_From, _To>::type
1329  { };
1330 
1331 
1332  // Const-volatile modifications.
1333 
1334  /// remove_const
1335  template<typename _Tp>
1336  struct remove_const
1337  { typedef _Tp type; };
1338 
1339  template<typename _Tp>
1340  struct remove_const<_Tp const>
1341  { typedef _Tp type; };
1342 
1343  /// remove_volatile
1344  template<typename _Tp>
1345  struct remove_volatile
1346  { typedef _Tp type; };
1347 
1348  template<typename _Tp>
1349  struct remove_volatile<_Tp volatile>
1350  { typedef _Tp type; };
1351 
1352  /// remove_cv
1353  template<typename _Tp>
1354  struct remove_cv
1355  {
1356  typedef typename
1357  remove_const<typename remove_volatile<_Tp>::type>::type type;
1358  };
1359 
1360  /// add_const
1361  template<typename _Tp>
1362  struct add_const
1363  { typedef _Tp const type; };
1364 
1365  /// add_volatile
1366  template<typename _Tp>
1367  struct add_volatile
1368  { typedef _Tp volatile type; };
1369 
1370  /// add_cv
1371  template<typename _Tp>
1372  struct add_cv
1373  {
1374  typedef typename
1375  add_const<typename add_volatile<_Tp>::type>::type type;
1376  };
1377 
1378 #if __cplusplus > 201103L
1379 
1380 #define __cpp_lib_transformation_trait_aliases 201304
1381 
1382  /// Alias template for remove_const
1383  template<typename _Tp>
1384  using remove_const_t = typename remove_const<_Tp>::type;
1385 
1386  /// Alias template for remove_volatile
1387  template<typename _Tp>
1388  using remove_volatile_t = typename remove_volatile<_Tp>::type;
1389 
1390  /// Alias template for remove_cv
1391  template<typename _Tp>
1392  using remove_cv_t = typename remove_cv<_Tp>::type;
1393 
1394  /// Alias template for add_const
1395  template<typename _Tp>
1396  using add_const_t = typename add_const<_Tp>::type;
1397 
1398  /// Alias template for add_volatile
1399  template<typename _Tp>
1400  using add_volatile_t = typename add_volatile<_Tp>::type;
1401 
1402  /// Alias template for add_cv
1403  template<typename _Tp>
1404  using add_cv_t = typename add_cv<_Tp>::type;
1405 #endif
1406 
1407  // Reference transformations.
1408 
1409  /// remove_reference
1410  template<typename _Tp>
1411  struct remove_reference
1412  { typedef _Tp type; };
1413 
1414  template<typename _Tp>
1415  struct remove_reference<_Tp&>
1416  { typedef _Tp type; };
1417 
1418  template<typename _Tp>
1419  struct remove_reference<_Tp&&>
1420  { typedef _Tp type; };
1421 
1422  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1423  struct __add_lvalue_reference_helper
1424  { typedef _Tp type; };
1425 
1426  template<typename _Tp>
1427  struct __add_lvalue_reference_helper<_Tp, true>
1428  { typedef _Tp& type; };
1429 
1430  /// add_lvalue_reference
1431  template<typename _Tp>
1432  struct add_lvalue_reference
1433  : public __add_lvalue_reference_helper<_Tp>
1434  { };
1435 
1436  template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1437  struct __add_rvalue_reference_helper
1438  { typedef _Tp type; };
1439 
1440  template<typename _Tp>
1441  struct __add_rvalue_reference_helper<_Tp, true>
1442  { typedef _Tp&& type; };
1443 
1444  /// add_rvalue_reference
1445  template<typename _Tp>
1446  struct add_rvalue_reference
1447  : public __add_rvalue_reference_helper<_Tp>
1448  { };
1449 
1450 #if __cplusplus > 201103L
1451  /// Alias template for remove_reference
1452  template<typename _Tp>
1453  using remove_reference_t = typename remove_reference<_Tp>::type;
1454 
1455  /// Alias template for add_lvalue_reference
1456  template<typename _Tp>
1457  using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
1458 
1459  /// Alias template for add_rvalue_reference
1460  template<typename _Tp>
1461  using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
1462 #endif
1463 
1464  // Sign modifications.
1465 
1466  // Utility for constructing identically cv-qualified types.
1467  template<typename _Unqualified, bool _IsConst, bool _IsVol>
1468  struct __cv_selector;
1469 
1470  template<typename _Unqualified>
1471  struct __cv_selector<_Unqualified, false, false>
1472  { typedef _Unqualified __type; };
1473 
1474  template<typename _Unqualified>
1475  struct __cv_selector<_Unqualified, false, true>
1476  { typedef volatile _Unqualified __type; };
1477 
1478  template<typename _Unqualified>
1479  struct __cv_selector<_Unqualified, true, false>
1480  { typedef const _Unqualified __type; };
1481 
1482  template<typename _Unqualified>
1483  struct __cv_selector<_Unqualified, true, true>
1484  { typedef const volatile _Unqualified __type; };
1485 
1486  template<typename _Qualified, typename _Unqualified,
1487  bool _IsConst = is_const<_Qualified>::value,
1488  bool _IsVol = is_volatile<_Qualified>::value>
1489  class __match_cv_qualifiers
1490  {
1491  typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
1492 
1493  public:
1494  typedef typename __match::__type __type;
1495  };
1496 
1497  // Utility for finding the unsigned versions of signed integral types.
1498  template<typename _Tp>
1499  struct __make_unsigned
1500  { typedef _Tp __type; };
1501 
1502  template<>
1503  struct __make_unsigned<char>
1504  { typedef unsigned char __type; };
1505 
1506  template<>
1507  struct __make_unsigned<signed char>
1508  { typedef unsigned char __type; };
1509 
1510  template<>
1511  struct __make_unsigned<short>
1512  { typedef unsigned short __type; };
1513 
1514  template<>
1515  struct __make_unsigned<int>
1516  { typedef unsigned int __type; };
1517 
1518  template<>
1519  struct __make_unsigned<long>
1520  { typedef unsigned long __type; };
1521 
1522  template<>
1523  struct __make_unsigned<long long>
1524  { typedef unsigned long long __type; };
1525 
1526 #if defined(__GLIBCXX_TYPE_INT_N_0)
1527  template<>
1528  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_0>
1529  { typedef unsigned __GLIBCXX_TYPE_INT_N_0 __type; };
1530 #endif
1531 #if defined(__GLIBCXX_TYPE_INT_N_1)
1532  template<>
1533  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_1>
1534  { typedef unsigned __GLIBCXX_TYPE_INT_N_1 __type; };
1535 #endif
1536 #if defined(__GLIBCXX_TYPE_INT_N_2)
1537  template<>
1538  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_2>
1539  { typedef unsigned __GLIBCXX_TYPE_INT_N_2 __type; };
1540 #endif
1541 #if defined(__GLIBCXX_TYPE_INT_N_3)
1542  template<>
1543  struct __make_unsigned<__GLIBCXX_TYPE_INT_N_3>
1544  { typedef unsigned __GLIBCXX_TYPE_INT_N_3 __type; };
1545 #endif
1546 
1547  // Select between integral and enum: not possible to be both.
1548  template<typename _Tp,
1549  bool _IsInt = is_integral<_Tp>::value,
1550  bool _IsEnum = is_enum<_Tp>::value>
1551  class __make_unsigned_selector;
1552 
1553  template<typename _Tp>
1554  class __make_unsigned_selector<_Tp, true, false>
1555  {
1556  typedef __make_unsigned<typename remove_cv<_Tp>::type> __unsignedt;
1557  typedef typename __unsignedt::__type __unsigned_type;
1558  typedef __match_cv_qualifiers<_Tp, __unsigned_type> __cv_unsigned;
1559 
1560  public:
1561  typedef typename __cv_unsigned::__type __type;
1562  };
1563 
1564  template<typename _Tp>
1565  class __make_unsigned_selector<_Tp, false, true>
1566  {
1567  // With -fshort-enums, an enum may be as small as a char.
1568  typedef unsigned char __smallest;
1569  static const bool __b0 = sizeof(_Tp) <= sizeof(__smallest);
1570  static const bool __b1 = sizeof(_Tp) <= sizeof(unsigned short);
1571  static const bool __b2 = sizeof(_Tp) <= sizeof(unsigned int);
1572  static const bool __b3 = sizeof(_Tp) <= sizeof(unsigned long);
1573  typedef conditional<__b3, unsigned long, unsigned long long> __cond3;
1574  typedef typename __cond3::type __cond3_type;
1575  typedef conditional<__b2, unsigned int, __cond3_type> __cond2;
1576  typedef typename __cond2::type __cond2_type;
1577  typedef conditional<__b1, unsigned short, __cond2_type> __cond1;
1578  typedef typename __cond1::type __cond1_type;
1579 
1580  typedef typename conditional<__b0, __smallest, __cond1_type>::type
1581  __unsigned_type;
1582  typedef __match_cv_qualifiers<_Tp, __unsigned_type> __cv_unsigned;
1583 
1584  public:
1585  typedef typename __cv_unsigned::__type __type;
1586  };
1587 
1588  // Given an integral/enum type, return the corresponding unsigned
1589  // integer type.
1590  // Primary template.
1591  /// make_unsigned
1592  template<typename _Tp>
1593  struct make_unsigned
1594  { typedef typename __make_unsigned_selector<_Tp>::__type type; };
1595 
1596  // Integral, but don't define.
1597  template<>
1598  struct make_unsigned<bool>;
1599 
1600 
1601  // Utility for finding the signed versions of unsigned integral types.
1602  template<typename _Tp>
1603  struct __make_signed
1604  { typedef _Tp __type; };
1605 
1606  template<>
1607  struct __make_signed<char>
1608  { typedef signed char __type; };
1609 
1610  template<>
1611  struct __make_signed<unsigned char>
1612  { typedef signed char __type; };
1613 
1614  template<>
1615  struct __make_signed<unsigned short>
1616  { typedef signed short __type; };
1617 
1618  template<>
1619  struct __make_signed<unsigned int>
1620  { typedef signed int __type; };
1621 
1622  template<>
1623  struct __make_signed<unsigned long>
1624  { typedef signed long __type; };
1625 
1626  template<>
1627  struct __make_signed<unsigned long long>
1628  { typedef signed long long __type; };
1629 
1630 #if defined(__GLIBCXX_TYPE_INT_N_0)
1631  template<>
1632  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_0>
1633  { typedef __GLIBCXX_TYPE_INT_N_0 __type; };
1634 #endif
1635 #if defined(__GLIBCXX_TYPE_INT_N_1)
1636  template<>
1637  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_1>
1638  { typedef __GLIBCXX_TYPE_INT_N_1 __type; };
1639 #endif
1640 #if defined(__GLIBCXX_TYPE_INT_N_2)
1641  template<>
1642  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_2>
1643  { typedef __GLIBCXX_TYPE_INT_N_2 __type; };
1644 #endif
1645 #if defined(__GLIBCXX_TYPE_INT_N_3)
1646  template<>
1647  struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_3>
1648  { typedef __GLIBCXX_TYPE_INT_N_3 __type; };
1649 #endif
1650 
1651  // Select between integral and enum: not possible to be both.
1652  template<typename _Tp,
1653  bool _IsInt = is_integral<_Tp>::value,
1654  bool _IsEnum = is_enum<_Tp>::value>
1655  class __make_signed_selector;
1656 
1657  template<typename _Tp>
1658  class __make_signed_selector<_Tp, true, false>
1659  {
1660  typedef __make_signed<typename remove_cv<_Tp>::type> __signedt;
1661  typedef typename __signedt::__type __signed_type;
1662  typedef __match_cv_qualifiers<_Tp, __signed_type> __cv_signed;
1663 
1664  public:
1665  typedef typename __cv_signed::__type __type;
1666  };
1667 
1668  template<typename _Tp>
1669  class __make_signed_selector<_Tp, false, true>
1670  {
1671  typedef typename __make_unsigned_selector<_Tp>::__type __unsigned_type;
1672 
1673  public:
1674  typedef typename __make_signed_selector<__unsigned_type>::__type __type;
1675  };
1676 
1677  // Given an integral/enum type, return the corresponding signed
1678  // integer type.
1679  // Primary template.
1680  /// make_signed
1681  template<typename _Tp>
1682  struct make_signed
1683  { typedef typename __make_signed_selector<_Tp>::__type type; };
1684 
1685  // Integral, but don't define.
1686  template<>
1687  struct make_signed<bool>;
1688 
1689 #if __cplusplus > 201103L
1690  /// Alias template for make_signed
1691  template<typename _Tp>
1692  using make_signed_t = typename make_signed<_Tp>::type;
1693 
1694  /// Alias template for make_unsigned
1695  template<typename _Tp>
1696  using make_unsigned_t = typename make_unsigned<_Tp>::type;
1697 #endif
1698 
1699  // Array modifications.
1700 
1701  /// remove_extent
1702  template<typename _Tp>
1703  struct remove_extent
1704  { typedef _Tp type; };
1705 
1706  template<typename _Tp, std::size_t _Size>
1707  struct remove_extent<_Tp[_Size]>
1708  { typedef _Tp type; };
1709 
1710  template<typename _Tp>
1711  struct remove_extent<_Tp[]>
1712  { typedef _Tp type; };
1713 
1714  /// remove_all_extents
1715  template<typename _Tp>
1716  struct remove_all_extents
1717  { typedef _Tp type; };
1718 
1719  template<typename _Tp, std::size_t _Size>
1720  struct remove_all_extents<_Tp[_Size]>
1721  { typedef typename remove_all_extents<_Tp>::type type; };
1722 
1723  template<typename _Tp>
1724  struct remove_all_extents<_Tp[]>
1725  { typedef typename remove_all_extents<_Tp>::type type; };
1726 
1727 #if __cplusplus > 201103L
1728  /// Alias template for remove_extent
1729  template<typename _Tp>
1730  using remove_extent_t = typename remove_extent<_Tp>::type;
1731 
1732  /// Alias template for remove_all_extents
1733  template<typename _Tp>
1734  using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
1735 #endif
1736 
1737  // Pointer modifications.
1738 
1739  template<typename _Tp, typename>
1740  struct __remove_pointer_helper
1741  { typedef _Tp type; };
1742 
1743  template<typename _Tp, typename _Up>
1744  struct __remove_pointer_helper<_Tp, _Up*>
1745  { typedef _Up type; };
1746 
1747  /// remove_pointer
1748  template<typename _Tp>
1749  struct remove_pointer
1750  : public __remove_pointer_helper<_Tp, typename remove_cv<_Tp>::type>
1751  { };
1752 
1753  /// add_pointer
1754  template<typename _Tp, bool = __or_<__is_referenceable<_Tp>,
1755  is_void<_Tp>>::value>
1756  struct __add_pointer_helper
1757  { typedef _Tp type; };
1758 
1759  template<typename _Tp>
1760  struct __add_pointer_helper<_Tp, true>
1761  { typedef typename remove_reference<_Tp>::type* type; };
1762 
1763  template<typename _Tp>
1764  struct add_pointer
1765  : public __add_pointer_helper<_Tp>
1766  { };
1767 
1768 #if __cplusplus > 201103L
1769  /// Alias template for remove_pointer
1770  template<typename _Tp>
1771  using remove_pointer_t = typename remove_pointer<_Tp>::type;
1772 
1773  /// Alias template for add_pointer
1774  template<typename _Tp>
1775  using add_pointer_t = typename add_pointer<_Tp>::type;
1776 #endif
1777 
1778  template<std::size_t _Len>
1779  struct __aligned_storage_msa
1780  {
1781  union __type
1782  {
1783  unsigned char __data[_Len];
1784  struct __attribute__((__aligned__)) { } __align;
1785  };
1786  };
1787 
1788  /**
1789  * @brief Alignment type.
1790  *
1791  * The value of _Align is a default-alignment which shall be the
1792  * most stringent alignment requirement for any C++ object type
1793  * whose size is no greater than _Len (3.9). The member typedef
1794  * type shall be a POD type suitable for use as uninitialized
1795  * storage for any object whose size is at most _Len and whose
1796  * alignment is a divisor of _Align.
1797  */
1798  template<std::size_t _Len, std::size_t _Align =
1799  __alignof__(typename __aligned_storage_msa<_Len>::__type)>
1800  struct aligned_storage
1801  {
1802  union type
1803  {
1804  unsigned char __data[_Len];
1805  struct __attribute__((__aligned__((_Align)))) { } __align;
1806  };
1807  };
1808 
1809  template <typename... _Types>
1810  struct __strictest_alignment
1811  {
1812  static const size_t _S_alignment = 0;
1813  static const size_t _S_size = 0;
1814  };
1815 
1816  template <typename _Tp, typename... _Types>
1817  struct __strictest_alignment<_Tp, _Types...>
1818  {
1819  static const size_t _S_alignment =
1820  alignof(_Tp) > __strictest_alignment<_Types...>::_S_alignment
1821  ? alignof(_Tp) : __strictest_alignment<_Types...>::_S_alignment;
1822  static const size_t _S_size =
1823  sizeof(_Tp) > __strictest_alignment<_Types...>::_S_size
1824  ? sizeof(_Tp) : __strictest_alignment<_Types...>::_S_size;
1825  };
1826 
1827  /**
1828  * @brief Provide aligned storage for types.
1829  *
1830  * [meta.trans.other]
1831  *
1832  * Provides aligned storage for any of the provided types of at
1833  * least size _Len.
1834  *
1835  * @see aligned_storage
1836  */
1837  template <size_t _Len, typename... _Types>
1838  struct aligned_union
1839  {
1840  private:
1841  static_assert(sizeof...(_Types) != 0, "At least one type is required");
1842 
1843  using __strictest = __strictest_alignment<_Types...>;
1844  static const size_t _S_len = _Len > __strictest::_S_size
1845  ? _Len : __strictest::_S_size;
1846  public:
1847  /// The value of the strictest alignment of _Types.
1848  static const size_t alignment_value = __strictest::_S_alignment;
1849  /// The storage.
1850  typedef typename aligned_storage<_S_len, alignment_value>::type type;
1851  };
1852 
1853  template <size_t _Len, typename... _Types>
1854  const size_t aligned_union<_Len, _Types...>::alignment_value;
1855 
1856  // Decay trait for arrays and functions, used for perfect forwarding
1857  // in make_pair, make_tuple, etc.
1858  template<typename _Up,
1859  bool _IsArray = is_array<_Up>::value,
1860  bool _IsFunction = is_function<_Up>::value>
1861  struct __decay_selector;
1862 
1863  // NB: DR 705.
1864  template<typename _Up>
1865  struct __decay_selector<_Up, false, false>
1866  { typedef typename remove_cv<_Up>::type __type; };
1867 
1868  template<typename _Up>
1869  struct __decay_selector<_Up, true, false>
1870  { typedef typename remove_extent<_Up>::type* __type; };
1871 
1872  template<typename _Up>
1873  struct __decay_selector<_Up, false, true>
1874  { typedef typename add_pointer<_Up>::type __type; };
1875 
1876  /// decay
1877  template<typename _Tp>
1878  class decay
1879  {
1880  typedef typename remove_reference<_Tp>::type __remove_type;
1881 
1882  public:
1883  typedef typename __decay_selector<__remove_type>::__type type;
1884  };
1885 
1886  template<typename _Tp>
1887  class reference_wrapper;
1888 
1889  // Helper which adds a reference to a type when given a reference_wrapper
1890  template<typename _Tp>
1891  struct __strip_reference_wrapper
1892  {
1893  typedef _Tp __type;
1894  };
1895 
1896  template<typename _Tp>
1897  struct __strip_reference_wrapper<reference_wrapper<_Tp> >
1898  {
1899  typedef _Tp& __type;
1900  };
1901 
1902  template<typename _Tp>
1903  struct __decay_and_strip
1904  {
1905  typedef typename __strip_reference_wrapper<
1906  typename decay<_Tp>::type>::__type __type;
1907  };
1908 
1909 
1910  // Primary template.
1911  /// Define a member typedef @c type only if a boolean constant is true.
1912  template<bool, typename _Tp = void>
1913  struct enable_if
1914  { };
1915 
1916  // Partial specialization for true.
1917  template<typename _Tp>
1918  struct enable_if<true, _Tp>
1919  { typedef _Tp type; };
1920 
1921  template<typename... _Cond>
1922  using _Require = typename enable_if<__and_<_Cond...>::value>::type;
1923 
1924  // Primary template.
1925  /// Define a member typedef @c type to one of two argument types.
1926  template<bool _Cond, typename _Iftrue, typename _Iffalse>
1927  struct conditional
1928  { typedef _Iftrue type; };
1929 
1930  // Partial specialization for false.
1931  template<typename _Iftrue, typename _Iffalse>
1932  struct conditional<false, _Iftrue, _Iffalse>
1933  { typedef _Iffalse type; };
1934 
1935  /// common_type
1936  template<typename... _Tp>
1937  struct common_type;
1938 
1939  // Sfinae-friendly common_type implementation:
1940 
1941  struct __do_common_type_impl
1942  {
1943  template<typename _Tp, typename _Up>
1944  static __success_type<typename decay<decltype
1945  (true ? std::declval<_Tp>()
1946  : std::declval<_Up>())>::type> _S_test(int);
1947 
1948  template<typename, typename>
1949  static __failure_type _S_test(...);
1950  };
1951 
1952  template<typename _Tp, typename _Up>
1953  struct __common_type_impl
1954  : private __do_common_type_impl
1955  {
1956  typedef decltype(_S_test<_Tp, _Up>(0)) type;
1957  };
1958 
1959  struct __do_member_type_wrapper
1960  {
1961  template<typename _Tp>
1962  static __success_type<typename _Tp::type> _S_test(int);
1963 
1964  template<typename>
1965  static __failure_type _S_test(...);
1966  };
1967 
1968  template<typename _Tp>
1969  struct __member_type_wrapper
1970  : private __do_member_type_wrapper
1971  {
1972  typedef decltype(_S_test<_Tp>(0)) type;
1973  };
1974 
1975  template<typename _CTp, typename... _Args>
1976  struct __expanded_common_type_wrapper
1977  {
1978  typedef common_type<typename _CTp::type, _Args...> type;
1979  };
1980 
1981  template<typename... _Args>
1982  struct __expanded_common_type_wrapper<__failure_type, _Args...>
1983  { typedef __failure_type type; };
1984 
1985  template<>
1986  struct common_type<>
1987  { };
1988 
1989  template<typename _Tp>
1990  struct common_type<_Tp>
1991  : common_type<_Tp, _Tp>
1992  { };
1993 
1994  template<typename _Tp, typename _Up>
1995  struct common_type<_Tp, _Up>
1996  : public __common_type_impl<_Tp, _Up>::type
1997  { };
1998 
1999  template<typename _Tp, typename _Up, typename... _Vp>
2000  struct common_type<_Tp, _Up, _Vp...>
2001  : public __expanded_common_type_wrapper<typename __member_type_wrapper<
2002  common_type<_Tp, _Up>>::type, _Vp...>::type
2003  { };
2004 
2005  /// The underlying type of an enum.
2006  template<typename _Tp>
2007  struct underlying_type
2008  {
2009  typedef __underlying_type(_Tp) type;
2010  };
2011 
2012  template<typename _Tp>
2013  struct __declval_protector
2014  {
2015  static const bool __stop = false;
2016  };
2017 
2018  template<typename _Tp>
2019  auto declval() noexcept -> decltype(__declval<_Tp>(0))
2020  {
2021  static_assert(__declval_protector<_Tp>::__stop,
2022  "declval() must not be used!");
2023  return __declval<_Tp>(0);
2024  }
2025 
2026  // wchar_t, char16_t and char32_t are integral types but are neither
2027  // signed integer types nor unsigned integer types, so must be
2028  // transformed to the integer type with the smallest rank that has the
2029  // same size and signedness.
2030  // Use the partial specialization for enumeration types to do that,
2031  // which means these explicit specializations must be defined after
2032  // std::conditional has been defined.
2033 
2034 #if defined(_GLIBCXX_USE_WCHAR_T)
2035  template<>
2036  struct __make_unsigned<wchar_t>
2037  {
2038  using __type
2039  = typename __make_unsigned_selector<wchar_t, false, true>::__type;
2040  };
2041 
2042  template<>
2043  struct __make_signed<wchar_t>
2044  {
2045  using __type
2046  = typename __make_signed_selector<wchar_t, false, true>::__type;
2047  };
2048 #endif
2049 
2050  template<>
2051  struct __make_unsigned<char16_t>
2052  {
2053  using __type
2054  = typename __make_unsigned_selector<char16_t, false, true>::__type;
2055  };
2056 
2057  template<>
2058  struct __make_signed<char16_t>
2059  {
2060  using __type
2061  = typename __make_signed_selector<char16_t, false, true>::__type;
2062  };
2063 
2064  template<>
2065  struct __make_unsigned<char32_t>
2066  {
2067  using __type
2068  = typename __make_unsigned_selector<char32_t, false, true>::__type;
2069  };
2070 
2071  template<>
2072  struct __make_signed<char32_t>
2073  {
2074  using __type
2075  = typename __make_signed_selector<char32_t, false, true>::__type;
2076  };
2077 
2078 
2079  /// result_of
2080  template<typename _Signature>
2081  class result_of;
2082 
2083  // Sfinae-friendly result_of implementation:
2084 
2085 #define __cpp_lib_result_of_sfinae 201210
2086 
2087  struct __invoke_memfun_ref { };
2088  struct __invoke_memfun_deref { };
2089  struct __invoke_memobj_ref { };
2090  struct __invoke_memobj_deref { };
2091  struct __invoke_other { };
2092 
2093  // Associate a tag type with a specialization of __success_type.
2094  template<typename _Tp, typename _Tag>
2095  struct __result_of_success : __success_type<_Tp>
2096  { using __invoke_type = _Tag; };
2097 
2098  // [func.require] paragraph 1 bullet 1:
2099  struct __result_of_memfun_ref_impl
2100  {
2101  template<typename _Fp, typename _Tp1, typename... _Args>
2102  static __result_of_success<decltype(
2103  (std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...)
2104  ), __invoke_memfun_ref> _S_test(int);
2105 
2106  template<typename...>
2107  static __failure_type _S_test(...);
2108  };
2109 
2110  template<typename _MemPtr, typename _Arg, typename... _Args>
2111  struct __result_of_memfun_ref
2112  : private __result_of_memfun_ref_impl
2113  {
2114  typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2115  };
2116 
2117  // [func.require] paragraph 1 bullet 2:
2118  struct __result_of_memfun_deref_impl
2119  {
2120  template<typename _Fp, typename _Tp1, typename... _Args>
2121  static __result_of_success<decltype(
2122  ((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...)
2123  ), __invoke_memfun_deref> _S_test(int);
2124 
2125  template<typename...>
2126  static __failure_type _S_test(...);
2127  };
2128 
2129  template<typename _MemPtr, typename _Arg, typename... _Args>
2130  struct __result_of_memfun_deref
2131  : private __result_of_memfun_deref_impl
2132  {
2133  typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2134  };
2135 
2136  // [func.require] paragraph 1 bullet 3:
2137  struct __result_of_memobj_ref_impl
2138  {
2139  template<typename _Fp, typename _Tp1>
2140  static __result_of_success<decltype(
2141  std::declval<_Tp1>().*std::declval<_Fp>()
2142  ), __invoke_memobj_ref> _S_test(int);
2143 
2144  template<typename, typename>
2145  static __failure_type _S_test(...);
2146  };
2147 
2148  template<typename _MemPtr, typename _Arg>
2149  struct __result_of_memobj_ref
2150  : private __result_of_memobj_ref_impl
2151  {
2152  typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2153  };
2154 
2155  // [func.require] paragraph 1 bullet 4:
2156  struct __result_of_memobj_deref_impl
2157  {
2158  template<typename _Fp, typename _Tp1>
2159  static __result_of_success<decltype(
2160  (*std::declval<_Tp1>()).*std::declval<_Fp>()
2161  ), __invoke_memobj_deref> _S_test(int);
2162 
2163  template<typename, typename>
2164  static __failure_type _S_test(...);
2165  };
2166 
2167  template<typename _MemPtr, typename _Arg>
2168  struct __result_of_memobj_deref
2169  : private __result_of_memobj_deref_impl
2170  {
2171  typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2172  };
2173 
2174  template<typename _MemPtr, typename _Arg>
2175  struct __result_of_memobj;
2176 
2177  template<typename _Res, typename _Class, typename _Arg>
2178  struct __result_of_memobj<_Res _Class::*, _Arg>
2179  {
2180  typedef typename remove_cv<typename remove_reference<
2181  _Arg>::type>::type _Argval;
2182  typedef _Res _Class::* _MemPtr;
2183  typedef typename conditional<__or_<is_same<_Argval, _Class>,
2184  is_base_of<_Class, _Argval>>::value,
2185  __result_of_memobj_ref<_MemPtr, _Arg>,
2186  __result_of_memobj_deref<_MemPtr, _Arg>
2187  >::type::type type;
2188  };
2189 
2190  template<typename _MemPtr, typename _Arg, typename... _Args>
2191  struct __result_of_memfun;
2192 
2193  template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2194  struct __result_of_memfun<_Res _Class::*, _Arg, _Args...>
2195  {
2196  typedef typename remove_cv<typename remove_reference<
2197  _Arg>::type>::type _Argval;
2198  typedef _Res _Class::* _MemPtr;
2199  typedef typename conditional<__or_<is_same<_Argval, _Class>,
2200  is_base_of<_Class, _Argval>>::value,
2201  __result_of_memfun_ref<_MemPtr, _Arg, _Args...>,
2202  __result_of_memfun_deref<_MemPtr, _Arg, _Args...>
2203  >::type::type type;
2204  };
2205 
2206  // _GLIBCXX_RESOLVE_LIB_DEFECTS
2207  // 2219. INVOKE-ing a pointer to member with a reference_wrapper
2208  // as the object expression
2209 
2210  // Used by result_of, invoke etc. to unwrap a reference_wrapper.
2211  template<typename _Tp, typename _Up = typename decay<_Tp>::type>
2212  struct __inv_unwrap
2213  {
2214  using type = _Tp;
2215  };
2216 
2217  template<typename _Tp, typename _Up>
2218  struct __inv_unwrap<_Tp, reference_wrapper<_Up>>
2219  {
2220  using type = _Up&;
2221  };
2222 
2223  template<bool, bool, typename _Functor, typename... _ArgTypes>
2224  struct __result_of_impl
2225  {
2226  typedef __failure_type type;
2227  };
2228 
2229  template<typename _MemPtr, typename _Arg>
2230  struct __result_of_impl<true, false, _MemPtr, _Arg>
2231  : public __result_of_memobj<typename decay<_MemPtr>::type,
2232  typename __inv_unwrap<_Arg>::type>
2233  { };
2234 
2235  template<typename _MemPtr, typename _Arg, typename... _Args>
2236  struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...>
2237  : public __result_of_memfun<typename decay<_MemPtr>::type,
2238  typename __inv_unwrap<_Arg>::type, _Args...>
2239  { };
2240 
2241  // [func.require] paragraph 1 bullet 5:
2242  struct __result_of_other_impl
2243  {
2244  template<typename _Fn, typename... _Args>
2245  static __result_of_success<decltype(
2246  std::declval<_Fn>()(std::declval<_Args>()...)
2247  ), __invoke_other> _S_test(int);
2248 
2249  template<typename...>
2250  static __failure_type _S_test(...);
2251  };
2252 
2253  template<typename _Functor, typename... _ArgTypes>
2254  struct __result_of_impl<false, false, _Functor, _ArgTypes...>
2255  : private __result_of_other_impl
2256  {
2257  typedef decltype(_S_test<_Functor, _ArgTypes...>(0)) type;
2258  };
2259 
2260  // __invoke_result (std::invoke_result for C++11)
2261  template<typename _Functor, typename... _ArgTypes>
2262  struct __invoke_result
2263  : public __result_of_impl<
2264  is_member_object_pointer<
2265  typename remove_reference<_Functor>::type
2266  >::value,
2267  is_member_function_pointer<
2268  typename remove_reference<_Functor>::type
2269  >::value,
2270  _Functor, _ArgTypes...
2271  >::type
2272  { };
2273 
2274  template<typename _Functor, typename... _ArgTypes>
2275  struct result_of<_Functor(_ArgTypes...)>
2276  : public __invoke_result<_Functor, _ArgTypes...>
2277  { };
2278 
2279 #if __cplusplus >= 201402L
2280  /// Alias template for aligned_storage
2281  template<size_t _Len, size_t _Align =
2282  __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2283  using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
2284 
2285  template <size_t _Len, typename... _Types>
2286  using aligned_union_t = typename aligned_union<_Len, _Types...>::type;
2287 
2288  /// Alias template for decay
2289  template<typename _Tp>
2290  using decay_t = typename decay<_Tp>::type;
2291 
2292  /// Alias template for enable_if
2293  template<bool _Cond, typename _Tp = void>
2294  using enable_if_t = typename enable_if<_Cond, _Tp>::type;
2295 
2296  /// Alias template for conditional
2297  template<bool _Cond, typename _Iftrue, typename _Iffalse>
2298  using conditional_t = typename conditional<_Cond, _Iftrue, _Iffalse>::type;
2299 
2300  /// Alias template for common_type
2301  template<typename... _Tp>
2302  using common_type_t = typename common_type<_Tp...>::type;
2303 
2304  /// Alias template for underlying_type
2305  template<typename _Tp>
2306  using underlying_type_t = typename underlying_type<_Tp>::type;
2307 
2308  /// Alias template for result_of
2309  template<typename _Tp>
2310  using result_of_t = typename result_of<_Tp>::type;
2311 #endif // C++14
2312 
2313  // __enable_if_t (std::enable_if_t for C++11)
2314  template<bool _Cond, typename _Tp = void>
2315  using __enable_if_t = typename enable_if<_Cond, _Tp>::type;
2316 
2317  // __void_t (std::void_t for C++11)
2318  template<typename...> using __void_t = void;
2319 
2320 #if __cplusplus >= 201703L || !defined(__STRICT_ANSI__) // c++17 or gnu++11
2321 #define __cpp_lib_void_t 201411
2322  /// A metafunction that always yields void, used for detecting valid types.
2323  template<typename...> using void_t = void;
2324 #endif
2325 
2326  /// Implementation of the detection idiom (negative case).
2327  template<typename _Default, typename _AlwaysVoid,
2328  template<typename...> class _Op, typename... _Args>
2329  struct __detector
2330  {
2331  using value_t = false_type;
2332  using type = _Default;
2333  };
2334 
2335  /// Implementation of the detection idiom (positive case).
2336  template<typename _Default, template<typename...> class _Op,
2337  typename... _Args>
2338  struct __detector<_Default, __void_t<_Op<_Args...>>, _Op, _Args...>
2339  {
2340  using value_t = true_type;
2341  using type = _Op<_Args...>;
2342  };
2343 
2344  // Detect whether _Op<_Args...> is a valid type, use _Default if not.
2345  template<typename _Default, template<typename...> class _Op,
2346  typename... _Args>
2347  using __detected_or = __detector<_Default, void, _Op, _Args...>;
2348 
2349  // _Op<_Args...> if that is a valid type, otherwise _Default.
2350  template<typename _Default, template<typename...> class _Op,
2351  typename... _Args>
2352  using __detected_or_t
2353  = typename __detected_or<_Default, _Op, _Args...>::type;
2354 
2355  /// @} group metaprogramming
2356 
2357  /**
2358  * Use SFINAE to determine if the type _Tp has a publicly-accessible
2359  * member type _NTYPE.
2360  */
2361 #define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \
2362  template<typename _Tp, typename = __void_t<>> \
2363  struct __has_##_NTYPE \
2364  : false_type \
2365  { }; \
2366  template<typename _Tp> \
2367  struct __has_##_NTYPE<_Tp, __void_t<typename _Tp::_NTYPE>> \
2368  : true_type \
2369  { };
2370 
2371  template <typename _Tp>
2372  struct __is_swappable;
2373 
2374  template <typename _Tp>
2375  struct __is_nothrow_swappable;
2376 
2377  template<typename... _Elements>
2378  class tuple;
2379 
2380  template<typename>
2381  struct __is_tuple_like_impl : false_type
2382  { };
2383 
2384  template<typename... _Tps>
2385  struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
2386  { };
2387 
2388  // Internal type trait that allows us to sfinae-protect tuple_cat.
2389  template<typename _Tp>
2390  struct __is_tuple_like
2391  : public __is_tuple_like_impl<typename remove_cv<
2392  typename remove_reference<_Tp>::type>::type>::type
2393  { };
2394 
2395  template<typename _Tp>
2396  inline
2397  typename enable_if<__and_<__not_<__is_tuple_like<_Tp>>,
2398  is_move_constructible<_Tp>,
2399  is_move_assignable<_Tp>>::value>::type
2400  swap(_Tp&, _Tp&)
2401  noexcept(__and_<is_nothrow_move_constructible<_Tp>,
2402  is_nothrow_move_assignable<_Tp>>::value);
2403 
2404  template<typename _Tp, size_t _Nm>
2405  inline
2406  typename enable_if<__is_swappable<_Tp>::value>::type
2407  swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
2408  noexcept(__is_nothrow_swappable<_Tp>::value);
2409 
2410  namespace __swappable_details {
2411  using std::swap;
2412 
2413  struct __do_is_swappable_impl
2414  {
2415  template<typename _Tp, typename
2416  = decltype(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))>
2417  static true_type __test(int);
2418 
2419  template<typename>
2420  static false_type __test(...);
2421  };
2422 
2423  struct __do_is_nothrow_swappable_impl
2424  {
2425  template<typename _Tp>
2426  static __bool_constant<
2427  noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))
2428  > __test(int);
2429 
2430  template<typename>
2431  static false_type __test(...);
2432  };
2433 
2434  } // namespace __swappable_details
2435 
2436  template<typename _Tp>
2437  struct __is_swappable_impl
2438  : public __swappable_details::__do_is_swappable_impl
2439  {
2440  typedef decltype(__test<_Tp>(0)) type;
2441  };
2442 
2443  template<typename _Tp>
2444  struct __is_nothrow_swappable_impl
2445  : public __swappable_details::__do_is_nothrow_swappable_impl
2446  {
2447  typedef decltype(__test<_Tp>(0)) type;
2448  };
2449 
2450  template<typename _Tp>
2451  struct __is_swappable
2452  : public __is_swappable_impl<_Tp>::type
2453  { };
2454 
2455  template<typename _Tp>
2456  struct __is_nothrow_swappable
2457  : public __is_nothrow_swappable_impl<_Tp>::type
2458  { };
2459 
2460 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
2461 #define __cpp_lib_is_swappable 201603
2462  /// Metafunctions used for detecting swappable types: p0185r1
2463 
2464  /// is_swappable
2465  template<typename _Tp>
2466  struct is_swappable
2467  : public __is_swappable_impl<_Tp>::type
2468  { };
2469 
2470  /// is_nothrow_swappable
2471  template<typename _Tp>
2472  struct is_nothrow_swappable
2473  : public __is_nothrow_swappable_impl<_Tp>::type
2474  { };
2475 
2476 #if __cplusplus >= 201402L
2477  /// is_swappable_v
2478  template<typename _Tp>
2479  _GLIBCXX17_INLINE constexpr bool is_swappable_v =
2480  is_swappable<_Tp>::value;
2481 
2482  /// is_nothrow_swappable_v
2483  template<typename _Tp>
2484  _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_v =
2485  is_nothrow_swappable<_Tp>::value;
2486 #endif // __cplusplus >= 201402L
2487 
2488  namespace __swappable_with_details {
2489  using std::swap;
2490 
2491  struct __do_is_swappable_with_impl
2492  {
2493  template<typename _Tp, typename _Up, typename
2494  = decltype(swap(std::declval<_Tp>(), std::declval<_Up>())),
2495  typename
2496  = decltype(swap(std::declval<_Up>(), std::declval<_Tp>()))>
2497  static true_type __test(int);
2498 
2499  template<typename, typename>
2500  static false_type __test(...);
2501  };
2502 
2503  struct __do_is_nothrow_swappable_with_impl
2504  {
2505  template<typename _Tp, typename _Up>
2506  static __bool_constant<
2507  noexcept(swap(std::declval<_Tp>(), std::declval<_Up>()))
2508  &&
2509  noexcept(swap(std::declval<_Up>(), std::declval<_Tp>()))
2510  > __test(int);
2511 
2512  template<typename, typename>
2513  static false_type __test(...);
2514  };
2515 
2516  } // namespace __swappable_with_details
2517 
2518  template<typename _Tp, typename _Up>
2519  struct __is_swappable_with_impl
2520  : public __swappable_with_details::__do_is_swappable_with_impl
2521  {
2522  typedef decltype(__test<_Tp, _Up>(0)) type;
2523  };
2524 
2525  // Optimization for the homogenous lvalue case, not required:
2526  template<typename _Tp>
2527  struct __is_swappable_with_impl<_Tp&, _Tp&>
2528  : public __swappable_details::__do_is_swappable_impl
2529  {
2530  typedef decltype(__test<_Tp&>(0)) type;
2531  };
2532 
2533  template<typename _Tp, typename _Up>
2534  struct __is_nothrow_swappable_with_impl
2535  : public __swappable_with_details::__do_is_nothrow_swappable_with_impl
2536  {
2537  typedef decltype(__test<_Tp, _Up>(0)) type;
2538  };
2539 
2540  // Optimization for the homogenous lvalue case, not required:
2541  template<typename _Tp>
2542  struct __is_nothrow_swappable_with_impl<_Tp&, _Tp&>
2543  : public __swappable_details::__do_is_nothrow_swappable_impl
2544  {
2545  typedef decltype(__test<_Tp&>(0)) type;
2546  };
2547 
2548  /// is_swappable_with
2549  template<typename _Tp, typename _Up>
2550  struct is_swappable_with
2551  : public __is_swappable_with_impl<_Tp, _Up>::type
2552  { };
2553 
2554  /// is_nothrow_swappable_with
2555  template<typename _Tp, typename _Up>
2556  struct is_nothrow_swappable_with
2557  : public __is_nothrow_swappable_with_impl<_Tp, _Up>::type
2558  { };
2559 
2560 #if __cplusplus >= 201402L
2561  /// is_swappable_with_v
2562  template<typename _Tp, typename _Up>
2563  _GLIBCXX17_INLINE constexpr bool is_swappable_with_v =
2564  is_swappable_with<_Tp, _Up>::value;
2565 
2566  /// is_nothrow_swappable_with_v
2567  template<typename _Tp, typename _Up>
2568  _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_with_v =
2569  is_nothrow_swappable_with<_Tp, _Up>::value;
2570 #endif // __cplusplus >= 201402L
2571 
2572 #endif// c++1z or gnu++11
2573 
2574  // __is_invocable (std::is_invocable for C++11)
2575 
2576  template<typename _Result, typename _Ret, typename = void>
2577  struct __is_invocable_impl : false_type { };
2578 
2579  template<typename _Result, typename _Ret>
2580  struct __is_invocable_impl<_Result, _Ret, __void_t<typename _Result::type>>
2581  : __or_<is_void<_Ret>, is_convertible<typename _Result::type, _Ret>>::type
2582  { };
2583 
2584  template<typename _Fn, typename... _ArgTypes>
2585  struct __is_invocable
2586  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2587  { };
2588 
2589  template<typename _Fn, typename _Tp, typename... _Args>
2590  constexpr bool __call_is_nt(__invoke_memfun_ref)
2591  {
2592  using _Up = typename __inv_unwrap<_Tp>::type;
2593  return noexcept((std::declval<_Up>().*std::declval<_Fn>())(
2594  std::declval<_Args>()...));
2595  }
2596 
2597  template<typename _Fn, typename _Tp, typename... _Args>
2598  constexpr bool __call_is_nt(__invoke_memfun_deref)
2599  {
2600  return noexcept(((*std::declval<_Tp>()).*std::declval<_Fn>())(
2601  std::declval<_Args>()...));
2602  }
2603 
2604  template<typename _Fn, typename _Tp>
2605  constexpr bool __call_is_nt(__invoke_memobj_ref)
2606  {
2607  using _Up = typename __inv_unwrap<_Tp>::type;
2608  return noexcept(std::declval<_Up>().*std::declval<_Fn>());
2609  }
2610 
2611  template<typename _Fn, typename _Tp>
2612  constexpr bool __call_is_nt(__invoke_memobj_deref)
2613  {
2614  return noexcept((*std::declval<_Tp>()).*std::declval<_Fn>());
2615  }
2616 
2617  template<typename _Fn, typename... _Args>
2618  constexpr bool __call_is_nt(__invoke_other)
2619  {
2620  return noexcept(std::declval<_Fn>()(std::declval<_Args>()...));
2621  }
2622 
2623  template<typename _Result, typename _Fn, typename... _Args>
2624  struct __call_is_nothrow
2625  : __bool_constant<
2626  std::__call_is_nt<_Fn, _Args...>(typename _Result::__invoke_type{})
2627  >
2628  { };
2629 
2630  template<typename _Fn, typename... _Args>
2631  using __call_is_nothrow_
2632  = __call_is_nothrow<__invoke_result<_Fn, _Args...>, _Fn, _Args...>;
2633 
2634  // __is_nothrow_invocable (std::is_nothrow_invocable for C++11)
2635  template<typename _Fn, typename... _Args>
2636  struct __is_nothrow_invocable
2637  : __and_<__is_invocable<_Fn, _Args...>,
2638  __call_is_nothrow_<_Fn, _Args...>>::type
2639  { };
2640 
2641  struct __nonesuch {
2642  __nonesuch() = delete;
2643  ~__nonesuch() = delete;
2644  __nonesuch(__nonesuch const&) = delete;
2645  void operator=(__nonesuch const&) = delete;
2646  };
2647 
2648 #if __cplusplus >= 201703L
2649 # define __cpp_lib_is_invocable 201703
2650 
2651  /// std::invoke_result
2652  template<typename _Functor, typename... _ArgTypes>
2653  struct invoke_result
2654  : public __invoke_result<_Functor, _ArgTypes...>
2655  { };
2656 
2657  /// std::invoke_result_t
2658  template<typename _Fn, typename... _Args>
2659  using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
2660 
2661  /// std::is_invocable
2662  template<typename _Fn, typename... _ArgTypes>
2663  struct is_invocable
2664  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2665  { };
2666 
2667  /// std::is_invocable_r
2668  template<typename _Ret, typename _Fn, typename... _ArgTypes>
2669  struct is_invocable_r
2670  : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>::type
2671  { };
2672 
2673  /// std::is_nothrow_invocable
2674  template<typename _Fn, typename... _ArgTypes>
2675  struct is_nothrow_invocable
2676  : __and_<__is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>,
2677  __call_is_nothrow_<_Fn, _ArgTypes...>>::type
2678  { };
2679 
2680  template<typename _Result, typename _Ret, typename = void>
2681  struct __is_nt_invocable_impl : false_type { };
2682 
2683  template<typename _Result, typename _Ret>
2684  struct __is_nt_invocable_impl<_Result, _Ret,
2685  __void_t<typename _Result::type>>
2686  : __or_<is_void<_Ret>,
2687  __and_<is_convertible<typename _Result::type, _Ret>,
2688  is_nothrow_constructible<_Ret, typename _Result::type>>>
2689  { };
2690 
2691  /// std::is_nothrow_invocable_r
2692  template<typename _Ret, typename _Fn, typename... _ArgTypes>
2693  struct is_nothrow_invocable_r
2694  : __and_<__is_nt_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>,
2695  __call_is_nothrow_<_Fn, _ArgTypes...>>::type
2696  { };
2697 
2698  /// std::is_invocable_v
2699  template<typename _Fn, typename... _Args>
2700  inline constexpr bool is_invocable_v = is_invocable<_Fn, _Args...>::value;
2701 
2702  /// std::is_nothrow_invocable_v
2703  template<typename _Fn, typename... _Args>
2704  inline constexpr bool is_nothrow_invocable_v
2705  = is_nothrow_invocable<_Fn, _Args...>::value;
2706 
2707  /// std::is_invocable_r_v
2708  template<typename _Fn, typename... _Args>
2709  inline constexpr bool is_invocable_r_v
2710  = is_invocable_r<_Fn, _Args...>::value;
2711 
2712  /// std::is_nothrow_invocable_r_v
2713  template<typename _Fn, typename... _Args>
2714  inline constexpr bool is_nothrow_invocable_r_v
2715  = is_nothrow_invocable_r<_Fn, _Args...>::value;
2716 #endif // C++17
2717 
2718 #if __cplusplus >= 201703L
2719 # define __cpp_lib_type_trait_variable_templates 201510L
2720 template <typename _Tp>
2721  inline constexpr bool is_void_v = is_void<_Tp>::value;
2722 template <typename _Tp>
2723  inline constexpr bool is_null_pointer_v = is_null_pointer<_Tp>::value;
2724 template <typename _Tp>
2725  inline constexpr bool is_integral_v = is_integral<_Tp>::value;
2726 template <typename _Tp>
2727  inline constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
2728 template <typename _Tp>
2729  inline constexpr bool is_array_v = is_array<_Tp>::value;
2730 template <typename _Tp>
2731  inline constexpr bool is_pointer_v = is_pointer<_Tp>::value;
2732 template <typename _Tp>
2733  inline constexpr bool is_lvalue_reference_v =
2734  is_lvalue_reference<_Tp>::value;
2735 template <typename _Tp>
2736  inline constexpr bool is_rvalue_reference_v =
2737  is_rvalue_reference<_Tp>::value;
2738 template <typename _Tp>
2739  inline constexpr bool is_member_object_pointer_v =
2740  is_member_object_pointer<_Tp>::value;
2741 template <typename _Tp>
2742  inline constexpr bool is_member_function_pointer_v =
2743  is_member_function_pointer<_Tp>::value;
2744 template <typename _Tp>
2745  inline constexpr bool is_enum_v = is_enum<_Tp>::value;
2746 template <typename _Tp>
2747  inline constexpr bool is_union_v = is_union<_Tp>::value;
2748 template <typename _Tp>
2749  inline constexpr bool is_class_v = is_class<_Tp>::value;
2750 template <typename _Tp>
2751  inline constexpr bool is_function_v = is_function<_Tp>::value;
2752 template <typename _Tp>
2753  inline constexpr bool is_reference_v = is_reference<_Tp>::value;
2754 template <typename _Tp>
2755  inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
2756 template <typename _Tp>
2757  inline constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
2758 template <typename _Tp>
2759  inline constexpr bool is_object_v = is_object<_Tp>::value;
2760 template <typename _Tp>
2761  inline constexpr bool is_scalar_v = is_scalar<_Tp>::value;
2762 template <typename _Tp>
2763  inline constexpr bool is_compound_v = is_compound<_Tp>::value;
2764 template <typename _Tp>
2765  inline constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value;
2766 template <typename _Tp>
2767  inline constexpr bool is_const_v = is_const<_Tp>::value;
2768 template <typename _Tp>
2769  inline constexpr bool is_volatile_v = is_volatile<_Tp>::value;
2770 template <typename _Tp>
2771  inline constexpr bool is_trivial_v = is_trivial<_Tp>::value;
2772 template <typename _Tp>
2773  inline constexpr bool is_trivially_copyable_v =
2774  is_trivially_copyable<_Tp>::value;
2775 template <typename _Tp>
2776  inline constexpr bool is_standard_layout_v = is_standard_layout<_Tp>::value;
2777 template <typename _Tp>
2778  inline constexpr bool is_pod_v = is_pod<_Tp>::value;
2779 template <typename _Tp>
2780  inline constexpr bool is_literal_type_v = is_literal_type<_Tp>::value;
2781 template <typename _Tp>
2782  inline constexpr bool is_empty_v = is_empty<_Tp>::value;
2783 template <typename _Tp>
2784  inline constexpr bool is_polymorphic_v = is_polymorphic<_Tp>::value;
2785 template <typename _Tp>
2786  inline constexpr bool is_abstract_v = is_abstract<_Tp>::value;
2787 template <typename _Tp>
2788  inline constexpr bool is_final_v = is_final<_Tp>::value;
2789 template <typename _Tp>
2790  inline constexpr bool is_signed_v = is_signed<_Tp>::value;
2791 template <typename _Tp>
2792  inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
2793 template <typename _Tp, typename... _Args>
2794  inline constexpr bool is_constructible_v =
2795  is_constructible<_Tp, _Args...>::value;
2796 template <typename _Tp>
2797  inline constexpr bool is_default_constructible_v =
2798  is_default_constructible<_Tp>::value;
2799 template <typename _Tp>
2800  inline constexpr bool is_copy_constructible_v =
2801  is_copy_constructible<_Tp>::value;
2802 template <typename _Tp>
2803  inline constexpr bool is_move_constructible_v =
2804  is_move_constructible<_Tp>::value;
2805 template <typename _Tp, typename _Up>
2806  inline constexpr bool is_assignable_v = is_assignable<_Tp, _Up>::value;
2807 template <typename _Tp>
2808  inline constexpr bool is_copy_assignable_v = is_copy_assignable<_Tp>::value;
2809 template <typename _Tp>
2810  inline constexpr bool is_move_assignable_v = is_move_assignable<_Tp>::value;
2811 template <typename _Tp>
2812  inline constexpr bool is_destructible_v = is_destructible<_Tp>::value;
2813 template <typename _Tp, typename... _Args>
2814  inline constexpr bool is_trivially_constructible_v =
2815  is_trivially_constructible<_Tp, _Args...>::value;
2816 template <typename _Tp>
2817  inline constexpr bool is_trivially_default_constructible_v =
2818  is_trivially_default_constructible<_Tp>::value;
2819 template <typename _Tp>
2820  inline constexpr bool is_trivially_copy_constructible_v =
2821  is_trivially_copy_constructible<_Tp>::value;
2822 template <typename _Tp>
2823  inline constexpr bool is_trivially_move_constructible_v =
2824  is_trivially_move_constructible<_Tp>::value;
2825 template <typename _Tp, typename _Up>
2826  inline constexpr bool is_trivially_assignable_v =
2827  is_trivially_assignable<_Tp, _Up>::value;
2828 template <typename _Tp>
2829  inline constexpr bool is_trivially_copy_assignable_v =
2830  is_trivially_copy_assignable<_Tp>::value;
2831 template <typename _Tp>
2832  inline constexpr bool is_trivially_move_assignable_v =
2833  is_trivially_move_assignable<_Tp>::value;
2834 template <typename _Tp>
2835  inline constexpr bool is_trivially_destructible_v =
2836  is_trivially_destructible<_Tp>::value;
2837 template <typename _Tp, typename... _Args>
2838  inline constexpr bool is_nothrow_constructible_v =
2839  is_nothrow_constructible<_Tp, _Args...>::value;
2840 template <typename _Tp>
2841  inline constexpr bool is_nothrow_default_constructible_v =
2842  is_nothrow_default_constructible<_Tp>::value;
2843 template <typename _Tp>
2844  inline constexpr bool is_nothrow_copy_constructible_v =
2845  is_nothrow_copy_constructible<_Tp>::value;
2846 template <typename _Tp>
2847  inline constexpr bool is_nothrow_move_constructible_v =
2848  is_nothrow_move_constructible<_Tp>::value;
2849 template <typename _Tp, typename _Up>
2850  inline constexpr bool is_nothrow_assignable_v =
2851  is_nothrow_assignable<_Tp, _Up>::value;
2852 template <typename _Tp>
2853  inline constexpr bool is_nothrow_copy_assignable_v =
2854  is_nothrow_copy_assignable<_Tp>::value;
2855 template <typename _Tp>
2856  inline constexpr bool is_nothrow_move_assignable_v =
2857  is_nothrow_move_assignable<_Tp>::value;
2858 template <typename _Tp>
2859  inline constexpr bool is_nothrow_destructible_v =
2860  is_nothrow_destructible<_Tp>::value;
2861 template <typename _Tp>
2862  inline constexpr bool has_virtual_destructor_v =
2863  has_virtual_destructor<_Tp>::value;
2864 template <typename _Tp>
2865  inline constexpr size_t alignment_of_v = alignment_of<_Tp>::value;
2866 template <typename _Tp>
2867  inline constexpr size_t rank_v = rank<_Tp>::value;
2868 template <typename _Tp, unsigned _Idx = 0>
2869  inline constexpr size_t extent_v = extent<_Tp, _Idx>::value;
2870 template <typename _Tp, typename _Up>
2871  inline constexpr bool is_same_v = is_same<_Tp, _Up>::value;
2872 template <typename _Base, typename _Derived>
2873  inline constexpr bool is_base_of_v = is_base_of<_Base, _Derived>::value;
2874 template <typename _From, typename _To>
2875  inline constexpr bool is_convertible_v = is_convertible<_From, _To>::value;
2876 
2877 #if __GNUC__ >= 7
2878 # define _GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP 1
2879 #elif defined(__is_identifier)
2880 // For non-GNU compilers:
2881 # if ! __is_identifier(__has_unique_object_representations)
2882 # define _GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP 1
2883 # endif
2884 #endif
2885 
2886 #ifdef _GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP
2887 # define __cpp_lib_has_unique_object_representations 201606
2888  /// has_unique_object_representations
2889  template<typename _Tp>
2890  struct has_unique_object_representations
2891  : bool_constant<__has_unique_object_representations(
2892  remove_cv_t<remove_all_extents_t<_Tp>>
2893  )>
2894  { };
2895 
2896  template<typename _Tp>
2897  inline constexpr bool has_unique_object_representations_v
2898  = has_unique_object_representations<_Tp>::value;
2899 #endif
2900 #undef _GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP
2901 
2902 #if __GNUC__ >= 7
2903 # define _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE 1
2904 #elif defined(__is_identifier)
2905 // For non-GNU compilers:
2906 # if ! __is_identifier(__is_aggregate)
2907 # define _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE 1
2908 # endif
2909 #endif
2910 
2911 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE
2912 #define __cpp_lib_is_aggregate 201703
2913  /// is_aggregate
2914  template<typename _Tp>
2915  struct is_aggregate
2916  : bool_constant<__is_aggregate(remove_cv_t<_Tp>)> { };
2917 
2918  /// is_aggregate_v
2919  template<typename _Tp>
2920  inline constexpr bool is_aggregate_v = is_aggregate<_Tp>::value;
2921 #endif
2922 #undef _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE
2923 
2924 #endif // C++17
2925 
2926 #if __cplusplus > 201703L
2927  /// Byte order
2928  enum class endian
2929  {
2930  little = __ORDER_LITTLE_ENDIAN__,
2931  big = __ORDER_BIG_ENDIAN__,
2932  native = __BYTE_ORDER__
2933  };
2934 #endif // C++2a
2935 
2936 _GLIBCXX_END_NAMESPACE_VERSION
2937 } // namespace std
2938 
2939 #endif // C++11
2940 
2941 #endif // _GLIBCXX_TYPE_TRAITS