type_traits revision 300770
1// -*- C++ -*-
2//===------------------------ type_traits ---------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_TYPE_TRAITS
12#define _LIBCPP_TYPE_TRAITS
13
14/*
15    type_traits synopsis
16
17namespace std
18{
19
20    // helper class:
21    template <class T, T v> struct integral_constant;
22    typedef integral_constant<bool, true>  true_type;   // C++11
23    typedef integral_constant<bool, false> false_type;  // C++11
24    
25    template <bool B>                                   // C++14
26    using bool_constant = integral_constant<bool, B>;   // C++14
27    typedef bool_constant<true> true_type;              // C++14
28    typedef bool_constant<false> false_type;            // C++14
29
30    // helper traits
31    template <bool, class T = void> struct enable_if;
32    template <bool, class T, class F> struct conditional;
33
34    // Primary classification traits:
35    template <class T> struct is_void;
36    template <class T> struct is_null_pointer;  // C++14
37    template <class T> struct is_integral;
38    template <class T> struct is_floating_point;
39    template <class T> struct is_array;
40    template <class T> struct is_pointer;
41    template <class T> struct is_lvalue_reference;
42    template <class T> struct is_rvalue_reference;
43    template <class T> struct is_member_object_pointer;
44    template <class T> struct is_member_function_pointer;
45    template <class T> struct is_enum;
46    template <class T> struct is_union;
47    template <class T> struct is_class;
48    template <class T> struct is_function;
49
50    // Secondary classification traits:
51    template <class T> struct is_reference;
52    template <class T> struct is_arithmetic;
53    template <class T> struct is_fundamental;
54    template <class T> struct is_member_pointer;
55    template <class T> struct is_scalar;
56    template <class T> struct is_object;
57    template <class T> struct is_compound;
58
59    // Const-volatile properties and transformations:
60    template <class T> struct is_const;
61    template <class T> struct is_volatile;
62    template <class T> struct remove_const;
63    template <class T> struct remove_volatile;
64    template <class T> struct remove_cv;
65    template <class T> struct add_const;
66    template <class T> struct add_volatile;
67    template <class T> struct add_cv;
68
69    // Reference transformations:
70    template <class T> struct remove_reference;
71    template <class T> struct add_lvalue_reference;
72    template <class T> struct add_rvalue_reference;
73
74    // Pointer transformations:
75    template <class T> struct remove_pointer;
76    template <class T> struct add_pointer;
77
78    // Integral properties:
79    template <class T> struct is_signed;
80    template <class T> struct is_unsigned;
81    template <class T> struct make_signed;
82    template <class T> struct make_unsigned;
83
84    // Array properties and transformations:
85    template <class T> struct rank;
86    template <class T, unsigned I = 0> struct extent;
87    template <class T> struct remove_extent;
88    template <class T> struct remove_all_extents;
89
90    // Member introspection:
91    template <class T> struct is_pod;
92    template <class T> struct is_trivial;
93    template <class T> struct is_trivially_copyable;
94    template <class T> struct is_standard_layout;
95    template <class T> struct is_literal_type;
96    template <class T> struct is_empty;
97    template <class T> struct is_polymorphic;
98    template <class T> struct is_abstract;
99    template <class T> struct is_final; // C++14
100
101    template <class T, class... Args> struct is_constructible;
102    template <class T>                struct is_default_constructible;
103    template <class T>                struct is_copy_constructible;
104    template <class T>                struct is_move_constructible;
105    template <class T, class U>       struct is_assignable;
106    template <class T>                struct is_copy_assignable;
107    template <class T>                struct is_move_assignable;
108    template <class T>                struct is_destructible;
109
110    template <class T, class... Args> struct is_trivially_constructible;
111    template <class T>                struct is_trivially_default_constructible;
112    template <class T>                struct is_trivially_copy_constructible;
113    template <class T>                struct is_trivially_move_constructible;
114    template <class T, class U>       struct is_trivially_assignable;
115    template <class T>                struct is_trivially_copy_assignable;
116    template <class T>                struct is_trivially_move_assignable;
117    template <class T>                struct is_trivially_destructible;
118
119    template <class T, class... Args> struct is_nothrow_constructible;
120    template <class T>                struct is_nothrow_default_constructible;
121    template <class T>                struct is_nothrow_copy_constructible;
122    template <class T>                struct is_nothrow_move_constructible;
123    template <class T, class U>       struct is_nothrow_assignable;
124    template <class T>                struct is_nothrow_copy_assignable;
125    template <class T>                struct is_nothrow_move_assignable;
126    template <class T>                struct is_nothrow_destructible;
127
128    template <class T> struct has_virtual_destructor;
129
130    // Relationships between types:
131    template <class T, class U> struct is_same;
132    template <class Base, class Derived> struct is_base_of;
133    template <class From, class To> struct is_convertible;
134
135    // Alignment properties and transformations:
136    template <class T> struct alignment_of;
137    template <size_t Len, size_t Align = most_stringent_alignment_requirement>
138        struct aligned_storage;
139    template <size_t Len, class... Types> struct aligned_union;
140
141    template <class T> struct decay;
142    template <class... T> struct common_type;
143    template <class T> struct underlying_type;
144    template <class> class result_of; // undefined
145    template <class Fn, class... ArgTypes> class result_of<Fn(ArgTypes...)>;
146
147    // const-volatile modifications:
148    template <class T>
149      using remove_const_t    = typename remove_const<T>::type;  // C++14
150    template <class T>
151      using remove_volatile_t = typename remove_volatile<T>::type;  // C++14
152    template <class T>
153      using remove_cv_t       = typename remove_cv<T>::type;  // C++14
154    template <class T>
155      using add_const_t       = typename add_const<T>::type;  // C++14
156    template <class T>
157      using add_volatile_t    = typename add_volatile<T>::type;  // C++14
158    template <class T>
159      using add_cv_t          = typename add_cv<T>::type;  // C++14
160  
161    // reference modifications:
162    template <class T>
163      using remove_reference_t     = typename remove_reference<T>::type;  // C++14
164    template <class T>
165      using add_lvalue_reference_t = typename add_lvalue_reference<T>::type;  // C++14
166    template <class T>
167      using add_rvalue_reference_t = typename add_rvalue_reference<T>::type;  // C++14
168  
169    // sign modifications:
170    template <class T>
171      using make_signed_t   = typename make_signed<T>::type;  // C++14
172    template <class T>
173      using make_unsigned_t = typename make_unsigned<T>::type;  // C++14
174  
175    // array modifications:
176    template <class T>
177      using remove_extent_t      = typename remove_extent<T>::type;  // C++14
178    template <class T>
179      using remove_all_extents_t = typename remove_all_extents<T>::type;  // C++14
180
181    // pointer modifications:
182    template <class T>
183      using remove_pointer_t = typename remove_pointer<T>::type;  // C++14
184    template <class T>
185      using add_pointer_t    = typename add_pointer<T>::type;  // C++14
186
187    // other transformations:
188    template <size_t Len, std::size_t Align=default-alignment>
189      using aligned_storage_t = typename aligned_storage<Len,Align>::type;  // C++14
190    template <std::size_t Len, class... Types>
191      using aligned_union_t   = typename aligned_union<Len,Types...>::type;  // C++14
192    template <class T>
193      using decay_t           = typename decay<T>::type;  // C++14
194    template <bool b, class T=void>
195      using enable_if_t       = typename enable_if<b,T>::type;  // C++14
196    template <bool b, class T, class F>
197      using conditional_t     = typename conditional<b,T,F>::type;  // C++14
198    template <class... T>
199      using common_type_t     = typename common_type<T...>::type;  // C++14
200    template <class T>
201      using underlying_type_t = typename underlying_type<T>::type;  // C++14
202    template <class F, class... ArgTypes>
203      using result_of_t       = typename result_of<F(ArgTypes...)>::type;  // C++14
204
205    template <class...>
206      using void_t = void;   // C++17
207      
208      // See C++14 20.10.4.1, primary type categories
209      template <class T> constexpr bool is_void_v
210        = is_void<T>::value;                                             // C++17
211      template <class T> constexpr bool is_null_pointer_v
212        = is_null_pointer<T>::value;                                     // C++17
213      template <class T> constexpr bool is_integral_v
214        = is_integral<T>::value;                                         // C++17
215      template <class T> constexpr bool is_floating_point_v
216        = is_floating_point<T>::value;                                   // C++17
217      template <class T> constexpr bool is_array_v
218        = is_array<T>::value;                                            // C++17
219      template <class T> constexpr bool is_pointer_v
220        = is_pointer<T>::value;                                          // C++17
221      template <class T> constexpr bool is_lvalue_reference_v
222        = is_lvalue_reference<T>::value;                                 // C++17
223      template <class T> constexpr bool is_rvalue_reference_v
224        = is_rvalue_reference<T>::value;                                 // C++17
225      template <class T> constexpr bool is_member_object_pointer_v
226        = is_member_object_pointer<T>::value;                            // C++17
227      template <class T> constexpr bool is_member_function_pointer_v
228        = is_member_function_pointer<T>::value;                          // C++17
229      template <class T> constexpr bool is_enum_v
230        = is_enum<T>::value;                                             // C++17
231      template <class T> constexpr bool is_union_v
232        = is_union<T>::value;                                            // C++17
233      template <class T> constexpr bool is_class_v
234        = is_class<T>::value;                                            // C++17
235      template <class T> constexpr bool is_function_v
236        = is_function<T>::value;                                         // C++17
237
238      // See C++14 20.10.4.2, composite type categories
239      template <class T> constexpr bool is_reference_v
240        = is_reference<T>::value;                                        // C++17
241      template <class T> constexpr bool is_arithmetic_v
242        = is_arithmetic<T>::value;                                       // C++17
243      template <class T> constexpr bool is_fundamental_v
244        = is_fundamental<T>::value;                                      // C++17
245      template <class T> constexpr bool is_object_v
246        = is_object<T>::value;                                           // C++17
247      template <class T> constexpr bool is_scalar_v
248        = is_scalar<T>::value;                                           // C++17
249      template <class T> constexpr bool is_compound_v
250        = is_compound<T>::value;                                         // C++17
251      template <class T> constexpr bool is_member_pointer_v
252        = is_member_pointer<T>::value;                                   // C++17
253
254      // See C++14 20.10.4.3, type properties
255      template <class T> constexpr bool is_const_v
256        = is_const<T>::value;                                            // C++17
257      template <class T> constexpr bool is_volatile_v
258        = is_volatile<T>::value;                                         // C++17
259      template <class T> constexpr bool is_trivial_v
260        = is_trivial<T>::value;                                          // C++17
261      template <class T> constexpr bool is_trivially_copyable_v
262        = is_trivially_copyable<T>::value;                               // C++17
263      template <class T> constexpr bool is_standard_layout_v
264        = is_standard_layout<T>::value;                                  // C++17
265      template <class T> constexpr bool is_pod_v
266        = is_pod<T>::value;                                              // C++17
267      template <class T> constexpr bool is_literal_type_v
268        = is_literal_type<T>::value;                                     // C++17
269      template <class T> constexpr bool is_empty_v
270        = is_empty<T>::value;                                            // C++17
271      template <class T> constexpr bool is_polymorphic_v
272        = is_polymorphic<T>::value;                                      // C++17
273      template <class T> constexpr bool is_abstract_v
274        = is_abstract<T>::value;                                         // C++17
275      template <class T> constexpr bool is_final_v
276        = is_final<T>::value;                                            // C++17
277      template <class T> constexpr bool is_signed_v
278        = is_signed<T>::value;                                           // C++17
279      template <class T> constexpr bool is_unsigned_v
280        = is_unsigned<T>::value;                                         // C++17
281      template <class T, class... Args> constexpr bool is_constructible_v
282        = is_constructible<T, Args...>::value;                           // C++17
283      template <class T> constexpr bool is_default_constructible_v
284        = is_default_constructible<T>::value;                            // C++17
285      template <class T> constexpr bool is_copy_constructible_v
286        = is_copy_constructible<T>::value;                               // C++17
287      template <class T> constexpr bool is_move_constructible_v
288        = is_move_constructible<T>::value;                               // C++17
289      template <class T, class U> constexpr bool is_assignable_v
290        = is_assignable<T, U>::value;                                    // C++17
291      template <class T> constexpr bool is_copy_assignable_v
292        = is_copy_assignable<T>::value;                                  // C++17
293      template <class T> constexpr bool is_move_assignable_v
294        = is_move_assignable<T>::value;                                  // C++17
295      template <class T> constexpr bool is_destructible_v
296        = is_destructible<T>::value;                                     // C++17
297      template <class T, class... Args> constexpr bool is_trivially_constructible_v
298        = is_trivially_constructible<T, Args...>::value;                 // C++17
299      template <class T> constexpr bool is_trivially_default_constructible_v
300        = is_trivially_default_constructible<T>::value;                  // C++17
301      template <class T> constexpr bool is_trivially_copy_constructible_v
302        = is_trivially_copy_constructible<T>::value;                     // C++17
303      template <class T> constexpr bool is_trivially_move_constructible_v
304        = is_trivially_move_constructible<T>::value;                     // C++17
305      template <class T, class U> constexpr bool is_trivially_assignable_v
306        = is_trivially_assignable<T, U>::value;                          // C++17
307      template <class T> constexpr bool is_trivially_copy_assignable_v
308        = is_trivially_copy_assignable<T>::value;                        // C++17
309      template <class T> constexpr bool is_trivially_move_assignable_v
310        = is_trivially_move_assignable<T>::value;                        // C++17
311      template <class T> constexpr bool is_trivially_destructible_v
312        = is_trivially_destructible<T>::value;                           // C++17
313      template <class T, class... Args> constexpr bool is_nothrow_constructible_v
314        = is_nothrow_constructible<T, Args...>::value;                   // C++17
315      template <class T> constexpr bool is_nothrow_default_constructible_v
316        = is_nothrow_default_constructible<T>::value;                    // C++17
317      template <class T> constexpr bool is_nothrow_copy_constructible_v
318        = is_nothrow_copy_constructible<T>::value;                       // C++17
319      template <class T> constexpr bool is_nothrow_move_constructible_v
320        = is_nothrow_move_constructible<T>::value;                       // C++17
321      template <class T, class U> constexpr bool is_nothrow_assignable_v
322        = is_nothrow_assignable<T, U>::value;                            // C++17
323      template <class T> constexpr bool is_nothrow_copy_assignable_v
324        = is_nothrow_copy_assignable<T>::value;                          // C++17
325      template <class T> constexpr bool is_nothrow_move_assignable_v
326        = is_nothrow_move_assignable<T>::value;                          // C++17
327      template <class T> constexpr bool is_nothrow_destructible_v
328        = is_nothrow_destructible<T>::value;                             // C++17
329      template <class T> constexpr bool has_virtual_destructor_v
330        = has_virtual_destructor<T>::value;                              // C++17
331
332      // See C++14 20.10.5, type property queries
333      template <class T> constexpr size_t alignment_of_v
334        = alignment_of<T>::value;                                        // C++17
335      template <class T> constexpr size_t rank_v
336        = rank<T>::value;                                                // C++17
337      template <class T, unsigned I = 0> constexpr size_t extent_v
338        = extent<T, I>::value;                                           // C++17
339
340      // See C++14 20.10.6, type relations
341      template <class T, class U> constexpr bool is_same_v
342        = is_same<T, U>::value;                                          // C++17
343      template <class Base, class Derived> constexpr bool is_base_of_v
344        = is_base_of<Base, Derived>::value;                              // C++17
345      template <class From, class To> constexpr bool is_convertible_v
346        = is_convertible<From, To>::value;                               // C++17
347
348      // [meta.logical], logical operator traits:
349      template<class... B> struct conjunction;                           // C++17
350      template<class... B> 
351        constexpr bool conjunction_v = conjunction<B...>::value;         // C++17
352      template<class... B> struct disjunction;                           // C++17
353      template<class... B>
354        constexpr bool disjunction_v = disjunction<B...>::value;         // C++17
355      template<class B> struct negation;                                 // C++17
356      template<class B> 
357        constexpr bool negation_v = negation<B>::value;                  // C++17
358
359}
360
361*/
362#include <__config>
363#include <cstddef>
364
365#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
366#pragma GCC system_header
367#endif
368
369_LIBCPP_BEGIN_NAMESPACE_STD
370
371template <class>
372struct __void_t { typedef void type; };
373
374template <class _Tp>
375struct __identity { typedef _Tp type; };
376
377template <class _Tp, bool>
378struct _LIBCPP_TYPE_VIS_ONLY __dependent_type : public _Tp {};
379
380template <bool _Bp, class _If, class _Then>
381    struct _LIBCPP_TYPE_VIS_ONLY conditional {typedef _If type;};
382template <class _If, class _Then>
383    struct _LIBCPP_TYPE_VIS_ONLY conditional<false, _If, _Then> {typedef _Then type;};
384
385#if _LIBCPP_STD_VER > 11
386template <bool _Bp, class _If, class _Then> using conditional_t = typename conditional<_Bp, _If, _Then>::type;
387#endif
388
389template <bool, class _Tp> struct _LIBCPP_TYPE_VIS_ONLY __lazy_enable_if {};
390template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY __lazy_enable_if<true, _Tp> {typedef typename _Tp::type type;};
391
392template <bool, class _Tp = void> struct _LIBCPP_TYPE_VIS_ONLY enable_if {};
393template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY enable_if<true, _Tp> {typedef _Tp type;};
394
395#if _LIBCPP_STD_VER > 11
396template <bool _Bp, class _Tp = void> using enable_if_t = typename enable_if<_Bp, _Tp>::type;
397#endif
398
399// addressof
400
401template <class _Tp>
402inline _LIBCPP_INLINE_VISIBILITY
403_Tp*
404addressof(_Tp& __x) _NOEXCEPT
405{
406    return (_Tp*)&reinterpret_cast<const volatile char&>(__x);
407}
408
409#if defined(_LIBCPP_HAS_OBJC_ARC) && !defined(_LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF)
410// Objective-C++ Automatic Reference Counting uses qualified pointers
411// that require special addressof() signatures. When
412// _LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF is defined, the compiler
413// itself is providing these definitions. Otherwise, we provide them.
414template <class _Tp>
415inline _LIBCPP_INLINE_VISIBILITY
416__strong _Tp*
417addressof(__strong _Tp& __x) _NOEXCEPT
418{
419  return &__x;
420}
421
422#ifdef _LIBCPP_HAS_OBJC_ARC_WEAK
423template <class _Tp>
424inline _LIBCPP_INLINE_VISIBILITY
425__weak _Tp*
426addressof(__weak _Tp& __x) _NOEXCEPT
427{
428  return &__x;
429}
430#endif
431
432template <class _Tp>
433inline _LIBCPP_INLINE_VISIBILITY
434__autoreleasing _Tp*
435addressof(__autoreleasing _Tp& __x) _NOEXCEPT
436{
437  return &__x;
438}
439
440template <class _Tp>
441inline _LIBCPP_INLINE_VISIBILITY
442__unsafe_unretained _Tp*
443addressof(__unsafe_unretained _Tp& __x) _NOEXCEPT
444{
445  return &__x;
446}
447#endif
448
449struct __two {char __lx[2];};
450
451// helper class:
452
453template <class _Tp, _Tp __v>
454struct _LIBCPP_TYPE_VIS_ONLY integral_constant
455{
456    static _LIBCPP_CONSTEXPR const _Tp      value = __v;
457    typedef _Tp               value_type;
458    typedef integral_constant type;
459    _LIBCPP_INLINE_VISIBILITY
460        _LIBCPP_CONSTEXPR operator value_type() const _NOEXCEPT {return value;}
461#if _LIBCPP_STD_VER > 11
462    _LIBCPP_INLINE_VISIBILITY
463         constexpr value_type operator ()() const _NOEXCEPT {return value;}
464#endif
465};
466
467template <class _Tp, _Tp __v>
468_LIBCPP_CONSTEXPR const _Tp integral_constant<_Tp, __v>::value;
469
470#if _LIBCPP_STD_VER > 14
471template <bool __b>
472using bool_constant = integral_constant<bool, __b>;
473#define _LIBCPP_BOOL_CONSTANT(__b) bool_constant<(__b)>
474#else
475#define _LIBCPP_BOOL_CONSTANT(__b) integral_constant<bool,(__b)>
476#endif
477
478typedef _LIBCPP_BOOL_CONSTANT(true)  true_type;
479typedef _LIBCPP_BOOL_CONSTANT(false) false_type;
480
481#if !defined(_LIBCPP_HAS_NO_VARIADICS)
482
483// __lazy_and
484
485template <bool _Last, class ..._Preds>
486struct __lazy_and_impl;
487
488template <class ..._Preds>
489struct __lazy_and_impl<false, _Preds...> : false_type {};
490
491template <>
492struct __lazy_and_impl<true> : true_type {};
493
494template <class _Pred>
495struct __lazy_and_impl<true, _Pred> : integral_constant<bool, _Pred::type::value> {};
496
497template <class _Hp, class ..._Tp>
498struct __lazy_and_impl<true, _Hp, _Tp...> : __lazy_and_impl<_Hp::type::value, _Tp...> {};
499
500template <class _P1, class ..._Pr>
501struct __lazy_and : __lazy_and_impl<_P1::type::value, _Pr...> {};
502
503// __lazy_or
504
505template <bool _List, class ..._Preds>
506struct __lazy_or_impl;
507
508template <class ..._Preds>
509struct __lazy_or_impl<true, _Preds...> : true_type {};
510
511template <>
512struct __lazy_or_impl<false> : false_type {};
513
514template <class _Hp, class ..._Tp>
515struct __lazy_or_impl<false, _Hp, _Tp...>
516        : __lazy_or_impl<_Hp::type::value, _Tp...> {};
517
518template <class _P1, class ..._Pr>
519struct __lazy_or : __lazy_or_impl<_P1::type::value, _Pr...> {};
520
521// __lazy_not
522
523template <class _Pred>
524struct __lazy_not : integral_constant<bool, !_Pred::type::value> {};
525
526// __and_
527template<class...> struct __and_;
528template<> struct __and_<> : true_type {};
529
530template<class _B0> struct __and_<_B0> : _B0 {};
531
532template<class _B0, class _B1>
533struct __and_<_B0, _B1> : conditional<_B0::value, _B1, _B0>::type {};
534
535template<class _B0, class _B1, class _B2, class... _Bn>
536struct __and_<_B0, _B1, _B2, _Bn...> 
537        : conditional<_B0::value, __and_<_B1, _B2, _Bn...>, _B0>::type {};
538
539// __or_
540template<class...> struct __or_;
541template<> struct __or_<> : false_type {};
542
543template<class _B0> struct __or_<_B0> : _B0 {};
544
545template<class _B0, class _B1>
546struct __or_<_B0, _B1> : conditional<_B0::value, _B0, _B1>::type {};
547
548template<class _B0, class _B1, class _B2, class... _Bn>
549struct __or_<_B0, _B1, _B2, _Bn...> 
550        : conditional<_B0::value, _B0, __or_<_B1, _B2, _Bn...> >::type {};
551
552// __not_
553template<class _Tp> 
554struct __not_ : conditional<_Tp::value, false_type, true_type>::type {};
555
556#endif // !defined(_LIBCPP_HAS_NO_VARIADICS)
557
558// is_const
559
560template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_const            : public false_type {};
561template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_const<_Tp const> : public true_type {};
562
563#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
564template <class _Tp> _LIBCPP_CONSTEXPR bool is_const_v
565    = is_const<_Tp>::value;
566#endif
567
568// is_volatile
569
570template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_volatile               : public false_type {};
571template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_volatile<_Tp volatile> : public true_type {};
572
573#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
574template <class _Tp> _LIBCPP_CONSTEXPR bool is_volatile_v
575    = is_volatile<_Tp>::value;
576#endif
577
578// remove_const
579
580template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_const            {typedef _Tp type;};
581template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_const<const _Tp> {typedef _Tp type;};
582#if _LIBCPP_STD_VER > 11
583template <class _Tp> using remove_const_t = typename remove_const<_Tp>::type;
584#endif
585
586// remove_volatile
587
588template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_volatile               {typedef _Tp type;};
589template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_volatile<volatile _Tp> {typedef _Tp type;};
590#if _LIBCPP_STD_VER > 11
591template <class _Tp> using remove_volatile_t = typename remove_volatile<_Tp>::type;
592#endif
593
594// remove_cv
595
596template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_cv
597{typedef typename remove_volatile<typename remove_const<_Tp>::type>::type type;};
598#if _LIBCPP_STD_VER > 11
599template <class _Tp> using remove_cv_t = typename remove_cv<_Tp>::type;
600#endif
601
602// is_void
603
604template <class _Tp> struct __libcpp_is_void       : public false_type {};
605template <>          struct __libcpp_is_void<void> : public true_type {};
606
607template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_void
608    : public __libcpp_is_void<typename remove_cv<_Tp>::type> {};
609
610#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
611template <class _Tp> _LIBCPP_CONSTEXPR bool is_void_v
612    = is_void<_Tp>::value;
613#endif
614
615// __is_nullptr_t
616
617template <class _Tp> struct __is_nullptr_t_impl       : public false_type {};
618template <>          struct __is_nullptr_t_impl<nullptr_t> : public true_type {};
619
620template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY __is_nullptr_t
621    : public __is_nullptr_t_impl<typename remove_cv<_Tp>::type> {};
622
623#if _LIBCPP_STD_VER > 11
624template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_null_pointer
625    : public __is_nullptr_t_impl<typename remove_cv<_Tp>::type> {};
626
627#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
628template <class _Tp> _LIBCPP_CONSTEXPR bool is_null_pointer_v
629    = is_null_pointer<_Tp>::value;
630#endif
631#endif
632
633// is_integral
634
635template <class _Tp> struct __libcpp_is_integral                     : public false_type {};
636template <>          struct __libcpp_is_integral<bool>               : public true_type {};
637template <>          struct __libcpp_is_integral<char>               : public true_type {};
638template <>          struct __libcpp_is_integral<signed char>        : public true_type {};
639template <>          struct __libcpp_is_integral<unsigned char>      : public true_type {};
640template <>          struct __libcpp_is_integral<wchar_t>            : public true_type {};
641#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
642template <>          struct __libcpp_is_integral<char16_t>           : public true_type {};
643template <>          struct __libcpp_is_integral<char32_t>           : public true_type {};
644#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
645template <>          struct __libcpp_is_integral<short>              : public true_type {};
646template <>          struct __libcpp_is_integral<unsigned short>     : public true_type {};
647template <>          struct __libcpp_is_integral<int>                : public true_type {};
648template <>          struct __libcpp_is_integral<unsigned int>       : public true_type {};
649template <>          struct __libcpp_is_integral<long>               : public true_type {};
650template <>          struct __libcpp_is_integral<unsigned long>      : public true_type {};
651template <>          struct __libcpp_is_integral<long long>          : public true_type {};
652template <>          struct __libcpp_is_integral<unsigned long long> : public true_type {};
653#ifndef _LIBCPP_HAS_NO_INT128
654template <>          struct __libcpp_is_integral<__int128_t>         : public true_type {};
655template <>          struct __libcpp_is_integral<__uint128_t>        : public true_type {};
656#endif
657
658template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_integral
659    : public __libcpp_is_integral<typename remove_cv<_Tp>::type> {};
660
661#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
662template <class _Tp> _LIBCPP_CONSTEXPR bool is_integral_v
663    = is_integral<_Tp>::value;
664#endif
665
666// is_floating_point
667
668template <class _Tp> struct __libcpp_is_floating_point              : public false_type {};
669template <>          struct __libcpp_is_floating_point<float>       : public true_type {};
670template <>          struct __libcpp_is_floating_point<double>      : public true_type {};
671template <>          struct __libcpp_is_floating_point<long double> : public true_type {};
672
673template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_floating_point
674    : public __libcpp_is_floating_point<typename remove_cv<_Tp>::type> {};
675
676#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
677template <class _Tp> _LIBCPP_CONSTEXPR bool is_floating_point_v
678    = is_floating_point<_Tp>::value;
679#endif
680
681// is_array
682
683template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_array
684    : public false_type {};
685template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_array<_Tp[]>
686    : public true_type {};
687template <class _Tp, size_t _Np> struct _LIBCPP_TYPE_VIS_ONLY is_array<_Tp[_Np]>
688    : public true_type {};
689
690#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
691template <class _Tp> _LIBCPP_CONSTEXPR bool is_array_v
692    = is_array<_Tp>::value;
693#endif
694
695// is_pointer
696
697template <class _Tp> struct __libcpp_is_pointer       : public false_type {};
698template <class _Tp> struct __libcpp_is_pointer<_Tp*> : public true_type {};
699
700template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_pointer
701    : public __libcpp_is_pointer<typename remove_cv<_Tp>::type> {};
702
703#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
704template <class _Tp> _LIBCPP_CONSTEXPR bool is_pointer_v
705    = is_pointer<_Tp>::value;
706#endif
707
708// is_reference
709
710template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_lvalue_reference       : public false_type {};
711template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_lvalue_reference<_Tp&> : public true_type {};
712
713template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_rvalue_reference        : public false_type {};
714#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
715template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_rvalue_reference<_Tp&&> : public true_type {};
716#endif
717
718template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_reference        : public false_type {};
719template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_reference<_Tp&>  : public true_type {};
720#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
721template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_reference<_Tp&&> : public true_type {};
722#endif
723
724#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
725template <class _Tp> _LIBCPP_CONSTEXPR bool is_reference_v
726    = is_reference<_Tp>::value;
727
728template <class _Tp> _LIBCPP_CONSTEXPR bool is_lvalue_reference_v
729    = is_lvalue_reference<_Tp>::value;
730
731template <class _Tp> _LIBCPP_CONSTEXPR bool is_rvalue_reference_v
732    = is_rvalue_reference<_Tp>::value;
733#endif
734// is_union
735
736#if __has_feature(is_union) || (_GNUC_VER >= 403)
737
738template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_union
739    : public integral_constant<bool, __is_union(_Tp)> {};
740
741#else
742
743template <class _Tp> struct __libcpp_union : public false_type {};
744template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_union
745    : public __libcpp_union<typename remove_cv<_Tp>::type> {};
746
747#endif
748
749#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
750template <class _Tp> _LIBCPP_CONSTEXPR bool is_union_v
751    = is_union<_Tp>::value;
752#endif
753
754// is_class
755
756#if __has_feature(is_class) || (_GNUC_VER >= 403)
757
758template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_class
759    : public integral_constant<bool, __is_class(_Tp)> {};
760
761#else
762
763namespace __is_class_imp
764{
765template <class _Tp> char  __test(int _Tp::*);
766template <class _Tp> __two __test(...);
767}
768
769template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_class
770    : public integral_constant<bool, sizeof(__is_class_imp::__test<_Tp>(0)) == 1 && !is_union<_Tp>::value> {};
771
772#endif
773
774#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
775template <class _Tp> _LIBCPP_CONSTEXPR bool is_class_v
776    = is_class<_Tp>::value;
777#endif
778
779// is_same
780
781template <class _Tp, class _Up> struct _LIBCPP_TYPE_VIS_ONLY is_same           : public false_type {};
782template <class _Tp>            struct _LIBCPP_TYPE_VIS_ONLY is_same<_Tp, _Tp> : public true_type {};
783
784#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
785template <class _Tp, class _Up> _LIBCPP_CONSTEXPR bool is_same_v
786    = is_same<_Tp, _Up>::value;
787#endif
788
789// is_function
790
791namespace __libcpp_is_function_imp
792{
793struct __dummy_type {};
794template <class _Tp> char  __test(_Tp*);
795template <class _Tp> char __test(__dummy_type);
796template <class _Tp> __two __test(...);
797template <class _Tp> _Tp&  __source(int);
798template <class _Tp> __dummy_type __source(...);
799}
800
801template <class _Tp, bool = is_class<_Tp>::value ||
802                            is_union<_Tp>::value ||
803                            is_void<_Tp>::value  ||
804                            is_reference<_Tp>::value ||
805                            __is_nullptr_t<_Tp>::value >
806struct __libcpp_is_function
807    : public integral_constant<bool, sizeof(__libcpp_is_function_imp::__test<_Tp>(__libcpp_is_function_imp::__source<_Tp>(0))) == 1>
808    {};
809template <class _Tp> struct __libcpp_is_function<_Tp, true> : public false_type {};
810
811template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_function
812    : public __libcpp_is_function<_Tp> {};
813
814#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
815template <class _Tp> _LIBCPP_CONSTEXPR bool is_function_v
816    = is_function<_Tp>::value;
817#endif
818
819// is_member_function_pointer
820
821// template <class _Tp> struct            __libcpp_is_member_function_pointer             : public false_type {};
822// template <class _Tp, class _Up> struct __libcpp_is_member_function_pointer<_Tp _Up::*> : public is_function<_Tp> {};
823// 
824
825template <class _MP, bool _IsMemberFunctionPtr, bool _IsMemberObjectPtr>
826struct __member_pointer_traits_imp
827{  // forward declaration; specializations later
828};
829
830
831template <class _Tp> struct __libcpp_is_member_function_pointer
832    : public false_type {};
833
834template <class _Ret, class _Class>
835struct __libcpp_is_member_function_pointer<_Ret _Class::*>
836    : public is_function<_Ret> {};
837
838template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_member_function_pointer
839    : public __libcpp_is_member_function_pointer<typename remove_cv<_Tp>::type>::type {};
840
841#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
842template <class _Tp> _LIBCPP_CONSTEXPR bool is_member_function_pointer_v
843    = is_member_function_pointer<_Tp>::value;
844#endif
845
846// is_member_pointer
847
848template <class _Tp>            struct __libcpp_is_member_pointer             : public false_type {};
849template <class _Tp, class _Up> struct __libcpp_is_member_pointer<_Tp _Up::*> : public true_type {};
850
851template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_member_pointer
852    : public __libcpp_is_member_pointer<typename remove_cv<_Tp>::type> {};
853
854#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
855template <class _Tp> _LIBCPP_CONSTEXPR bool is_member_pointer_v
856    = is_member_pointer<_Tp>::value;
857#endif
858
859// is_member_object_pointer
860
861template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_member_object_pointer
862    : public integral_constant<bool, is_member_pointer<_Tp>::value &&
863                                    !is_member_function_pointer<_Tp>::value> {};
864
865#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
866template <class _Tp> _LIBCPP_CONSTEXPR bool is_member_object_pointer_v
867    = is_member_object_pointer<_Tp>::value;
868#endif
869
870// is_enum
871
872#if __has_feature(is_enum) || (_GNUC_VER >= 403)
873
874template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_enum
875    : public integral_constant<bool, __is_enum(_Tp)> {};
876
877#else
878
879template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_enum
880    : public integral_constant<bool, !is_void<_Tp>::value             &&
881                                     !is_integral<_Tp>::value         &&
882                                     !is_floating_point<_Tp>::value   &&
883                                     !is_array<_Tp>::value            &&
884                                     !is_pointer<_Tp>::value          &&
885                                     !is_reference<_Tp>::value        &&
886                                     !is_member_pointer<_Tp>::value   &&
887                                     !is_union<_Tp>::value            &&
888                                     !is_class<_Tp>::value            &&
889                                     !is_function<_Tp>::value         > {};
890
891#endif
892
893#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
894template <class _Tp> _LIBCPP_CONSTEXPR bool is_enum_v
895    = is_enum<_Tp>::value;
896#endif
897
898// is_arithmetic
899
900template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_arithmetic
901    : public integral_constant<bool, is_integral<_Tp>::value      ||
902                                     is_floating_point<_Tp>::value> {};
903
904#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
905template <class _Tp> _LIBCPP_CONSTEXPR bool is_arithmetic_v
906    = is_arithmetic<_Tp>::value;
907#endif
908
909// is_fundamental
910
911template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_fundamental
912    : public integral_constant<bool, is_void<_Tp>::value        ||
913                                     __is_nullptr_t<_Tp>::value ||
914                                     is_arithmetic<_Tp>::value> {};
915
916#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
917template <class _Tp> _LIBCPP_CONSTEXPR bool is_fundamental_v
918    = is_fundamental<_Tp>::value;
919#endif
920
921// is_scalar
922
923template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_scalar
924    : public integral_constant<bool, is_arithmetic<_Tp>::value     ||
925                                     is_member_pointer<_Tp>::value ||
926                                     is_pointer<_Tp>::value        ||
927                                     __is_nullptr_t<_Tp>::value    ||
928                                     is_enum<_Tp>::value           > {};
929
930template <> struct _LIBCPP_TYPE_VIS_ONLY is_scalar<nullptr_t> : public true_type {};
931
932#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
933template <class _Tp> _LIBCPP_CONSTEXPR bool is_scalar_v
934    = is_scalar<_Tp>::value;
935#endif
936
937// is_object
938
939template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_object
940    : public integral_constant<bool, is_scalar<_Tp>::value ||
941                                     is_array<_Tp>::value  ||
942                                     is_union<_Tp>::value  ||
943                                     is_class<_Tp>::value  > {};
944
945#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
946template <class _Tp> _LIBCPP_CONSTEXPR bool is_object_v
947    = is_object<_Tp>::value;
948#endif
949
950// is_compound
951
952template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_compound
953    : public integral_constant<bool, !is_fundamental<_Tp>::value> {};
954
955#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
956template <class _Tp> _LIBCPP_CONSTEXPR bool is_compound_v
957    = is_compound<_Tp>::value;
958#endif
959
960// add_const
961
962template <class _Tp, bool = is_reference<_Tp>::value ||
963                            is_function<_Tp>::value  ||
964                            is_const<_Tp>::value     >
965struct __add_const             {typedef _Tp type;};
966
967template <class _Tp>
968struct __add_const<_Tp, false> {typedef const _Tp type;};
969
970template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY add_const
971    {typedef typename __add_const<_Tp>::type type;};
972
973#if _LIBCPP_STD_VER > 11
974template <class _Tp> using add_const_t = typename add_const<_Tp>::type;
975#endif
976
977// add_volatile
978
979template <class _Tp, bool = is_reference<_Tp>::value ||
980                            is_function<_Tp>::value  ||
981                            is_volatile<_Tp>::value  >
982struct __add_volatile             {typedef _Tp type;};
983
984template <class _Tp>
985struct __add_volatile<_Tp, false> {typedef volatile _Tp type;};
986
987template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY add_volatile
988    {typedef typename __add_volatile<_Tp>::type type;};
989
990#if _LIBCPP_STD_VER > 11
991template <class _Tp> using add_volatile_t = typename add_volatile<_Tp>::type;
992#endif
993
994// add_cv
995
996template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY add_cv
997    {typedef typename add_const<typename add_volatile<_Tp>::type>::type type;};
998
999#if _LIBCPP_STD_VER > 11
1000template <class _Tp> using add_cv_t = typename add_cv<_Tp>::type;
1001#endif
1002
1003// remove_reference
1004
1005template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_reference        {typedef _Tp type;};
1006template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_reference<_Tp&>  {typedef _Tp type;};
1007#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1008template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_reference<_Tp&&> {typedef _Tp type;};
1009#endif
1010
1011#if _LIBCPP_STD_VER > 11
1012template <class _Tp> using remove_reference_t = typename remove_reference<_Tp>::type;
1013#endif
1014
1015// add_lvalue_reference
1016
1017template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY add_lvalue_reference                      {typedef _Tp& type;};
1018template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY add_lvalue_reference<_Tp&>                {typedef _Tp& type;};  // for older compiler
1019template <>          struct _LIBCPP_TYPE_VIS_ONLY add_lvalue_reference<void>                {typedef void type;};
1020template <>          struct _LIBCPP_TYPE_VIS_ONLY add_lvalue_reference<const void>          {typedef const void type;};
1021template <>          struct _LIBCPP_TYPE_VIS_ONLY add_lvalue_reference<volatile void>       {typedef volatile void type;};
1022template <>          struct _LIBCPP_TYPE_VIS_ONLY add_lvalue_reference<const volatile void> {typedef const volatile void type;};
1023
1024#if _LIBCPP_STD_VER > 11
1025template <class _Tp> using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
1026#endif
1027
1028#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1029
1030template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY  add_rvalue_reference                     {typedef _Tp&& type;};
1031template <>          struct _LIBCPP_TYPE_VIS_ONLY add_rvalue_reference<void>                {typedef void type;};
1032template <>          struct _LIBCPP_TYPE_VIS_ONLY add_rvalue_reference<const void>          {typedef const void type;};
1033template <>          struct _LIBCPP_TYPE_VIS_ONLY add_rvalue_reference<volatile void>       {typedef volatile void type;};
1034template <>          struct _LIBCPP_TYPE_VIS_ONLY add_rvalue_reference<const volatile void> {typedef const volatile void type;};
1035
1036#if _LIBCPP_STD_VER > 11
1037template <class _Tp> using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
1038#endif
1039
1040#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1041
1042#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1043
1044template <class _Tp>
1045typename add_rvalue_reference<_Tp>::type
1046declval() _NOEXCEPT;
1047
1048#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1049
1050template <class _Tp>
1051typename add_lvalue_reference<_Tp>::type
1052declval();
1053
1054#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1055
1056struct __any
1057{
1058    __any(...);
1059};
1060
1061// remove_pointer
1062
1063template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_pointer                      {typedef _Tp type;};
1064template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_pointer<_Tp*>                {typedef _Tp type;};
1065template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_pointer<_Tp* const>          {typedef _Tp type;};
1066template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_pointer<_Tp* volatile>       {typedef _Tp type;};
1067template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_pointer<_Tp* const volatile> {typedef _Tp type;};
1068
1069#if _LIBCPP_STD_VER > 11
1070template <class _Tp> using remove_pointer_t = typename remove_pointer<_Tp>::type;
1071#endif
1072
1073// add_pointer
1074
1075template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY add_pointer
1076    {typedef typename remove_reference<_Tp>::type* type;};
1077
1078#if _LIBCPP_STD_VER > 11
1079template <class _Tp> using add_pointer_t = typename add_pointer<_Tp>::type;
1080#endif
1081
1082// is_signed
1083
1084template <class _Tp, bool = is_integral<_Tp>::value>
1085struct __libcpp_is_signed_impl : public _LIBCPP_BOOL_CONSTANT(_Tp(-1) < _Tp(0)) {};
1086
1087template <class _Tp>
1088struct __libcpp_is_signed_impl<_Tp, false> : public true_type {};  // floating point
1089
1090template <class _Tp, bool = is_arithmetic<_Tp>::value>
1091struct __libcpp_is_signed : public __libcpp_is_signed_impl<_Tp> {};
1092
1093template <class _Tp> struct __libcpp_is_signed<_Tp, false> : public false_type {};
1094
1095template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_signed : public __libcpp_is_signed<_Tp> {};
1096
1097#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1098template <class _Tp> _LIBCPP_CONSTEXPR bool is_signed_v
1099    = is_signed<_Tp>::value;
1100#endif
1101
1102// is_unsigned
1103
1104template <class _Tp, bool = is_integral<_Tp>::value>
1105struct __libcpp_is_unsigned_impl : public _LIBCPP_BOOL_CONSTANT(_Tp(0) < _Tp(-1)) {};
1106
1107template <class _Tp>
1108struct __libcpp_is_unsigned_impl<_Tp, false> : public false_type {};  // floating point
1109
1110template <class _Tp, bool = is_arithmetic<_Tp>::value>
1111struct __libcpp_is_unsigned : public __libcpp_is_unsigned_impl<_Tp> {};
1112
1113template <class _Tp> struct __libcpp_is_unsigned<_Tp, false> : public false_type {};
1114
1115template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_unsigned : public __libcpp_is_unsigned<_Tp> {};
1116
1117#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1118template <class _Tp> _LIBCPP_CONSTEXPR bool is_unsigned_v
1119    = is_unsigned<_Tp>::value;
1120#endif
1121
1122// rank
1123
1124template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY rank
1125    : public integral_constant<size_t, 0> {};
1126template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY rank<_Tp[]>
1127    : public integral_constant<size_t, rank<_Tp>::value + 1> {};
1128template <class _Tp, size_t _Np> struct _LIBCPP_TYPE_VIS_ONLY rank<_Tp[_Np]>
1129    : public integral_constant<size_t, rank<_Tp>::value + 1> {};
1130
1131#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1132template <class _Tp> _LIBCPP_CONSTEXPR size_t rank_v
1133    = rank<_Tp>::value;
1134#endif
1135
1136// extent
1137
1138template <class _Tp, unsigned _Ip = 0> struct _LIBCPP_TYPE_VIS_ONLY extent
1139    : public integral_constant<size_t, 0> {};
1140template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY extent<_Tp[], 0>
1141    : public integral_constant<size_t, 0> {};
1142template <class _Tp, unsigned _Ip> struct _LIBCPP_TYPE_VIS_ONLY extent<_Tp[], _Ip>
1143    : public integral_constant<size_t, extent<_Tp, _Ip-1>::value> {};
1144template <class _Tp, size_t _Np> struct _LIBCPP_TYPE_VIS_ONLY extent<_Tp[_Np], 0>
1145    : public integral_constant<size_t, _Np> {};
1146template <class _Tp, size_t _Np, unsigned _Ip> struct _LIBCPP_TYPE_VIS_ONLY extent<_Tp[_Np], _Ip>
1147    : public integral_constant<size_t, extent<_Tp, _Ip-1>::value> {};
1148
1149#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1150template <class _Tp, unsigned _Ip = 0> _LIBCPP_CONSTEXPR size_t extent_v
1151    = extent<_Tp, _Ip>::value;
1152#endif
1153
1154// remove_extent
1155
1156template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_extent
1157    {typedef _Tp type;};
1158template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_extent<_Tp[]>
1159    {typedef _Tp type;};
1160template <class _Tp, size_t _Np> struct _LIBCPP_TYPE_VIS_ONLY remove_extent<_Tp[_Np]>
1161    {typedef _Tp type;};
1162
1163#if _LIBCPP_STD_VER > 11
1164template <class _Tp> using remove_extent_t = typename remove_extent<_Tp>::type;
1165#endif
1166
1167// remove_all_extents
1168
1169template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_all_extents
1170    {typedef _Tp type;};
1171template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY remove_all_extents<_Tp[]>
1172    {typedef typename remove_all_extents<_Tp>::type type;};
1173template <class _Tp, size_t _Np> struct _LIBCPP_TYPE_VIS_ONLY remove_all_extents<_Tp[_Np]>
1174    {typedef typename remove_all_extents<_Tp>::type type;};
1175
1176#if _LIBCPP_STD_VER > 11
1177template <class _Tp> using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
1178#endif
1179
1180// decay
1181
1182template <class _Tp>
1183struct _LIBCPP_TYPE_VIS_ONLY decay
1184{
1185private:
1186    typedef typename remove_reference<_Tp>::type _Up;
1187public:
1188    typedef typename conditional
1189                     <
1190                         is_array<_Up>::value,
1191                         typename remove_extent<_Up>::type*,
1192                         typename conditional
1193                         <
1194                              is_function<_Up>::value,
1195                              typename add_pointer<_Up>::type,
1196                              typename remove_cv<_Up>::type
1197                         >::type
1198                     >::type type;
1199};
1200
1201#if _LIBCPP_STD_VER > 11
1202template <class _Tp> using decay_t = typename decay<_Tp>::type;
1203#endif
1204
1205// is_abstract
1206
1207namespace __is_abstract_imp
1208{
1209template <class _Tp> char  __test(_Tp (*)[1]);
1210template <class _Tp> __two __test(...);
1211}
1212
1213template <class _Tp, bool = is_class<_Tp>::value>
1214struct __libcpp_abstract : public integral_constant<bool, sizeof(__is_abstract_imp::__test<_Tp>(0)) != 1> {};
1215
1216template <class _Tp> struct __libcpp_abstract<_Tp, false> : public false_type {};
1217
1218template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_abstract : public __libcpp_abstract<_Tp> {};
1219
1220#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1221template <class _Tp> _LIBCPP_CONSTEXPR bool is_abstract_v
1222    = is_abstract<_Tp>::value;
1223#endif
1224
1225// is_final
1226
1227#if defined(_LIBCPP_HAS_IS_FINAL)
1228template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY
1229__libcpp_is_final : public integral_constant<bool, __is_final(_Tp)> {};
1230#else
1231template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY
1232__libcpp_is_final : public false_type {};
1233#endif
1234
1235#if defined(_LIBCPP_HAS_IS_FINAL) && _LIBCPP_STD_VER > 11
1236template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY
1237is_final : public integral_constant<bool, __is_final(_Tp)> {};
1238#endif
1239
1240#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1241template <class _Tp> _LIBCPP_CONSTEXPR bool is_final_v
1242    = is_final<_Tp>::value;
1243#endif
1244
1245// is_base_of
1246
1247#ifdef _LIBCPP_HAS_IS_BASE_OF
1248
1249template <class _Bp, class _Dp>
1250struct _LIBCPP_TYPE_VIS_ONLY is_base_of
1251    : public integral_constant<bool, __is_base_of(_Bp, _Dp)> {};
1252
1253#else  // _LIBCPP_HAS_IS_BASE_OF
1254
1255namespace __is_base_of_imp
1256{
1257template <class _Tp>
1258struct _Dst
1259{
1260    _Dst(const volatile _Tp &);
1261};
1262template <class _Tp>
1263struct _Src
1264{
1265    operator const volatile _Tp &();
1266    template <class _Up> operator const _Dst<_Up> &();
1267};
1268template <size_t> struct __one { typedef char type; };
1269template <class _Bp, class _Dp> typename __one<sizeof(_Dst<_Bp>(declval<_Src<_Dp> >()))>::type __test(int);
1270template <class _Bp, class _Dp> __two __test(...);
1271}
1272
1273template <class _Bp, class _Dp>
1274struct _LIBCPP_TYPE_VIS_ONLY is_base_of
1275    : public integral_constant<bool, is_class<_Bp>::value &&
1276                                     sizeof(__is_base_of_imp::__test<_Bp, _Dp>(0)) == 2> {};
1277
1278#endif  // _LIBCPP_HAS_IS_BASE_OF
1279
1280#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1281template <class _Bp, class _Dp> _LIBCPP_CONSTEXPR bool is_base_of_v
1282    = is_base_of<_Bp, _Dp>::value;
1283#endif
1284
1285// is_convertible
1286
1287#if __has_feature(is_convertible_to) && !defined(_LIBCPP_USE_IS_CONVERTIBLE_FALLBACK)
1288
1289template <class _T1, class _T2> struct _LIBCPP_TYPE_VIS_ONLY is_convertible
1290    : public integral_constant<bool, __is_convertible_to(_T1, _T2) &&
1291                                     !is_abstract<_T2>::value> {};
1292
1293#else  // __has_feature(is_convertible_to)
1294
1295namespace __is_convertible_imp
1296{
1297template <class _Tp> void  __test_convert(_Tp);
1298
1299template <class _From, class _To, class = void>
1300struct __is_convertible_test : public false_type {};
1301
1302template <class _From, class _To>
1303struct __is_convertible_test<_From, _To,
1304    decltype(__test_convert<_To>(_VSTD::declval<_From>()))> : public true_type
1305{};
1306
1307template <class _Tp> __two __test(...);
1308#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1309template <class _Tp> _Tp&& __source();
1310#else
1311template <class _Tp> typename remove_reference<_Tp>::type& __source();
1312#endif
1313
1314template <class _Tp, bool _IsArray =    is_array<_Tp>::value,
1315                     bool _IsFunction = is_function<_Tp>::value,
1316                     bool _IsVoid =     is_void<_Tp>::value>
1317                     struct __is_array_function_or_void                          {enum {value = 0};};
1318template <class _Tp> struct __is_array_function_or_void<_Tp, true, false, false> {enum {value = 1};};
1319template <class _Tp> struct __is_array_function_or_void<_Tp, false, true, false> {enum {value = 2};};
1320template <class _Tp> struct __is_array_function_or_void<_Tp, false, false, true> {enum {value = 3};};
1321}
1322
1323template <class _Tp,
1324    unsigned = __is_convertible_imp::__is_array_function_or_void<typename remove_reference<_Tp>::type>::value>
1325struct __is_convertible_check
1326{
1327    static const size_t __v = 0;
1328};
1329
1330template <class _Tp>
1331struct __is_convertible_check<_Tp, 0>
1332{
1333    static const size_t __v = sizeof(_Tp);
1334};
1335
1336template <class _T1, class _T2,
1337    unsigned _T1_is_array_function_or_void = __is_convertible_imp::__is_array_function_or_void<_T1>::value,
1338    unsigned _T2_is_array_function_or_void = __is_convertible_imp::__is_array_function_or_void<_T2>::value>
1339struct __is_convertible
1340    : public integral_constant<bool,
1341        __is_convertible_imp::__is_convertible_test<_T1, _T2>::value
1342#if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1343         && !(!is_function<_T1>::value && !is_reference<_T1>::value && is_reference<_T2>::value
1344              && (!is_const<typename remove_reference<_T2>::type>::value
1345                  || is_volatile<typename remove_reference<_T2>::type>::value)
1346                  && (is_same<typename remove_cv<_T1>::type,
1347                              typename remove_cv<typename remove_reference<_T2>::type>::type>::value
1348                      || is_base_of<typename remove_reference<_T2>::type, _T1>::value))
1349#endif
1350    >
1351{};
1352
1353template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 1, 0> : false_type {};
1354
1355template <class _T1> struct __is_convertible<_T1, const _T1&, 1, 0> : true_type {};
1356template <class _T1> struct __is_convertible<const _T1, const _T1&, 1, 0> : true_type {};
1357#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1358template <class _T1> struct __is_convertible<_T1, _T1&&, 1, 0> : true_type {};
1359template <class _T1> struct __is_convertible<_T1, const _T1&&, 1, 0> : true_type {};
1360template <class _T1> struct __is_convertible<_T1, volatile _T1&&, 1, 0> : true_type {};
1361template <class _T1> struct __is_convertible<_T1, const volatile _T1&&, 1, 0> : true_type {};
1362#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1363
1364template <class _T1, class _T2> struct __is_convertible<_T1, _T2*, 1, 0>
1365    : public integral_constant<bool, __is_convertible<typename remove_all_extents<_T1>::type*, _T2*>::value> {};
1366
1367template <class _T1, class _T2> struct __is_convertible<_T1, _T2* const, 1, 0>
1368    : public integral_constant<bool, __is_convertible<typename remove_all_extents<_T1>::type*, _T2*const>::value> {};
1369
1370template <class _T1, class _T2> struct __is_convertible<_T1, _T2* volatile, 1, 0>
1371    : public integral_constant<bool, __is_convertible<typename remove_all_extents<_T1>::type*, _T2*volatile>::value> {};
1372
1373template <class _T1, class _T2> struct __is_convertible<_T1, _T2* const volatile, 1, 0>
1374    : public integral_constant<bool, __is_convertible<typename remove_all_extents<_T1>::type*, _T2*const volatile>::value> {};
1375
1376template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 2, 0>                : public false_type {};
1377#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1378template <class _T1>            struct __is_convertible<_T1, _T1&&, 2, 0>               : public true_type {};
1379#endif
1380template <class _T1>            struct __is_convertible<_T1, _T1&, 2, 0>               : public true_type {};
1381template <class _T1>            struct __is_convertible<_T1, _T1*, 2, 0>               : public true_type {};
1382template <class _T1>            struct __is_convertible<_T1, _T1*const, 2, 0>          : public true_type {};
1383template <class _T1>            struct __is_convertible<_T1, _T1*volatile, 2, 0>       : public true_type {};
1384template <class _T1>            struct __is_convertible<_T1, _T1*const volatile, 2, 0> : public true_type {};
1385
1386template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 3, 0> : public false_type {};
1387
1388template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 0, 1> : public false_type {};
1389template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 1, 1> : public false_type {};
1390template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 2, 1> : public false_type {};
1391template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 3, 1> : public false_type {};
1392
1393template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 0, 2> : public false_type {};
1394template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 1, 2> : public false_type {};
1395template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 2, 2> : public false_type {};
1396template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 3, 2> : public false_type {};
1397
1398template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 0, 3> : public false_type {};
1399template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 1, 3> : public false_type {};
1400template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 2, 3> : public false_type {};
1401template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 3, 3> : public true_type {};
1402
1403template <class _T1, class _T2> struct _LIBCPP_TYPE_VIS_ONLY is_convertible
1404    : public __is_convertible<_T1, _T2>
1405{
1406    static const size_t __complete_check1 = __is_convertible_check<_T1>::__v;
1407    static const size_t __complete_check2 = __is_convertible_check<_T2>::__v;
1408};
1409
1410#endif  // __has_feature(is_convertible_to)
1411
1412#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1413template <class _From, class _To> _LIBCPP_CONSTEXPR bool is_convertible_v
1414    = is_convertible<_From, _To>::value;
1415#endif
1416
1417// is_empty
1418
1419#if __has_feature(is_empty) || (_GNUC_VER >= 407)
1420
1421template <class _Tp>
1422struct _LIBCPP_TYPE_VIS_ONLY is_empty
1423    : public integral_constant<bool, __is_empty(_Tp)> {};
1424
1425#else  // __has_feature(is_empty)
1426
1427template <class _Tp>
1428struct __is_empty1
1429    : public _Tp
1430{
1431    double __lx;
1432};
1433
1434struct __is_empty2
1435{
1436    double __lx;
1437};
1438
1439template <class _Tp, bool = is_class<_Tp>::value>
1440struct __libcpp_empty : public integral_constant<bool, sizeof(__is_empty1<_Tp>) == sizeof(__is_empty2)> {};
1441
1442template <class _Tp> struct __libcpp_empty<_Tp, false> : public false_type {};
1443
1444template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_empty : public __libcpp_empty<_Tp> {};
1445
1446#endif  // __has_feature(is_empty)
1447
1448#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1449template <class _Tp> _LIBCPP_CONSTEXPR bool is_empty_v
1450    = is_empty<_Tp>::value;
1451#endif
1452
1453// is_polymorphic
1454
1455#if __has_feature(is_polymorphic) || defined(_LIBCPP_MSVC)
1456
1457template <class _Tp>
1458struct _LIBCPP_TYPE_VIS_ONLY is_polymorphic
1459    : public integral_constant<bool, __is_polymorphic(_Tp)> {};
1460
1461#else
1462
1463template<typename _Tp> char &__is_polymorphic_impl(
1464    typename enable_if<sizeof((_Tp*)dynamic_cast<const volatile void*>(declval<_Tp*>())) != 0,
1465                       int>::type);
1466template<typename _Tp> __two &__is_polymorphic_impl(...);
1467
1468template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_polymorphic
1469    : public integral_constant<bool, sizeof(__is_polymorphic_impl<_Tp>(0)) == 1> {};
1470
1471#endif // __has_feature(is_polymorphic)
1472
1473#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1474template <class _Tp> _LIBCPP_CONSTEXPR bool is_polymorphic_v
1475    = is_polymorphic<_Tp>::value;
1476#endif
1477
1478// has_virtual_destructor
1479
1480#if __has_feature(has_virtual_destructor) || (_GNUC_VER >= 403)
1481
1482template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY has_virtual_destructor
1483    : public integral_constant<bool, __has_virtual_destructor(_Tp)> {};
1484
1485#else
1486
1487template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY has_virtual_destructor
1488    : public false_type {};
1489
1490#endif
1491
1492#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1493template <class _Tp> _LIBCPP_CONSTEXPR bool has_virtual_destructor_v
1494    = has_virtual_destructor<_Tp>::value;
1495#endif
1496
1497// alignment_of
1498
1499template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY alignment_of
1500    : public integral_constant<size_t, __alignof__(_Tp)> {};
1501
1502#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
1503template <class _Tp> _LIBCPP_CONSTEXPR size_t alignment_of_v
1504    = alignment_of<_Tp>::value;
1505#endif
1506
1507// aligned_storage
1508
1509template <class _Hp, class _Tp>
1510struct __type_list
1511{
1512    typedef _Hp _Head;
1513    typedef _Tp _Tail;
1514};
1515
1516struct __nat
1517{
1518#ifndef _LIBCPP_HAS_NO_DELETED_FUNCTIONS
1519    __nat() = delete;
1520    __nat(const __nat&) = delete;
1521    __nat& operator=(const __nat&) = delete;
1522    ~__nat() = delete;
1523#endif
1524};
1525
1526template <class _Tp>
1527struct __align_type
1528{
1529    static const size_t value = alignment_of<_Tp>::value;
1530    typedef _Tp type;
1531};
1532
1533struct __struct_double {long double __lx;};
1534struct __struct_double4 {double __lx[4];};
1535
1536typedef
1537    __type_list<__align_type<unsigned char>,
1538    __type_list<__align_type<unsigned short>,
1539    __type_list<__align_type<unsigned int>,
1540    __type_list<__align_type<unsigned long>,
1541    __type_list<__align_type<unsigned long long>,
1542    __type_list<__align_type<double>,
1543    __type_list<__align_type<long double>,
1544    __type_list<__align_type<__struct_double>,
1545    __type_list<__align_type<__struct_double4>,
1546    __type_list<__align_type<int*>,
1547    __nat
1548    > > > > > > > > > > __all_types;
1549
1550template <class _TL, size_t _Align> struct __find_pod;
1551
1552template <class _Hp, size_t _Align>
1553struct __find_pod<__type_list<_Hp, __nat>, _Align>
1554{
1555    typedef typename conditional<
1556                             _Align == _Hp::value,
1557                             typename _Hp::type,
1558                             void
1559                         >::type type;
1560};
1561
1562template <class _Hp, class _Tp, size_t _Align>
1563struct __find_pod<__type_list<_Hp, _Tp>, _Align>
1564{
1565    typedef typename conditional<
1566                             _Align == _Hp::value,
1567                             typename _Hp::type,
1568                             typename __find_pod<_Tp, _Align>::type
1569                         >::type type;
1570};
1571
1572template <class _TL, size_t _Len> struct __find_max_align;
1573
1574template <class _Hp, size_t _Len>
1575struct __find_max_align<__type_list<_Hp, __nat>, _Len> : public integral_constant<size_t, _Hp::value> {};
1576
1577template <size_t _Len, size_t _A1, size_t _A2>
1578struct __select_align
1579{
1580private:
1581    static const size_t __min = _A2 < _A1 ? _A2 : _A1;
1582    static const size_t __max = _A1 < _A2 ? _A2 : _A1;
1583public:
1584    static const size_t value = _Len < __max ? __min : __max;
1585};
1586
1587template <class _Hp, class _Tp, size_t _Len>
1588struct __find_max_align<__type_list<_Hp, _Tp>, _Len>
1589    : public integral_constant<size_t, __select_align<_Len, _Hp::value, __find_max_align<_Tp, _Len>::value>::value> {};
1590
1591template <size_t _Len, size_t _Align = __find_max_align<__all_types, _Len>::value>
1592struct _LIBCPP_TYPE_VIS_ONLY aligned_storage
1593{
1594    typedef typename __find_pod<__all_types, _Align>::type _Aligner;
1595    static_assert(!is_void<_Aligner>::value, "");
1596    union type
1597    {
1598        _Aligner __align;
1599        unsigned char __data[(_Len + _Align - 1)/_Align * _Align];
1600    };
1601};
1602
1603#if _LIBCPP_STD_VER > 11
1604template <size_t _Len, size_t _Align = __find_max_align<__all_types, _Len>::value>
1605    using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
1606#endif
1607
1608#define _CREATE_ALIGNED_STORAGE_SPECIALIZATION(n) \
1609template <size_t _Len>\
1610struct _LIBCPP_TYPE_VIS_ONLY aligned_storage<_Len, n>\
1611{\
1612    struct _ALIGNAS(n) type\
1613    {\
1614        unsigned char __lx[(_Len + n - 1)/n * n];\
1615    };\
1616}
1617
1618_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x1);
1619_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x2);
1620_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x4);
1621_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x8);
1622_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x10);
1623_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x20);
1624_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x40);
1625_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x80);
1626_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x100);
1627_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x200);
1628_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x400);
1629_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x800);
1630_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x1000);
1631_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x2000);
1632// MSDN says that MSVC does not support alignment beyond 8192 (=0x2000)
1633#if !defined(_LIBCPP_MSVC)
1634_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x4000);
1635#endif // !_LIBCPP_MSVC
1636
1637#undef _CREATE_ALIGNED_STORAGE_SPECIALIZATION
1638
1639#ifndef _LIBCPP_HAS_NO_VARIADICS
1640
1641// aligned_union
1642
1643template <size_t _I0, size_t ..._In>
1644struct __static_max;
1645
1646template <size_t _I0>
1647struct __static_max<_I0>
1648{
1649    static const size_t value = _I0;
1650};
1651
1652template <size_t _I0, size_t _I1, size_t ..._In>
1653struct __static_max<_I0, _I1, _In...>
1654{
1655    static const size_t value = _I0 >= _I1 ? __static_max<_I0, _In...>::value :
1656                                             __static_max<_I1, _In...>::value;
1657};
1658
1659template <size_t _Len, class _Type0, class ..._Types>
1660struct aligned_union
1661{
1662    static const size_t alignment_value = __static_max<__alignof__(_Type0),
1663                                                       __alignof__(_Types)...>::value;
1664    static const size_t __len = __static_max<_Len, sizeof(_Type0),
1665                                             sizeof(_Types)...>::value;
1666    typedef typename aligned_storage<__len, alignment_value>::type type;
1667};
1668
1669#if _LIBCPP_STD_VER > 11
1670template <size_t _Len, class ..._Types> using aligned_union_t = typename aligned_union<_Len, _Types...>::type;
1671#endif
1672
1673#endif  // _LIBCPP_HAS_NO_VARIADICS
1674
1675template <class _Tp>
1676struct __numeric_type
1677{
1678   static void __test(...);
1679   static float __test(float);
1680   static double __test(char);
1681   static double __test(int);
1682   static double __test(unsigned);
1683   static double __test(long);
1684   static double __test(unsigned long);
1685   static double __test(long long);
1686   static double __test(unsigned long long);
1687   static double __test(double);
1688   static long double __test(long double);
1689
1690   typedef decltype(__test(declval<_Tp>())) type;
1691   static const bool value = !is_same<type, void>::value;
1692};
1693
1694template <>
1695struct __numeric_type<void>
1696{
1697   static const bool value = true;
1698};
1699
1700// __promote
1701
1702template <class _A1, class _A2 = void, class _A3 = void,
1703          bool = __numeric_type<_A1>::value &&
1704                 __numeric_type<_A2>::value &&
1705                 __numeric_type<_A3>::value>
1706class __promote_imp
1707{
1708public:
1709    static const bool value = false;
1710};
1711
1712template <class _A1, class _A2, class _A3>
1713class __promote_imp<_A1, _A2, _A3, true>
1714{
1715private:
1716    typedef typename __promote_imp<_A1>::type __type1;
1717    typedef typename __promote_imp<_A2>::type __type2;
1718    typedef typename __promote_imp<_A3>::type __type3;
1719public:
1720    typedef decltype(__type1() + __type2() + __type3()) type;
1721    static const bool value = true;
1722};
1723
1724template <class _A1, class _A2>
1725class __promote_imp<_A1, _A2, void, true>
1726{
1727private:
1728    typedef typename __promote_imp<_A1>::type __type1;
1729    typedef typename __promote_imp<_A2>::type __type2;
1730public:
1731    typedef decltype(__type1() + __type2()) type;
1732    static const bool value = true;
1733};
1734
1735template <class _A1>
1736class __promote_imp<_A1, void, void, true>
1737{
1738public:
1739    typedef typename __numeric_type<_A1>::type type;
1740    static const bool value = true;
1741};
1742
1743template <class _A1, class _A2 = void, class _A3 = void>
1744class __promote : public __promote_imp<_A1, _A2, _A3> {};
1745
1746// make_signed / make_unsigned
1747
1748typedef
1749    __type_list<signed char,
1750    __type_list<signed short,
1751    __type_list<signed int,
1752    __type_list<signed long,
1753    __type_list<signed long long,
1754#ifndef _LIBCPP_HAS_NO_INT128
1755    __type_list<__int128_t,
1756#endif
1757    __nat
1758#ifndef _LIBCPP_HAS_NO_INT128
1759    >
1760#endif
1761    > > > > > __signed_types;
1762
1763typedef
1764    __type_list<unsigned char,
1765    __type_list<unsigned short,
1766    __type_list<unsigned int,
1767    __type_list<unsigned long,
1768    __type_list<unsigned long long,
1769#ifndef _LIBCPP_HAS_NO_INT128
1770    __type_list<__uint128_t,
1771#endif
1772    __nat
1773#ifndef _LIBCPP_HAS_NO_INT128
1774    >
1775#endif
1776    > > > > > __unsigned_types;
1777
1778template <class _TypeList, size_t _Size, bool = _Size <= sizeof(typename _TypeList::_Head)> struct __find_first;
1779
1780template <class _Hp, class _Tp, size_t _Size>
1781struct __find_first<__type_list<_Hp, _Tp>, _Size, true>
1782{
1783    typedef _Hp type;
1784};
1785
1786template <class _Hp, class _Tp, size_t _Size>
1787struct __find_first<__type_list<_Hp, _Tp>, _Size, false>
1788{
1789    typedef typename __find_first<_Tp, _Size>::type type;
1790};
1791
1792template <class _Tp, class _Up, bool = is_const<typename remove_reference<_Tp>::type>::value,
1793                             bool = is_volatile<typename remove_reference<_Tp>::type>::value>
1794struct __apply_cv
1795{
1796    typedef _Up type;
1797};
1798
1799template <class _Tp, class _Up>
1800struct __apply_cv<_Tp, _Up, true, false>
1801{
1802    typedef const _Up type;
1803};
1804
1805template <class _Tp, class _Up>
1806struct __apply_cv<_Tp, _Up, false, true>
1807{
1808    typedef volatile _Up type;
1809};
1810
1811template <class _Tp, class _Up>
1812struct __apply_cv<_Tp, _Up, true, true>
1813{
1814    typedef const volatile _Up type;
1815};
1816
1817template <class _Tp, class _Up>
1818struct __apply_cv<_Tp&, _Up, false, false>
1819{
1820    typedef _Up& type;
1821};
1822
1823template <class _Tp, class _Up>
1824struct __apply_cv<_Tp&, _Up, true, false>
1825{
1826    typedef const _Up& type;
1827};
1828
1829template <class _Tp, class _Up>
1830struct __apply_cv<_Tp&, _Up, false, true>
1831{
1832    typedef volatile _Up& type;
1833};
1834
1835template <class _Tp, class _Up>
1836struct __apply_cv<_Tp&, _Up, true, true>
1837{
1838    typedef const volatile _Up& type;
1839};
1840
1841template <class _Tp, bool = is_integral<_Tp>::value || is_enum<_Tp>::value>
1842struct __make_signed {};
1843
1844template <class _Tp>
1845struct __make_signed<_Tp, true>
1846{
1847    typedef typename __find_first<__signed_types, sizeof(_Tp)>::type type;
1848};
1849
1850template <> struct __make_signed<bool,               true> {};
1851template <> struct __make_signed<  signed short,     true> {typedef short     type;};
1852template <> struct __make_signed<unsigned short,     true> {typedef short     type;};
1853template <> struct __make_signed<  signed int,       true> {typedef int       type;};
1854template <> struct __make_signed<unsigned int,       true> {typedef int       type;};
1855template <> struct __make_signed<  signed long,      true> {typedef long      type;};
1856template <> struct __make_signed<unsigned long,      true> {typedef long      type;};
1857template <> struct __make_signed<  signed long long, true> {typedef long long type;};
1858template <> struct __make_signed<unsigned long long, true> {typedef long long type;};
1859#ifndef _LIBCPP_HAS_NO_INT128
1860template <> struct __make_signed<__int128_t,         true> {typedef __int128_t type;};
1861template <> struct __make_signed<__uint128_t,        true> {typedef __int128_t type;};
1862#endif
1863
1864template <class _Tp>
1865struct _LIBCPP_TYPE_VIS_ONLY make_signed
1866{
1867    typedef typename __apply_cv<_Tp, typename __make_signed<typename remove_cv<_Tp>::type>::type>::type type;
1868};
1869
1870#if _LIBCPP_STD_VER > 11
1871template <class _Tp> using make_signed_t = typename make_signed<_Tp>::type;
1872#endif
1873
1874template <class _Tp, bool = is_integral<_Tp>::value || is_enum<_Tp>::value>
1875struct __make_unsigned {};
1876
1877template <class _Tp>
1878struct __make_unsigned<_Tp, true>
1879{
1880    typedef typename __find_first<__unsigned_types, sizeof(_Tp)>::type type;
1881};
1882
1883template <> struct __make_unsigned<bool,               true> {};
1884template <> struct __make_unsigned<  signed short,     true> {typedef unsigned short     type;};
1885template <> struct __make_unsigned<unsigned short,     true> {typedef unsigned short     type;};
1886template <> struct __make_unsigned<  signed int,       true> {typedef unsigned int       type;};
1887template <> struct __make_unsigned<unsigned int,       true> {typedef unsigned int       type;};
1888template <> struct __make_unsigned<  signed long,      true> {typedef unsigned long      type;};
1889template <> struct __make_unsigned<unsigned long,      true> {typedef unsigned long      type;};
1890template <> struct __make_unsigned<  signed long long, true> {typedef unsigned long long type;};
1891template <> struct __make_unsigned<unsigned long long, true> {typedef unsigned long long type;};
1892#ifndef _LIBCPP_HAS_NO_INT128
1893template <> struct __make_unsigned<__int128_t,         true> {typedef __uint128_t        type;};
1894template <> struct __make_unsigned<__uint128_t,        true> {typedef __uint128_t        type;};
1895#endif
1896
1897template <class _Tp>
1898struct _LIBCPP_TYPE_VIS_ONLY make_unsigned
1899{
1900    typedef typename __apply_cv<_Tp, typename __make_unsigned<typename remove_cv<_Tp>::type>::type>::type type;
1901};
1902
1903#if _LIBCPP_STD_VER > 11
1904template <class _Tp> using make_unsigned_t = typename make_unsigned<_Tp>::type;
1905#endif
1906
1907#ifdef _LIBCPP_HAS_NO_VARIADICS
1908
1909template <class _Tp, class _Up = void, class _Vp = void>
1910struct _LIBCPP_TYPE_VIS_ONLY common_type
1911{
1912public:
1913    typedef typename common_type<typename common_type<_Tp, _Up>::type, _Vp>::type type;
1914};
1915
1916template <class _Tp>
1917struct _LIBCPP_TYPE_VIS_ONLY common_type<_Tp, void, void>
1918{
1919public:
1920    typedef typename decay<_Tp>::type type;
1921};
1922
1923template <class _Tp, class _Up>
1924struct _LIBCPP_TYPE_VIS_ONLY common_type<_Tp, _Up, void>
1925{
1926    typedef typename decay<decltype(
1927        true ? _VSTD::declval<_Tp>() : _VSTD::declval<_Up>()
1928      )>::type type;
1929};
1930
1931#else  // _LIBCPP_HAS_NO_VARIADICS
1932
1933// bullet 1 - sizeof...(Tp) == 0
1934
1935template <class ..._Tp>
1936struct _LIBCPP_TYPE_VIS_ONLY common_type {};
1937
1938// bullet 2 - sizeof...(Tp) == 1
1939
1940template <class _Tp>
1941struct _LIBCPP_TYPE_VIS_ONLY common_type<_Tp>
1942{
1943    typedef typename decay<_Tp>::type type;
1944};
1945
1946// bullet 3 - sizeof...(Tp) == 2
1947
1948template <class _Tp, class _Up, class = void>
1949struct __common_type2 {};
1950
1951template <class _Tp, class _Up>
1952struct __common_type2<_Tp, _Up,
1953    typename __void_t<decltype(
1954        true ? _VSTD::declval<_Tp>() : _VSTD::declval<_Up>()
1955    )>::type>
1956{
1957    typedef typename decay<decltype(
1958        true ? _VSTD::declval<_Tp>() : _VSTD::declval<_Up>()
1959    )>::type type;
1960};
1961
1962template <class _Tp, class _Up>
1963struct _LIBCPP_TYPE_VIS_ONLY common_type<_Tp, _Up>
1964    : __common_type2<_Tp, _Up> {};
1965
1966// bullet 4 - sizeof...(Tp) > 2
1967
1968template <class ...Tp> struct __common_types;
1969
1970template <class, class = void>
1971struct __common_type_impl {};
1972
1973template <class _Tp, class _Up, class ..._Vp>
1974struct __common_type_impl<__common_types<_Tp, _Up, _Vp...>,
1975    typename __void_t<typename common_type<_Tp, _Up>::type>::type>
1976{
1977    typedef typename common_type<
1978        typename common_type<_Tp, _Up>::type, _Vp...
1979    >::type type;
1980};
1981
1982template <class _Tp, class _Up, class ..._Vp>
1983struct _LIBCPP_TYPE_VIS_ONLY common_type<_Tp, _Up, _Vp...>
1984    : __common_type_impl<__common_types<_Tp, _Up, _Vp...> > {};
1985
1986#if _LIBCPP_STD_VER > 11
1987template <class ..._Tp> using common_type_t = typename common_type<_Tp...>::type;
1988#endif
1989
1990#endif  // _LIBCPP_HAS_NO_VARIADICS
1991
1992// is_assignable
1993
1994template<typename, typename _Tp> struct __select_2nd { typedef _Tp type; };
1995
1996template <class _Tp, class _Arg>
1997typename __select_2nd<decltype((_VSTD::declval<_Tp>() = _VSTD::declval<_Arg>())), true_type>::type
1998#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1999__is_assignable_test(_Tp&&, _Arg&&);
2000#else
2001__is_assignable_test(_Tp, _Arg&);
2002#endif
2003
2004template <class _Arg>
2005false_type
2006#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2007__is_assignable_test(__any, _Arg&&);
2008#else
2009__is_assignable_test(__any, _Arg&);
2010#endif
2011
2012template <class _Tp, class _Arg, bool = is_void<_Tp>::value || is_void<_Arg>::value>
2013struct __is_assignable_imp
2014    : public common_type
2015        <
2016            decltype(_VSTD::__is_assignable_test(declval<_Tp>(), declval<_Arg>()))
2017        >::type {};
2018
2019template <class _Tp, class _Arg>
2020struct __is_assignable_imp<_Tp, _Arg, true>
2021    : public false_type
2022{
2023};
2024
2025template <class _Tp, class _Arg>
2026struct is_assignable
2027    : public __is_assignable_imp<_Tp, _Arg> {};
2028
2029#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
2030template <class _Tp, class _Arg> _LIBCPP_CONSTEXPR bool is_assignable_v
2031    = is_assignable<_Tp, _Arg>::value;
2032#endif
2033
2034// is_copy_assignable
2035
2036template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_copy_assignable
2037    : public is_assignable<typename add_lvalue_reference<_Tp>::type,
2038                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
2039
2040#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
2041template <class _Tp> _LIBCPP_CONSTEXPR bool is_copy_assignable_v
2042    = is_copy_assignable<_Tp>::value;
2043#endif
2044
2045// is_move_assignable
2046
2047template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_move_assignable
2048#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2049    : public is_assignable<typename add_lvalue_reference<_Tp>::type,
2050                     const typename add_rvalue_reference<_Tp>::type> {};
2051#else
2052    : public is_copy_assignable<_Tp> {};
2053#endif
2054
2055#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
2056template <class _Tp> _LIBCPP_CONSTEXPR bool is_move_assignable_v
2057    = is_move_assignable<_Tp>::value;
2058#endif
2059
2060// is_destructible
2061
2062//  if it's a reference, return true
2063//  if it's a function, return false
2064//  if it's   void,     return false
2065//  if it's an array of unknown bound, return false
2066//  Otherwise, return "std::declval<_Up&>().~_Up()" is well-formed
2067//    where _Up is remove_all_extents<_Tp>::type
2068
2069template <class>
2070struct __is_destructible_apply { typedef int type; };
2071
2072template <typename _Tp>
2073struct __is_destructor_wellformed {
2074    template <typename _Tp1>
2075    static char  __test (
2076        typename __is_destructible_apply<decltype(_VSTD::declval<_Tp1&>().~_Tp1())>::type
2077    );
2078
2079    template <typename _Tp1>
2080    static __two __test (...);
2081    
2082    static const bool value = sizeof(__test<_Tp>(12)) == sizeof(char);
2083};
2084
2085template <class _Tp, bool>
2086struct __destructible_imp;
2087
2088template <class _Tp>
2089struct __destructible_imp<_Tp, false> 
2090   : public _VSTD::integral_constant<bool, 
2091        __is_destructor_wellformed<typename _VSTD::remove_all_extents<_Tp>::type>::value> {};
2092
2093template <class _Tp>
2094struct __destructible_imp<_Tp, true>
2095    : public _VSTD::true_type {};
2096
2097template <class _Tp, bool>
2098struct __destructible_false;
2099
2100template <class _Tp>
2101struct __destructible_false<_Tp, false> : public __destructible_imp<_Tp, _VSTD::is_reference<_Tp>::value> {};
2102
2103template <class _Tp>
2104struct __destructible_false<_Tp, true> : public _VSTD::false_type {};
2105
2106template <class _Tp>
2107struct is_destructible
2108    : public __destructible_false<_Tp, _VSTD::is_function<_Tp>::value> {};
2109
2110template <class _Tp>
2111struct is_destructible<_Tp[]>
2112    : public _VSTD::false_type {};
2113
2114template <>
2115struct is_destructible<void>
2116    : public _VSTD::false_type {};
2117
2118#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
2119template <class _Tp> _LIBCPP_CONSTEXPR bool is_destructible_v
2120    = is_destructible<_Tp>::value;
2121#endif
2122
2123// move
2124
2125#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2126
2127template <class _Tp>
2128inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
2129typename remove_reference<_Tp>::type&&
2130move(_Tp&& __t) _NOEXCEPT
2131{
2132    typedef typename remove_reference<_Tp>::type _Up;
2133    return static_cast<_Up&&>(__t);
2134}
2135
2136template <class _Tp>
2137inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
2138_Tp&&
2139forward(typename std::remove_reference<_Tp>::type& __t) _NOEXCEPT
2140{
2141    return static_cast<_Tp&&>(__t);
2142}
2143
2144template <class _Tp>
2145inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
2146_Tp&&
2147forward(typename std::remove_reference<_Tp>::type&& __t) _NOEXCEPT
2148{
2149    static_assert(!std::is_lvalue_reference<_Tp>::value,
2150                  "Can not forward an rvalue as an lvalue.");
2151    return static_cast<_Tp&&>(__t);
2152}
2153
2154#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2155
2156template <class _Tp>
2157inline _LIBCPP_INLINE_VISIBILITY
2158_Tp&
2159move(_Tp& __t)
2160{
2161    return __t;
2162}
2163
2164template <class _Tp>
2165inline _LIBCPP_INLINE_VISIBILITY
2166const _Tp&
2167move(const _Tp& __t)
2168{
2169    return __t;
2170}
2171
2172template <class _Tp>
2173inline _LIBCPP_INLINE_VISIBILITY
2174_Tp&
2175forward(typename std::remove_reference<_Tp>::type& __t) _NOEXCEPT
2176{
2177    return __t;
2178}
2179
2180
2181template <class _Tp>
2182class __rv
2183{
2184    typedef typename remove_reference<_Tp>::type _Trr;
2185    _Trr& t_;
2186public:
2187    _LIBCPP_INLINE_VISIBILITY
2188    _Trr* operator->() {return &t_;}
2189    _LIBCPP_INLINE_VISIBILITY
2190    explicit __rv(_Trr& __t) : t_(__t) {}
2191};
2192
2193#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2194
2195#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2196
2197template <class _Tp>
2198inline _LIBCPP_INLINE_VISIBILITY
2199typename decay<_Tp>::type
2200__decay_copy(_Tp&& __t)
2201{
2202    return _VSTD::forward<_Tp>(__t);
2203}
2204
2205#else
2206
2207template <class _Tp>
2208inline _LIBCPP_INLINE_VISIBILITY
2209typename decay<_Tp>::type
2210__decay_copy(const _Tp& __t)
2211{
2212    return _VSTD::forward<_Tp>(__t);
2213}
2214
2215#endif
2216
2217#ifndef _LIBCPP_HAS_NO_VARIADICS
2218
2219template <class _Rp, class _Class, class ..._Param>
2220struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...), true, false>
2221{
2222    typedef _Class _ClassType;
2223    typedef _Rp _ReturnType;
2224    typedef _Rp (_FnType) (_Param...);
2225};
2226
2227template <class _Rp, class _Class, class ..._Param>
2228struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...), true, false>
2229{
2230    typedef _Class _ClassType;
2231    typedef _Rp _ReturnType;
2232    typedef _Rp (_FnType) (_Param..., ...);
2233};
2234
2235template <class _Rp, class _Class, class ..._Param>
2236struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const, true, false>
2237{
2238    typedef _Class const _ClassType;
2239    typedef _Rp _ReturnType;
2240    typedef _Rp (_FnType) (_Param...);
2241};
2242
2243template <class _Rp, class _Class, class ..._Param>
2244struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const, true, false>
2245{
2246    typedef _Class const _ClassType;
2247    typedef _Rp _ReturnType;
2248    typedef _Rp (_FnType) (_Param..., ...);
2249};
2250
2251template <class _Rp, class _Class, class ..._Param>
2252struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) volatile, true, false>
2253{
2254    typedef _Class volatile _ClassType;
2255    typedef _Rp _ReturnType;
2256    typedef _Rp (_FnType) (_Param...);
2257};
2258
2259template <class _Rp, class _Class, class ..._Param>
2260struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) volatile, true, false>
2261{
2262    typedef _Class volatile _ClassType;
2263    typedef _Rp _ReturnType;
2264    typedef _Rp (_FnType) (_Param..., ...);
2265};
2266
2267template <class _Rp, class _Class, class ..._Param>
2268struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const volatile, true, false>
2269{
2270    typedef _Class const volatile _ClassType;
2271    typedef _Rp _ReturnType;
2272    typedef _Rp (_FnType) (_Param...);
2273};
2274
2275template <class _Rp, class _Class, class ..._Param>
2276struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const volatile, true, false>
2277{
2278    typedef _Class const volatile _ClassType;
2279    typedef _Rp _ReturnType;
2280    typedef _Rp (_FnType) (_Param..., ...);
2281};
2282
2283#if __has_feature(cxx_reference_qualified_functions) || \
2284    (defined(_GNUC_VER) && _GNUC_VER >= 409)
2285
2286template <class _Rp, class _Class, class ..._Param>
2287struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) &, true, false>
2288{
2289    typedef _Class& _ClassType;
2290    typedef _Rp _ReturnType;
2291    typedef _Rp (_FnType) (_Param...);
2292};
2293
2294template <class _Rp, class _Class, class ..._Param>
2295struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) &, true, false>
2296{
2297    typedef _Class& _ClassType;
2298    typedef _Rp _ReturnType;
2299    typedef _Rp (_FnType) (_Param..., ...);
2300};
2301
2302template <class _Rp, class _Class, class ..._Param>
2303struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const&, true, false>
2304{
2305    typedef _Class const& _ClassType;
2306    typedef _Rp _ReturnType;
2307    typedef _Rp (_FnType) (_Param...);
2308};
2309
2310template <class _Rp, class _Class, class ..._Param>
2311struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const&, true, false>
2312{
2313    typedef _Class const& _ClassType;
2314    typedef _Rp _ReturnType;
2315    typedef _Rp (_FnType) (_Param..., ...);
2316};
2317
2318template <class _Rp, class _Class, class ..._Param>
2319struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) volatile&, true, false>
2320{
2321    typedef _Class volatile& _ClassType;
2322    typedef _Rp _ReturnType;
2323    typedef _Rp (_FnType) (_Param...);
2324};
2325
2326template <class _Rp, class _Class, class ..._Param>
2327struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) volatile&, true, false>
2328{
2329    typedef _Class volatile& _ClassType;
2330    typedef _Rp _ReturnType;
2331    typedef _Rp (_FnType) (_Param..., ...);
2332};
2333
2334template <class _Rp, class _Class, class ..._Param>
2335struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const volatile&, true, false>
2336{
2337    typedef _Class const volatile& _ClassType;
2338    typedef _Rp _ReturnType;
2339    typedef _Rp (_FnType) (_Param...);
2340};
2341
2342template <class _Rp, class _Class, class ..._Param>
2343struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const volatile&, true, false>
2344{
2345    typedef _Class const volatile& _ClassType;
2346    typedef _Rp _ReturnType;
2347    typedef _Rp (_FnType) (_Param..., ...);
2348};
2349
2350template <class _Rp, class _Class, class ..._Param>
2351struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) &&, true, false>
2352{
2353    typedef _Class&& _ClassType;
2354    typedef _Rp _ReturnType;
2355    typedef _Rp (_FnType) (_Param...);
2356};
2357
2358template <class _Rp, class _Class, class ..._Param>
2359struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) &&, true, false>
2360{
2361    typedef _Class&& _ClassType;
2362    typedef _Rp _ReturnType;
2363    typedef _Rp (_FnType) (_Param..., ...);
2364};
2365
2366template <class _Rp, class _Class, class ..._Param>
2367struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const&&, true, false>
2368{
2369    typedef _Class const&& _ClassType;
2370    typedef _Rp _ReturnType;
2371    typedef _Rp (_FnType) (_Param...);
2372};
2373
2374template <class _Rp, class _Class, class ..._Param>
2375struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const&&, true, false>
2376{
2377    typedef _Class const&& _ClassType;
2378    typedef _Rp _ReturnType;
2379    typedef _Rp (_FnType) (_Param..., ...);
2380};
2381
2382template <class _Rp, class _Class, class ..._Param>
2383struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) volatile&&, true, false>
2384{
2385    typedef _Class volatile&& _ClassType;
2386    typedef _Rp _ReturnType;
2387    typedef _Rp (_FnType) (_Param...);
2388};
2389
2390template <class _Rp, class _Class, class ..._Param>
2391struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) volatile&&, true, false>
2392{
2393    typedef _Class volatile&& _ClassType;
2394    typedef _Rp _ReturnType;
2395    typedef _Rp (_FnType) (_Param..., ...);
2396};
2397
2398template <class _Rp, class _Class, class ..._Param>
2399struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const volatile&&, true, false>
2400{
2401    typedef _Class const volatile&& _ClassType;
2402    typedef _Rp _ReturnType;
2403    typedef _Rp (_FnType) (_Param...);
2404};
2405
2406template <class _Rp, class _Class, class ..._Param>
2407struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const volatile&&, true, false>
2408{
2409    typedef _Class const volatile&& _ClassType;
2410    typedef _Rp _ReturnType;
2411    typedef _Rp (_FnType) (_Param..., ...);
2412};
2413
2414#endif  // __has_feature(cxx_reference_qualified_functions) || _GNUC_VER >= 409
2415
2416#else  // _LIBCPP_HAS_NO_VARIADICS
2417
2418template <class _Rp, class _Class>
2419struct __member_pointer_traits_imp<_Rp (_Class::*)(), true, false>
2420{
2421    typedef _Class _ClassType;
2422    typedef _Rp _ReturnType;
2423    typedef _Rp (_FnType) ();
2424};
2425
2426template <class _Rp, class _Class>
2427struct __member_pointer_traits_imp<_Rp (_Class::*)(...), true, false>
2428{
2429    typedef _Class _ClassType;
2430    typedef _Rp _ReturnType;
2431    typedef _Rp (_FnType) (...);
2432};
2433
2434template <class _Rp, class _Class, class _P0>
2435struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0), true, false>
2436{
2437    typedef _Class _ClassType;
2438    typedef _Rp _ReturnType;
2439    typedef _Rp (_FnType) (_P0);
2440};
2441
2442template <class _Rp, class _Class, class _P0>
2443struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, ...), true, false>
2444{
2445    typedef _Class _ClassType;
2446    typedef _Rp _ReturnType;
2447    typedef _Rp (_FnType) (_P0, ...);
2448};
2449
2450template <class _Rp, class _Class, class _P0, class _P1>
2451struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1), true, false>
2452{
2453    typedef _Class _ClassType;
2454    typedef _Rp _ReturnType;
2455    typedef _Rp (_FnType) (_P0, _P1);
2456};
2457
2458template <class _Rp, class _Class, class _P0, class _P1>
2459struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, ...), true, false>
2460{
2461    typedef _Class _ClassType;
2462    typedef _Rp _ReturnType;
2463    typedef _Rp (_FnType) (_P0, _P1, ...);
2464};
2465
2466template <class _Rp, class _Class, class _P0, class _P1, class _P2>
2467struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2), true, false>
2468{
2469    typedef _Class _ClassType;
2470    typedef _Rp _ReturnType;
2471    typedef _Rp (_FnType) (_P0, _P1, _P2);
2472};
2473
2474template <class _Rp, class _Class, class _P0, class _P1, class _P2>
2475struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2, ...), true, false>
2476{
2477    typedef _Class _ClassType;
2478    typedef _Rp _ReturnType;
2479    typedef _Rp (_FnType) (_P0, _P1, _P2, ...);
2480};
2481
2482template <class _Rp, class _Class>
2483struct __member_pointer_traits_imp<_Rp (_Class::*)() const, true, false>
2484{
2485    typedef _Class const _ClassType;
2486    typedef _Rp _ReturnType;
2487    typedef _Rp (_FnType) ();
2488};
2489
2490template <class _Rp, class _Class>
2491struct __member_pointer_traits_imp<_Rp (_Class::*)(...) const, true, false>
2492{
2493    typedef _Class const _ClassType;
2494    typedef _Rp _ReturnType;
2495    typedef _Rp (_FnType) (...);
2496};
2497
2498template <class _Rp, class _Class, class _P0>
2499struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0) const, true, false>
2500{
2501    typedef _Class const _ClassType;
2502    typedef _Rp _ReturnType;
2503    typedef _Rp (_FnType) (_P0);
2504};
2505
2506template <class _Rp, class _Class, class _P0>
2507struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, ...) const, true, false>
2508{
2509    typedef _Class const _ClassType;
2510    typedef _Rp _ReturnType;
2511    typedef _Rp (_FnType) (_P0, ...);
2512};
2513
2514template <class _Rp, class _Class, class _P0, class _P1>
2515struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1) const, true, false>
2516{
2517    typedef _Class const _ClassType;
2518    typedef _Rp _ReturnType;
2519    typedef _Rp (_FnType) (_P0, _P1);
2520};
2521
2522template <class _Rp, class _Class, class _P0, class _P1>
2523struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, ...) const, true, false>
2524{
2525    typedef _Class const _ClassType;
2526    typedef _Rp _ReturnType;
2527    typedef _Rp (_FnType) (_P0, _P1, ...);
2528};
2529
2530template <class _Rp, class _Class, class _P0, class _P1, class _P2>
2531struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2) const, true, false>
2532{
2533    typedef _Class const _ClassType;
2534    typedef _Rp _ReturnType;
2535    typedef _Rp (_FnType) (_P0, _P1, _P2);
2536};
2537
2538template <class _Rp, class _Class, class _P0, class _P1, class _P2>
2539struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2, ...) const, true, false>
2540{
2541    typedef _Class const _ClassType;
2542    typedef _Rp _ReturnType;
2543    typedef _Rp (_FnType) (_P0, _P1, _P2, ...);
2544};
2545
2546template <class _Rp, class _Class>
2547struct __member_pointer_traits_imp<_Rp (_Class::*)() volatile, true, false>
2548{
2549    typedef _Class volatile _ClassType;
2550    typedef _Rp _ReturnType;
2551    typedef _Rp (_FnType) ();
2552};
2553
2554template <class _Rp, class _Class>
2555struct __member_pointer_traits_imp<_Rp (_Class::*)(...) volatile, true, false>
2556{
2557    typedef _Class volatile _ClassType;
2558    typedef _Rp _ReturnType;
2559    typedef _Rp (_FnType) (...);
2560};
2561
2562template <class _Rp, class _Class, class _P0>
2563struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0) volatile, true, false>
2564{
2565    typedef _Class volatile _ClassType;
2566    typedef _Rp _ReturnType;
2567    typedef _Rp (_FnType) (_P0);
2568};
2569
2570template <class _Rp, class _Class, class _P0>
2571struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, ...) volatile, true, false>
2572{
2573    typedef _Class volatile _ClassType;
2574    typedef _Rp _ReturnType;
2575    typedef _Rp (_FnType) (_P0, ...);
2576};
2577
2578template <class _Rp, class _Class, class _P0, class _P1>
2579struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1) volatile, true, false>
2580{
2581    typedef _Class volatile _ClassType;
2582    typedef _Rp _ReturnType;
2583    typedef _Rp (_FnType) (_P0, _P1);
2584};
2585
2586template <class _Rp, class _Class, class _P0, class _P1>
2587struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, ...) volatile, true, false>
2588{
2589    typedef _Class volatile _ClassType;
2590    typedef _Rp _ReturnType;
2591    typedef _Rp (_FnType) (_P0, _P1, ...);
2592};
2593
2594template <class _Rp, class _Class, class _P0, class _P1, class _P2>
2595struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2) volatile, true, false>
2596{
2597    typedef _Class volatile _ClassType;
2598    typedef _Rp _ReturnType;
2599    typedef _Rp (_FnType) (_P0, _P1, _P2);
2600};
2601
2602template <class _Rp, class _Class, class _P0, class _P1, class _P2>
2603struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2, ...) volatile, true, false>
2604{
2605    typedef _Class volatile _ClassType;
2606    typedef _Rp _ReturnType;
2607    typedef _Rp (_FnType) (_P0, _P1, _P2, ...);
2608};
2609
2610template <class _Rp, class _Class>
2611struct __member_pointer_traits_imp<_Rp (_Class::*)() const volatile, true, false>
2612{
2613    typedef _Class const volatile _ClassType;
2614    typedef _Rp _ReturnType;
2615    typedef _Rp (_FnType) ();
2616};
2617
2618template <class _Rp, class _Class>
2619struct __member_pointer_traits_imp<_Rp (_Class::*)(...) const volatile, true, false>
2620{
2621    typedef _Class const volatile _ClassType;
2622    typedef _Rp _ReturnType;
2623    typedef _Rp (_FnType) (...);
2624};
2625
2626template <class _Rp, class _Class, class _P0>
2627struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0) const volatile, true, false>
2628{
2629    typedef _Class const volatile _ClassType;
2630    typedef _Rp _ReturnType;
2631    typedef _Rp (_FnType) (_P0);
2632};
2633
2634template <class _Rp, class _Class, class _P0>
2635struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, ...) const volatile, true, false>
2636{
2637    typedef _Class const volatile _ClassType;
2638    typedef _Rp _ReturnType;
2639    typedef _Rp (_FnType) (_P0, ...);
2640};
2641
2642template <class _Rp, class _Class, class _P0, class _P1>
2643struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1) const volatile, true, false>
2644{
2645    typedef _Class const volatile _ClassType;
2646    typedef _Rp _ReturnType;
2647    typedef _Rp (_FnType) (_P0, _P1);
2648};
2649
2650template <class _Rp, class _Class, class _P0, class _P1>
2651struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, ...) const volatile, true, false>
2652{
2653    typedef _Class const volatile _ClassType;
2654    typedef _Rp _ReturnType;
2655    typedef _Rp (_FnType) (_P0, _P1, ...);
2656};
2657
2658template <class _Rp, class _Class, class _P0, class _P1, class _P2>
2659struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2) const volatile, true, false>
2660{
2661    typedef _Class const volatile _ClassType;
2662    typedef _Rp _ReturnType;
2663    typedef _Rp (_FnType) (_P0, _P1, _P2);
2664};
2665
2666template <class _Rp, class _Class, class _P0, class _P1, class _P2>
2667struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2, ...) const volatile, true, false>
2668{
2669    typedef _Class const volatile _ClassType;
2670    typedef _Rp _ReturnType;
2671    typedef _Rp (_FnType) (_P0, _P1, _P2, ...);
2672};
2673
2674#endif  // _LIBCPP_HAS_NO_VARIADICS
2675
2676template <class _Rp, class _Class>
2677struct __member_pointer_traits_imp<_Rp _Class::*, false, true>
2678{
2679    typedef _Class _ClassType;
2680    typedef _Rp _ReturnType;
2681};
2682
2683template <class _MP>
2684struct __member_pointer_traits
2685    : public __member_pointer_traits_imp<typename remove_cv<_MP>::type,
2686                    is_member_function_pointer<_MP>::value,
2687                    is_member_object_pointer<_MP>::value>
2688{
2689//     typedef ... _ClassType;
2690//     typedef ... _ReturnType;
2691//     typedef ... _FnType;
2692};
2693
2694// result_of
2695
2696template <class _Callable> class result_of;
2697
2698#ifdef _LIBCPP_HAS_NO_VARIADICS
2699
2700template <class _Fn, bool, bool>
2701class __result_of
2702{
2703};
2704
2705template <class _Fn>
2706class __result_of<_Fn(), true, false>
2707{
2708public:
2709    typedef decltype(declval<_Fn>()()) type;
2710};
2711
2712template <class _Fn, class _A0>
2713class __result_of<_Fn(_A0), true, false>
2714{
2715public:
2716    typedef decltype(declval<_Fn>()(declval<_A0>())) type;
2717};
2718
2719template <class _Fn, class _A0, class _A1>
2720class __result_of<_Fn(_A0, _A1), true, false>
2721{
2722public:
2723    typedef decltype(declval<_Fn>()(declval<_A0>(), declval<_A1>())) type;
2724};
2725
2726template <class _Fn, class _A0, class _A1, class _A2>
2727class __result_of<_Fn(_A0, _A1, _A2), true, false>
2728{
2729public:
2730    typedef decltype(declval<_Fn>()(declval<_A0>(), declval<_A1>(), declval<_A2>())) type;
2731};
2732
2733template <class _MP, class _Tp, bool _IsMemberFunctionPtr>
2734struct __result_of_mp;
2735
2736// member function pointer
2737
2738template <class _MP, class _Tp>
2739struct __result_of_mp<_MP, _Tp, true>
2740    : public __identity<typename __member_pointer_traits<_MP>::_ReturnType>
2741{
2742};
2743
2744// member data pointer
2745
2746template <class _MP, class _Tp, bool>
2747struct __result_of_mdp;
2748
2749template <class _Rp, class _Class, class _Tp>
2750struct __result_of_mdp<_Rp _Class::*, _Tp, false>
2751{
2752    typedef typename __apply_cv<decltype(*_VSTD::declval<_Tp>()), _Rp>::type& type;
2753};
2754
2755template <class _Rp, class _Class, class _Tp>
2756struct __result_of_mdp<_Rp _Class::*, _Tp, true>
2757{
2758    typedef typename __apply_cv<_Tp, _Rp>::type& type;
2759};
2760
2761template <class _Rp, class _Class, class _Tp>
2762struct __result_of_mp<_Rp _Class::*, _Tp, false>
2763    : public __result_of_mdp<_Rp _Class::*, _Tp,
2764            is_base_of<_Class, typename remove_reference<_Tp>::type>::value>
2765{
2766};
2767
2768
2769
2770template <class _Fn, class _Tp>
2771class __result_of<_Fn(_Tp), false, true>  // _Fn must be member pointer
2772    : public __result_of_mp<typename remove_reference<_Fn>::type,
2773                            _Tp,
2774                            is_member_function_pointer<typename remove_reference<_Fn>::type>::value>
2775{
2776};
2777
2778template <class _Fn, class _Tp, class _A0>
2779class __result_of<_Fn(_Tp, _A0), false, true>  // _Fn must be member pointer
2780    : public __result_of_mp<typename remove_reference<_Fn>::type,
2781                            _Tp,
2782                            is_member_function_pointer<typename remove_reference<_Fn>::type>::value>
2783{
2784};
2785
2786template <class _Fn, class _Tp, class _A0, class _A1>
2787class __result_of<_Fn(_Tp, _A0, _A1), false, true>  // _Fn must be member pointer
2788    : public __result_of_mp<typename remove_reference<_Fn>::type,
2789                            _Tp,
2790                            is_member_function_pointer<typename remove_reference<_Fn>::type>::value>
2791{
2792};
2793
2794template <class _Fn, class _Tp, class _A0, class _A1, class _A2>
2795class __result_of<_Fn(_Tp, _A0, _A1, _A2), false, true>  // _Fn must be member pointer
2796    : public __result_of_mp<typename remove_reference<_Fn>::type,
2797                            _Tp,
2798                            is_member_function_pointer<typename remove_reference<_Fn>::type>::value>
2799{
2800};
2801
2802// result_of
2803
2804template <class _Fn>
2805class _LIBCPP_TYPE_VIS_ONLY result_of<_Fn()>
2806    : public __result_of<_Fn(),
2807                         is_class<typename remove_reference<_Fn>::type>::value ||
2808                         is_function<typename remove_pointer<typename remove_reference<_Fn>::type>::type>::value,
2809                         is_member_pointer<typename remove_reference<_Fn>::type>::value
2810                        >
2811{
2812};
2813
2814template <class _Fn, class _A0>
2815class _LIBCPP_TYPE_VIS_ONLY result_of<_Fn(_A0)>
2816    : public __result_of<_Fn(_A0),
2817                         is_class<typename remove_reference<_Fn>::type>::value ||
2818                         is_function<typename remove_pointer<typename remove_reference<_Fn>::type>::type>::value,
2819                         is_member_pointer<typename remove_reference<_Fn>::type>::value
2820                        >
2821{
2822};
2823
2824template <class _Fn, class _A0, class _A1>
2825class _LIBCPP_TYPE_VIS_ONLY result_of<_Fn(_A0, _A1)>
2826    : public __result_of<_Fn(_A0, _A1),
2827                         is_class<typename remove_reference<_Fn>::type>::value ||
2828                         is_function<typename remove_pointer<typename remove_reference<_Fn>::type>::type>::value,
2829                         is_member_pointer<typename remove_reference<_Fn>::type>::value
2830                        >
2831{
2832};
2833
2834template <class _Fn, class _A0, class _A1, class _A2>
2835class _LIBCPP_TYPE_VIS_ONLY result_of<_Fn(_A0, _A1, _A2)>
2836    : public __result_of<_Fn(_A0, _A1, _A2),
2837                         is_class<typename remove_reference<_Fn>::type>::value ||
2838                         is_function<typename remove_pointer<typename remove_reference<_Fn>::type>::type>::value,
2839                         is_member_pointer<typename remove_reference<_Fn>::type>::value
2840                        >
2841{
2842};
2843
2844#endif  // _LIBCPP_HAS_NO_VARIADICS
2845
2846// template <class T, class... Args> struct is_constructible;
2847
2848namespace __is_construct
2849{
2850struct __nat {};
2851}
2852
2853#if __has_feature(is_constructible)
2854
2855template <class _Tp, class ..._Args>
2856struct _LIBCPP_TYPE_VIS_ONLY is_constructible
2857    : public integral_constant<bool, __is_constructible(_Tp, _Args...)>
2858    {};
2859
2860#else
2861
2862#ifndef _LIBCPP_HAS_NO_VARIADICS
2863
2864//      main is_constructible test
2865
2866template <class _Tp, class ..._Args>
2867typename __select_2nd<decltype(_VSTD::move(_Tp(_VSTD::declval<_Args>()...))), true_type>::type
2868__is_constructible_test(_Tp&&, _Args&& ...);
2869
2870template <class ..._Args>
2871false_type
2872__is_constructible_test(__any, _Args&& ...);
2873
2874template <bool, class _Tp, class... _Args>
2875struct __libcpp_is_constructible // false, _Tp is not a scalar
2876    : public common_type
2877             <
2878                 decltype(__is_constructible_test(declval<_Tp>(), declval<_Args>()...))
2879             >::type
2880    {};
2881
2882//      function types are not constructible
2883
2884template <class _Rp, class... _A1, class... _A2>
2885struct __libcpp_is_constructible<false, _Rp(_A1...), _A2...>
2886    : public false_type
2887    {};
2888
2889//      handle scalars and reference types
2890
2891//      Scalars are default constructible, references are not
2892
2893template <class _Tp>
2894struct __libcpp_is_constructible<true, _Tp>
2895    : public is_scalar<_Tp>
2896    {};
2897
2898//      Scalars and references are constructible from one arg if that arg is
2899//          implicitly convertible to the scalar or reference.
2900
2901template <class _Tp>
2902struct __is_constructible_ref
2903{
2904    true_type static __lxx(_Tp);
2905    false_type static __lxx(...);
2906};
2907
2908template <class _Tp, class _A0>
2909struct __libcpp_is_constructible<true, _Tp, _A0>
2910    : public common_type
2911             <
2912                 decltype(__is_constructible_ref<_Tp>::__lxx(declval<_A0>()))
2913             >::type
2914    {};
2915
2916//      Scalars and references are not constructible from multiple args.
2917
2918template <class _Tp, class _A0, class ..._Args>
2919struct __libcpp_is_constructible<true, _Tp, _A0, _Args...>
2920    : public false_type
2921    {};
2922
2923//      Treat scalars and reference types separately
2924
2925template <bool, class _Tp, class... _Args>
2926struct __is_constructible_void_check
2927    : public __libcpp_is_constructible<is_scalar<_Tp>::value || is_reference<_Tp>::value,
2928                                _Tp, _Args...>
2929    {};
2930
2931//      If any of T or Args is void, is_constructible should be false
2932
2933template <class _Tp, class... _Args>
2934struct __is_constructible_void_check<true, _Tp, _Args...>
2935    : public false_type
2936    {};
2937
2938template <class ..._Args> struct __contains_void;
2939
2940template <> struct __contains_void<> : false_type {};
2941
2942template <class _A0, class ..._Args>
2943struct __contains_void<_A0, _Args...>
2944{
2945    static const bool value = is_void<_A0>::value ||
2946                              __contains_void<_Args...>::value;
2947};
2948
2949//      is_constructible entry point
2950
2951template <class _Tp, class... _Args>
2952struct _LIBCPP_TYPE_VIS_ONLY is_constructible
2953    : public __is_constructible_void_check<__contains_void<_Tp, _Args...>::value
2954                                        || is_abstract<_Tp>::value,
2955                                           _Tp, _Args...>
2956    {};
2957
2958//      Array types are default constructible if their element type
2959//      is default constructible
2960
2961template <class _Ap, size_t _Np>
2962struct __libcpp_is_constructible<false, _Ap[_Np]>
2963    : public is_constructible<typename remove_all_extents<_Ap>::type>
2964    {};
2965
2966//      Otherwise array types are not constructible by this syntax
2967
2968template <class _Ap, size_t _Np, class ..._Args>
2969struct __libcpp_is_constructible<false, _Ap[_Np], _Args...>
2970    : public false_type
2971    {};
2972
2973//      Incomplete array types are not constructible
2974
2975template <class _Ap, class ..._Args>
2976struct __libcpp_is_constructible<false, _Ap[], _Args...>
2977    : public false_type
2978    {};
2979
2980#else  // _LIBCPP_HAS_NO_VARIADICS
2981
2982// template <class T> struct is_constructible0;
2983
2984//      main is_constructible0 test
2985
2986template <class _Tp>
2987decltype((_Tp(), true_type()))
2988__is_constructible0_test(_Tp&);
2989
2990false_type
2991__is_constructible0_test(__any);
2992
2993template <class _Tp, class _A0>
2994decltype((_Tp(_VSTD::declval<_A0>()), true_type()))
2995__is_constructible1_test(_Tp&, _A0&);
2996
2997template <class _A0>
2998false_type
2999__is_constructible1_test(__any, _A0&);
3000
3001template <class _Tp, class _A0, class _A1>
3002decltype((_Tp(_VSTD::declval<_A0>(), _VSTD::declval<_A1>()), true_type()))
3003__is_constructible2_test(_Tp&, _A0&, _A1&);
3004
3005template <class _A0, class _A1>
3006false_type
3007__is_constructible2_test(__any, _A0&, _A1&);
3008
3009template <bool, class _Tp>
3010struct __is_constructible0_imp // false, _Tp is not a scalar
3011    : public common_type
3012             <
3013                 decltype(__is_constructible0_test(declval<_Tp&>()))
3014             >::type
3015    {};
3016
3017template <bool, class _Tp, class _A0>
3018struct __is_constructible1_imp // false, _Tp is not a scalar
3019    : public common_type
3020             <
3021                 decltype(__is_constructible1_test(declval<_Tp&>(), declval<_A0&>()))
3022             >::type
3023    {};
3024
3025template <bool, class _Tp, class _A0, class _A1>
3026struct __is_constructible2_imp // false, _Tp is not a scalar
3027    : public common_type
3028             <
3029                 decltype(__is_constructible2_test(declval<_Tp&>(), declval<_A0>(), declval<_A1>()))
3030             >::type
3031    {};
3032
3033//      handle scalars and reference types
3034
3035//      Scalars are default constructible, references are not
3036
3037template <class _Tp>
3038struct __is_constructible0_imp<true, _Tp>
3039    : public is_scalar<_Tp>
3040    {};
3041
3042template <class _Tp, class _A0>
3043struct __is_constructible1_imp<true, _Tp, _A0>
3044    : public is_convertible<_A0, _Tp>
3045    {};
3046
3047template <class _Tp, class _A0, class _A1>
3048struct __is_constructible2_imp<true, _Tp, _A0, _A1>
3049    : public false_type
3050    {};
3051
3052//      Treat scalars and reference types separately
3053
3054template <bool, class _Tp>
3055struct __is_constructible0_void_check
3056    : public __is_constructible0_imp<is_scalar<_Tp>::value || is_reference<_Tp>::value,
3057                                _Tp>
3058    {};
3059
3060template <bool, class _Tp, class _A0>
3061struct __is_constructible1_void_check
3062    : public __is_constructible1_imp<is_scalar<_Tp>::value || is_reference<_Tp>::value,
3063                                _Tp, _A0>
3064    {};
3065
3066template <bool, class _Tp, class _A0, class _A1>
3067struct __is_constructible2_void_check
3068    : public __is_constructible2_imp<is_scalar<_Tp>::value || is_reference<_Tp>::value,
3069                                _Tp, _A0, _A1>
3070    {};
3071
3072//      If any of T or Args is void, is_constructible should be false
3073
3074template <class _Tp>
3075struct __is_constructible0_void_check<true, _Tp>
3076    : public false_type
3077    {};
3078
3079template <class _Tp, class _A0>
3080struct __is_constructible1_void_check<true, _Tp, _A0>
3081    : public false_type
3082    {};
3083
3084template <class _Tp, class _A0, class _A1>
3085struct __is_constructible2_void_check<true, _Tp, _A0, _A1>
3086    : public false_type
3087    {};
3088
3089//      is_constructible entry point
3090
3091template <class _Tp, class _A0 = __is_construct::__nat,
3092                     class _A1 = __is_construct::__nat>
3093struct _LIBCPP_TYPE_VIS_ONLY is_constructible
3094    : public __is_constructible2_void_check<is_void<_Tp>::value
3095                                        || is_abstract<_Tp>::value
3096                                        || is_function<_Tp>::value
3097                                        || is_void<_A0>::value
3098                                        || is_void<_A1>::value,
3099                                           _Tp, _A0, _A1>
3100    {};
3101
3102template <class _Tp>
3103struct _LIBCPP_TYPE_VIS_ONLY is_constructible<_Tp, __is_construct::__nat, __is_construct::__nat>
3104    : public __is_constructible0_void_check<is_void<_Tp>::value
3105                                        || is_abstract<_Tp>::value
3106                                        || is_function<_Tp>::value,
3107                                           _Tp>
3108    {};
3109
3110template <class _Tp, class _A0>
3111struct _LIBCPP_TYPE_VIS_ONLY is_constructible<_Tp, _A0, __is_construct::__nat>
3112    : public __is_constructible1_void_check<is_void<_Tp>::value
3113                                        || is_abstract<_Tp>::value
3114                                        || is_function<_Tp>::value
3115                                        || is_void<_A0>::value,
3116                                           _Tp, _A0>
3117    {};
3118
3119//      Array types are default constructible if their element type
3120//      is default constructible
3121
3122template <class _Ap, size_t _Np>
3123struct __is_constructible0_imp<false, _Ap[_Np]>
3124    : public is_constructible<typename remove_all_extents<_Ap>::type>
3125    {};
3126
3127template <class _Ap, size_t _Np, class _A0>
3128struct __is_constructible1_imp<false, _Ap[_Np], _A0>
3129    : public false_type
3130    {};
3131
3132template <class _Ap, size_t _Np, class _A0, class _A1>
3133struct __is_constructible2_imp<false, _Ap[_Np], _A0, _A1>
3134    : public false_type
3135    {};
3136
3137//      Incomplete array types are not constructible
3138
3139template <class _Ap>
3140struct __is_constructible0_imp<false, _Ap[]>
3141    : public false_type
3142    {};
3143
3144template <class _Ap, class _A0>
3145struct __is_constructible1_imp<false, _Ap[], _A0>
3146    : public false_type
3147    {};
3148
3149template <class _Ap, class _A0, class _A1>
3150struct __is_constructible2_imp<false, _Ap[], _A0, _A1>
3151    : public false_type
3152    {};
3153
3154#endif  // _LIBCPP_HAS_NO_VARIADICS
3155#endif  // __has_feature(is_constructible)
3156
3157#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
3158template <class _Tp, class ..._Args> _LIBCPP_CONSTEXPR bool is_constructible_v
3159    = is_constructible<_Tp, _Args...>::value;
3160#endif
3161
3162// is_default_constructible
3163
3164template <class _Tp>
3165struct _LIBCPP_TYPE_VIS_ONLY is_default_constructible
3166    : public is_constructible<_Tp>
3167    {};
3168
3169#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3170template <class _Tp> _LIBCPP_CONSTEXPR bool is_default_constructible_v
3171    = is_default_constructible<_Tp>::value;
3172#endif
3173
3174// is_copy_constructible
3175
3176template <class _Tp>
3177struct _LIBCPP_TYPE_VIS_ONLY is_copy_constructible
3178    : public is_constructible<_Tp, 
3179                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
3180
3181#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3182template <class _Tp> _LIBCPP_CONSTEXPR bool is_copy_constructible_v
3183    = is_copy_constructible<_Tp>::value;
3184#endif
3185
3186// is_move_constructible
3187
3188template <class _Tp>
3189struct _LIBCPP_TYPE_VIS_ONLY is_move_constructible
3190#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3191    : public is_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
3192#else
3193    : public is_copy_constructible<_Tp>
3194#endif
3195    {};
3196
3197#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3198template <class _Tp> _LIBCPP_CONSTEXPR bool is_move_constructible_v
3199    = is_move_constructible<_Tp>::value;
3200#endif
3201
3202// is_trivially_constructible
3203
3204#ifndef _LIBCPP_HAS_NO_VARIADICS
3205
3206#if __has_feature(is_trivially_constructible) || _GNUC_VER >= 501
3207
3208template <class _Tp, class... _Args>
3209struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible
3210    : integral_constant<bool, __is_trivially_constructible(_Tp, _Args...)>
3211{
3212};
3213
3214#else  // !__has_feature(is_trivially_constructible)
3215
3216template <class _Tp, class... _Args>
3217struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible
3218    : false_type
3219{
3220};
3221
3222template <class _Tp>
3223struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp>
3224#if __has_feature(has_trivial_constructor) || (_GNUC_VER >= 403)
3225    : integral_constant<bool, __has_trivial_constructor(_Tp)>
3226#else
3227    : integral_constant<bool, is_scalar<_Tp>::value>
3228#endif
3229{
3230};
3231
3232template <class _Tp>
3233#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3234struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, _Tp&&>
3235#else
3236struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, _Tp>
3237#endif
3238    : integral_constant<bool, is_scalar<_Tp>::value>
3239{
3240};
3241
3242template <class _Tp>
3243struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, const _Tp&>
3244    : integral_constant<bool, is_scalar<_Tp>::value>
3245{
3246};
3247
3248template <class _Tp>
3249struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, _Tp&>
3250    : integral_constant<bool, is_scalar<_Tp>::value>
3251{
3252};
3253
3254#endif  // !__has_feature(is_trivially_constructible)
3255
3256#else  // _LIBCPP_HAS_NO_VARIADICS
3257
3258template <class _Tp, class _A0 = __is_construct::__nat,
3259                     class _A1 = __is_construct::__nat>
3260struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible
3261    : false_type
3262{
3263};
3264
3265#if __has_feature(is_trivially_constructible) || _GNUC_VER >= 501
3266
3267template <class _Tp>
3268struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, __is_construct::__nat,
3269                                                       __is_construct::__nat>
3270    : integral_constant<bool, __is_trivially_constructible(_Tp)>
3271{
3272};
3273
3274template <class _Tp>
3275struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, _Tp,
3276                                                       __is_construct::__nat>
3277    : integral_constant<bool, __is_trivially_constructible(_Tp, _Tp)>
3278{
3279};
3280
3281template <class _Tp>
3282struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, const _Tp&,
3283                                                       __is_construct::__nat>
3284    : integral_constant<bool, __is_trivially_constructible(_Tp, const _Tp&)>
3285{
3286};
3287
3288template <class _Tp>
3289struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, _Tp&,
3290                                                       __is_construct::__nat>
3291    : integral_constant<bool, __is_trivially_constructible(_Tp, _Tp&)>
3292{
3293};
3294
3295#else  // !__has_feature(is_trivially_constructible)
3296
3297template <class _Tp>
3298struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, __is_construct::__nat,
3299                                                       __is_construct::__nat>
3300    : integral_constant<bool, is_scalar<_Tp>::value>
3301{
3302};
3303
3304template <class _Tp>
3305struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, _Tp,
3306                                                       __is_construct::__nat>
3307    : integral_constant<bool, is_scalar<_Tp>::value>
3308{
3309};
3310
3311template <class _Tp>
3312struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, const _Tp&,
3313                                                       __is_construct::__nat>
3314    : integral_constant<bool, is_scalar<_Tp>::value>
3315{
3316};
3317
3318template <class _Tp>
3319struct _LIBCPP_TYPE_VIS_ONLY is_trivially_constructible<_Tp, _Tp&,
3320                                                       __is_construct::__nat>
3321    : integral_constant<bool, is_scalar<_Tp>::value>
3322{
3323};
3324
3325#endif  // !__has_feature(is_trivially_constructible)
3326
3327#endif  // _LIBCPP_HAS_NO_VARIADICS
3328
3329#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
3330template <class _Tp, class... _Args> _LIBCPP_CONSTEXPR bool is_trivially_constructible_v
3331    = is_trivially_constructible<_Tp, _Args...>::value;
3332#endif
3333
3334// is_trivially_default_constructible
3335
3336template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_trivially_default_constructible
3337    : public is_trivially_constructible<_Tp>
3338    {};
3339
3340#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3341template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_default_constructible_v
3342    = is_trivially_default_constructible<_Tp>::value;
3343#endif
3344
3345// is_trivially_copy_constructible
3346
3347template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_trivially_copy_constructible
3348    : public is_trivially_constructible<_Tp, typename add_lvalue_reference<const _Tp>::type>
3349    {};
3350
3351#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3352template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_copy_constructible_v
3353    = is_trivially_copy_constructible<_Tp>::value;
3354#endif
3355
3356// is_trivially_move_constructible
3357
3358template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_trivially_move_constructible
3359#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3360    : public is_trivially_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
3361#else
3362    : public is_trivially_copy_constructible<_Tp>
3363#endif
3364    {};
3365
3366#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3367template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_move_constructible_v
3368    = is_trivially_move_constructible<_Tp>::value;
3369#endif
3370
3371// is_trivially_assignable
3372
3373#if __has_feature(is_trivially_assignable) || _GNUC_VER >= 501
3374
3375template <class _Tp, class _Arg>
3376struct is_trivially_assignable
3377    : integral_constant<bool, __is_trivially_assignable(_Tp, _Arg)>
3378{
3379};
3380
3381#else  // !__has_feature(is_trivially_assignable)
3382
3383template <class _Tp, class _Arg>
3384struct is_trivially_assignable
3385    : public false_type {};
3386
3387template <class _Tp>
3388struct is_trivially_assignable<_Tp&, _Tp>
3389    : integral_constant<bool, is_scalar<_Tp>::value> {};
3390
3391template <class _Tp>
3392struct is_trivially_assignable<_Tp&, _Tp&>
3393    : integral_constant<bool, is_scalar<_Tp>::value> {};
3394
3395template <class _Tp>
3396struct is_trivially_assignable<_Tp&, const _Tp&>
3397    : integral_constant<bool, is_scalar<_Tp>::value> {};
3398
3399#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3400
3401template <class _Tp>
3402struct is_trivially_assignable<_Tp&, _Tp&&>
3403    : integral_constant<bool, is_scalar<_Tp>::value> {};
3404
3405#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3406
3407#endif  // !__has_feature(is_trivially_assignable)
3408
3409#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3410template <class _Tp, class _Arg> _LIBCPP_CONSTEXPR bool is_trivially_assignable_v
3411    = is_trivially_assignable<_Tp, _Arg>::value;
3412#endif
3413
3414// is_trivially_copy_assignable
3415
3416template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_trivially_copy_assignable
3417    : public is_trivially_assignable<typename add_lvalue_reference<_Tp>::type,
3418                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
3419
3420#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3421template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_copy_assignable_v
3422    = is_trivially_copy_assignable<_Tp>::value;
3423#endif
3424
3425// is_trivially_move_assignable
3426
3427template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_trivially_move_assignable
3428    : public is_trivially_assignable<typename add_lvalue_reference<_Tp>::type,
3429#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3430                                     typename add_rvalue_reference<_Tp>::type>
3431#else
3432                                     typename add_lvalue_reference<_Tp>::type>
3433#endif
3434    {};
3435
3436#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3437template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_move_assignable_v
3438    = is_trivially_move_assignable<_Tp>::value;
3439#endif
3440
3441// is_trivially_destructible
3442
3443#if __has_feature(has_trivial_destructor) || (_GNUC_VER >= 403)
3444
3445template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_trivially_destructible
3446    : public integral_constant<bool, is_destructible<_Tp>::value && __has_trivial_destructor(_Tp)> {};
3447
3448#else
3449
3450template <class _Tp> struct __libcpp_trivial_destructor
3451    : public integral_constant<bool, is_scalar<_Tp>::value ||
3452                                     is_reference<_Tp>::value> {};
3453
3454template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_trivially_destructible
3455    : public __libcpp_trivial_destructor<typename remove_all_extents<_Tp>::type> {};
3456
3457template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_trivially_destructible<_Tp[]>
3458    : public false_type {};
3459
3460#endif
3461
3462#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3463template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_destructible_v
3464    = is_trivially_destructible<_Tp>::value;
3465#endif
3466
3467// is_nothrow_constructible
3468
3469#if 0
3470template <class _Tp, class... _Args>
3471struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible
3472    : public integral_constant<bool, __is_nothrow_constructible(_Tp(_Args...))>
3473{
3474};
3475
3476#else
3477
3478#ifndef _LIBCPP_HAS_NO_VARIADICS
3479
3480#if __has_feature(cxx_noexcept) || (_GNUC_VER >= 407 && __cplusplus >= 201103L)
3481
3482template <bool, bool, class _Tp, class... _Args> struct __libcpp_is_nothrow_constructible;
3483
3484template <class _Tp, class... _Args>
3485struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/false, _Tp, _Args...>
3486    : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))>
3487{
3488};
3489
3490template <class _Tp>
3491void __implicit_conversion_to(_Tp) noexcept { }
3492
3493template <class _Tp, class _Arg>
3494struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/true, _Tp, _Arg>
3495    : public integral_constant<bool, noexcept(__implicit_conversion_to<_Tp>(declval<_Arg>()))>
3496{
3497};
3498
3499template <class _Tp, bool _IsReference, class... _Args>
3500struct __libcpp_is_nothrow_constructible</*is constructible*/false, _IsReference, _Tp, _Args...>
3501    : public false_type
3502{
3503};
3504
3505template <class _Tp, class... _Args>
3506struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible
3507    : __libcpp_is_nothrow_constructible<is_constructible<_Tp, _Args...>::value, is_reference<_Tp>::value, _Tp, _Args...>
3508{
3509};
3510
3511template <class _Tp, size_t _Ns>
3512struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp[_Ns]>
3513    : __libcpp_is_nothrow_constructible<is_constructible<_Tp>::value, is_reference<_Tp>::value, _Tp>
3514{
3515};
3516
3517#else  // __has_feature(cxx_noexcept)
3518
3519template <class _Tp, class... _Args>
3520struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible
3521    : false_type
3522{
3523};
3524
3525template <class _Tp>
3526struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp>
3527#if __has_feature(has_nothrow_constructor) || (_GNUC_VER >= 403)
3528    : integral_constant<bool, __has_nothrow_constructor(_Tp)>
3529#else
3530    : integral_constant<bool, is_scalar<_Tp>::value>
3531#endif
3532{
3533};
3534
3535template <class _Tp>
3536#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3537struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp, _Tp&&>
3538#else
3539struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp, _Tp>
3540#endif
3541#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
3542    : integral_constant<bool, __has_nothrow_copy(_Tp)>
3543#else
3544    : integral_constant<bool, is_scalar<_Tp>::value>
3545#endif
3546{
3547};
3548
3549template <class _Tp>
3550struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp, const _Tp&>
3551#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
3552    : integral_constant<bool, __has_nothrow_copy(_Tp)>
3553#else
3554    : integral_constant<bool, is_scalar<_Tp>::value>
3555#endif
3556{
3557};
3558
3559template <class _Tp>
3560struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp, _Tp&>
3561#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
3562    : integral_constant<bool, __has_nothrow_copy(_Tp)>
3563#else
3564    : integral_constant<bool, is_scalar<_Tp>::value>
3565#endif
3566{
3567};
3568
3569#endif  // __has_feature(cxx_noexcept)
3570
3571#else  // _LIBCPP_HAS_NO_VARIADICS
3572
3573template <class _Tp, class _A0 = __is_construct::__nat,
3574                     class _A1 = __is_construct::__nat>
3575struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible
3576    : false_type
3577{
3578};
3579
3580template <class _Tp>
3581struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp, __is_construct::__nat,
3582                                                       __is_construct::__nat>
3583#if __has_feature(has_nothrow_constructor) || (_GNUC_VER >= 403)
3584    : integral_constant<bool, __has_nothrow_constructor(_Tp)>
3585#else
3586    : integral_constant<bool, is_scalar<_Tp>::value>
3587#endif
3588{
3589};
3590
3591template <class _Tp>
3592struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp, _Tp,
3593                                                       __is_construct::__nat>
3594#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
3595    : integral_constant<bool, __has_nothrow_copy(_Tp)>
3596#else
3597    : integral_constant<bool, is_scalar<_Tp>::value>
3598#endif
3599{
3600};
3601
3602template <class _Tp>
3603struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp, const _Tp&,
3604                                                       __is_construct::__nat>
3605#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
3606    : integral_constant<bool, __has_nothrow_copy(_Tp)>
3607#else
3608    : integral_constant<bool, is_scalar<_Tp>::value>
3609#endif
3610{
3611};
3612
3613template <class _Tp>
3614struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp, _Tp&,
3615                                                       __is_construct::__nat>
3616#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
3617    : integral_constant<bool, __has_nothrow_copy(_Tp)>
3618#else
3619    : integral_constant<bool, is_scalar<_Tp>::value>
3620#endif
3621{
3622};
3623
3624#endif  // _LIBCPP_HAS_NO_VARIADICS
3625#endif  // __has_feature(is_nothrow_constructible)
3626
3627#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
3628template <class _Tp, class ..._Args> _LIBCPP_CONSTEXPR bool is_nothrow_constructible_v
3629    = is_nothrow_constructible<_Tp, _Args...>::value;
3630#endif
3631
3632// is_nothrow_default_constructible
3633
3634template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_default_constructible
3635    : public is_nothrow_constructible<_Tp>
3636    {};
3637
3638#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3639template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_default_constructible_v
3640    = is_nothrow_default_constructible<_Tp>::value;
3641#endif
3642
3643// is_nothrow_copy_constructible
3644
3645template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_copy_constructible
3646    : public is_nothrow_constructible<_Tp,
3647                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
3648
3649#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3650template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_copy_constructible_v
3651    = is_nothrow_copy_constructible<_Tp>::value;
3652#endif
3653
3654// is_nothrow_move_constructible
3655
3656template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_move_constructible
3657#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3658    : public is_nothrow_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
3659#else
3660    : public is_nothrow_copy_constructible<_Tp>
3661#endif
3662    {};
3663
3664#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3665template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_move_constructible_v
3666    = is_nothrow_move_constructible<_Tp>::value;
3667#endif
3668
3669// is_nothrow_assignable
3670
3671#if __has_feature(cxx_noexcept) || (_GNUC_VER >= 407 && __cplusplus >= 201103L)
3672
3673template <bool, class _Tp, class _Arg> struct __libcpp_is_nothrow_assignable;
3674
3675template <class _Tp, class _Arg>
3676struct __libcpp_is_nothrow_assignable<false, _Tp, _Arg>
3677    : public false_type
3678{
3679};
3680
3681template <class _Tp, class _Arg>
3682struct __libcpp_is_nothrow_assignable<true, _Tp, _Arg>
3683    : public integral_constant<bool, noexcept(_VSTD::declval<_Tp>() = _VSTD::declval<_Arg>()) >
3684{
3685};
3686
3687template <class _Tp, class _Arg>
3688struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_assignable
3689    : public __libcpp_is_nothrow_assignable<is_assignable<_Tp, _Arg>::value, _Tp, _Arg>
3690{
3691};
3692
3693#else  // __has_feature(cxx_noexcept)
3694
3695template <class _Tp, class _Arg>
3696struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_assignable
3697    : public false_type {};
3698
3699template <class _Tp>
3700struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_assignable<_Tp&, _Tp>
3701#if __has_feature(has_nothrow_assign) || (_GNUC_VER >= 403)
3702    : integral_constant<bool, __has_nothrow_assign(_Tp)> {};
3703#else
3704    : integral_constant<bool, is_scalar<_Tp>::value> {};
3705#endif
3706
3707template <class _Tp>
3708struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_assignable<_Tp&, _Tp&>
3709#if __has_feature(has_nothrow_assign) || (_GNUC_VER >= 403)
3710    : integral_constant<bool, __has_nothrow_assign(_Tp)> {};
3711#else
3712    : integral_constant<bool, is_scalar<_Tp>::value> {};
3713#endif
3714
3715template <class _Tp>
3716struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_assignable<_Tp&, const _Tp&>
3717#if __has_feature(has_nothrow_assign) || (_GNUC_VER >= 403)
3718    : integral_constant<bool, __has_nothrow_assign(_Tp)> {};
3719#else
3720    : integral_constant<bool, is_scalar<_Tp>::value> {};
3721#endif
3722
3723#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3724
3725template <class _Tp>
3726struct is_nothrow_assignable<_Tp&, _Tp&&>
3727#if __has_feature(has_nothrow_assign) || (_GNUC_VER >= 403)
3728    : integral_constant<bool, __has_nothrow_assign(_Tp)> {};
3729#else
3730    : integral_constant<bool, is_scalar<_Tp>::value> {};
3731#endif
3732
3733#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3734
3735#endif  // __has_feature(cxx_noexcept)
3736
3737#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3738template <class _Tp, class _Arg> _LIBCPP_CONSTEXPR bool is_nothrow_assignable_v
3739    = is_nothrow_assignable<_Tp, _Arg>::value;
3740#endif
3741
3742// is_nothrow_copy_assignable
3743
3744template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_copy_assignable
3745    : public is_nothrow_assignable<typename add_lvalue_reference<_Tp>::type,
3746                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
3747
3748#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3749template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_copy_assignable_v
3750    = is_nothrow_copy_assignable<_Tp>::value;
3751#endif
3752
3753// is_nothrow_move_assignable
3754
3755template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_move_assignable
3756    : public is_nothrow_assignable<typename add_lvalue_reference<_Tp>::type,
3757#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3758                                     typename add_rvalue_reference<_Tp>::type>
3759#else
3760                                     typename add_lvalue_reference<_Tp>::type>
3761#endif
3762    {};
3763
3764#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3765template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_move_assignable_v
3766    = is_nothrow_move_assignable<_Tp>::value;
3767#endif
3768
3769// is_nothrow_destructible
3770
3771#if __has_feature(cxx_noexcept) || (_GNUC_VER >= 407 && __cplusplus >= 201103L)
3772
3773template <bool, class _Tp> struct __libcpp_is_nothrow_destructible;
3774
3775template <class _Tp>
3776struct __libcpp_is_nothrow_destructible<false, _Tp>
3777    : public false_type
3778{
3779};
3780
3781template <class _Tp>
3782struct __libcpp_is_nothrow_destructible<true, _Tp>
3783    : public integral_constant<bool, noexcept(_VSTD::declval<_Tp>().~_Tp()) >
3784{
3785};
3786
3787template <class _Tp>
3788struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_destructible
3789    : public __libcpp_is_nothrow_destructible<is_destructible<_Tp>::value, _Tp>
3790{
3791};
3792
3793template <class _Tp, size_t _Ns>
3794struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_destructible<_Tp[_Ns]>
3795    : public is_nothrow_destructible<_Tp>
3796{
3797};
3798
3799template <class _Tp>
3800struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_destructible<_Tp&>
3801    : public true_type
3802{
3803};
3804
3805#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3806
3807template <class _Tp>
3808struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_destructible<_Tp&&>
3809    : public true_type
3810{
3811};
3812
3813#endif
3814
3815#else
3816
3817template <class _Tp> struct __libcpp_nothrow_destructor
3818    : public integral_constant<bool, is_scalar<_Tp>::value ||
3819                                     is_reference<_Tp>::value> {};
3820
3821template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_destructible
3822    : public __libcpp_nothrow_destructor<typename remove_all_extents<_Tp>::type> {};
3823
3824template <class _Tp>
3825struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_destructible<_Tp[]>
3826    : public false_type {};
3827
3828#endif
3829
3830#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3831template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_destructible_v
3832    = is_nothrow_destructible<_Tp>::value;
3833#endif
3834
3835// is_pod
3836
3837#if __has_feature(is_pod) || (_GNUC_VER >= 403)
3838
3839template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_pod
3840    : public integral_constant<bool, __is_pod(_Tp)> {};
3841
3842#else
3843
3844template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_pod
3845    : public integral_constant<bool, is_trivially_default_constructible<_Tp>::value   &&
3846                                     is_trivially_copy_constructible<_Tp>::value      &&
3847                                     is_trivially_copy_assignable<_Tp>::value    &&
3848                                     is_trivially_destructible<_Tp>::value> {};
3849
3850#endif
3851
3852#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3853template <class _Tp> _LIBCPP_CONSTEXPR bool is_pod_v
3854    = is_pod<_Tp>::value;
3855#endif
3856
3857// is_literal_type;
3858
3859template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_literal_type
3860#ifdef _LIBCPP_IS_LITERAL
3861    : public integral_constant<bool, _LIBCPP_IS_LITERAL(_Tp)>
3862#else
3863    : integral_constant<bool, is_scalar<typename remove_all_extents<_Tp>::type>::value ||
3864                              is_reference<typename remove_all_extents<_Tp>::type>::value>
3865#endif
3866    {};
3867    
3868#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3869template <class _Tp> _LIBCPP_CONSTEXPR bool is_literal_type_v
3870    = is_literal_type<_Tp>::value;
3871#endif
3872
3873// is_standard_layout;
3874
3875template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_standard_layout
3876#if __has_feature(is_standard_layout) || (_GNUC_VER >= 407)
3877    : public integral_constant<bool, __is_standard_layout(_Tp)>
3878#else
3879    : integral_constant<bool, is_scalar<typename remove_all_extents<_Tp>::type>::value>
3880#endif
3881    {};
3882    
3883#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3884template <class _Tp> _LIBCPP_CONSTEXPR bool is_standard_layout_v
3885    = is_standard_layout<_Tp>::value;
3886#endif
3887
3888// is_trivially_copyable;
3889
3890template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_trivially_copyable
3891#if __has_feature(is_trivially_copyable)
3892    : public integral_constant<bool, __is_trivially_copyable(_Tp)>
3893#elif _GNUC_VER >= 501
3894    : public integral_constant<bool, !is_volatile<_Tp>::value && __is_trivially_copyable(_Tp)>
3895#else
3896    : integral_constant<bool, is_scalar<typename remove_all_extents<_Tp>::type>::value>
3897#endif
3898    {};
3899    
3900#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3901template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_copyable_v
3902    = is_trivially_copyable<_Tp>::value;
3903#endif
3904
3905// is_trivial;
3906
3907template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_trivial
3908#if __has_feature(is_trivial) || _GNUC_VER >= 407
3909    : public integral_constant<bool, __is_trivial(_Tp)>
3910#else
3911    : integral_constant<bool, is_trivially_copyable<_Tp>::value &&
3912                                 is_trivially_default_constructible<_Tp>::value>
3913#endif
3914    {};
3915
3916#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
3917template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivial_v
3918    = is_trivial<_Tp>::value;
3919#endif
3920
3921#ifndef _LIBCPP_HAS_NO_VARIADICS
3922
3923// Check for complete types
3924
3925template <class ..._Tp> struct __check_complete;
3926
3927template <>
3928struct __check_complete<>
3929{
3930};
3931
3932template <class _Hp, class _T0, class ..._Tp>
3933struct __check_complete<_Hp, _T0, _Tp...>
3934    : private __check_complete<_Hp>,
3935      private __check_complete<_T0, _Tp...>
3936{
3937};
3938
3939template <class _Hp>
3940struct __check_complete<_Hp, _Hp>
3941    : private __check_complete<_Hp>
3942{
3943};
3944
3945template <class _Tp>
3946struct __check_complete<_Tp>
3947{
3948    static_assert(sizeof(_Tp) > 0, "Type must be complete.");
3949};
3950
3951template <class _Tp>
3952struct __check_complete<_Tp&>
3953    : private __check_complete<_Tp>
3954{
3955};
3956
3957template <class _Tp>
3958struct __check_complete<_Tp&&>
3959    : private __check_complete<_Tp>
3960{
3961};
3962
3963template <class _Rp, class ..._Param>
3964struct __check_complete<_Rp (*)(_Param...)>
3965    : private __check_complete<_Rp>
3966{
3967};
3968
3969template <class ..._Param>
3970struct __check_complete<void (*)(_Param...)>
3971{
3972};
3973
3974template <class _Rp, class ..._Param>
3975struct __check_complete<_Rp (_Param...)>
3976    : private __check_complete<_Rp>
3977{
3978};
3979
3980template <class ..._Param>
3981struct __check_complete<void (_Param...)>
3982{
3983};
3984
3985template <class _Rp, class _Class, class ..._Param>
3986struct __check_complete<_Rp (_Class::*)(_Param...)>
3987    : private __check_complete<_Class>
3988{
3989};
3990
3991template <class _Rp, class _Class, class ..._Param>
3992struct __check_complete<_Rp (_Class::*)(_Param...) const>
3993    : private __check_complete<_Class>
3994{
3995};
3996
3997template <class _Rp, class _Class, class ..._Param>
3998struct __check_complete<_Rp (_Class::*)(_Param...) volatile>
3999    : private __check_complete<_Class>
4000{
4001};
4002
4003template <class _Rp, class _Class, class ..._Param>
4004struct __check_complete<_Rp (_Class::*)(_Param...) const volatile>
4005    : private __check_complete<_Class>
4006{
4007};
4008
4009#if __has_feature(cxx_reference_qualified_functions)
4010
4011template <class _Rp, class _Class, class ..._Param>
4012struct __check_complete<_Rp (_Class::*)(_Param...) &>
4013    : private __check_complete<_Class>
4014{
4015};
4016
4017template <class _Rp, class _Class, class ..._Param>
4018struct __check_complete<_Rp (_Class::*)(_Param...) const&>
4019    : private __check_complete<_Class>
4020{
4021};
4022
4023template <class _Rp, class _Class, class ..._Param>
4024struct __check_complete<_Rp (_Class::*)(_Param...) volatile&>
4025    : private __check_complete<_Class>
4026{
4027};
4028
4029template <class _Rp, class _Class, class ..._Param>
4030struct __check_complete<_Rp (_Class::*)(_Param...) const volatile&>
4031    : private __check_complete<_Class>
4032{
4033};
4034
4035template <class _Rp, class _Class, class ..._Param>
4036struct __check_complete<_Rp (_Class::*)(_Param...) &&>
4037    : private __check_complete<_Class>
4038{
4039};
4040
4041template <class _Rp, class _Class, class ..._Param>
4042struct __check_complete<_Rp (_Class::*)(_Param...) const&&>
4043    : private __check_complete<_Class>
4044{
4045};
4046
4047template <class _Rp, class _Class, class ..._Param>
4048struct __check_complete<_Rp (_Class::*)(_Param...) volatile&&>
4049    : private __check_complete<_Class>
4050{
4051};
4052
4053template <class _Rp, class _Class, class ..._Param>
4054struct __check_complete<_Rp (_Class::*)(_Param...) const volatile&&>
4055    : private __check_complete<_Class>
4056{
4057};
4058
4059#endif
4060
4061template <class _Rp, class _Class>
4062struct __check_complete<_Rp _Class::*>
4063    : private __check_complete<_Class>
4064{
4065};
4066
4067// __invoke forward declarations
4068
4069// fall back - none of the bullets
4070
4071template <class ..._Args>
4072auto
4073__invoke(__any, _Args&& ...__args)
4074    -> __nat;
4075
4076// bullets 1 and 2
4077
4078template <class _Fp, class _A0, class ..._Args,
4079            class = typename enable_if
4080            <
4081                is_member_function_pointer<typename remove_reference<_Fp>::type>::value &&
4082                is_base_of<typename remove_reference<typename __member_pointer_traits<typename remove_reference<_Fp>::type>::_ClassType>::type,
4083                           typename remove_reference<_A0>::type>::value
4084            >::type
4085         >
4086_LIBCPP_INLINE_VISIBILITY
4087auto
4088__invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
4089    -> decltype((_VSTD::forward<_A0>(__a0).*__f)(_VSTD::forward<_Args>(__args)...));
4090
4091template <class _Fp, class _A0, class ..._Args,
4092            class = typename enable_if
4093            <
4094                is_member_function_pointer<typename remove_reference<_Fp>::type>::value &&
4095                !is_base_of<typename remove_reference<typename __member_pointer_traits<typename remove_reference<_Fp>::type>::_ClassType>::type,
4096                           typename remove_reference<_A0>::type>::value
4097            >::type
4098         >
4099_LIBCPP_INLINE_VISIBILITY
4100auto
4101__invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
4102    -> decltype(((*_VSTD::forward<_A0>(__a0)).*__f)(_VSTD::forward<_Args>(__args)...));
4103
4104// bullets 3 and 4
4105
4106template <class _Fp, class _A0,
4107            class = typename enable_if
4108            <
4109                is_member_object_pointer<typename remove_reference<_Fp>::type>::value &&
4110                is_base_of<typename __member_pointer_traits<typename remove_reference<_Fp>::type>::_ClassType,
4111                           typename remove_reference<_A0>::type>::value
4112            >::type
4113         >
4114_LIBCPP_INLINE_VISIBILITY
4115auto
4116__invoke(_Fp&& __f, _A0&& __a0)
4117    -> decltype(_VSTD::forward<_A0>(__a0).*__f);
4118
4119template <class _Fp, class _A0,
4120            class = typename enable_if
4121            <
4122                is_member_object_pointer<typename remove_reference<_Fp>::type>::value &&
4123                !is_base_of<typename __member_pointer_traits<typename remove_reference<_Fp>::type>::_ClassType,
4124                           typename remove_reference<_A0>::type>::value
4125            >::type
4126         >
4127_LIBCPP_INLINE_VISIBILITY
4128auto
4129__invoke(_Fp&& __f, _A0&& __a0)
4130    -> decltype((*_VSTD::forward<_A0>(__a0)).*__f);
4131
4132// bullet 5
4133
4134template <class _Fp, class ..._Args>
4135_LIBCPP_INLINE_VISIBILITY
4136auto
4137__invoke(_Fp&& __f, _Args&& ...__args)
4138    -> decltype(_VSTD::forward<_Fp>(__f)(_VSTD::forward<_Args>(__args)...));
4139
4140// __invokable
4141
4142template <class _Fp, class ..._Args>
4143struct __invokable_imp
4144    : private __check_complete<_Fp>
4145{
4146    typedef decltype(
4147            __invoke(_VSTD::declval<_Fp>(), _VSTD::declval<_Args>()...)
4148                    ) type;
4149    static const bool value = !is_same<type, __nat>::value;
4150};
4151
4152template <class _Fp, class ..._Args>
4153struct __invokable
4154    : public integral_constant<bool,
4155          __invokable_imp<_Fp, _Args...>::value>
4156{
4157};
4158
4159// __invoke_of
4160
4161template <bool _Invokable, class _Fp, class ..._Args>
4162struct __invoke_of_imp  // false
4163{
4164};
4165
4166template <class _Fp, class ..._Args>
4167struct __invoke_of_imp<true, _Fp, _Args...>
4168{
4169    typedef typename __invokable_imp<_Fp, _Args...>::type type;
4170};
4171
4172template <class _Fp, class ..._Args>
4173struct __invoke_of
4174    : public __invoke_of_imp<__invokable<_Fp, _Args...>::value, _Fp, _Args...>
4175{
4176};
4177
4178template <class _Fp, class ..._Args>
4179class _LIBCPP_TYPE_VIS_ONLY result_of<_Fp(_Args...)>
4180    : public __invoke_of<_Fp, _Args...>
4181{
4182};
4183
4184#if _LIBCPP_STD_VER > 11
4185template <class _Tp> using result_of_t = typename result_of<_Tp>::type;
4186#endif
4187
4188#endif  // _LIBCPP_HAS_NO_VARIADICS
4189
4190template <class _Tp>
4191inline _LIBCPP_INLINE_VISIBILITY
4192#ifndef _LIBCPP_HAS_NO_ADVANCED_SFINAE
4193typename enable_if
4194<
4195    is_move_constructible<_Tp>::value &&
4196    is_move_assignable<_Tp>::value
4197>::type
4198#else
4199void
4200#endif
4201swap(_Tp& __x, _Tp& __y) _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value &&
4202                                    is_nothrow_move_assignable<_Tp>::value)
4203{
4204    _Tp __t(_VSTD::move(__x));
4205    __x = _VSTD::move(__y);
4206    __y = _VSTD::move(__t);
4207}
4208
4209template <class _ForwardIterator1, class _ForwardIterator2>
4210inline _LIBCPP_INLINE_VISIBILITY
4211void
4212iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
4213    //                                  _NOEXCEPT_(_NOEXCEPT_(swap(*__a, *__b)))
4214               _NOEXCEPT_(_NOEXCEPT_(swap(*_VSTD::declval<_ForwardIterator1>(),
4215                                          *_VSTD::declval<_ForwardIterator2>())))
4216{
4217    swap(*__a, *__b);
4218}
4219
4220// __swappable
4221
4222namespace __detail
4223{
4224
4225using _VSTD::swap;
4226__nat swap(__any, __any);
4227
4228template <class _Tp>
4229struct __swappable
4230{
4231    typedef decltype(swap(_VSTD::declval<_Tp&>(), _VSTD::declval<_Tp&>())) type;
4232    static const bool value = !is_same<type, __nat>::value;
4233};
4234
4235}  // __detail
4236
4237template <class _Tp>
4238struct __is_swappable
4239    : public integral_constant<bool, __detail::__swappable<_Tp>::value>
4240{
4241};
4242
4243#if __has_feature(cxx_noexcept) || (_GNUC_VER >= 407 && __cplusplus >= 201103L)
4244
4245template <bool, class _Tp>
4246struct __is_nothrow_swappable_imp
4247    : public integral_constant<bool, noexcept(swap(_VSTD::declval<_Tp&>(),
4248                                                   _VSTD::declval<_Tp&>()))>
4249{
4250};
4251
4252template <class _Tp>
4253struct __is_nothrow_swappable_imp<false, _Tp>
4254    : public false_type
4255{
4256};
4257
4258template <class _Tp>
4259struct __is_nothrow_swappable
4260    : public __is_nothrow_swappable_imp<__is_swappable<_Tp>::value, _Tp>
4261{
4262};
4263
4264#else  // __has_feature(cxx_noexcept)
4265
4266template <class _Tp>
4267struct __is_nothrow_swappable
4268    : public false_type
4269{
4270};
4271
4272#endif  // __has_feature(cxx_noexcept)
4273
4274#ifdef _LIBCPP_UNDERLYING_TYPE
4275
4276template <class _Tp>
4277struct underlying_type
4278{
4279    typedef _LIBCPP_UNDERLYING_TYPE(_Tp) type;
4280};
4281
4282#if _LIBCPP_STD_VER > 11
4283template <class _Tp> using underlying_type_t = typename underlying_type<_Tp>::type;
4284#endif
4285
4286#else  // _LIBCPP_UNDERLYING_TYPE
4287
4288template <class _Tp, bool _Support = false>
4289struct underlying_type
4290{
4291    static_assert(_Support, "The underyling_type trait requires compiler "
4292                            "support. Either no such support exists or "
4293                            "libc++ does not know how to use it.");
4294};
4295
4296#endif // _LIBCPP_UNDERLYING_TYPE
4297
4298
4299template <class _Tp, bool = std::is_enum<_Tp>::value>
4300struct __sfinae_underlying_type
4301{
4302    typedef typename underlying_type<_Tp>::type type;
4303    typedef decltype(((type)1) + 0) __promoted_type;
4304};
4305
4306template <class _Tp>
4307struct __sfinae_underlying_type<_Tp, false> {};
4308
4309inline _LIBCPP_INLINE_VISIBILITY
4310int __convert_to_integral(int __val) { return __val; }
4311
4312inline _LIBCPP_INLINE_VISIBILITY
4313unsigned __convert_to_integral(unsigned __val) { return __val; }
4314
4315inline _LIBCPP_INLINE_VISIBILITY
4316long __convert_to_integral(long __val) { return __val; }
4317
4318inline _LIBCPP_INLINE_VISIBILITY
4319unsigned long __convert_to_integral(unsigned long __val) { return __val; }
4320
4321inline _LIBCPP_INLINE_VISIBILITY
4322long long __convert_to_integral(long long __val) { return __val; }
4323
4324inline _LIBCPP_INLINE_VISIBILITY
4325unsigned long long __convert_to_integral(unsigned long long __val) {return __val; }
4326
4327#ifndef _LIBCPP_HAS_NO_INT128
4328inline _LIBCPP_INLINE_VISIBILITY
4329__int128_t __convert_to_integral(__int128_t __val) { return __val; }
4330
4331inline _LIBCPP_INLINE_VISIBILITY
4332__uint128_t __convert_to_integral(__uint128_t __val) { return __val; }
4333#endif
4334
4335template <class _Tp>
4336inline _LIBCPP_INLINE_VISIBILITY
4337typename __sfinae_underlying_type<_Tp>::__promoted_type
4338__convert_to_integral(_Tp __val) { return __val; }
4339
4340#ifndef _LIBCPP_HAS_NO_ADVANCED_SFINAE
4341
4342template <class _Tp>
4343struct __has_operator_addressof_member_imp
4344{
4345    template <class _Up>
4346        static auto __test(int)
4347            -> typename __select_2nd<decltype(_VSTD::declval<_Up>().operator&()), true_type>::type;
4348    template <class>
4349        static auto __test(long) -> false_type;
4350
4351    static const bool value = decltype(__test<_Tp>(0))::value;
4352};
4353
4354template <class _Tp>
4355struct __has_operator_addressof_free_imp
4356{
4357    template <class _Up>
4358        static auto __test(int)
4359            -> typename __select_2nd<decltype(operator&(_VSTD::declval<_Up>())), true_type>::type;
4360    template <class>
4361        static auto __test(long) -> false_type;
4362
4363    static const bool value = decltype(__test<_Tp>(0))::value;
4364};
4365
4366template <class _Tp>
4367struct __has_operator_addressof
4368    : public integral_constant<bool, __has_operator_addressof_member_imp<_Tp>::value
4369                                  || __has_operator_addressof_free_imp<_Tp>::value>
4370{};
4371
4372#endif  // _LIBCPP_HAS_NO_ADVANCED_SFINAE
4373
4374#if _LIBCPP_STD_VER > 14
4375template <class...> using void_t = void;
4376
4377# ifndef _LIBCPP_HAS_NO_VARIADICS
4378template <class... _Args>
4379struct conjunction : __and_<_Args...> {};
4380template<class... _Args> constexpr bool conjunction_v = conjunction<_Args...>::value;
4381
4382template <class... _Args>
4383struct disjunction : __or_<_Args...> {};
4384template<class... _Args> constexpr bool disjunction_v = disjunction<_Args...>::value;
4385
4386template <class _Tp>
4387struct negation : __not_<_Tp> {};
4388template<class _Tp> constexpr bool negation_v = negation<_Tp>::value;
4389# endif // _LIBCPP_HAS_NO_VARIADICS
4390#endif  // _LIBCPP_STD_VER > 14
4391
4392_LIBCPP_END_NAMESPACE_STD
4393
4394#endif  // _LIBCPP_TYPE_TRAITS
4395