1// -*- C++ -*-
2//===-------------------------- utility -----------------------------------===//
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_UTILITY
12#define _LIBCPP_UTILITY
13
14/*
15    utility synopsis
16
17namespace std
18{
19
20template <class T>
21    void
22    swap(T& a, T& b);
23
24namespace rel_ops
25{
26    template<class T> bool operator!=(const T&, const T&);
27    template<class T> bool operator> (const T&, const T&);
28    template<class T> bool operator<=(const T&, const T&);
29    template<class T> bool operator>=(const T&, const T&);
30}
31
32template<class T>
33void
34swap(T& a, T& b) noexcept(is_nothrow_move_constructible<T>::value &&
35                          is_nothrow_move_assignable<T>::value);
36
37template <class T, size_t N>
38void
39swap(T (&a)[N], T (&b)[N]) noexcept(noexcept(swap(*a, *b)));
40
41template <class T> T&& forward(typename remove_reference<T>::type& t) noexcept;  // constexpr in C++14
42template <class T> T&& forward(typename remove_reference<T>::type&& t) noexcept; // constexpr in C++14
43
44template <class T> typename remove_reference<T>::type&& move(T&&) noexcept;      // constexpr in C++14
45
46template <class T>
47    typename conditional
48    <
49        !is_nothrow_move_constructible<T>::value && is_copy_constructible<T>::value,
50        const T&,
51        T&&
52    >::type
53    move_if_noexcept(T& x) noexcept; // constexpr in C++14
54
55template <class T> constexpr add_const<T>_t& as_const(T& t) noexcept;      // C++17
56template <class T>                      void as_const(const T&&) = delete; // C++17
57
58template <class T> typename add_rvalue_reference<T>::type declval() noexcept;
59
60template <class T1, class T2>
61struct pair
62{
63    typedef T1 first_type;
64    typedef T2 second_type;
65
66    T1 first;
67    T2 second;
68
69    pair(const pair&) = default;
70    pair(pair&&) = default;
71    constexpr pair();
72    pair(const T1& x, const T2& y);                          // constexpr in C++14
73    template <class U, class V> pair(U&& x, V&& y);          // constexpr in C++14
74    template <class U, class V> pair(const pair<U, V>& p);   // constexpr in C++14
75    template <class U, class V> pair(pair<U, V>&& p);        // constexpr in C++14
76    template <class... Args1, class... Args2>
77        pair(piecewise_construct_t, tuple<Args1...> first_args,
78             tuple<Args2...> second_args);
79
80    template <class U, class V> pair& operator=(const pair<U, V>& p);
81    pair& operator=(pair&& p) noexcept(is_nothrow_move_assignable<T1>::value &&
82                                       is_nothrow_move_assignable<T2>::value);
83    template <class U, class V> pair& operator=(pair<U, V>&& p);
84
85    void swap(pair& p) noexcept(is_nothrow_swappable_v<T1> &&
86                                is_nothrow_swappable_v<T2>);
87};
88
89template <class T1, class T2> bool operator==(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
90template <class T1, class T2> bool operator!=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
91template <class T1, class T2> bool operator< (const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
92template <class T1, class T2> bool operator> (const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
93template <class T1, class T2> bool operator>=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
94template <class T1, class T2> bool operator<=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
95
96template <class T1, class T2> pair<V1, V2> make_pair(T1&&, T2&&);   // constexpr in C++14
97template <class T1, class T2>
98void
99swap(pair<T1, T2>& x, pair<T1, T2>& y) noexcept(noexcept(x.swap(y)));
100
101struct piecewise_construct_t { };
102constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
103
104template <class T> class tuple_size;
105template <size_t I, class T> class tuple_element;
106
107template <class T1, class T2> struct tuple_size<pair<T1, T2> >;
108template <class T1, class T2> struct tuple_element<0, pair<T1, T2> >;
109template <class T1, class T2> struct tuple_element<1, pair<T1, T2> >;
110
111template<size_t I, class T1, class T2>
112    typename tuple_element<I, pair<T1, T2> >::type&
113    get(pair<T1, T2>&) noexcept; // constexpr in C++14
114
115template<size_t I, class T1, class T2>
116    const typename tuple_element<I, pair<T1, T2> >::type&
117    get(const pair<T1, T2>&) noexcept; // constexpr in C++14
118
119template<size_t I, class T1, class T2>
120    typename tuple_element<I, pair<T1, T2> >::type&&
121    get(pair<T1, T2>&&) noexcept; // constexpr in C++14
122
123template<size_t I, class T1, class T2>
124    const typename tuple_element<I, pair<T1, T2> >::type&&
125    get(const pair<T1, T2>&&) noexcept; // constexpr in C++14
126
127template<class T1, class T2>
128    constexpr T1& get(pair<T1, T2>&) noexcept; // C++14
129
130template<class T1, class T2>
131    constexpr const T1& get(const pair<T1, T2>&) noexcept; // C++14
132
133template<class T1, class T2>
134    constexpr T1&& get(pair<T1, T2>&&) noexcept; // C++14
135
136template<class T1, class T2>
137    constexpr const T1&& get(const pair<T1, T2>&&) noexcept; // C++14
138
139template<class T1, class T2>
140    constexpr T1& get(pair<T2, T1>&) noexcept; // C++14
141
142template<class T1, class T2>
143    constexpr const T1& get(const pair<T2, T1>&) noexcept; // C++14
144
145template<class T1, class T2>
146    constexpr T1&& get(pair<T2, T1>&&) noexcept; // C++14
147
148template<class T1, class T2>
149    constexpr const T1&& get(const pair<T2, T1>&&) noexcept; // C++14
150
151// C++14
152
153template<class T, T... I>
154struct integer_sequence
155{
156    typedef T value_type;
157
158    static constexpr size_t size() noexcept;
159};
160
161template<size_t... I>
162  using index_sequence = integer_sequence<size_t, I...>;
163
164template<class T, T N>
165  using make_integer_sequence = integer_sequence<T, 0, 1, ..., N-1>;
166template<size_t N>
167  using make_index_sequence = make_integer_sequence<size_t, N>;
168
169template<class... T>
170  using index_sequence_for = make_index_sequence<sizeof...(T)>;
171
172template<class T, class U=T>
173    T exchange(T& obj, U&& new_value);
174
175// 20.2.7, in-place construction // C++17
176struct in_place_t {
177  explicit in_place_t() = default;
178};
179inline constexpr in_place_t in_place{};
180template <class T>
181  struct in_place_type_t {
182    explicit in_place_type_t() = default;
183  };
184template <class T>
185  inline constexpr in_place_type_t<T> in_place_type{};
186template <size_t I>
187  struct in_place_index_t {
188    explicit in_place_index_t() = default;
189  };
190template <size_t I>
191  inline constexpr in_place_index_t<I> in_place_index{};
192
193}  // std
194
195*/
196
197#include <__config>
198#include <__tuple>
199#include <type_traits>
200#include <initializer_list>
201#include <cstddef>
202#include <cstring>
203#include <cstdint>
204#include <__debug>
205
206#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
207#pragma GCC system_header
208#endif
209
210_LIBCPP_BEGIN_NAMESPACE_STD
211
212namespace rel_ops
213{
214
215template<class _Tp>
216inline _LIBCPP_INLINE_VISIBILITY
217bool
218operator!=(const _Tp& __x, const _Tp& __y)
219{
220    return !(__x == __y);
221}
222
223template<class _Tp>
224inline _LIBCPP_INLINE_VISIBILITY
225bool
226operator> (const _Tp& __x, const _Tp& __y)
227{
228    return __y < __x;
229}
230
231template<class _Tp>
232inline _LIBCPP_INLINE_VISIBILITY
233bool
234operator<=(const _Tp& __x, const _Tp& __y)
235{
236    return !(__y < __x);
237}
238
239template<class _Tp>
240inline _LIBCPP_INLINE_VISIBILITY
241bool
242operator>=(const _Tp& __x, const _Tp& __y)
243{
244    return !(__x < __y);
245}
246
247}  // rel_ops
248
249// swap_ranges
250
251
252template <class _ForwardIterator1, class _ForwardIterator2>
253inline _LIBCPP_INLINE_VISIBILITY
254_ForwardIterator2
255swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2)
256{
257    for(; __first1 != __last1; ++__first1, (void) ++__first2)
258        swap(*__first1, *__first2);
259    return __first2;
260}
261
262// forward declared in <type_traits>
263template<class _Tp, size_t _Np>
264inline _LIBCPP_INLINE_VISIBILITY
265typename enable_if<
266    __is_swappable<_Tp>::value
267>::type
268swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value)
269{
270    _VSTD::swap_ranges(__a, __a + _Np, __b);
271}
272
273template <class _Tp>
274inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
275#ifndef _LIBCPP_CXX03_LANG
276typename conditional
277<
278    !is_nothrow_move_constructible<_Tp>::value && is_copy_constructible<_Tp>::value,
279    const _Tp&,
280    _Tp&&
281>::type
282#else  // _LIBCPP_CXX03_LANG
283const _Tp&
284#endif
285move_if_noexcept(_Tp& __x) _NOEXCEPT
286{
287    return _VSTD::move(__x);
288}
289
290#if _LIBCPP_STD_VER > 14
291template <class _Tp> constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
292template <class _Tp>                        void as_const(const _Tp&&) = delete;
293#endif
294
295struct _LIBCPP_TEMPLATE_VIS piecewise_construct_t { };
296#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_UTILITY)
297extern const piecewise_construct_t piecewise_construct;// = piecewise_construct_t();
298#else
299constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
300#endif
301
302#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
303struct __non_trivially_copyable_base {
304  _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
305  __non_trivially_copyable_base() _NOEXCEPT {}
306  _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
307  __non_trivially_copyable_base(__non_trivially_copyable_base const&) _NOEXCEPT {}
308};
309#endif
310
311template <class _T1, class _T2>
312struct _LIBCPP_TEMPLATE_VIS pair
313#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
314: private __non_trivially_copyable_base
315#endif
316{
317    typedef _T1 first_type;
318    typedef _T2 second_type;
319
320    _T1 first;
321    _T2 second;
322
323#if !defined(_LIBCPP_CXX03_LANG)
324    pair(pair const&) = default;
325    pair(pair&&) = default;
326#else
327  // Use the implicitly declared copy constructor in C++03
328#endif
329
330#ifdef _LIBCPP_CXX03_LANG
331    _LIBCPP_INLINE_VISIBILITY
332    pair() : first(), second() {}
333
334    _LIBCPP_INLINE_VISIBILITY
335    pair(_T1 const& __t1, _T2 const& __t2) : first(__t1), second(__t2) {}
336
337    template <class _U1, class _U2>
338    _LIBCPP_INLINE_VISIBILITY
339    pair(const pair<_U1, _U2>& __p) : first(__p.first), second(__p.second) {}
340
341    _LIBCPP_INLINE_VISIBILITY
342    pair& operator=(pair const& __p) {
343        first = __p.first;
344        second = __p.second;
345        return *this;
346    }
347#else
348    template <bool _Val>
349    using _EnableB = typename enable_if<_Val, bool>::type;
350
351    struct _CheckArgs {
352      template <class _U1, class _U2>
353      static constexpr bool __enable_default() {
354          return is_default_constructible<_U1>::value
355              && is_default_constructible<_U2>::value;
356      }
357
358      template <class _U1, class _U2>
359      static constexpr bool __enable_explicit() {
360          return is_constructible<first_type, _U1>::value
361              && is_constructible<second_type, _U2>::value
362              && (!is_convertible<_U1, first_type>::value
363                  || !is_convertible<_U2, second_type>::value);
364      }
365
366      template <class _U1, class _U2>
367      static constexpr bool __enable_implicit() {
368          return is_constructible<first_type, _U1>::value
369              && is_constructible<second_type, _U2>::value
370              && is_convertible<_U1, first_type>::value
371              && is_convertible<_U2, second_type>::value;
372      }
373    };
374
375    template <bool _MaybeEnable>
376    using _CheckArgsDep = typename conditional<
377      _MaybeEnable, _CheckArgs, __check_tuple_constructor_fail>::type;
378
379    struct _CheckTupleLikeConstructor {
380        template <class _Tuple>
381        static constexpr bool __enable_implicit() {
382            return __tuple_convertible<_Tuple, pair>::value;
383        }
384
385        template <class _Tuple>
386        static constexpr bool __enable_explicit() {
387            return __tuple_constructible<_Tuple, pair>::value
388               && !__tuple_convertible<_Tuple, pair>::value;
389        }
390
391        template <class _Tuple>
392        static constexpr bool __enable_assign() {
393            return __tuple_assignable<_Tuple, pair>::value;
394        }
395    };
396
397    template <class _Tuple>
398    using _CheckTLC = typename conditional<
399        __tuple_like_with_size<_Tuple, 2>::value
400            && !is_same<typename decay<_Tuple>::type, pair>::value,
401        _CheckTupleLikeConstructor,
402        __check_tuple_constructor_fail
403    >::type;
404
405    template<bool _Dummy = true, _EnableB<
406            _CheckArgsDep<_Dummy>::template __enable_default<_T1, _T2>()
407    > = false>
408    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
409    pair() : first(), second() {}
410
411    template <bool _Dummy = true, _EnableB<
412             _CheckArgsDep<_Dummy>::template __enable_explicit<_T1 const&, _T2 const&>()
413    > = false>
414    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
415    explicit pair(_T1 const& __t1, _T2 const& __t2)
416        : first(__t1), second(__t2) {}
417
418    template<bool _Dummy = true, _EnableB<
419            _CheckArgsDep<_Dummy>::template __enable_implicit<_T1 const&, _T2 const&>()
420    > = false>
421    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
422    pair(_T1 const& __t1, _T2 const& __t2)
423        : first(__t1), second(__t2) {}
424
425    template<class _U1, class _U2, _EnableB<
426             _CheckArgs::template __enable_explicit<_U1, _U2>()
427    > = false>
428    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
429    explicit pair(_U1&& __u1, _U2&& __u2)
430        : first(_VSTD::forward<_U1>(__u1)), second(_VSTD::forward<_U2>(__u2)) {}
431
432    template<class _U1, class _U2, _EnableB<
433            _CheckArgs::template __enable_implicit<_U1, _U2>()
434    > = false>
435    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
436    pair(_U1&& __u1, _U2&& __u2)
437        : first(_VSTD::forward<_U1>(__u1)), second(_VSTD::forward<_U2>(__u2)) {}
438
439    template<class _U1, class _U2, _EnableB<
440            _CheckArgs::template __enable_explicit<_U1 const&, _U2 const&>()
441    > = false>
442    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
443    explicit pair(pair<_U1, _U2> const& __p)
444        : first(__p.first), second(__p.second) {}
445
446    template<class _U1, class _U2, _EnableB<
447            _CheckArgs::template __enable_implicit<_U1 const&, _U2 const&>()
448    > = false>
449    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
450    pair(pair<_U1, _U2> const& __p)
451        : first(__p.first), second(__p.second) {}
452
453    template<class _U1, class _U2, _EnableB<
454            _CheckArgs::template __enable_explicit<_U1, _U2>()
455    > = false>
456    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
457    explicit pair(pair<_U1, _U2>&&__p)
458        : first(_VSTD::forward<_U1>(__p.first)), second(_VSTD::forward<_U2>(__p.second)) {}
459
460    template<class _U1, class _U2, _EnableB<
461            _CheckArgs::template __enable_implicit<_U1, _U2>()
462    > = false>
463    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
464    pair(pair<_U1, _U2>&& __p)
465        : first(_VSTD::forward<_U1>(__p.first)), second(_VSTD::forward<_U2>(__p.second)) {}
466
467    template<class _Tuple, _EnableB<
468            _CheckTLC<_Tuple>::template __enable_explicit<_Tuple>()
469    > = false>
470    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
471    explicit pair(_Tuple&& __p)
472        : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
473          second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
474
475    template<class _Tuple, _EnableB<
476            _CheckTLC<_Tuple>::template __enable_implicit<_Tuple>()
477    > = false>
478    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
479    pair(_Tuple&& __p)
480        : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
481          second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
482
483    template <class... _Args1, class... _Args2>
484    _LIBCPP_INLINE_VISIBILITY
485    pair(piecewise_construct_t __pc,
486         tuple<_Args1...> __first_args, tuple<_Args2...> __second_args)
487        : pair(__pc, __first_args, __second_args,
488                typename __make_tuple_indices<sizeof...(_Args1)>::type(),
489                typename __make_tuple_indices<sizeof...(_Args2) >::type()) {}
490
491    _LIBCPP_INLINE_VISIBILITY
492    pair& operator=(typename conditional<
493                        is_copy_assignable<first_type>::value &&
494                        is_copy_assignable<second_type>::value,
495                    pair, __nat>::type const& __p)
496        _NOEXCEPT_(is_nothrow_copy_assignable<first_type>::value &&
497                   is_nothrow_copy_assignable<second_type>::value)
498    {
499        first = __p.first;
500        second = __p.second;
501        return *this;
502    }
503
504    _LIBCPP_INLINE_VISIBILITY
505    pair& operator=(typename conditional<
506                        is_move_assignable<first_type>::value &&
507                        is_move_assignable<second_type>::value,
508                    pair, __nat>::type&& __p)
509        _NOEXCEPT_(is_nothrow_move_assignable<first_type>::value &&
510                   is_nothrow_move_assignable<second_type>::value)
511    {
512        first = _VSTD::forward<first_type>(__p.first);
513        second = _VSTD::forward<second_type>(__p.second);
514        return *this;
515    }
516
517    template <class _Tuple, _EnableB<
518            _CheckTLC<_Tuple>::template __enable_assign<_Tuple>()
519     > = false>
520    _LIBCPP_INLINE_VISIBILITY
521    pair& operator=(_Tuple&& __p) {
522        first = _VSTD::get<0>(_VSTD::forward<_Tuple>(__p));
523        second = _VSTD::get<1>(_VSTD::forward<_Tuple>(__p));
524        return *this;
525    }
526#endif
527
528    _LIBCPP_INLINE_VISIBILITY
529    void
530    swap(pair& __p) _NOEXCEPT_(__is_nothrow_swappable<first_type>::value &&
531                               __is_nothrow_swappable<second_type>::value)
532    {
533        using _VSTD::swap;
534        swap(first,  __p.first);
535        swap(second, __p.second);
536    }
537private:
538
539#ifndef _LIBCPP_CXX03_LANG
540    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
541        _LIBCPP_INLINE_VISIBILITY
542        pair(piecewise_construct_t,
543             tuple<_Args1...>& __first_args, tuple<_Args2...>& __second_args,
544             __tuple_indices<_I1...>, __tuple_indices<_I2...>);
545#endif
546};
547
548#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
549template<class _T1, class _T2>
550pair(_T1, _T2) -> pair<_T1, _T2>;
551#endif // _LIBCPP_HAS_NO_DEDUCTION_GUIDES
552
553template <class _T1, class _T2>
554inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
555bool
556operator==(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
557{
558    return __x.first == __y.first && __x.second == __y.second;
559}
560
561template <class _T1, class _T2>
562inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
563bool
564operator!=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
565{
566    return !(__x == __y);
567}
568
569template <class _T1, class _T2>
570inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
571bool
572operator< (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
573{
574    return __x.first < __y.first || (!(__y.first < __x.first) && __x.second < __y.second);
575}
576
577template <class _T1, class _T2>
578inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
579bool
580operator> (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
581{
582    return __y < __x;
583}
584
585template <class _T1, class _T2>
586inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
587bool
588operator>=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
589{
590    return !(__x < __y);
591}
592
593template <class _T1, class _T2>
594inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
595bool
596operator<=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
597{
598    return !(__y < __x);
599}
600
601template <class _T1, class _T2>
602inline _LIBCPP_INLINE_VISIBILITY
603typename enable_if
604<
605    __is_swappable<_T1>::value &&
606    __is_swappable<_T2>::value,
607    void
608>::type
609swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)
610                     _NOEXCEPT_((__is_nothrow_swappable<_T1>::value &&
611                                 __is_nothrow_swappable<_T2>::value))
612{
613    __x.swap(__y);
614}
615
616#ifndef _LIBCPP_CXX03_LANG
617
618template <class _Tp>
619struct __make_pair_return_impl
620{
621    typedef _Tp type;
622};
623
624template <class _Tp>
625struct __make_pair_return_impl<reference_wrapper<_Tp>>
626{
627    typedef _Tp& type;
628};
629
630template <class _Tp>
631struct __make_pair_return
632{
633    typedef typename __make_pair_return_impl<typename decay<_Tp>::type>::type type;
634};
635
636template <class _T1, class _T2>
637inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
638pair<typename __make_pair_return<_T1>::type, typename __make_pair_return<_T2>::type>
639make_pair(_T1&& __t1, _T2&& __t2)
640{
641    return pair<typename __make_pair_return<_T1>::type, typename __make_pair_return<_T2>::type>
642               (_VSTD::forward<_T1>(__t1), _VSTD::forward<_T2>(__t2));
643}
644
645#else  // _LIBCPP_CXX03_LANG
646
647template <class _T1, class _T2>
648inline _LIBCPP_INLINE_VISIBILITY
649pair<_T1,_T2>
650make_pair(_T1 __x, _T2 __y)
651{
652    return pair<_T1, _T2>(__x, __y);
653}
654
655#endif  // _LIBCPP_CXX03_LANG
656
657template <class _T1, class _T2>
658  class _LIBCPP_TEMPLATE_VIS tuple_size<pair<_T1, _T2> >
659    : public integral_constant<size_t, 2> {};
660
661template <size_t _Ip, class _T1, class _T2>
662class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, pair<_T1, _T2> >
663{
664    static_assert(_Ip < 2, "Index out of bounds in std::tuple_element<std::pair<T1, T2>>");
665};
666
667template <class _T1, class _T2>
668class _LIBCPP_TEMPLATE_VIS tuple_element<0, pair<_T1, _T2> >
669{
670public:
671    typedef _T1 type;
672};
673
674template <class _T1, class _T2>
675class _LIBCPP_TEMPLATE_VIS tuple_element<1, pair<_T1, _T2> >
676{
677public:
678    typedef _T2 type;
679};
680
681template <size_t _Ip> struct __get_pair;
682
683template <>
684struct __get_pair<0>
685{
686    template <class _T1, class _T2>
687    static
688    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
689    _T1&
690    get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
691
692    template <class _T1, class _T2>
693    static
694    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
695    const _T1&
696    get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
697
698#ifndef _LIBCPP_CXX03_LANG
699    template <class _T1, class _T2>
700    static
701    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
702    _T1&&
703    get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T1>(__p.first);}
704
705    template <class _T1, class _T2>
706    static
707    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
708    const _T1&&
709    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T1>(__p.first);}
710#endif  // _LIBCPP_CXX03_LANG
711};
712
713template <>
714struct __get_pair<1>
715{
716    template <class _T1, class _T2>
717    static
718    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
719    _T2&
720    get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
721
722    template <class _T1, class _T2>
723    static
724    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
725    const _T2&
726    get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
727
728#ifndef _LIBCPP_CXX03_LANG
729    template <class _T1, class _T2>
730    static
731    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
732    _T2&&
733    get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T2>(__p.second);}
734
735    template <class _T1, class _T2>
736    static
737    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
738    const _T2&&
739    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T2>(__p.second);}
740#endif  // _LIBCPP_CXX03_LANG
741};
742
743template <size_t _Ip, class _T1, class _T2>
744inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
745typename tuple_element<_Ip, pair<_T1, _T2> >::type&
746get(pair<_T1, _T2>& __p) _NOEXCEPT
747{
748    return __get_pair<_Ip>::get(__p);
749}
750
751template <size_t _Ip, class _T1, class _T2>
752inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
753const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
754get(const pair<_T1, _T2>& __p) _NOEXCEPT
755{
756    return __get_pair<_Ip>::get(__p);
757}
758
759#ifndef _LIBCPP_CXX03_LANG
760template <size_t _Ip, class _T1, class _T2>
761inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
762typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
763get(pair<_T1, _T2>&& __p) _NOEXCEPT
764{
765    return __get_pair<_Ip>::get(_VSTD::move(__p));
766}
767
768template <size_t _Ip, class _T1, class _T2>
769inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
770const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
771get(const pair<_T1, _T2>&& __p) _NOEXCEPT
772{
773    return __get_pair<_Ip>::get(_VSTD::move(__p));
774}
775#endif  // _LIBCPP_CXX03_LANG
776
777#if _LIBCPP_STD_VER > 11
778template <class _T1, class _T2>
779inline _LIBCPP_INLINE_VISIBILITY
780constexpr _T1 & get(pair<_T1, _T2>& __p) _NOEXCEPT
781{
782    return __get_pair<0>::get(__p);
783}
784
785template <class _T1, class _T2>
786inline _LIBCPP_INLINE_VISIBILITY
787constexpr _T1 const & get(pair<_T1, _T2> const& __p) _NOEXCEPT
788{
789    return __get_pair<0>::get(__p);
790}
791
792template <class _T1, class _T2>
793inline _LIBCPP_INLINE_VISIBILITY
794constexpr _T1 && get(pair<_T1, _T2>&& __p) _NOEXCEPT
795{
796    return __get_pair<0>::get(_VSTD::move(__p));
797}
798
799template <class _T1, class _T2>
800inline _LIBCPP_INLINE_VISIBILITY
801constexpr _T1 const && get(pair<_T1, _T2> const&& __p) _NOEXCEPT
802{
803    return __get_pair<0>::get(_VSTD::move(__p));
804}
805
806template <class _T1, class _T2>
807inline _LIBCPP_INLINE_VISIBILITY
808constexpr _T1 & get(pair<_T2, _T1>& __p) _NOEXCEPT
809{
810    return __get_pair<1>::get(__p);
811}
812
813template <class _T1, class _T2>
814inline _LIBCPP_INLINE_VISIBILITY
815constexpr _T1 const & get(pair<_T2, _T1> const& __p) _NOEXCEPT
816{
817    return __get_pair<1>::get(__p);
818}
819
820template <class _T1, class _T2>
821inline _LIBCPP_INLINE_VISIBILITY
822constexpr _T1 && get(pair<_T2, _T1>&& __p) _NOEXCEPT
823{
824    return __get_pair<1>::get(_VSTD::move(__p));
825}
826
827template <class _T1, class _T2>
828inline _LIBCPP_INLINE_VISIBILITY
829constexpr _T1 const && get(pair<_T2, _T1> const&& __p) _NOEXCEPT
830{
831    return __get_pair<1>::get(_VSTD::move(__p));
832}
833
834#endif
835
836#if _LIBCPP_STD_VER > 11
837
838template<class _Tp, _Tp... _Ip>
839struct _LIBCPP_TEMPLATE_VIS integer_sequence
840{
841    typedef _Tp value_type;
842    static_assert( is_integral<_Tp>::value,
843                  "std::integer_sequence can only be instantiated with an integral type" );
844    static
845    _LIBCPP_INLINE_VISIBILITY
846    constexpr
847    size_t
848    size() noexcept { return sizeof...(_Ip); }
849};
850
851template<size_t... _Ip>
852    using index_sequence = integer_sequence<size_t, _Ip...>;
853
854#if __has_builtin(__make_integer_seq) && !defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)
855
856template <class _Tp, _Tp _Ep>
857using __make_integer_sequence = __make_integer_seq<integer_sequence, _Tp, _Ep>;
858
859#else
860
861template<typename _Tp, _Tp _Np> using __make_integer_sequence_unchecked =
862  typename __detail::__make<_Np>::type::template __convert<integer_sequence, _Tp>;
863
864template <class _Tp, _Tp _Ep>
865struct __make_integer_sequence_checked
866{
867    static_assert(is_integral<_Tp>::value,
868                  "std::make_integer_sequence can only be instantiated with an integral type" );
869    static_assert(0 <= _Ep, "std::make_integer_sequence must have a non-negative sequence length");
870    // Workaround GCC bug by preventing bad installations when 0 <= _Ep
871    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68929
872    typedef __make_integer_sequence_unchecked<_Tp, 0 <= _Ep ? _Ep : 0> type;
873};
874
875template <class _Tp, _Tp _Ep>
876using __make_integer_sequence = typename __make_integer_sequence_checked<_Tp, _Ep>::type;
877
878#endif
879
880template<class _Tp, _Tp _Np>
881    using make_integer_sequence = __make_integer_sequence<_Tp, _Np>;
882
883template<size_t _Np>
884    using make_index_sequence = make_integer_sequence<size_t, _Np>;
885
886template<class... _Tp>
887    using index_sequence_for = make_index_sequence<sizeof...(_Tp)>;
888
889#endif  // _LIBCPP_STD_VER > 11
890
891#if _LIBCPP_STD_VER > 11
892template<class _T1, class _T2 = _T1>
893inline _LIBCPP_INLINE_VISIBILITY
894_T1 exchange(_T1& __obj, _T2 && __new_value)
895{
896    _T1 __old_value = _VSTD::move(__obj);
897    __obj = _VSTD::forward<_T2>(__new_value);
898    return __old_value;
899}
900#endif  // _LIBCPP_STD_VER > 11
901
902#if _LIBCPP_STD_VER > 14
903
904struct _LIBCPP_TYPE_VIS in_place_t {
905    explicit in_place_t() = default;
906};
907#ifndef _LIBCPP_HAS_NO_INLINE_VARIABLES
908inline
909#endif
910constexpr in_place_t in_place{};
911
912template <class _Tp>
913struct _LIBCPP_TEMPLATE_VIS in_place_type_t {
914    explicit in_place_type_t() = default;
915};
916template <class _Tp>
917#ifndef _LIBCPP_HAS_NO_INLINE_VARIABLES
918inline
919#endif
920constexpr in_place_type_t<_Tp> in_place_type{};
921
922template <size_t _Idx>
923struct _LIBCPP_TYPE_VIS in_place_index_t {
924    explicit in_place_index_t() = default;
925};
926template <size_t _Idx>
927#ifndef _LIBCPP_HAS_NO_INLINE_VARIABLES
928inline
929#endif
930constexpr in_place_index_t<_Idx> in_place_index{};
931
932template <class _Tp> struct __is_inplace_type_imp : false_type {};
933template <class _Tp> struct __is_inplace_type_imp<in_place_type_t<_Tp>> : true_type {};
934
935template <class _Tp>
936using __is_inplace_type = __is_inplace_type_imp<__uncvref_t<_Tp>>;
937
938template <class _Tp> struct __is_inplace_index_imp : false_type {};
939template <size_t _Idx> struct __is_inplace_index_imp<in_place_index_t<_Idx>> : true_type {};
940
941template <class _Tp>
942using __is_inplace_index = __is_inplace_index_imp<__uncvref_t<_Tp>>;
943
944#endif // _LIBCPP_STD_VER > 14
945
946template <class _Arg, class _Result>
947struct _LIBCPP_TEMPLATE_VIS unary_function
948{
949    typedef _Arg    argument_type;
950    typedef _Result result_type;
951};
952
953template <class _Size>
954inline _LIBCPP_INLINE_VISIBILITY
955_Size
956__loadword(const void* __p)
957{
958    _Size __r;
959    std::memcpy(&__r, __p, sizeof(__r));
960    return __r;
961}
962
963// We use murmur2 when size_t is 32 bits, and cityhash64 when size_t
964// is 64 bits.  This is because cityhash64 uses 64bit x 64bit
965// multiplication, which can be very slow on 32-bit systems.
966template <class _Size, size_t = sizeof(_Size)*__CHAR_BIT__>
967struct __murmur2_or_cityhash;
968
969template <class _Size>
970struct __murmur2_or_cityhash<_Size, 32>
971{
972    inline _Size operator()(const void* __key, _Size __len)
973         _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK;
974};
975
976// murmur2
977template <class _Size>
978_Size
979__murmur2_or_cityhash<_Size, 32>::operator()(const void* __key, _Size __len)
980{
981    const _Size __m = 0x5bd1e995;
982    const _Size __r = 24;
983    _Size __h = __len;
984    const unsigned char* __data = static_cast<const unsigned char*>(__key);
985    for (; __len >= 4; __data += 4, __len -= 4)
986    {
987        _Size __k = __loadword<_Size>(__data);
988        __k *= __m;
989        __k ^= __k >> __r;
990        __k *= __m;
991        __h *= __m;
992        __h ^= __k;
993    }
994    switch (__len)
995    {
996    case 3:
997        __h ^= __data[2] << 16;
998    case 2:
999        __h ^= __data[1] << 8;
1000    case 1:
1001        __h ^= __data[0];
1002        __h *= __m;
1003    }
1004    __h ^= __h >> 13;
1005    __h *= __m;
1006    __h ^= __h >> 15;
1007    return __h;
1008}
1009
1010template <class _Size>
1011struct __murmur2_or_cityhash<_Size, 64>
1012{
1013    inline _Size operator()(const void* __key, _Size __len)  _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK;
1014
1015 private:
1016  // Some primes between 2^63 and 2^64.
1017  static const _Size __k0 = 0xc3a5c85c97cb3127ULL;
1018  static const _Size __k1 = 0xb492b66fbe98f273ULL;
1019  static const _Size __k2 = 0x9ae16a3b2f90404fULL;
1020  static const _Size __k3 = 0xc949d7c7509e6557ULL;
1021
1022  static _Size __rotate(_Size __val, int __shift) {
1023    return __shift == 0 ? __val : ((__val >> __shift) | (__val << (64 - __shift)));
1024  }
1025
1026  static _Size __rotate_by_at_least_1(_Size __val, int __shift) {
1027    return (__val >> __shift) | (__val << (64 - __shift));
1028  }
1029
1030  static _Size __shift_mix(_Size __val) {
1031    return __val ^ (__val >> 47);
1032  }
1033
1034  static _Size __hash_len_16(_Size __u, _Size __v)
1035     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1036  {
1037    const _Size __mul = 0x9ddfea08eb382d69ULL;
1038    _Size __a = (__u ^ __v) * __mul;
1039    __a ^= (__a >> 47);
1040    _Size __b = (__v ^ __a) * __mul;
1041    __b ^= (__b >> 47);
1042    __b *= __mul;
1043    return __b;
1044  }
1045
1046  static _Size __hash_len_0_to_16(const char* __s, _Size __len)
1047     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1048  {
1049    if (__len > 8) {
1050      const _Size __a = __loadword<_Size>(__s);
1051      const _Size __b = __loadword<_Size>(__s + __len - 8);
1052      return __hash_len_16(__a, __rotate_by_at_least_1(__b + __len, __len)) ^ __b;
1053    }
1054    if (__len >= 4) {
1055      const uint32_t __a = __loadword<uint32_t>(__s);
1056      const uint32_t __b = __loadword<uint32_t>(__s + __len - 4);
1057      return __hash_len_16(__len + (__a << 3), __b);
1058    }
1059    if (__len > 0) {
1060      const unsigned char __a = __s[0];
1061      const unsigned char __b = __s[__len >> 1];
1062      const unsigned char __c = __s[__len - 1];
1063      const uint32_t __y = static_cast<uint32_t>(__a) +
1064                           (static_cast<uint32_t>(__b) << 8);
1065      const uint32_t __z = __len + (static_cast<uint32_t>(__c) << 2);
1066      return __shift_mix(__y * __k2 ^ __z * __k3) * __k2;
1067    }
1068    return __k2;
1069  }
1070
1071  static _Size __hash_len_17_to_32(const char *__s, _Size __len)
1072     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1073  {
1074    const _Size __a = __loadword<_Size>(__s) * __k1;
1075    const _Size __b = __loadword<_Size>(__s + 8);
1076    const _Size __c = __loadword<_Size>(__s + __len - 8) * __k2;
1077    const _Size __d = __loadword<_Size>(__s + __len - 16) * __k0;
1078    return __hash_len_16(__rotate(__a - __b, 43) + __rotate(__c, 30) + __d,
1079                         __a + __rotate(__b ^ __k3, 20) - __c + __len);
1080  }
1081
1082  // Return a 16-byte hash for 48 bytes.  Quick and dirty.
1083  // Callers do best to use "random-looking" values for a and b.
1084  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
1085      _Size __w, _Size __x, _Size __y, _Size __z, _Size __a, _Size __b)
1086        _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1087  {
1088    __a += __w;
1089    __b = __rotate(__b + __a + __z, 21);
1090    const _Size __c = __a;
1091    __a += __x;
1092    __a += __y;
1093    __b += __rotate(__a, 44);
1094    return pair<_Size, _Size>(__a + __z, __b + __c);
1095  }
1096
1097  // Return a 16-byte hash for s[0] ... s[31], a, and b.  Quick and dirty.
1098  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
1099      const char* __s, _Size __a, _Size __b)
1100    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1101  {
1102    return __weak_hash_len_32_with_seeds(__loadword<_Size>(__s),
1103                                         __loadword<_Size>(__s + 8),
1104                                         __loadword<_Size>(__s + 16),
1105                                         __loadword<_Size>(__s + 24),
1106                                         __a,
1107                                         __b);
1108  }
1109
1110  // Return an 8-byte hash for 33 to 64 bytes.
1111  static _Size __hash_len_33_to_64(const char *__s, size_t __len)
1112    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1113  {
1114    _Size __z = __loadword<_Size>(__s + 24);
1115    _Size __a = __loadword<_Size>(__s) +
1116                (__len + __loadword<_Size>(__s + __len - 16)) * __k0;
1117    _Size __b = __rotate(__a + __z, 52);
1118    _Size __c = __rotate(__a, 37);
1119    __a += __loadword<_Size>(__s + 8);
1120    __c += __rotate(__a, 7);
1121    __a += __loadword<_Size>(__s + 16);
1122    _Size __vf = __a + __z;
1123    _Size __vs = __b + __rotate(__a, 31) + __c;
1124    __a = __loadword<_Size>(__s + 16) + __loadword<_Size>(__s + __len - 32);
1125    __z += __loadword<_Size>(__s + __len - 8);
1126    __b = __rotate(__a + __z, 52);
1127    __c = __rotate(__a, 37);
1128    __a += __loadword<_Size>(__s + __len - 24);
1129    __c += __rotate(__a, 7);
1130    __a += __loadword<_Size>(__s + __len - 16);
1131    _Size __wf = __a + __z;
1132    _Size __ws = __b + __rotate(__a, 31) + __c;
1133    _Size __r = __shift_mix((__vf + __ws) * __k2 + (__wf + __vs) * __k0);
1134    return __shift_mix(__r * __k0 + __vs) * __k2;
1135  }
1136};
1137
1138// cityhash64
1139template <class _Size>
1140_Size
1141__murmur2_or_cityhash<_Size, 64>::operator()(const void* __key, _Size __len)
1142{
1143  const char* __s = static_cast<const char*>(__key);
1144  if (__len <= 32) {
1145    if (__len <= 16) {
1146      return __hash_len_0_to_16(__s, __len);
1147    } else {
1148      return __hash_len_17_to_32(__s, __len);
1149    }
1150  } else if (__len <= 64) {
1151    return __hash_len_33_to_64(__s, __len);
1152  }
1153
1154  // For strings over 64 bytes we hash the end first, and then as we
1155  // loop we keep 56 bytes of state: v, w, x, y, and z.
1156  _Size __x = __loadword<_Size>(__s + __len - 40);
1157  _Size __y = __loadword<_Size>(__s + __len - 16) +
1158              __loadword<_Size>(__s + __len - 56);
1159  _Size __z = __hash_len_16(__loadword<_Size>(__s + __len - 48) + __len,
1160                          __loadword<_Size>(__s + __len - 24));
1161  pair<_Size, _Size> __v = __weak_hash_len_32_with_seeds(__s + __len - 64, __len, __z);
1162  pair<_Size, _Size> __w = __weak_hash_len_32_with_seeds(__s + __len - 32, __y + __k1, __x);
1163  __x = __x * __k1 + __loadword<_Size>(__s);
1164
1165  // Decrease len to the nearest multiple of 64, and operate on 64-byte chunks.
1166  __len = (__len - 1) & ~static_cast<_Size>(63);
1167  do {
1168    __x = __rotate(__x + __y + __v.first + __loadword<_Size>(__s + 8), 37) * __k1;
1169    __y = __rotate(__y + __v.second + __loadword<_Size>(__s + 48), 42) * __k1;
1170    __x ^= __w.second;
1171    __y += __v.first + __loadword<_Size>(__s + 40);
1172    __z = __rotate(__z + __w.first, 33) * __k1;
1173    __v = __weak_hash_len_32_with_seeds(__s, __v.second * __k1, __x + __w.first);
1174    __w = __weak_hash_len_32_with_seeds(__s + 32, __z + __w.second,
1175                                        __y + __loadword<_Size>(__s + 16));
1176    std::swap(__z, __x);
1177    __s += 64;
1178    __len -= 64;
1179  } while (__len != 0);
1180  return __hash_len_16(
1181      __hash_len_16(__v.first, __w.first) + __shift_mix(__y) * __k1 + __z,
1182      __hash_len_16(__v.second, __w.second) + __x);
1183}
1184
1185template <class _Tp, size_t = sizeof(_Tp) / sizeof(size_t)>
1186struct __scalar_hash;
1187
1188template <class _Tp>
1189struct __scalar_hash<_Tp, 0>
1190    : public unary_function<_Tp, size_t>
1191{
1192    _LIBCPP_INLINE_VISIBILITY
1193    size_t operator()(_Tp __v) const _NOEXCEPT
1194    {
1195        union
1196        {
1197            _Tp    __t;
1198            size_t __a;
1199        } __u;
1200        __u.__a = 0;
1201        __u.__t = __v;
1202        return __u.__a;
1203    }
1204};
1205
1206template <class _Tp>
1207struct __scalar_hash<_Tp, 1>
1208    : public unary_function<_Tp, size_t>
1209{
1210    _LIBCPP_INLINE_VISIBILITY
1211    size_t operator()(_Tp __v) const _NOEXCEPT
1212    {
1213        union
1214        {
1215            _Tp    __t;
1216            size_t __a;
1217        } __u;
1218        __u.__t = __v;
1219        return __u.__a;
1220    }
1221};
1222
1223template <class _Tp>
1224struct __scalar_hash<_Tp, 2>
1225    : public unary_function<_Tp, size_t>
1226{
1227    _LIBCPP_INLINE_VISIBILITY
1228    size_t operator()(_Tp __v) const _NOEXCEPT
1229    {
1230        union
1231        {
1232            _Tp __t;
1233            struct
1234            {
1235                size_t __a;
1236                size_t __b;
1237            } __s;
1238        } __u;
1239        __u.__t = __v;
1240        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1241    }
1242};
1243
1244template <class _Tp>
1245struct __scalar_hash<_Tp, 3>
1246    : public unary_function<_Tp, size_t>
1247{
1248    _LIBCPP_INLINE_VISIBILITY
1249    size_t operator()(_Tp __v) const _NOEXCEPT
1250    {
1251        union
1252        {
1253            _Tp __t;
1254            struct
1255            {
1256                size_t __a;
1257                size_t __b;
1258                size_t __c;
1259            } __s;
1260        } __u;
1261        __u.__t = __v;
1262        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1263    }
1264};
1265
1266template <class _Tp>
1267struct __scalar_hash<_Tp, 4>
1268    : public unary_function<_Tp, size_t>
1269{
1270    _LIBCPP_INLINE_VISIBILITY
1271    size_t operator()(_Tp __v) const _NOEXCEPT
1272    {
1273        union
1274        {
1275            _Tp __t;
1276            struct
1277            {
1278                size_t __a;
1279                size_t __b;
1280                size_t __c;
1281                size_t __d;
1282            } __s;
1283        } __u;
1284        __u.__t = __v;
1285        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1286    }
1287};
1288
1289struct _PairT {
1290  size_t first;
1291  size_t second;
1292};
1293
1294_LIBCPP_INLINE_VISIBILITY
1295inline size_t __hash_combine(size_t __lhs, size_t __rhs) _NOEXCEPT {
1296    typedef __scalar_hash<_PairT> _HashT;
1297    const _PairT __p = {__lhs, __rhs};
1298    return _HashT()(__p);
1299}
1300
1301template<class _Tp>
1302struct _LIBCPP_TEMPLATE_VIS hash<_Tp*>
1303    : public unary_function<_Tp*, size_t>
1304{
1305    _LIBCPP_INLINE_VISIBILITY
1306    size_t operator()(_Tp* __v) const _NOEXCEPT
1307    {
1308        union
1309        {
1310            _Tp* __t;
1311            size_t __a;
1312        } __u;
1313        __u.__t = __v;
1314        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1315    }
1316};
1317
1318
1319template <>
1320struct _LIBCPP_TEMPLATE_VIS hash<bool>
1321    : public unary_function<bool, size_t>
1322{
1323    _LIBCPP_INLINE_VISIBILITY
1324    size_t operator()(bool __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1325};
1326
1327template <>
1328struct _LIBCPP_TEMPLATE_VIS hash<char>
1329    : public unary_function<char, size_t>
1330{
1331    _LIBCPP_INLINE_VISIBILITY
1332    size_t operator()(char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1333};
1334
1335template <>
1336struct _LIBCPP_TEMPLATE_VIS hash<signed char>
1337    : public unary_function<signed char, size_t>
1338{
1339    _LIBCPP_INLINE_VISIBILITY
1340    size_t operator()(signed char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1341};
1342
1343template <>
1344struct _LIBCPP_TEMPLATE_VIS hash<unsigned char>
1345    : public unary_function<unsigned char, size_t>
1346{
1347    _LIBCPP_INLINE_VISIBILITY
1348    size_t operator()(unsigned char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1349};
1350
1351#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
1352
1353template <>
1354struct _LIBCPP_TEMPLATE_VIS hash<char16_t>
1355    : public unary_function<char16_t, size_t>
1356{
1357    _LIBCPP_INLINE_VISIBILITY
1358    size_t operator()(char16_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1359};
1360
1361template <>
1362struct _LIBCPP_TEMPLATE_VIS hash<char32_t>
1363    : public unary_function<char32_t, size_t>
1364{
1365    _LIBCPP_INLINE_VISIBILITY
1366    size_t operator()(char32_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1367};
1368
1369#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
1370
1371template <>
1372struct _LIBCPP_TEMPLATE_VIS hash<wchar_t>
1373    : public unary_function<wchar_t, size_t>
1374{
1375    _LIBCPP_INLINE_VISIBILITY
1376    size_t operator()(wchar_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1377};
1378
1379template <>
1380struct _LIBCPP_TEMPLATE_VIS hash<short>
1381    : public unary_function<short, size_t>
1382{
1383    _LIBCPP_INLINE_VISIBILITY
1384    size_t operator()(short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1385};
1386
1387template <>
1388struct _LIBCPP_TEMPLATE_VIS hash<unsigned short>
1389    : public unary_function<unsigned short, size_t>
1390{
1391    _LIBCPP_INLINE_VISIBILITY
1392    size_t operator()(unsigned short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1393};
1394
1395template <>
1396struct _LIBCPP_TEMPLATE_VIS hash<int>
1397    : public unary_function<int, size_t>
1398{
1399    _LIBCPP_INLINE_VISIBILITY
1400    size_t operator()(int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1401};
1402
1403template <>
1404struct _LIBCPP_TEMPLATE_VIS hash<unsigned int>
1405    : public unary_function<unsigned int, size_t>
1406{
1407    _LIBCPP_INLINE_VISIBILITY
1408    size_t operator()(unsigned int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1409};
1410
1411template <>
1412struct _LIBCPP_TEMPLATE_VIS hash<long>
1413    : public unary_function<long, size_t>
1414{
1415    _LIBCPP_INLINE_VISIBILITY
1416    size_t operator()(long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1417};
1418
1419template <>
1420struct _LIBCPP_TEMPLATE_VIS hash<unsigned long>
1421    : public unary_function<unsigned long, size_t>
1422{
1423    _LIBCPP_INLINE_VISIBILITY
1424    size_t operator()(unsigned long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1425};
1426
1427template <>
1428struct _LIBCPP_TEMPLATE_VIS hash<long long>
1429    : public __scalar_hash<long long>
1430{
1431};
1432
1433template <>
1434struct _LIBCPP_TEMPLATE_VIS hash<unsigned long long>
1435    : public __scalar_hash<unsigned long long>
1436{
1437};
1438
1439#ifndef _LIBCPP_HAS_NO_INT128
1440
1441template <>
1442struct _LIBCPP_TEMPLATE_VIS hash<__int128_t>
1443    : public __scalar_hash<__int128_t>
1444{
1445};
1446
1447template <>
1448struct _LIBCPP_TEMPLATE_VIS hash<__uint128_t>
1449    : public __scalar_hash<__uint128_t>
1450{
1451};
1452
1453#endif
1454
1455template <>
1456struct _LIBCPP_TEMPLATE_VIS hash<float>
1457    : public __scalar_hash<float>
1458{
1459    _LIBCPP_INLINE_VISIBILITY
1460    size_t operator()(float __v) const _NOEXCEPT
1461    {
1462        // -0.0 and 0.0 should return same hash
1463       if (__v == 0)
1464           return 0;
1465        return __scalar_hash<float>::operator()(__v);
1466    }
1467};
1468
1469template <>
1470struct _LIBCPP_TEMPLATE_VIS hash<double>
1471    : public __scalar_hash<double>
1472{
1473    _LIBCPP_INLINE_VISIBILITY
1474    size_t operator()(double __v) const _NOEXCEPT
1475    {
1476        // -0.0 and 0.0 should return same hash
1477       if (__v == 0)
1478           return 0;
1479        return __scalar_hash<double>::operator()(__v);
1480    }
1481};
1482
1483template <>
1484struct _LIBCPP_TEMPLATE_VIS hash<long double>
1485    : public __scalar_hash<long double>
1486{
1487    _LIBCPP_INLINE_VISIBILITY
1488    size_t operator()(long double __v) const _NOEXCEPT
1489    {
1490        // -0.0 and 0.0 should return same hash
1491        if (__v == 0)
1492            return 0;
1493#if defined(__i386__)
1494        // Zero out padding bits
1495        union
1496        {
1497            long double __t;
1498            struct
1499            {
1500                size_t __a;
1501                size_t __b;
1502                size_t __c;
1503                size_t __d;
1504            } __s;
1505        } __u;
1506        __u.__s.__a = 0;
1507        __u.__s.__b = 0;
1508        __u.__s.__c = 0;
1509        __u.__s.__d = 0;
1510        __u.__t = __v;
1511        return __u.__s.__a ^ __u.__s.__b ^ __u.__s.__c ^ __u.__s.__d;
1512#elif defined(__x86_64__)
1513        // Zero out padding bits
1514        union
1515        {
1516            long double __t;
1517            struct
1518            {
1519                size_t __a;
1520                size_t __b;
1521            } __s;
1522        } __u;
1523        __u.__s.__a = 0;
1524        __u.__s.__b = 0;
1525        __u.__t = __v;
1526        return __u.__s.__a ^ __u.__s.__b;
1527#else
1528        return __scalar_hash<long double>::operator()(__v);
1529#endif
1530    }
1531};
1532
1533#if _LIBCPP_STD_VER > 11
1534
1535template <class _Tp, bool = is_enum<_Tp>::value>
1536struct _LIBCPP_TEMPLATE_VIS __enum_hash
1537    : public unary_function<_Tp, size_t>
1538{
1539    _LIBCPP_INLINE_VISIBILITY
1540    size_t operator()(_Tp __v) const _NOEXCEPT
1541    {
1542        typedef typename underlying_type<_Tp>::type type;
1543        return hash<type>{}(static_cast<type>(__v));
1544    }
1545};
1546template <class _Tp>
1547struct _LIBCPP_TEMPLATE_VIS __enum_hash<_Tp, false> {
1548    __enum_hash() = delete;
1549    __enum_hash(__enum_hash const&) = delete;
1550    __enum_hash& operator=(__enum_hash const&) = delete;
1551};
1552
1553template <class _Tp>
1554struct _LIBCPP_TEMPLATE_VIS hash : public __enum_hash<_Tp>
1555{
1556};
1557#endif
1558
1559#if _LIBCPP_STD_VER > 14
1560
1561template <>
1562struct _LIBCPP_TEMPLATE_VIS hash<nullptr_t>
1563  : public unary_function<nullptr_t, size_t>
1564{
1565  _LIBCPP_INLINE_VISIBILITY
1566  size_t operator()(nullptr_t) const _NOEXCEPT {
1567    return 662607004ull;
1568  }
1569};
1570#endif
1571
1572#ifndef _LIBCPP_CXX03_LANG
1573template <class _Key, class _Hash>
1574using __check_hash_requirements = integral_constant<bool,
1575    is_copy_constructible<_Hash>::value &&
1576    is_move_constructible<_Hash>::value &&
1577    __invokable_r<size_t, _Hash, _Key const&>::value
1578>;
1579
1580template <class _Key, class _Hash = std::hash<_Key> >
1581using __has_enabled_hash = integral_constant<bool,
1582    __check_hash_requirements<_Key, _Hash>::value &&
1583    is_default_constructible<_Hash>::value
1584>;
1585
1586#if _LIBCPP_STD_VER > 14
1587template <class _Type, class>
1588using __enable_hash_helper_imp = _Type;
1589
1590template <class _Type, class ..._Keys>
1591using __enable_hash_helper = __enable_hash_helper_imp<_Type,
1592  typename enable_if<__all<__has_enabled_hash<_Keys>::value...>::value>::type
1593>;
1594#else
1595template <class _Type, class ...>
1596using __enable_hash_helper = _Type;
1597#endif
1598
1599#endif // !_LIBCPP_CXX03_LANG
1600
1601_LIBCPP_END_NAMESPACE_STD
1602
1603#endif  // _LIBCPP_UTILITY
1604