xref: /freebsd/contrib/llvm-project/libcxx/include/utility (revision 4b50c451720d8b427757a6da1dd2bb4c52cd9e35)
1// -*- C++ -*-
2//===-------------------------- utility -----------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_UTILITY
11#define _LIBCPP_UTILITY
12
13/*
14    utility synopsis
15
16#include <initializer_list>
17
18namespace std
19{
20
21template <class T>
22    void
23    swap(T& a, T& b);
24
25namespace rel_ops
26{
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    template<class T> bool operator>=(const T&, const T&);
31}
32
33template<class T>
34void
35swap(T& a, T& b) noexcept(is_nothrow_move_constructible<T>::value &&
36                          is_nothrow_move_assignable<T>::value);
37
38template <class T, size_t N>
39void
40swap(T (&a)[N], T (&b)[N]) noexcept(noexcept(swap(*a, *b)));
41
42template <class T> T&& forward(typename remove_reference<T>::type& t) noexcept;  // constexpr in C++14
43template <class T> T&& forward(typename remove_reference<T>::type&& t) noexcept; // constexpr in C++14
44
45template <class T> typename remove_reference<T>::type&& move(T&&) noexcept;      // constexpr in C++14
46
47template <class T>
48    typename conditional
49    <
50        !is_nothrow_move_constructible<T>::value && is_copy_constructible<T>::value,
51        const T&,
52        T&&
53    >::type
54    move_if_noexcept(T& x) noexcept; // constexpr in C++14
55
56template <class T> constexpr add_const_t<T>& as_const(T& t) noexcept;      // C++17
57template <class T>                      void as_const(const T&&) = delete; // C++17
58
59template <class T> typename add_rvalue_reference<T>::type declval() noexcept;
60
61template <class T1, class T2>
62struct pair
63{
64    typedef T1 first_type;
65    typedef T2 second_type;
66
67    T1 first;
68    T2 second;
69
70    pair(const pair&) = default;
71    pair(pair&&) = default;
72    constexpr pair();
73    pair(const T1& x, const T2& y);                          // constexpr in C++14
74    template <class U, class V> pair(U&& x, V&& y);          // constexpr in C++14
75    template <class U, class V> pair(const pair<U, V>& p);   // constexpr in C++14
76    template <class U, class V> pair(pair<U, V>&& p);        // constexpr in C++14
77    template <class... Args1, class... Args2>
78        pair(piecewise_construct_t, tuple<Args1...> first_args,
79             tuple<Args2...> second_args);
80
81    template <class U, class V> pair& operator=(const pair<U, V>& p);
82    pair& operator=(pair&& p) noexcept(is_nothrow_move_assignable<T1>::value &&
83                                       is_nothrow_move_assignable<T2>::value);
84    template <class U, class V> pair& operator=(pair<U, V>&& p);
85
86    void swap(pair& p) noexcept(is_nothrow_swappable_v<T1> &&
87                                is_nothrow_swappable_v<T2>);
88};
89
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
95template <class T1, class T2> bool operator<=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
96
97template <class T1, class T2> pair<V1, V2> make_pair(T1&&, T2&&);   // constexpr in C++14
98template <class T1, class T2>
99void
100swap(pair<T1, T2>& x, pair<T1, T2>& y) noexcept(noexcept(x.swap(y)));
101
102struct piecewise_construct_t { };
103inline constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
104
105template <class T> struct tuple_size;
106template <size_t I, class T> struct tuple_element;
107
108template <class T1, class T2> struct tuple_size<pair<T1, T2> >;
109template <class T1, class T2> struct tuple_element<0, pair<T1, T2> >;
110template <class T1, class T2> struct tuple_element<1, pair<T1, T2> >;
111
112template<size_t I, class T1, class T2>
113    typename tuple_element<I, pair<T1, T2> >::type&
114    get(pair<T1, T2>&) noexcept; // constexpr in C++14
115
116template<size_t I, class T1, class T2>
117    const typename tuple_element<I, pair<T1, T2> >::type&
118    get(const pair<T1, T2>&) noexcept; // constexpr in C++14
119
120template<size_t I, class T1, class T2>
121    typename tuple_element<I, pair<T1, T2> >::type&&
122    get(pair<T1, T2>&&) noexcept; // constexpr in C++14
123
124template<size_t I, class T1, class T2>
125    const typename tuple_element<I, pair<T1, T2> >::type&&
126    get(const pair<T1, T2>&&) noexcept; // constexpr in C++14
127
128template<class T1, class T2>
129    constexpr T1& get(pair<T1, T2>&) noexcept; // C++14
130
131template<class T1, class T2>
132    constexpr const T1& get(const pair<T1, T2>&) noexcept; // C++14
133
134template<class T1, class T2>
135    constexpr T1&& get(pair<T1, T2>&&) noexcept; // C++14
136
137template<class T1, class T2>
138    constexpr const T1&& get(const pair<T1, T2>&&) noexcept; // C++14
139
140template<class T1, class T2>
141    constexpr T1& get(pair<T2, T1>&) noexcept; // C++14
142
143template<class T1, class T2>
144    constexpr const T1& get(const pair<T2, T1>&) noexcept; // C++14
145
146template<class T1, class T2>
147    constexpr T1&& get(pair<T2, T1>&&) noexcept; // C++14
148
149template<class T1, class T2>
150    constexpr const T1&& get(const pair<T2, T1>&&) noexcept; // C++14
151
152// C++14
153
154template<class T, T... I>
155struct integer_sequence
156{
157    typedef T value_type;
158
159    static constexpr size_t size() noexcept;
160};
161
162template<size_t... I>
163  using index_sequence = integer_sequence<size_t, I...>;
164
165template<class T, T N>
166  using make_integer_sequence = integer_sequence<T, 0, 1, ..., N-1>;
167template<size_t N>
168  using make_index_sequence = make_integer_sequence<size_t, N>;
169
170template<class... T>
171  using index_sequence_for = make_index_sequence<sizeof...(T)>;
172
173template<class T, class U=T>
174    T exchange(T& obj, U&& new_value);
175
176// 20.2.7, in-place construction // C++17
177struct in_place_t {
178  explicit in_place_t() = default;
179};
180inline constexpr in_place_t in_place{};
181template <class T>
182  struct in_place_type_t {
183    explicit in_place_type_t() = default;
184  };
185template <class T>
186  inline constexpr in_place_type_t<T> in_place_type{};
187template <size_t I>
188  struct in_place_index_t {
189    explicit in_place_index_t() = default;
190  };
191template <size_t I>
192  inline constexpr in_place_index_t<I> in_place_index{};
193
194}  // std
195
196*/
197
198#include <__config>
199#include <__tuple>
200#include <type_traits>
201#include <initializer_list>
202#include <cstddef>
203#include <cstring>
204#include <cstdint>
205#include <version>
206#include <__debug>
207
208#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
209#pragma GCC system_header
210#endif
211
212_LIBCPP_BEGIN_NAMESPACE_STD
213
214namespace rel_ops
215{
216
217template<class _Tp>
218inline _LIBCPP_INLINE_VISIBILITY
219bool
220operator!=(const _Tp& __x, const _Tp& __y)
221{
222    return !(__x == __y);
223}
224
225template<class _Tp>
226inline _LIBCPP_INLINE_VISIBILITY
227bool
228operator> (const _Tp& __x, const _Tp& __y)
229{
230    return __y < __x;
231}
232
233template<class _Tp>
234inline _LIBCPP_INLINE_VISIBILITY
235bool
236operator<=(const _Tp& __x, const _Tp& __y)
237{
238    return !(__y < __x);
239}
240
241template<class _Tp>
242inline _LIBCPP_INLINE_VISIBILITY
243bool
244operator>=(const _Tp& __x, const _Tp& __y)
245{
246    return !(__x < __y);
247}
248
249}  // rel_ops
250
251// swap_ranges
252
253
254template <class _ForwardIterator1, class _ForwardIterator2>
255inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
256_ForwardIterator2
257swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2)
258{
259    for(; __first1 != __last1; ++__first1, (void) ++__first2)
260        swap(*__first1, *__first2);
261    return __first2;
262}
263
264// forward declared in <type_traits>
265template<class _Tp, size_t _Np>
266inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
267typename enable_if<
268    __is_swappable<_Tp>::value
269>::type
270swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value)
271{
272    _VSTD::swap_ranges(__a, __a + _Np, __b);
273}
274
275template <class _Tp>
276inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
277#ifndef _LIBCPP_CXX03_LANG
278typename conditional
279<
280    !is_nothrow_move_constructible<_Tp>::value && is_copy_constructible<_Tp>::value,
281    const _Tp&,
282    _Tp&&
283>::type
284#else  // _LIBCPP_CXX03_LANG
285const _Tp&
286#endif
287move_if_noexcept(_Tp& __x) _NOEXCEPT
288{
289    return _VSTD::move(__x);
290}
291
292#if _LIBCPP_STD_VER > 14
293template <class _Tp> constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
294template <class _Tp>                        void as_const(const _Tp&&) = delete;
295#endif
296
297struct _LIBCPP_TEMPLATE_VIS piecewise_construct_t { };
298#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
299extern _LIBCPP_EXPORTED_FROM_ABI const piecewise_construct_t piecewise_construct;// = piecewise_construct_t();
300#else
301/* _LIBCPP_INLINE_VAR */ constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
302#endif
303
304#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
305template <class, class>
306struct __non_trivially_copyable_base {
307  _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
308  __non_trivially_copyable_base() _NOEXCEPT {}
309  _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
310  __non_trivially_copyable_base(__non_trivially_copyable_base const&) _NOEXCEPT {}
311};
312#endif
313
314template <class _T1, class _T2>
315struct _LIBCPP_TEMPLATE_VIS pair
316#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
317: private __non_trivially_copyable_base<_T1, _T2>
318#endif
319{
320    typedef _T1 first_type;
321    typedef _T2 second_type;
322
323    _T1 first;
324    _T2 second;
325
326#if !defined(_LIBCPP_CXX03_LANG)
327    pair(pair const&) = default;
328    pair(pair&&) = default;
329#else
330  // Use the implicitly declared copy constructor in C++03
331#endif
332
333#ifdef _LIBCPP_CXX03_LANG
334    _LIBCPP_INLINE_VISIBILITY
335    pair() : first(), second() {}
336
337    _LIBCPP_INLINE_VISIBILITY
338    pair(_T1 const& __t1, _T2 const& __t2) : first(__t1), second(__t2) {}
339
340    template <class _U1, class _U2>
341    _LIBCPP_INLINE_VISIBILITY
342    pair(const pair<_U1, _U2>& __p) : first(__p.first), second(__p.second) {}
343
344    _LIBCPP_INLINE_VISIBILITY
345    pair& operator=(pair const& __p) {
346        first = __p.first;
347        second = __p.second;
348        return *this;
349    }
350#else
351    template <bool _Val>
352    using _EnableB _LIBCPP_NODEBUG_TYPE = typename enable_if<_Val, bool>::type;
353
354    struct _CheckArgs {
355      template <class _U1, class _U2>
356      static constexpr bool __enable_default() {
357          return is_default_constructible<_U1>::value
358              && is_default_constructible<_U2>::value;
359      }
360
361      template <class _U1, class _U2>
362      static constexpr bool __enable_explicit() {
363          return is_constructible<first_type, _U1>::value
364              && is_constructible<second_type, _U2>::value
365              && (!is_convertible<_U1, first_type>::value
366                  || !is_convertible<_U2, second_type>::value);
367      }
368
369      template <class _U1, class _U2>
370      static constexpr bool __enable_implicit() {
371          return is_constructible<first_type, _U1>::value
372              && is_constructible<second_type, _U2>::value
373              && is_convertible<_U1, first_type>::value
374              && is_convertible<_U2, second_type>::value;
375      }
376    };
377
378    template <bool _MaybeEnable>
379    using _CheckArgsDep _LIBCPP_NODEBUG_TYPE = typename conditional<
380      _MaybeEnable, _CheckArgs, __check_tuple_constructor_fail>::type;
381
382    struct _CheckTupleLikeConstructor {
383        template <class _Tuple>
384        static constexpr bool __enable_implicit() {
385            return __tuple_convertible<_Tuple, pair>::value;
386        }
387
388        template <class _Tuple>
389        static constexpr bool __enable_explicit() {
390            return __tuple_constructible<_Tuple, pair>::value
391               && !__tuple_convertible<_Tuple, pair>::value;
392        }
393
394        template <class _Tuple>
395        static constexpr bool __enable_assign() {
396            return __tuple_assignable<_Tuple, pair>::value;
397        }
398    };
399
400    template <class _Tuple>
401    using _CheckTLC _LIBCPP_NODEBUG_TYPE = typename conditional<
402        __tuple_like_with_size<_Tuple, 2>::value
403            && !is_same<typename decay<_Tuple>::type, pair>::value,
404        _CheckTupleLikeConstructor,
405        __check_tuple_constructor_fail
406    >::type;
407
408    template<bool _Dummy = true, _EnableB<
409            _CheckArgsDep<_Dummy>::template __enable_default<_T1, _T2>()
410    > = false>
411    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
412    pair() _NOEXCEPT_(is_nothrow_default_constructible<first_type>::value &&
413                      is_nothrow_default_constructible<second_type>::value)
414        : first(), second() {}
415
416    template <bool _Dummy = true, _EnableB<
417             _CheckArgsDep<_Dummy>::template __enable_explicit<_T1 const&, _T2 const&>()
418    > = false>
419    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
420    explicit pair(_T1 const& __t1, _T2 const& __t2)
421        _NOEXCEPT_(is_nothrow_copy_constructible<first_type>::value &&
422                   is_nothrow_copy_constructible<second_type>::value)
423        : first(__t1), second(__t2) {}
424
425    template<bool _Dummy = true, _EnableB<
426            _CheckArgsDep<_Dummy>::template __enable_implicit<_T1 const&, _T2 const&>()
427    > = false>
428    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
429    pair(_T1 const& __t1, _T2 const& __t2)
430        _NOEXCEPT_(is_nothrow_copy_constructible<first_type>::value &&
431                   is_nothrow_copy_constructible<second_type>::value)
432        : first(__t1), second(__t2) {}
433
434    template<class _U1, class _U2, _EnableB<
435             _CheckArgs::template __enable_explicit<_U1, _U2>()
436    > = false>
437    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
438    explicit pair(_U1&& __u1, _U2&& __u2)
439        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1>::value &&
440                    is_nothrow_constructible<second_type, _U2>::value))
441        : first(_VSTD::forward<_U1>(__u1)), second(_VSTD::forward<_U2>(__u2)) {}
442
443    template<class _U1, class _U2, _EnableB<
444            _CheckArgs::template __enable_implicit<_U1, _U2>()
445    > = false>
446    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
447    pair(_U1&& __u1, _U2&& __u2)
448        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1>::value &&
449                    is_nothrow_constructible<second_type, _U2>::value))
450        : first(_VSTD::forward<_U1>(__u1)), second(_VSTD::forward<_U2>(__u2)) {}
451
452    template<class _U1, class _U2, _EnableB<
453            _CheckArgs::template __enable_explicit<_U1 const&, _U2 const&>()
454    > = false>
455    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
456    explicit pair(pair<_U1, _U2> const& __p)
457        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1 const&>::value &&
458                    is_nothrow_constructible<second_type, _U2 const&>::value))
459        : first(__p.first), second(__p.second) {}
460
461    template<class _U1, class _U2, _EnableB<
462            _CheckArgs::template __enable_implicit<_U1 const&, _U2 const&>()
463    > = false>
464    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
465    pair(pair<_U1, _U2> const& __p)
466        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1 const&>::value &&
467                    is_nothrow_constructible<second_type, _U2 const&>::value))
468        : first(__p.first), second(__p.second) {}
469
470    template<class _U1, class _U2, _EnableB<
471            _CheckArgs::template __enable_explicit<_U1, _U2>()
472    > = false>
473    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
474    explicit pair(pair<_U1, _U2>&&__p)
475        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1&&>::value &&
476                    is_nothrow_constructible<second_type, _U2&&>::value))
477        : first(_VSTD::forward<_U1>(__p.first)), second(_VSTD::forward<_U2>(__p.second)) {}
478
479    template<class _U1, class _U2, _EnableB<
480            _CheckArgs::template __enable_implicit<_U1, _U2>()
481    > = false>
482    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
483    pair(pair<_U1, _U2>&& __p)
484        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1&&>::value &&
485                    is_nothrow_constructible<second_type, _U2&&>::value))
486        : first(_VSTD::forward<_U1>(__p.first)), second(_VSTD::forward<_U2>(__p.second)) {}
487
488    template<class _Tuple, _EnableB<
489            _CheckTLC<_Tuple>::template __enable_explicit<_Tuple>()
490    > = false>
491    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
492    explicit pair(_Tuple&& __p)
493        : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
494          second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
495
496    template<class _Tuple, _EnableB<
497            _CheckTLC<_Tuple>::template __enable_implicit<_Tuple>()
498    > = false>
499    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
500    pair(_Tuple&& __p)
501        : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
502          second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
503
504    template <class... _Args1, class... _Args2>
505    _LIBCPP_INLINE_VISIBILITY
506    pair(piecewise_construct_t __pc,
507         tuple<_Args1...> __first_args, tuple<_Args2...> __second_args)
508        _NOEXCEPT_((is_nothrow_constructible<first_type, _Args1...>::value &&
509                    is_nothrow_constructible<second_type, _Args2...>::value))
510        : pair(__pc, __first_args, __second_args,
511                typename __make_tuple_indices<sizeof...(_Args1)>::type(),
512                typename __make_tuple_indices<sizeof...(_Args2) >::type()) {}
513
514    _LIBCPP_INLINE_VISIBILITY
515    pair& operator=(typename conditional<
516                        is_copy_assignable<first_type>::value &&
517                        is_copy_assignable<second_type>::value,
518                    pair, __nat>::type const& __p)
519        _NOEXCEPT_(is_nothrow_copy_assignable<first_type>::value &&
520                   is_nothrow_copy_assignable<second_type>::value)
521    {
522        first = __p.first;
523        second = __p.second;
524        return *this;
525    }
526
527    _LIBCPP_INLINE_VISIBILITY
528    pair& operator=(typename conditional<
529                        is_move_assignable<first_type>::value &&
530                        is_move_assignable<second_type>::value,
531                    pair, __nat>::type&& __p)
532        _NOEXCEPT_(is_nothrow_move_assignable<first_type>::value &&
533                   is_nothrow_move_assignable<second_type>::value)
534    {
535        first = _VSTD::forward<first_type>(__p.first);
536        second = _VSTD::forward<second_type>(__p.second);
537        return *this;
538    }
539
540    template <class _Tuple, _EnableB<
541            _CheckTLC<_Tuple>::template __enable_assign<_Tuple>()
542     > = false>
543    _LIBCPP_INLINE_VISIBILITY
544    pair& operator=(_Tuple&& __p) {
545        first = _VSTD::get<0>(_VSTD::forward<_Tuple>(__p));
546        second = _VSTD::get<1>(_VSTD::forward<_Tuple>(__p));
547        return *this;
548    }
549#endif
550
551    _LIBCPP_INLINE_VISIBILITY
552    void
553    swap(pair& __p) _NOEXCEPT_(__is_nothrow_swappable<first_type>::value &&
554                               __is_nothrow_swappable<second_type>::value)
555    {
556        using _VSTD::swap;
557        swap(first,  __p.first);
558        swap(second, __p.second);
559    }
560private:
561
562#ifndef _LIBCPP_CXX03_LANG
563    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
564        _LIBCPP_INLINE_VISIBILITY
565        pair(piecewise_construct_t,
566             tuple<_Args1...>& __first_args, tuple<_Args2...>& __second_args,
567             __tuple_indices<_I1...>, __tuple_indices<_I2...>);
568#endif
569};
570
571#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
572template<class _T1, class _T2>
573pair(_T1, _T2) -> pair<_T1, _T2>;
574#endif // _LIBCPP_HAS_NO_DEDUCTION_GUIDES
575
576template <class _T1, class _T2>
577inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
578bool
579operator==(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
580{
581    return __x.first == __y.first && __x.second == __y.second;
582}
583
584template <class _T1, class _T2>
585inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
586bool
587operator!=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
588{
589    return !(__x == __y);
590}
591
592template <class _T1, class _T2>
593inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
594bool
595operator< (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
596{
597    return __x.first < __y.first || (!(__y.first < __x.first) && __x.second < __y.second);
598}
599
600template <class _T1, class _T2>
601inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
602bool
603operator> (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
604{
605    return __y < __x;
606}
607
608template <class _T1, class _T2>
609inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
610bool
611operator>=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
612{
613    return !(__x < __y);
614}
615
616template <class _T1, class _T2>
617inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
618bool
619operator<=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
620{
621    return !(__y < __x);
622}
623
624template <class _T1, class _T2>
625inline _LIBCPP_INLINE_VISIBILITY
626typename enable_if
627<
628    __is_swappable<_T1>::value &&
629    __is_swappable<_T2>::value,
630    void
631>::type
632swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)
633                     _NOEXCEPT_((__is_nothrow_swappable<_T1>::value &&
634                                 __is_nothrow_swappable<_T2>::value))
635{
636    __x.swap(__y);
637}
638
639template <class _Tp>
640struct __unwrap_reference { typedef _LIBCPP_NODEBUG_TYPE _Tp type; };
641
642template <class _Tp>
643struct __unwrap_reference<reference_wrapper<_Tp> > { typedef _LIBCPP_NODEBUG_TYPE _Tp& type; };
644
645#if _LIBCPP_STD_VER > 17
646template <class _Tp>
647struct unwrap_reference : __unwrap_reference<_Tp> { };
648
649template <class _Tp>
650struct unwrap_ref_decay : unwrap_reference<typename decay<_Tp>::type> { };
651#endif // > C++17
652
653template <class _Tp>
654struct __unwrap_ref_decay
655#if _LIBCPP_STD_VER > 17
656    : unwrap_ref_decay<_Tp>
657#else
658    : __unwrap_reference<typename decay<_Tp>::type>
659#endif
660{ };
661
662#ifndef _LIBCPP_CXX03_LANG
663
664template <class _T1, class _T2>
665inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
666pair<typename __unwrap_ref_decay<_T1>::type, typename __unwrap_ref_decay<_T2>::type>
667make_pair(_T1&& __t1, _T2&& __t2)
668{
669    return pair<typename __unwrap_ref_decay<_T1>::type, typename __unwrap_ref_decay<_T2>::type>
670               (_VSTD::forward<_T1>(__t1), _VSTD::forward<_T2>(__t2));
671}
672
673#else  // _LIBCPP_CXX03_LANG
674
675template <class _T1, class _T2>
676inline _LIBCPP_INLINE_VISIBILITY
677pair<_T1,_T2>
678make_pair(_T1 __x, _T2 __y)
679{
680    return pair<_T1, _T2>(__x, __y);
681}
682
683#endif  // _LIBCPP_CXX03_LANG
684
685template <class _T1, class _T2>
686  struct _LIBCPP_TEMPLATE_VIS tuple_size<pair<_T1, _T2> >
687    : public integral_constant<size_t, 2> {};
688
689template <size_t _Ip, class _T1, class _T2>
690struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, pair<_T1, _T2> >
691{
692    static_assert(_Ip < 2, "Index out of bounds in std::tuple_element<std::pair<T1, T2>>");
693};
694
695template <class _T1, class _T2>
696struct _LIBCPP_TEMPLATE_VIS tuple_element<0, pair<_T1, _T2> >
697{
698    typedef _LIBCPP_NODEBUG_TYPE _T1 type;
699};
700
701template <class _T1, class _T2>
702struct _LIBCPP_TEMPLATE_VIS tuple_element<1, pair<_T1, _T2> >
703{
704    typedef _LIBCPP_NODEBUG_TYPE _T2 type;
705};
706
707template <size_t _Ip> struct __get_pair;
708
709template <>
710struct __get_pair<0>
711{
712    template <class _T1, class _T2>
713    static
714    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
715    _T1&
716    get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
717
718    template <class _T1, class _T2>
719    static
720    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
721    const _T1&
722    get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
723
724#ifndef _LIBCPP_CXX03_LANG
725    template <class _T1, class _T2>
726    static
727    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
728    _T1&&
729    get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T1>(__p.first);}
730
731    template <class _T1, class _T2>
732    static
733    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
734    const _T1&&
735    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T1>(__p.first);}
736#endif  // _LIBCPP_CXX03_LANG
737};
738
739template <>
740struct __get_pair<1>
741{
742    template <class _T1, class _T2>
743    static
744    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
745    _T2&
746    get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
747
748    template <class _T1, class _T2>
749    static
750    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
751    const _T2&
752    get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
753
754#ifndef _LIBCPP_CXX03_LANG
755    template <class _T1, class _T2>
756    static
757    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
758    _T2&&
759    get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T2>(__p.second);}
760
761    template <class _T1, class _T2>
762    static
763    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
764    const _T2&&
765    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T2>(__p.second);}
766#endif  // _LIBCPP_CXX03_LANG
767};
768
769template <size_t _Ip, class _T1, class _T2>
770inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
771typename tuple_element<_Ip, pair<_T1, _T2> >::type&
772get(pair<_T1, _T2>& __p) _NOEXCEPT
773{
774    return __get_pair<_Ip>::get(__p);
775}
776
777template <size_t _Ip, class _T1, class _T2>
778inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
779const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
780get(const pair<_T1, _T2>& __p) _NOEXCEPT
781{
782    return __get_pair<_Ip>::get(__p);
783}
784
785#ifndef _LIBCPP_CXX03_LANG
786template <size_t _Ip, class _T1, class _T2>
787inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
788typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
789get(pair<_T1, _T2>&& __p) _NOEXCEPT
790{
791    return __get_pair<_Ip>::get(_VSTD::move(__p));
792}
793
794template <size_t _Ip, class _T1, class _T2>
795inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
796const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
797get(const pair<_T1, _T2>&& __p) _NOEXCEPT
798{
799    return __get_pair<_Ip>::get(_VSTD::move(__p));
800}
801#endif  // _LIBCPP_CXX03_LANG
802
803#if _LIBCPP_STD_VER > 11
804template <class _T1, class _T2>
805inline _LIBCPP_INLINE_VISIBILITY
806constexpr _T1 & get(pair<_T1, _T2>& __p) _NOEXCEPT
807{
808    return __get_pair<0>::get(__p);
809}
810
811template <class _T1, class _T2>
812inline _LIBCPP_INLINE_VISIBILITY
813constexpr _T1 const & get(pair<_T1, _T2> const& __p) _NOEXCEPT
814{
815    return __get_pair<0>::get(__p);
816}
817
818template <class _T1, class _T2>
819inline _LIBCPP_INLINE_VISIBILITY
820constexpr _T1 && get(pair<_T1, _T2>&& __p) _NOEXCEPT
821{
822    return __get_pair<0>::get(_VSTD::move(__p));
823}
824
825template <class _T1, class _T2>
826inline _LIBCPP_INLINE_VISIBILITY
827constexpr _T1 const && get(pair<_T1, _T2> const&& __p) _NOEXCEPT
828{
829    return __get_pair<0>::get(_VSTD::move(__p));
830}
831
832template <class _T1, class _T2>
833inline _LIBCPP_INLINE_VISIBILITY
834constexpr _T1 & get(pair<_T2, _T1>& __p) _NOEXCEPT
835{
836    return __get_pair<1>::get(__p);
837}
838
839template <class _T1, class _T2>
840inline _LIBCPP_INLINE_VISIBILITY
841constexpr _T1 const & get(pair<_T2, _T1> const& __p) _NOEXCEPT
842{
843    return __get_pair<1>::get(__p);
844}
845
846template <class _T1, class _T2>
847inline _LIBCPP_INLINE_VISIBILITY
848constexpr _T1 && get(pair<_T2, _T1>&& __p) _NOEXCEPT
849{
850    return __get_pair<1>::get(_VSTD::move(__p));
851}
852
853template <class _T1, class _T2>
854inline _LIBCPP_INLINE_VISIBILITY
855constexpr _T1 const && get(pair<_T2, _T1> const&& __p) _NOEXCEPT
856{
857    return __get_pair<1>::get(_VSTD::move(__p));
858}
859
860#endif
861
862#if _LIBCPP_STD_VER > 11
863
864template<class _Tp, _Tp... _Ip>
865struct _LIBCPP_TEMPLATE_VIS integer_sequence
866{
867    typedef _Tp value_type;
868    static_assert( is_integral<_Tp>::value,
869                  "std::integer_sequence can only be instantiated with an integral type" );
870    static
871    _LIBCPP_INLINE_VISIBILITY
872    constexpr
873    size_t
874    size() noexcept { return sizeof...(_Ip); }
875};
876
877template<size_t... _Ip>
878    using index_sequence = integer_sequence<size_t, _Ip...>;
879
880#if __has_builtin(__make_integer_seq) && !defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)
881
882template <class _Tp, _Tp _Ep>
883using __make_integer_sequence _LIBCPP_NODEBUG_TYPE = __make_integer_seq<integer_sequence, _Tp, _Ep>;
884
885#else
886
887template<typename _Tp, _Tp _Np> using __make_integer_sequence_unchecked _LIBCPP_NODEBUG_TYPE  =
888  typename __detail::__make<_Np>::type::template __convert<integer_sequence, _Tp>;
889
890template <class _Tp, _Tp _Ep>
891struct __make_integer_sequence_checked
892{
893    static_assert(is_integral<_Tp>::value,
894                  "std::make_integer_sequence can only be instantiated with an integral type" );
895    static_assert(0 <= _Ep, "std::make_integer_sequence must have a non-negative sequence length");
896    // Workaround GCC bug by preventing bad installations when 0 <= _Ep
897    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68929
898    typedef _LIBCPP_NODEBUG_TYPE  __make_integer_sequence_unchecked<_Tp, 0 <= _Ep ? _Ep : 0> type;
899};
900
901template <class _Tp, _Tp _Ep>
902using __make_integer_sequence _LIBCPP_NODEBUG_TYPE = typename __make_integer_sequence_checked<_Tp, _Ep>::type;
903
904#endif
905
906template<class _Tp, _Tp _Np>
907    using make_integer_sequence = __make_integer_sequence<_Tp, _Np>;
908
909template<size_t _Np>
910    using make_index_sequence = make_integer_sequence<size_t, _Np>;
911
912template<class... _Tp>
913    using index_sequence_for = make_index_sequence<sizeof...(_Tp)>;
914
915#endif  // _LIBCPP_STD_VER > 11
916
917#if _LIBCPP_STD_VER > 11
918template<class _T1, class _T2 = _T1>
919inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
920_T1 exchange(_T1& __obj, _T2 && __new_value)
921{
922    _T1 __old_value = _VSTD::move(__obj);
923    __obj = _VSTD::forward<_T2>(__new_value);
924    return __old_value;
925}
926#endif  // _LIBCPP_STD_VER > 11
927
928#if _LIBCPP_STD_VER > 14
929
930struct _LIBCPP_TYPE_VIS in_place_t {
931    explicit in_place_t() = default;
932};
933_LIBCPP_INLINE_VAR constexpr in_place_t in_place{};
934
935template <class _Tp>
936struct _LIBCPP_TEMPLATE_VIS in_place_type_t {
937    explicit in_place_type_t() = default;
938};
939template <class _Tp>
940_LIBCPP_INLINE_VAR constexpr in_place_type_t<_Tp> in_place_type{};
941
942template <size_t _Idx>
943struct _LIBCPP_TYPE_VIS in_place_index_t {
944    explicit in_place_index_t() = default;
945};
946template <size_t _Idx>
947_LIBCPP_INLINE_VAR constexpr in_place_index_t<_Idx> in_place_index{};
948
949template <class _Tp> struct __is_inplace_type_imp : false_type {};
950template <class _Tp> struct __is_inplace_type_imp<in_place_type_t<_Tp>> : true_type {};
951
952template <class _Tp>
953using __is_inplace_type = __is_inplace_type_imp<__uncvref_t<_Tp>>;
954
955template <class _Tp> struct __is_inplace_index_imp : false_type {};
956template <size_t _Idx> struct __is_inplace_index_imp<in_place_index_t<_Idx>> : true_type {};
957
958template <class _Tp>
959using __is_inplace_index = __is_inplace_index_imp<__uncvref_t<_Tp>>;
960
961#endif // _LIBCPP_STD_VER > 14
962
963template <class _Arg, class _Result>
964struct _LIBCPP_TEMPLATE_VIS unary_function
965{
966    typedef _Arg    argument_type;
967    typedef _Result result_type;
968};
969
970template <class _Size>
971inline _LIBCPP_INLINE_VISIBILITY
972_Size
973__loadword(const void* __p)
974{
975    _Size __r;
976    std::memcpy(&__r, __p, sizeof(__r));
977    return __r;
978}
979
980// We use murmur2 when size_t is 32 bits, and cityhash64 when size_t
981// is 64 bits.  This is because cityhash64 uses 64bit x 64bit
982// multiplication, which can be very slow on 32-bit systems.
983template <class _Size, size_t = sizeof(_Size)*__CHAR_BIT__>
984struct __murmur2_or_cityhash;
985
986template <class _Size>
987struct __murmur2_or_cityhash<_Size, 32>
988{
989    inline _Size operator()(const void* __key, _Size __len)
990         _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK;
991};
992
993// murmur2
994template <class _Size>
995_Size
996__murmur2_or_cityhash<_Size, 32>::operator()(const void* __key, _Size __len)
997{
998    const _Size __m = 0x5bd1e995;
999    const _Size __r = 24;
1000    _Size __h = __len;
1001    const unsigned char* __data = static_cast<const unsigned char*>(__key);
1002    for (; __len >= 4; __data += 4, __len -= 4)
1003    {
1004        _Size __k = __loadword<_Size>(__data);
1005        __k *= __m;
1006        __k ^= __k >> __r;
1007        __k *= __m;
1008        __h *= __m;
1009        __h ^= __k;
1010    }
1011    switch (__len)
1012    {
1013    case 3:
1014        __h ^= __data[2] << 16;
1015        _LIBCPP_FALLTHROUGH();
1016    case 2:
1017        __h ^= __data[1] << 8;
1018        _LIBCPP_FALLTHROUGH();
1019    case 1:
1020        __h ^= __data[0];
1021        __h *= __m;
1022    }
1023    __h ^= __h >> 13;
1024    __h *= __m;
1025    __h ^= __h >> 15;
1026    return __h;
1027}
1028
1029template <class _Size>
1030struct __murmur2_or_cityhash<_Size, 64>
1031{
1032    inline _Size operator()(const void* __key, _Size __len)  _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK;
1033
1034 private:
1035  // Some primes between 2^63 and 2^64.
1036  static const _Size __k0 = 0xc3a5c85c97cb3127ULL;
1037  static const _Size __k1 = 0xb492b66fbe98f273ULL;
1038  static const _Size __k2 = 0x9ae16a3b2f90404fULL;
1039  static const _Size __k3 = 0xc949d7c7509e6557ULL;
1040
1041  static _Size __rotate(_Size __val, int __shift) {
1042    return __shift == 0 ? __val : ((__val >> __shift) | (__val << (64 - __shift)));
1043  }
1044
1045  static _Size __rotate_by_at_least_1(_Size __val, int __shift) {
1046    return (__val >> __shift) | (__val << (64 - __shift));
1047  }
1048
1049  static _Size __shift_mix(_Size __val) {
1050    return __val ^ (__val >> 47);
1051  }
1052
1053  static _Size __hash_len_16(_Size __u, _Size __v)
1054     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1055  {
1056    const _Size __mul = 0x9ddfea08eb382d69ULL;
1057    _Size __a = (__u ^ __v) * __mul;
1058    __a ^= (__a >> 47);
1059    _Size __b = (__v ^ __a) * __mul;
1060    __b ^= (__b >> 47);
1061    __b *= __mul;
1062    return __b;
1063  }
1064
1065  static _Size __hash_len_0_to_16(const char* __s, _Size __len)
1066     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1067  {
1068    if (__len > 8) {
1069      const _Size __a = __loadword<_Size>(__s);
1070      const _Size __b = __loadword<_Size>(__s + __len - 8);
1071      return __hash_len_16(__a, __rotate_by_at_least_1(__b + __len, __len)) ^ __b;
1072    }
1073    if (__len >= 4) {
1074      const uint32_t __a = __loadword<uint32_t>(__s);
1075      const uint32_t __b = __loadword<uint32_t>(__s + __len - 4);
1076      return __hash_len_16(__len + (__a << 3), __b);
1077    }
1078    if (__len > 0) {
1079      const unsigned char __a = __s[0];
1080      const unsigned char __b = __s[__len >> 1];
1081      const unsigned char __c = __s[__len - 1];
1082      const uint32_t __y = static_cast<uint32_t>(__a) +
1083                           (static_cast<uint32_t>(__b) << 8);
1084      const uint32_t __z = __len + (static_cast<uint32_t>(__c) << 2);
1085      return __shift_mix(__y * __k2 ^ __z * __k3) * __k2;
1086    }
1087    return __k2;
1088  }
1089
1090  static _Size __hash_len_17_to_32(const char *__s, _Size __len)
1091     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1092  {
1093    const _Size __a = __loadword<_Size>(__s) * __k1;
1094    const _Size __b = __loadword<_Size>(__s + 8);
1095    const _Size __c = __loadword<_Size>(__s + __len - 8) * __k2;
1096    const _Size __d = __loadword<_Size>(__s + __len - 16) * __k0;
1097    return __hash_len_16(__rotate(__a - __b, 43) + __rotate(__c, 30) + __d,
1098                         __a + __rotate(__b ^ __k3, 20) - __c + __len);
1099  }
1100
1101  // Return a 16-byte hash for 48 bytes.  Quick and dirty.
1102  // Callers do best to use "random-looking" values for a and b.
1103  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
1104      _Size __w, _Size __x, _Size __y, _Size __z, _Size __a, _Size __b)
1105        _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1106  {
1107    __a += __w;
1108    __b = __rotate(__b + __a + __z, 21);
1109    const _Size __c = __a;
1110    __a += __x;
1111    __a += __y;
1112    __b += __rotate(__a, 44);
1113    return pair<_Size, _Size>(__a + __z, __b + __c);
1114  }
1115
1116  // Return a 16-byte hash for s[0] ... s[31], a, and b.  Quick and dirty.
1117  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
1118      const char* __s, _Size __a, _Size __b)
1119    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1120  {
1121    return __weak_hash_len_32_with_seeds(__loadword<_Size>(__s),
1122                                         __loadword<_Size>(__s + 8),
1123                                         __loadword<_Size>(__s + 16),
1124                                         __loadword<_Size>(__s + 24),
1125                                         __a,
1126                                         __b);
1127  }
1128
1129  // Return an 8-byte hash for 33 to 64 bytes.
1130  static _Size __hash_len_33_to_64(const char *__s, size_t __len)
1131    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1132  {
1133    _Size __z = __loadword<_Size>(__s + 24);
1134    _Size __a = __loadword<_Size>(__s) +
1135                (__len + __loadword<_Size>(__s + __len - 16)) * __k0;
1136    _Size __b = __rotate(__a + __z, 52);
1137    _Size __c = __rotate(__a, 37);
1138    __a += __loadword<_Size>(__s + 8);
1139    __c += __rotate(__a, 7);
1140    __a += __loadword<_Size>(__s + 16);
1141    _Size __vf = __a + __z;
1142    _Size __vs = __b + __rotate(__a, 31) + __c;
1143    __a = __loadword<_Size>(__s + 16) + __loadword<_Size>(__s + __len - 32);
1144    __z += __loadword<_Size>(__s + __len - 8);
1145    __b = __rotate(__a + __z, 52);
1146    __c = __rotate(__a, 37);
1147    __a += __loadword<_Size>(__s + __len - 24);
1148    __c += __rotate(__a, 7);
1149    __a += __loadword<_Size>(__s + __len - 16);
1150    _Size __wf = __a + __z;
1151    _Size __ws = __b + __rotate(__a, 31) + __c;
1152    _Size __r = __shift_mix((__vf + __ws) * __k2 + (__wf + __vs) * __k0);
1153    return __shift_mix(__r * __k0 + __vs) * __k2;
1154  }
1155};
1156
1157// cityhash64
1158template <class _Size>
1159_Size
1160__murmur2_or_cityhash<_Size, 64>::operator()(const void* __key, _Size __len)
1161{
1162  const char* __s = static_cast<const char*>(__key);
1163  if (__len <= 32) {
1164    if (__len <= 16) {
1165      return __hash_len_0_to_16(__s, __len);
1166    } else {
1167      return __hash_len_17_to_32(__s, __len);
1168    }
1169  } else if (__len <= 64) {
1170    return __hash_len_33_to_64(__s, __len);
1171  }
1172
1173  // For strings over 64 bytes we hash the end first, and then as we
1174  // loop we keep 56 bytes of state: v, w, x, y, and z.
1175  _Size __x = __loadword<_Size>(__s + __len - 40);
1176  _Size __y = __loadword<_Size>(__s + __len - 16) +
1177              __loadword<_Size>(__s + __len - 56);
1178  _Size __z = __hash_len_16(__loadword<_Size>(__s + __len - 48) + __len,
1179                          __loadword<_Size>(__s + __len - 24));
1180  pair<_Size, _Size> __v = __weak_hash_len_32_with_seeds(__s + __len - 64, __len, __z);
1181  pair<_Size, _Size> __w = __weak_hash_len_32_with_seeds(__s + __len - 32, __y + __k1, __x);
1182  __x = __x * __k1 + __loadword<_Size>(__s);
1183
1184  // Decrease len to the nearest multiple of 64, and operate on 64-byte chunks.
1185  __len = (__len - 1) & ~static_cast<_Size>(63);
1186  do {
1187    __x = __rotate(__x + __y + __v.first + __loadword<_Size>(__s + 8), 37) * __k1;
1188    __y = __rotate(__y + __v.second + __loadword<_Size>(__s + 48), 42) * __k1;
1189    __x ^= __w.second;
1190    __y += __v.first + __loadword<_Size>(__s + 40);
1191    __z = __rotate(__z + __w.first, 33) * __k1;
1192    __v = __weak_hash_len_32_with_seeds(__s, __v.second * __k1, __x + __w.first);
1193    __w = __weak_hash_len_32_with_seeds(__s + 32, __z + __w.second,
1194                                        __y + __loadword<_Size>(__s + 16));
1195    std::swap(__z, __x);
1196    __s += 64;
1197    __len -= 64;
1198  } while (__len != 0);
1199  return __hash_len_16(
1200      __hash_len_16(__v.first, __w.first) + __shift_mix(__y) * __k1 + __z,
1201      __hash_len_16(__v.second, __w.second) + __x);
1202}
1203
1204template <class _Tp, size_t = sizeof(_Tp) / sizeof(size_t)>
1205struct __scalar_hash;
1206
1207template <class _Tp>
1208struct __scalar_hash<_Tp, 0>
1209    : public unary_function<_Tp, size_t>
1210{
1211    _LIBCPP_INLINE_VISIBILITY
1212    size_t operator()(_Tp __v) const _NOEXCEPT
1213    {
1214        union
1215        {
1216            _Tp    __t;
1217            size_t __a;
1218        } __u;
1219        __u.__a = 0;
1220        __u.__t = __v;
1221        return __u.__a;
1222    }
1223};
1224
1225template <class _Tp>
1226struct __scalar_hash<_Tp, 1>
1227    : public unary_function<_Tp, size_t>
1228{
1229    _LIBCPP_INLINE_VISIBILITY
1230    size_t operator()(_Tp __v) const _NOEXCEPT
1231    {
1232        union
1233        {
1234            _Tp    __t;
1235            size_t __a;
1236        } __u;
1237        __u.__t = __v;
1238        return __u.__a;
1239    }
1240};
1241
1242template <class _Tp>
1243struct __scalar_hash<_Tp, 2>
1244    : public unary_function<_Tp, size_t>
1245{
1246    _LIBCPP_INLINE_VISIBILITY
1247    size_t operator()(_Tp __v) const _NOEXCEPT
1248    {
1249        union
1250        {
1251            _Tp __t;
1252            struct
1253            {
1254                size_t __a;
1255                size_t __b;
1256            } __s;
1257        } __u;
1258        __u.__t = __v;
1259        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1260    }
1261};
1262
1263template <class _Tp>
1264struct __scalar_hash<_Tp, 3>
1265    : public unary_function<_Tp, size_t>
1266{
1267    _LIBCPP_INLINE_VISIBILITY
1268    size_t operator()(_Tp __v) const _NOEXCEPT
1269    {
1270        union
1271        {
1272            _Tp __t;
1273            struct
1274            {
1275                size_t __a;
1276                size_t __b;
1277                size_t __c;
1278            } __s;
1279        } __u;
1280        __u.__t = __v;
1281        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1282    }
1283};
1284
1285template <class _Tp>
1286struct __scalar_hash<_Tp, 4>
1287    : public unary_function<_Tp, size_t>
1288{
1289    _LIBCPP_INLINE_VISIBILITY
1290    size_t operator()(_Tp __v) const _NOEXCEPT
1291    {
1292        union
1293        {
1294            _Tp __t;
1295            struct
1296            {
1297                size_t __a;
1298                size_t __b;
1299                size_t __c;
1300                size_t __d;
1301            } __s;
1302        } __u;
1303        __u.__t = __v;
1304        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1305    }
1306};
1307
1308struct _PairT {
1309  size_t first;
1310  size_t second;
1311};
1312
1313_LIBCPP_INLINE_VISIBILITY
1314inline size_t __hash_combine(size_t __lhs, size_t __rhs) _NOEXCEPT {
1315    typedef __scalar_hash<_PairT> _HashT;
1316    const _PairT __p = {__lhs, __rhs};
1317    return _HashT()(__p);
1318}
1319
1320template<class _Tp>
1321struct _LIBCPP_TEMPLATE_VIS hash<_Tp*>
1322    : public unary_function<_Tp*, size_t>
1323{
1324    _LIBCPP_INLINE_VISIBILITY
1325    size_t operator()(_Tp* __v) const _NOEXCEPT
1326    {
1327        union
1328        {
1329            _Tp* __t;
1330            size_t __a;
1331        } __u;
1332        __u.__t = __v;
1333        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1334    }
1335};
1336
1337
1338template <>
1339struct _LIBCPP_TEMPLATE_VIS hash<bool>
1340    : public unary_function<bool, size_t>
1341{
1342    _LIBCPP_INLINE_VISIBILITY
1343    size_t operator()(bool __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1344};
1345
1346template <>
1347struct _LIBCPP_TEMPLATE_VIS hash<char>
1348    : public unary_function<char, size_t>
1349{
1350    _LIBCPP_INLINE_VISIBILITY
1351    size_t operator()(char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1352};
1353
1354template <>
1355struct _LIBCPP_TEMPLATE_VIS hash<signed char>
1356    : public unary_function<signed char, size_t>
1357{
1358    _LIBCPP_INLINE_VISIBILITY
1359    size_t operator()(signed char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1360};
1361
1362template <>
1363struct _LIBCPP_TEMPLATE_VIS hash<unsigned char>
1364    : public unary_function<unsigned char, size_t>
1365{
1366    _LIBCPP_INLINE_VISIBILITY
1367    size_t operator()(unsigned char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1368};
1369
1370#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
1371
1372template <>
1373struct _LIBCPP_TEMPLATE_VIS hash<char16_t>
1374    : public unary_function<char16_t, size_t>
1375{
1376    _LIBCPP_INLINE_VISIBILITY
1377    size_t operator()(char16_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1378};
1379
1380template <>
1381struct _LIBCPP_TEMPLATE_VIS hash<char32_t>
1382    : public unary_function<char32_t, size_t>
1383{
1384    _LIBCPP_INLINE_VISIBILITY
1385    size_t operator()(char32_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1386};
1387
1388#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
1389
1390template <>
1391struct _LIBCPP_TEMPLATE_VIS hash<wchar_t>
1392    : public unary_function<wchar_t, size_t>
1393{
1394    _LIBCPP_INLINE_VISIBILITY
1395    size_t operator()(wchar_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1396};
1397
1398template <>
1399struct _LIBCPP_TEMPLATE_VIS hash<short>
1400    : public unary_function<short, size_t>
1401{
1402    _LIBCPP_INLINE_VISIBILITY
1403    size_t operator()(short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1404};
1405
1406template <>
1407struct _LIBCPP_TEMPLATE_VIS hash<unsigned short>
1408    : public unary_function<unsigned short, size_t>
1409{
1410    _LIBCPP_INLINE_VISIBILITY
1411    size_t operator()(unsigned short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1412};
1413
1414template <>
1415struct _LIBCPP_TEMPLATE_VIS hash<int>
1416    : public unary_function<int, size_t>
1417{
1418    _LIBCPP_INLINE_VISIBILITY
1419    size_t operator()(int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1420};
1421
1422template <>
1423struct _LIBCPP_TEMPLATE_VIS hash<unsigned int>
1424    : public unary_function<unsigned int, size_t>
1425{
1426    _LIBCPP_INLINE_VISIBILITY
1427    size_t operator()(unsigned int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1428};
1429
1430template <>
1431struct _LIBCPP_TEMPLATE_VIS hash<long>
1432    : public unary_function<long, size_t>
1433{
1434    _LIBCPP_INLINE_VISIBILITY
1435    size_t operator()(long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1436};
1437
1438template <>
1439struct _LIBCPP_TEMPLATE_VIS hash<unsigned long>
1440    : public unary_function<unsigned long, size_t>
1441{
1442    _LIBCPP_INLINE_VISIBILITY
1443    size_t operator()(unsigned long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1444};
1445
1446template <>
1447struct _LIBCPP_TEMPLATE_VIS hash<long long>
1448    : public __scalar_hash<long long>
1449{
1450};
1451
1452template <>
1453struct _LIBCPP_TEMPLATE_VIS hash<unsigned long long>
1454    : public __scalar_hash<unsigned long long>
1455{
1456};
1457
1458#ifndef _LIBCPP_HAS_NO_INT128
1459
1460template <>
1461struct _LIBCPP_TEMPLATE_VIS hash<__int128_t>
1462    : public __scalar_hash<__int128_t>
1463{
1464};
1465
1466template <>
1467struct _LIBCPP_TEMPLATE_VIS hash<__uint128_t>
1468    : public __scalar_hash<__uint128_t>
1469{
1470};
1471
1472#endif
1473
1474template <>
1475struct _LIBCPP_TEMPLATE_VIS hash<float>
1476    : public __scalar_hash<float>
1477{
1478    _LIBCPP_INLINE_VISIBILITY
1479    size_t operator()(float __v) const _NOEXCEPT
1480    {
1481        // -0.0 and 0.0 should return same hash
1482       if (__v == 0.0f)
1483           return 0;
1484        return __scalar_hash<float>::operator()(__v);
1485    }
1486};
1487
1488template <>
1489struct _LIBCPP_TEMPLATE_VIS hash<double>
1490    : public __scalar_hash<double>
1491{
1492    _LIBCPP_INLINE_VISIBILITY
1493    size_t operator()(double __v) const _NOEXCEPT
1494    {
1495        // -0.0 and 0.0 should return same hash
1496       if (__v == 0.0)
1497           return 0;
1498        return __scalar_hash<double>::operator()(__v);
1499    }
1500};
1501
1502template <>
1503struct _LIBCPP_TEMPLATE_VIS hash<long double>
1504    : public __scalar_hash<long double>
1505{
1506    _LIBCPP_INLINE_VISIBILITY
1507    size_t operator()(long double __v) const _NOEXCEPT
1508    {
1509        // -0.0 and 0.0 should return same hash
1510        if (__v == 0.0L)
1511            return 0;
1512#if defined(__i386__)
1513        // Zero out padding bits
1514        union
1515        {
1516            long double __t;
1517            struct
1518            {
1519                size_t __a;
1520                size_t __b;
1521                size_t __c;
1522                size_t __d;
1523            } __s;
1524        } __u;
1525        __u.__s.__a = 0;
1526        __u.__s.__b = 0;
1527        __u.__s.__c = 0;
1528        __u.__s.__d = 0;
1529        __u.__t = __v;
1530        return __u.__s.__a ^ __u.__s.__b ^ __u.__s.__c ^ __u.__s.__d;
1531#elif defined(__x86_64__)
1532        // Zero out padding bits
1533        union
1534        {
1535            long double __t;
1536            struct
1537            {
1538                size_t __a;
1539                size_t __b;
1540            } __s;
1541        } __u;
1542        __u.__s.__a = 0;
1543        __u.__s.__b = 0;
1544        __u.__t = __v;
1545        return __u.__s.__a ^ __u.__s.__b;
1546#else
1547        return __scalar_hash<long double>::operator()(__v);
1548#endif
1549    }
1550};
1551
1552#if _LIBCPP_STD_VER > 11
1553
1554template <class _Tp, bool = is_enum<_Tp>::value>
1555struct _LIBCPP_TEMPLATE_VIS __enum_hash
1556    : public unary_function<_Tp, size_t>
1557{
1558    _LIBCPP_INLINE_VISIBILITY
1559    size_t operator()(_Tp __v) const _NOEXCEPT
1560    {
1561        typedef typename underlying_type<_Tp>::type type;
1562        return hash<type>{}(static_cast<type>(__v));
1563    }
1564};
1565template <class _Tp>
1566struct _LIBCPP_TEMPLATE_VIS __enum_hash<_Tp, false> {
1567    __enum_hash() = delete;
1568    __enum_hash(__enum_hash const&) = delete;
1569    __enum_hash& operator=(__enum_hash const&) = delete;
1570};
1571
1572template <class _Tp>
1573struct _LIBCPP_TEMPLATE_VIS hash : public __enum_hash<_Tp>
1574{
1575};
1576#endif
1577
1578#if _LIBCPP_STD_VER > 14
1579
1580template <>
1581struct _LIBCPP_TEMPLATE_VIS hash<nullptr_t>
1582  : public unary_function<nullptr_t, size_t>
1583{
1584  _LIBCPP_INLINE_VISIBILITY
1585  size_t operator()(nullptr_t) const _NOEXCEPT {
1586    return 662607004ull;
1587  }
1588};
1589#endif
1590
1591#ifndef _LIBCPP_CXX03_LANG
1592template <class _Key, class _Hash>
1593using __check_hash_requirements _LIBCPP_NODEBUG_TYPE  = integral_constant<bool,
1594    is_copy_constructible<_Hash>::value &&
1595    is_move_constructible<_Hash>::value &&
1596    __invokable_r<size_t, _Hash, _Key const&>::value
1597>;
1598
1599template <class _Key, class _Hash = std::hash<_Key> >
1600using __has_enabled_hash _LIBCPP_NODEBUG_TYPE = integral_constant<bool,
1601    __check_hash_requirements<_Key, _Hash>::value &&
1602    is_default_constructible<_Hash>::value
1603>;
1604
1605#if _LIBCPP_STD_VER > 14
1606template <class _Type, class>
1607using __enable_hash_helper_imp _LIBCPP_NODEBUG_TYPE  = _Type;
1608
1609template <class _Type, class ..._Keys>
1610using __enable_hash_helper _LIBCPP_NODEBUG_TYPE  = __enable_hash_helper_imp<_Type,
1611  typename enable_if<__all<__has_enabled_hash<_Keys>::value...>::value>::type
1612>;
1613#else
1614template <class _Type, class ...>
1615using __enable_hash_helper _LIBCPP_NODEBUG_TYPE = _Type;
1616#endif
1617
1618#endif // !_LIBCPP_CXX03_LANG
1619
1620_LIBCPP_END_NAMESPACE_STD
1621
1622#endif  // _LIBCPP_UTILITY
1623