• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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
17#include <initializer_list>
18
19namespace std
20{
21
22template <class T>
23    void
24    swap(T& a, T& b);
25
26namespace rel_ops
27{
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    template<class T> bool operator>=(const T&, const T&);
32}
33
34template<class T>
35void
36swap(T& a, T& b) noexcept(is_nothrow_move_constructible<T>::value &&
37                          is_nothrow_move_assignable<T>::value);
38
39template <class T, size_t N>
40void
41swap(T (&a)[N], T (&b)[N]) noexcept(noexcept(swap(*a, *b)));
42
43template <class T> T&& forward(typename remove_reference<T>::type& t) noexcept;  // constexpr in C++14
44template <class T> T&& forward(typename remove_reference<T>::type&& t) noexcept; // constexpr in C++14
45
46template <class T> typename remove_reference<T>::type&& move(T&&) noexcept;      // constexpr in C++14
47
48template <class T>
49    typename conditional
50    <
51        !is_nothrow_move_constructible<T>::value && is_copy_constructible<T>::value,
52        const T&,
53        T&&
54    >::type
55    move_if_noexcept(T& x) noexcept; // constexpr in C++14
56
57template <class T> constexpr add_const_t<T>& as_const(T& t) noexcept;      // C++17
58template <class T>                      void as_const(const T&&) = delete; // C++17
59
60template <class T> typename add_rvalue_reference<T>::type declval() noexcept;
61
62template <class T1, class T2>
63struct pair
64{
65    typedef T1 first_type;
66    typedef T2 second_type;
67
68    T1 first;
69    T2 second;
70
71    pair(const pair&) = default;
72    pair(pair&&) = default;
73    constexpr pair();
74    pair(const T1& x, const T2& y);                          // constexpr in C++14
75    template <class U, class V> pair(U&& x, V&& y);          // constexpr in C++14
76    template <class U, class V> pair(const pair<U, V>& p);   // constexpr in C++14
77    template <class U, class V> pair(pair<U, V>&& p);        // constexpr in C++14
78    template <class... Args1, class... Args2>
79        pair(piecewise_construct_t, tuple<Args1...> first_args,
80             tuple<Args2...> second_args);
81
82    template <class U, class V> pair& operator=(const pair<U, V>& p);
83    pair& operator=(pair&& p) noexcept(is_nothrow_move_assignable<T1>::value &&
84                                       is_nothrow_move_assignable<T2>::value);
85    template <class U, class V> pair& operator=(pair<U, V>&& p);
86
87    void swap(pair& p) noexcept(is_nothrow_swappable_v<T1> &&
88                                is_nothrow_swappable_v<T2>);
89};
90
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
96template <class T1, class T2> bool operator<=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
97
98template <class T1, class T2> pair<V1, V2> make_pair(T1&&, T2&&);   // constexpr in C++14
99template <class T1, class T2>
100void
101swap(pair<T1, T2>& x, pair<T1, T2>& y) noexcept(noexcept(x.swap(y)));
102
103struct piecewise_construct_t { };
104inline constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
105
106template <class T> struct tuple_size;
107template <size_t I, class T> class tuple_element;
108
109template <class T1, class T2> struct tuple_size<pair<T1, T2> >;
110template <class T1, class T2> struct tuple_element<0, pair<T1, T2> >;
111template <class T1, class T2> struct tuple_element<1, pair<T1, T2> >;
112
113template<size_t I, class T1, class T2>
114    typename tuple_element<I, pair<T1, T2> >::type&
115    get(pair<T1, T2>&) noexcept; // constexpr in C++14
116
117template<size_t I, class T1, class T2>
118    const typename tuple_element<I, pair<T1, T2> >::type&
119    get(const pair<T1, T2>&) noexcept; // constexpr in C++14
120
121template<size_t I, class T1, class T2>
122    typename tuple_element<I, pair<T1, T2> >::type&&
123    get(pair<T1, T2>&&) noexcept; // constexpr in C++14
124
125template<size_t I, class T1, class T2>
126    const typename tuple_element<I, pair<T1, T2> >::type&&
127    get(const pair<T1, T2>&&) noexcept; // constexpr in C++14
128
129template<class T1, class T2>
130    constexpr T1& get(pair<T1, T2>&) noexcept; // C++14
131
132template<class T1, class T2>
133    constexpr const T1& get(const pair<T1, T2>&) noexcept; // C++14
134
135template<class T1, class T2>
136    constexpr T1&& get(pair<T1, T2>&&) noexcept; // C++14
137
138template<class T1, class T2>
139    constexpr const T1&& get(const pair<T1, T2>&&) noexcept; // C++14
140
141template<class T1, class T2>
142    constexpr T1& get(pair<T2, T1>&) noexcept; // C++14
143
144template<class T1, class T2>
145    constexpr const T1& get(const pair<T2, T1>&) noexcept; // C++14
146
147template<class T1, class T2>
148    constexpr T1&& get(pair<T2, T1>&&) noexcept; // C++14
149
150template<class T1, class T2>
151    constexpr const T1&& get(const pair<T2, T1>&&) noexcept; // C++14
152
153// C++14
154
155template<class T, T... I>
156struct integer_sequence
157{
158    typedef T value_type;
159
160    static constexpr size_t size() noexcept;
161};
162
163template<size_t... I>
164  using index_sequence = integer_sequence<size_t, I...>;
165
166template<class T, T N>
167  using make_integer_sequence = integer_sequence<T, 0, 1, ..., N-1>;
168template<size_t N>
169  using make_index_sequence = make_integer_sequence<size_t, N>;
170
171template<class... T>
172  using index_sequence_for = make_index_sequence<sizeof...(T)>;
173
174template<class T, class U=T>
175    T exchange(T& obj, U&& new_value);
176
177// 20.2.7, in-place construction // C++17
178struct in_place_t {
179  explicit in_place_t() = default;
180};
181inline constexpr in_place_t in_place{};
182template <class T>
183  struct in_place_type_t {
184    explicit in_place_type_t() = default;
185  };
186template <class T>
187  inline constexpr in_place_type_t<T> in_place_type{};
188template <size_t I>
189  struct in_place_index_t {
190    explicit in_place_index_t() = default;
191  };
192template <size_t I>
193  inline constexpr in_place_index_t<I> in_place_index{};
194
195}  // std
196
197*/
198
199#include <__config>
200#include <__tuple>
201#include <type_traits>
202#include <initializer_list>
203#include <cstddef>
204#include <cstring>
205#include <cstdint>
206#include <version>
207#include <__debug>
208
209#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
210#pragma GCC system_header
211#endif
212
213_LIBCPP_BEGIN_NAMESPACE_STD
214
215namespace rel_ops
216{
217
218template<class _Tp>
219inline _LIBCPP_INLINE_VISIBILITY
220bool
221operator!=(const _Tp& __x, const _Tp& __y)
222{
223    return !(__x == __y);
224}
225
226template<class _Tp>
227inline _LIBCPP_INLINE_VISIBILITY
228bool
229operator> (const _Tp& __x, const _Tp& __y)
230{
231    return __y < __x;
232}
233
234template<class _Tp>
235inline _LIBCPP_INLINE_VISIBILITY
236bool
237operator<=(const _Tp& __x, const _Tp& __y)
238{
239    return !(__y < __x);
240}
241
242template<class _Tp>
243inline _LIBCPP_INLINE_VISIBILITY
244bool
245operator>=(const _Tp& __x, const _Tp& __y)
246{
247    return !(__x < __y);
248}
249
250}  // rel_ops
251
252// swap_ranges
253
254
255template <class _ForwardIterator1, class _ForwardIterator2>
256inline _LIBCPP_INLINE_VISIBILITY
257_ForwardIterator2
258swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2)
259{
260    for(; __first1 != __last1; ++__first1, (void) ++__first2)
261        swap(*__first1, *__first2);
262    return __first2;
263}
264
265// forward declared in <type_traits>
266template<class _Tp, size_t _Np>
267inline _LIBCPP_INLINE_VISIBILITY
268typename enable_if<
269    __is_swappable<_Tp>::value
270>::type
271swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value)
272{
273    _VSTD::swap_ranges(__a, __a + _Np, __b);
274}
275
276template <class _Tp>
277inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
278#ifndef _LIBCPP_CXX03_LANG
279typename conditional
280<
281    !is_nothrow_move_constructible<_Tp>::value && is_copy_constructible<_Tp>::value,
282    const _Tp&,
283    _Tp&&
284>::type
285#else  // _LIBCPP_CXX03_LANG
286const _Tp&
287#endif
288move_if_noexcept(_Tp& __x) _NOEXCEPT
289{
290    return _VSTD::move(__x);
291}
292
293#if _LIBCPP_STD_VER > 14
294template <class _Tp> constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
295template <class _Tp>                        void as_const(const _Tp&&) = delete;
296#endif
297
298struct _LIBCPP_TEMPLATE_VIS piecewise_construct_t { };
299#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
300extern _LIBCPP_EXPORTED_FROM_ABI const piecewise_construct_t piecewise_construct;// = piecewise_construct_t();
301#else
302/* _LIBCPP_INLINE_VAR */ constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
303#endif
304
305#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
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
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 = 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 = 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 = 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 _Tp type; };
641
642template <class _Tp>
643struct __unwrap_reference<reference_wrapper<_Tp> > { typedef _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>
690class _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>
696class _LIBCPP_TEMPLATE_VIS tuple_element<0, pair<_T1, _T2> >
697{
698public:
699    typedef _T1 type;
700};
701
702template <class _T1, class _T2>
703class _LIBCPP_TEMPLATE_VIS tuple_element<1, pair<_T1, _T2> >
704{
705public:
706    typedef _T2 type;
707};
708
709template <size_t _Ip> struct __get_pair;
710
711template <>
712struct __get_pair<0>
713{
714    template <class _T1, class _T2>
715    static
716    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
717    _T1&
718    get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
719
720    template <class _T1, class _T2>
721    static
722    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
723    const _T1&
724    get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
725
726#ifndef _LIBCPP_CXX03_LANG
727    template <class _T1, class _T2>
728    static
729    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
730    _T1&&
731    get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T1>(__p.first);}
732
733    template <class _T1, class _T2>
734    static
735    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
736    const _T1&&
737    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T1>(__p.first);}
738#endif  // _LIBCPP_CXX03_LANG
739};
740
741template <>
742struct __get_pair<1>
743{
744    template <class _T1, class _T2>
745    static
746    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
747    _T2&
748    get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
749
750    template <class _T1, class _T2>
751    static
752    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
753    const _T2&
754    get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
755
756#ifndef _LIBCPP_CXX03_LANG
757    template <class _T1, class _T2>
758    static
759    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
760    _T2&&
761    get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T2>(__p.second);}
762
763    template <class _T1, class _T2>
764    static
765    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
766    const _T2&&
767    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T2>(__p.second);}
768#endif  // _LIBCPP_CXX03_LANG
769};
770
771template <size_t _Ip, class _T1, class _T2>
772inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
773typename tuple_element<_Ip, pair<_T1, _T2> >::type&
774get(pair<_T1, _T2>& __p) _NOEXCEPT
775{
776    return __get_pair<_Ip>::get(__p);
777}
778
779template <size_t _Ip, class _T1, class _T2>
780inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
781const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
782get(const pair<_T1, _T2>& __p) _NOEXCEPT
783{
784    return __get_pair<_Ip>::get(__p);
785}
786
787#ifndef _LIBCPP_CXX03_LANG
788template <size_t _Ip, class _T1, class _T2>
789inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
790typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
791get(pair<_T1, _T2>&& __p) _NOEXCEPT
792{
793    return __get_pair<_Ip>::get(_VSTD::move(__p));
794}
795
796template <size_t _Ip, class _T1, class _T2>
797inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
798const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
799get(const pair<_T1, _T2>&& __p) _NOEXCEPT
800{
801    return __get_pair<_Ip>::get(_VSTD::move(__p));
802}
803#endif  // _LIBCPP_CXX03_LANG
804
805#if _LIBCPP_STD_VER > 11
806template <class _T1, class _T2>
807inline _LIBCPP_INLINE_VISIBILITY
808constexpr _T1 & get(pair<_T1, _T2>& __p) _NOEXCEPT
809{
810    return __get_pair<0>::get(__p);
811}
812
813template <class _T1, class _T2>
814inline _LIBCPP_INLINE_VISIBILITY
815constexpr _T1 const & get(pair<_T1, _T2> const& __p) _NOEXCEPT
816{
817    return __get_pair<0>::get(__p);
818}
819
820template <class _T1, class _T2>
821inline _LIBCPP_INLINE_VISIBILITY
822constexpr _T1 && get(pair<_T1, _T2>&& __p) _NOEXCEPT
823{
824    return __get_pair<0>::get(_VSTD::move(__p));
825}
826
827template <class _T1, class _T2>
828inline _LIBCPP_INLINE_VISIBILITY
829constexpr _T1 const && get(pair<_T1, _T2> const&& __p) _NOEXCEPT
830{
831    return __get_pair<0>::get(_VSTD::move(__p));
832}
833
834template <class _T1, class _T2>
835inline _LIBCPP_INLINE_VISIBILITY
836constexpr _T1 & get(pair<_T2, _T1>& __p) _NOEXCEPT
837{
838    return __get_pair<1>::get(__p);
839}
840
841template <class _T1, class _T2>
842inline _LIBCPP_INLINE_VISIBILITY
843constexpr _T1 const & get(pair<_T2, _T1> const& __p) _NOEXCEPT
844{
845    return __get_pair<1>::get(__p);
846}
847
848template <class _T1, class _T2>
849inline _LIBCPP_INLINE_VISIBILITY
850constexpr _T1 && get(pair<_T2, _T1>&& __p) _NOEXCEPT
851{
852    return __get_pair<1>::get(_VSTD::move(__p));
853}
854
855template <class _T1, class _T2>
856inline _LIBCPP_INLINE_VISIBILITY
857constexpr _T1 const && get(pair<_T2, _T1> const&& __p) _NOEXCEPT
858{
859    return __get_pair<1>::get(_VSTD::move(__p));
860}
861
862#endif
863
864#if _LIBCPP_STD_VER > 11
865
866template<class _Tp, _Tp... _Ip>
867struct _LIBCPP_TEMPLATE_VIS integer_sequence
868{
869    typedef _Tp value_type;
870    static_assert( is_integral<_Tp>::value,
871                  "std::integer_sequence can only be instantiated with an integral type" );
872    static
873    _LIBCPP_INLINE_VISIBILITY
874    constexpr
875    size_t
876    size() noexcept { return sizeof...(_Ip); }
877};
878
879template<size_t... _Ip>
880    using index_sequence = integer_sequence<size_t, _Ip...>;
881
882#if __has_builtin(__make_integer_seq) && !defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)
883
884template <class _Tp, _Tp _Ep>
885using __make_integer_sequence = __make_integer_seq<integer_sequence, _Tp, _Ep>;
886
887#else
888
889template<typename _Tp, _Tp _Np> using __make_integer_sequence_unchecked =
890  typename __detail::__make<_Np>::type::template __convert<integer_sequence, _Tp>;
891
892template <class _Tp, _Tp _Ep>
893struct __make_integer_sequence_checked
894{
895    static_assert(is_integral<_Tp>::value,
896                  "std::make_integer_sequence can only be instantiated with an integral type" );
897    static_assert(0 <= _Ep, "std::make_integer_sequence must have a non-negative sequence length");
898    // Workaround GCC bug by preventing bad installations when 0 <= _Ep
899    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68929
900    typedef __make_integer_sequence_unchecked<_Tp, 0 <= _Ep ? _Ep : 0> type;
901};
902
903template <class _Tp, _Tp _Ep>
904using __make_integer_sequence = typename __make_integer_sequence_checked<_Tp, _Ep>::type;
905
906#endif
907
908template<class _Tp, _Tp _Np>
909    using make_integer_sequence = __make_integer_sequence<_Tp, _Np>;
910
911template<size_t _Np>
912    using make_index_sequence = make_integer_sequence<size_t, _Np>;
913
914template<class... _Tp>
915    using index_sequence_for = make_index_sequence<sizeof...(_Tp)>;
916
917#endif  // _LIBCPP_STD_VER > 11
918
919#if _LIBCPP_STD_VER > 11
920template<class _T1, class _T2 = _T1>
921inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
922_T1 exchange(_T1& __obj, _T2 && __new_value)
923{
924    _T1 __old_value = _VSTD::move(__obj);
925    __obj = _VSTD::forward<_T2>(__new_value);
926    return __old_value;
927}
928#endif  // _LIBCPP_STD_VER > 11
929
930#if _LIBCPP_STD_VER > 14
931
932struct _LIBCPP_TYPE_VIS in_place_t {
933    explicit in_place_t() = default;
934};
935_LIBCPP_INLINE_VAR constexpr in_place_t in_place{};
936
937template <class _Tp>
938struct _LIBCPP_TEMPLATE_VIS in_place_type_t {
939    explicit in_place_type_t() = default;
940};
941template <class _Tp>
942_LIBCPP_INLINE_VAR constexpr in_place_type_t<_Tp> in_place_type{};
943
944template <size_t _Idx>
945struct _LIBCPP_TYPE_VIS in_place_index_t {
946    explicit in_place_index_t() = default;
947};
948template <size_t _Idx>
949_LIBCPP_INLINE_VAR constexpr in_place_index_t<_Idx> in_place_index{};
950
951template <class _Tp> struct __is_inplace_type_imp : false_type {};
952template <class _Tp> struct __is_inplace_type_imp<in_place_type_t<_Tp>> : true_type {};
953
954template <class _Tp>
955using __is_inplace_type = __is_inplace_type_imp<__uncvref_t<_Tp>>;
956
957template <class _Tp> struct __is_inplace_index_imp : false_type {};
958template <size_t _Idx> struct __is_inplace_index_imp<in_place_index_t<_Idx>> : true_type {};
959
960template <class _Tp>
961using __is_inplace_index = __is_inplace_index_imp<__uncvref_t<_Tp>>;
962
963#endif // _LIBCPP_STD_VER > 14
964
965template <class _Arg, class _Result>
966struct _LIBCPP_TEMPLATE_VIS unary_function
967{
968    typedef _Arg    argument_type;
969    typedef _Result result_type;
970};
971
972template <class _Size>
973inline _LIBCPP_INLINE_VISIBILITY
974_Size
975__loadword(const void* __p)
976{
977    _Size __r;
978    std::memcpy(&__r, __p, sizeof(__r));
979    return __r;
980}
981
982// We use murmur2 when size_t is 32 bits, and cityhash64 when size_t
983// is 64 bits.  This is because cityhash64 uses 64bit x 64bit
984// multiplication, which can be very slow on 32-bit systems.
985template <class _Size, size_t = sizeof(_Size)*__CHAR_BIT__>
986struct __murmur2_or_cityhash;
987
988template <class _Size>
989struct __murmur2_or_cityhash<_Size, 32>
990{
991    inline _Size operator()(const void* __key, _Size __len)
992         _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK;
993};
994
995// murmur2
996template <class _Size>
997_Size
998__murmur2_or_cityhash<_Size, 32>::operator()(const void* __key, _Size __len)
999{
1000    const _Size __m = 0x5bd1e995;
1001    const _Size __r = 24;
1002    _Size __h = __len;
1003    const unsigned char* __data = static_cast<const unsigned char*>(__key);
1004    for (; __len >= 4; __data += 4, __len -= 4)
1005    {
1006        _Size __k = __loadword<_Size>(__data);
1007        __k *= __m;
1008        __k ^= __k >> __r;
1009        __k *= __m;
1010        __h *= __m;
1011        __h ^= __k;
1012    }
1013    switch (__len)
1014    {
1015    case 3:
1016        __h ^= __data[2] << 16;
1017        _LIBCPP_FALLTHROUGH();
1018    case 2:
1019        __h ^= __data[1] << 8;
1020        _LIBCPP_FALLTHROUGH();
1021    case 1:
1022        __h ^= __data[0];
1023        __h *= __m;
1024    }
1025    __h ^= __h >> 13;
1026    __h *= __m;
1027    __h ^= __h >> 15;
1028    return __h;
1029}
1030
1031template <class _Size>
1032struct __murmur2_or_cityhash<_Size, 64>
1033{
1034    inline _Size operator()(const void* __key, _Size __len)  _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK;
1035
1036 private:
1037  // Some primes between 2^63 and 2^64.
1038  static const _Size __k0 = 0xc3a5c85c97cb3127ULL;
1039  static const _Size __k1 = 0xb492b66fbe98f273ULL;
1040  static const _Size __k2 = 0x9ae16a3b2f90404fULL;
1041  static const _Size __k3 = 0xc949d7c7509e6557ULL;
1042
1043  static _Size __rotate(_Size __val, int __shift) {
1044    return __shift == 0 ? __val : ((__val >> __shift) | (__val << (64 - __shift)));
1045  }
1046
1047  static _Size __rotate_by_at_least_1(_Size __val, int __shift) {
1048    return (__val >> __shift) | (__val << (64 - __shift));
1049  }
1050
1051  static _Size __shift_mix(_Size __val) {
1052    return __val ^ (__val >> 47);
1053  }
1054
1055  static _Size __hash_len_16(_Size __u, _Size __v)
1056     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1057  {
1058    const _Size __mul = 0x9ddfea08eb382d69ULL;
1059    _Size __a = (__u ^ __v) * __mul;
1060    __a ^= (__a >> 47);
1061    _Size __b = (__v ^ __a) * __mul;
1062    __b ^= (__b >> 47);
1063    __b *= __mul;
1064    return __b;
1065  }
1066
1067  static _Size __hash_len_0_to_16(const char* __s, _Size __len)
1068     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1069  {
1070    if (__len > 8) {
1071      const _Size __a = __loadword<_Size>(__s);
1072      const _Size __b = __loadword<_Size>(__s + __len - 8);
1073      return __hash_len_16(__a, __rotate_by_at_least_1(__b + __len, __len)) ^ __b;
1074    }
1075    if (__len >= 4) {
1076      const uint32_t __a = __loadword<uint32_t>(__s);
1077      const uint32_t __b = __loadword<uint32_t>(__s + __len - 4);
1078      return __hash_len_16(__len + (__a << 3), __b);
1079    }
1080    if (__len > 0) {
1081      const unsigned char __a = __s[0];
1082      const unsigned char __b = __s[__len >> 1];
1083      const unsigned char __c = __s[__len - 1];
1084      const uint32_t __y = static_cast<uint32_t>(__a) +
1085                           (static_cast<uint32_t>(__b) << 8);
1086      const uint32_t __z = __len + (static_cast<uint32_t>(__c) << 2);
1087      return __shift_mix(__y * __k2 ^ __z * __k3) * __k2;
1088    }
1089    return __k2;
1090  }
1091
1092  static _Size __hash_len_17_to_32(const char *__s, _Size __len)
1093     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1094  {
1095    const _Size __a = __loadword<_Size>(__s) * __k1;
1096    const _Size __b = __loadword<_Size>(__s + 8);
1097    const _Size __c = __loadword<_Size>(__s + __len - 8) * __k2;
1098    const _Size __d = __loadword<_Size>(__s + __len - 16) * __k0;
1099    return __hash_len_16(__rotate(__a - __b, 43) + __rotate(__c, 30) + __d,
1100                         __a + __rotate(__b ^ __k3, 20) - __c + __len);
1101  }
1102
1103  // Return a 16-byte hash for 48 bytes.  Quick and dirty.
1104  // Callers do best to use "random-looking" values for a and b.
1105  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
1106      _Size __w, _Size __x, _Size __y, _Size __z, _Size __a, _Size __b)
1107        _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1108  {
1109    __a += __w;
1110    __b = __rotate(__b + __a + __z, 21);
1111    const _Size __c = __a;
1112    __a += __x;
1113    __a += __y;
1114    __b += __rotate(__a, 44);
1115    return pair<_Size, _Size>(__a + __z, __b + __c);
1116  }
1117
1118  // Return a 16-byte hash for s[0] ... s[31], a, and b.  Quick and dirty.
1119  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
1120      const char* __s, _Size __a, _Size __b)
1121    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1122  {
1123    return __weak_hash_len_32_with_seeds(__loadword<_Size>(__s),
1124                                         __loadword<_Size>(__s + 8),
1125                                         __loadword<_Size>(__s + 16),
1126                                         __loadword<_Size>(__s + 24),
1127                                         __a,
1128                                         __b);
1129  }
1130
1131  // Return an 8-byte hash for 33 to 64 bytes.
1132  static _Size __hash_len_33_to_64(const char *__s, size_t __len)
1133    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1134  {
1135    _Size __z = __loadword<_Size>(__s + 24);
1136    _Size __a = __loadword<_Size>(__s) +
1137                (__len + __loadword<_Size>(__s + __len - 16)) * __k0;
1138    _Size __b = __rotate(__a + __z, 52);
1139    _Size __c = __rotate(__a, 37);
1140    __a += __loadword<_Size>(__s + 8);
1141    __c += __rotate(__a, 7);
1142    __a += __loadword<_Size>(__s + 16);
1143    _Size __vf = __a + __z;
1144    _Size __vs = __b + __rotate(__a, 31) + __c;
1145    __a = __loadword<_Size>(__s + 16) + __loadword<_Size>(__s + __len - 32);
1146    __z += __loadword<_Size>(__s + __len - 8);
1147    __b = __rotate(__a + __z, 52);
1148    __c = __rotate(__a, 37);
1149    __a += __loadword<_Size>(__s + __len - 24);
1150    __c += __rotate(__a, 7);
1151    __a += __loadword<_Size>(__s + __len - 16);
1152    _Size __wf = __a + __z;
1153    _Size __ws = __b + __rotate(__a, 31) + __c;
1154    _Size __r = __shift_mix((__vf + __ws) * __k2 + (__wf + __vs) * __k0);
1155    return __shift_mix(__r * __k0 + __vs) * __k2;
1156  }
1157};
1158
1159// cityhash64
1160template <class _Size>
1161_Size
1162__murmur2_or_cityhash<_Size, 64>::operator()(const void* __key, _Size __len)
1163{
1164  const char* __s = static_cast<const char*>(__key);
1165  if (__len <= 32) {
1166    if (__len <= 16) {
1167      return __hash_len_0_to_16(__s, __len);
1168    } else {
1169      return __hash_len_17_to_32(__s, __len);
1170    }
1171  } else if (__len <= 64) {
1172    return __hash_len_33_to_64(__s, __len);
1173  }
1174
1175  // For strings over 64 bytes we hash the end first, and then as we
1176  // loop we keep 56 bytes of state: v, w, x, y, and z.
1177  _Size __x = __loadword<_Size>(__s + __len - 40);
1178  _Size __y = __loadword<_Size>(__s + __len - 16) +
1179              __loadword<_Size>(__s + __len - 56);
1180  _Size __z = __hash_len_16(__loadword<_Size>(__s + __len - 48) + __len,
1181                          __loadword<_Size>(__s + __len - 24));
1182  pair<_Size, _Size> __v = __weak_hash_len_32_with_seeds(__s + __len - 64, __len, __z);
1183  pair<_Size, _Size> __w = __weak_hash_len_32_with_seeds(__s + __len - 32, __y + __k1, __x);
1184  __x = __x * __k1 + __loadword<_Size>(__s);
1185
1186  // Decrease len to the nearest multiple of 64, and operate on 64-byte chunks.
1187  __len = (__len - 1) & ~static_cast<_Size>(63);
1188  do {
1189    __x = __rotate(__x + __y + __v.first + __loadword<_Size>(__s + 8), 37) * __k1;
1190    __y = __rotate(__y + __v.second + __loadword<_Size>(__s + 48), 42) * __k1;
1191    __x ^= __w.second;
1192    __y += __v.first + __loadword<_Size>(__s + 40);
1193    __z = __rotate(__z + __w.first, 33) * __k1;
1194    __v = __weak_hash_len_32_with_seeds(__s, __v.second * __k1, __x + __w.first);
1195    __w = __weak_hash_len_32_with_seeds(__s + 32, __z + __w.second,
1196                                        __y + __loadword<_Size>(__s + 16));
1197    std::swap(__z, __x);
1198    __s += 64;
1199    __len -= 64;
1200  } while (__len != 0);
1201  return __hash_len_16(
1202      __hash_len_16(__v.first, __w.first) + __shift_mix(__y) * __k1 + __z,
1203      __hash_len_16(__v.second, __w.second) + __x);
1204}
1205
1206template <class _Tp, size_t = sizeof(_Tp) / sizeof(size_t)>
1207struct __scalar_hash;
1208
1209template <class _Tp>
1210struct __scalar_hash<_Tp, 0>
1211    : public unary_function<_Tp, size_t>
1212{
1213    _LIBCPP_INLINE_VISIBILITY
1214    size_t operator()(_Tp __v) const _NOEXCEPT
1215    {
1216        union
1217        {
1218            _Tp    __t;
1219            size_t __a;
1220        } __u;
1221        __u.__a = 0;
1222        __u.__t = __v;
1223        return __u.__a;
1224    }
1225};
1226
1227template <class _Tp>
1228struct __scalar_hash<_Tp, 1>
1229    : public unary_function<_Tp, size_t>
1230{
1231    _LIBCPP_INLINE_VISIBILITY
1232    size_t operator()(_Tp __v) const _NOEXCEPT
1233    {
1234        union
1235        {
1236            _Tp    __t;
1237            size_t __a;
1238        } __u;
1239        __u.__t = __v;
1240        return __u.__a;
1241    }
1242};
1243
1244template <class _Tp>
1245struct __scalar_hash<_Tp, 2>
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            } __s;
1259        } __u;
1260        __u.__t = __v;
1261        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1262    }
1263};
1264
1265template <class _Tp>
1266struct __scalar_hash<_Tp, 3>
1267    : public unary_function<_Tp, size_t>
1268{
1269    _LIBCPP_INLINE_VISIBILITY
1270    size_t operator()(_Tp __v) const _NOEXCEPT
1271    {
1272        union
1273        {
1274            _Tp __t;
1275            struct
1276            {
1277                size_t __a;
1278                size_t __b;
1279                size_t __c;
1280            } __s;
1281        } __u;
1282        __u.__t = __v;
1283        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1284    }
1285};
1286
1287template <class _Tp>
1288struct __scalar_hash<_Tp, 4>
1289    : public unary_function<_Tp, size_t>
1290{
1291    _LIBCPP_INLINE_VISIBILITY
1292    size_t operator()(_Tp __v) const _NOEXCEPT
1293    {
1294        union
1295        {
1296            _Tp __t;
1297            struct
1298            {
1299                size_t __a;
1300                size_t __b;
1301                size_t __c;
1302                size_t __d;
1303            } __s;
1304        } __u;
1305        __u.__t = __v;
1306        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1307    }
1308};
1309
1310struct _PairT {
1311  size_t first;
1312  size_t second;
1313};
1314
1315_LIBCPP_INLINE_VISIBILITY
1316inline size_t __hash_combine(size_t __lhs, size_t __rhs) _NOEXCEPT {
1317    typedef __scalar_hash<_PairT> _HashT;
1318    const _PairT __p = {__lhs, __rhs};
1319    return _HashT()(__p);
1320}
1321
1322template<class _Tp>
1323struct _LIBCPP_TEMPLATE_VIS hash<_Tp*>
1324    : public unary_function<_Tp*, size_t>
1325{
1326    _LIBCPP_INLINE_VISIBILITY
1327    size_t operator()(_Tp* __v) const _NOEXCEPT
1328    {
1329        union
1330        {
1331            _Tp* __t;
1332            size_t __a;
1333        } __u;
1334        __u.__t = __v;
1335        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
1336    }
1337};
1338
1339
1340template <>
1341struct _LIBCPP_TEMPLATE_VIS hash<bool>
1342    : public unary_function<bool, size_t>
1343{
1344    _LIBCPP_INLINE_VISIBILITY
1345    size_t operator()(bool __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1346};
1347
1348template <>
1349struct _LIBCPP_TEMPLATE_VIS hash<char>
1350    : public unary_function<char, size_t>
1351{
1352    _LIBCPP_INLINE_VISIBILITY
1353    size_t operator()(char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1354};
1355
1356template <>
1357struct _LIBCPP_TEMPLATE_VIS hash<signed char>
1358    : public unary_function<signed char, size_t>
1359{
1360    _LIBCPP_INLINE_VISIBILITY
1361    size_t operator()(signed char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1362};
1363
1364template <>
1365struct _LIBCPP_TEMPLATE_VIS hash<unsigned char>
1366    : public unary_function<unsigned char, size_t>
1367{
1368    _LIBCPP_INLINE_VISIBILITY
1369    size_t operator()(unsigned char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1370};
1371
1372#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
1373
1374template <>
1375struct _LIBCPP_TEMPLATE_VIS hash<char16_t>
1376    : public unary_function<char16_t, size_t>
1377{
1378    _LIBCPP_INLINE_VISIBILITY
1379    size_t operator()(char16_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1380};
1381
1382template <>
1383struct _LIBCPP_TEMPLATE_VIS hash<char32_t>
1384    : public unary_function<char32_t, size_t>
1385{
1386    _LIBCPP_INLINE_VISIBILITY
1387    size_t operator()(char32_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1388};
1389
1390#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
1391
1392template <>
1393struct _LIBCPP_TEMPLATE_VIS hash<wchar_t>
1394    : public unary_function<wchar_t, size_t>
1395{
1396    _LIBCPP_INLINE_VISIBILITY
1397    size_t operator()(wchar_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1398};
1399
1400template <>
1401struct _LIBCPP_TEMPLATE_VIS hash<short>
1402    : public unary_function<short, size_t>
1403{
1404    _LIBCPP_INLINE_VISIBILITY
1405    size_t operator()(short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1406};
1407
1408template <>
1409struct _LIBCPP_TEMPLATE_VIS hash<unsigned short>
1410    : public unary_function<unsigned short, size_t>
1411{
1412    _LIBCPP_INLINE_VISIBILITY
1413    size_t operator()(unsigned short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1414};
1415
1416template <>
1417struct _LIBCPP_TEMPLATE_VIS hash<int>
1418    : public unary_function<int, size_t>
1419{
1420    _LIBCPP_INLINE_VISIBILITY
1421    size_t operator()(int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1422};
1423
1424template <>
1425struct _LIBCPP_TEMPLATE_VIS hash<unsigned int>
1426    : public unary_function<unsigned int, size_t>
1427{
1428    _LIBCPP_INLINE_VISIBILITY
1429    size_t operator()(unsigned int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1430};
1431
1432template <>
1433struct _LIBCPP_TEMPLATE_VIS hash<long>
1434    : public unary_function<long, size_t>
1435{
1436    _LIBCPP_INLINE_VISIBILITY
1437    size_t operator()(long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1438};
1439
1440template <>
1441struct _LIBCPP_TEMPLATE_VIS hash<unsigned long>
1442    : public unary_function<unsigned long, size_t>
1443{
1444    _LIBCPP_INLINE_VISIBILITY
1445    size_t operator()(unsigned long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
1446};
1447
1448template <>
1449struct _LIBCPP_TEMPLATE_VIS hash<long long>
1450    : public __scalar_hash<long long>
1451{
1452};
1453
1454template <>
1455struct _LIBCPP_TEMPLATE_VIS hash<unsigned long long>
1456    : public __scalar_hash<unsigned long long>
1457{
1458};
1459
1460#ifndef _LIBCPP_HAS_NO_INT128
1461
1462template <>
1463struct _LIBCPP_TEMPLATE_VIS hash<__int128_t>
1464    : public __scalar_hash<__int128_t>
1465{
1466};
1467
1468template <>
1469struct _LIBCPP_TEMPLATE_VIS hash<__uint128_t>
1470    : public __scalar_hash<__uint128_t>
1471{
1472};
1473
1474#endif
1475
1476template <>
1477struct _LIBCPP_TEMPLATE_VIS hash<float>
1478    : public __scalar_hash<float>
1479{
1480    _LIBCPP_INLINE_VISIBILITY
1481    size_t operator()(float __v) const _NOEXCEPT
1482    {
1483        // -0.0 and 0.0 should return same hash
1484       if (__v == 0.0)
1485           return 0;
1486        return __scalar_hash<float>::operator()(__v);
1487    }
1488};
1489
1490template <>
1491struct _LIBCPP_TEMPLATE_VIS hash<double>
1492    : public __scalar_hash<double>
1493{
1494    _LIBCPP_INLINE_VISIBILITY
1495    size_t operator()(double __v) const _NOEXCEPT
1496    {
1497        // -0.0 and 0.0 should return same hash
1498       if (__v == 0.0)
1499           return 0;
1500        return __scalar_hash<double>::operator()(__v);
1501    }
1502};
1503
1504template <>
1505struct _LIBCPP_TEMPLATE_VIS hash<long double>
1506    : public __scalar_hash<long double>
1507{
1508    _LIBCPP_INLINE_VISIBILITY
1509    size_t operator()(long double __v) const _NOEXCEPT
1510    {
1511        // -0.0 and 0.0 should return same hash
1512        if (__v == 0.0)
1513            return 0;
1514#if defined(__i386__)
1515        // Zero out padding bits
1516        union
1517        {
1518            long double __t;
1519            struct
1520            {
1521                size_t __a;
1522                size_t __b;
1523                size_t __c;
1524                size_t __d;
1525            } __s;
1526        } __u;
1527        __u.__s.__a = 0;
1528        __u.__s.__b = 0;
1529        __u.__s.__c = 0;
1530        __u.__s.__d = 0;
1531        __u.__t = __v;
1532        return __u.__s.__a ^ __u.__s.__b ^ __u.__s.__c ^ __u.__s.__d;
1533#elif defined(__x86_64__)
1534        // Zero out padding bits
1535        union
1536        {
1537            long double __t;
1538            struct
1539            {
1540                size_t __a;
1541                size_t __b;
1542            } __s;
1543        } __u;
1544        __u.__s.__a = 0;
1545        __u.__s.__b = 0;
1546        __u.__t = __v;
1547        return __u.__s.__a ^ __u.__s.__b;
1548#else
1549        return __scalar_hash<long double>::operator()(__v);
1550#endif
1551    }
1552};
1553
1554#if _LIBCPP_STD_VER > 11
1555
1556template <class _Tp, bool = is_enum<_Tp>::value>
1557struct _LIBCPP_TEMPLATE_VIS __enum_hash
1558    : public unary_function<_Tp, size_t>
1559{
1560    _LIBCPP_INLINE_VISIBILITY
1561    size_t operator()(_Tp __v) const _NOEXCEPT
1562    {
1563        typedef typename underlying_type<_Tp>::type type;
1564        return hash<type>{}(static_cast<type>(__v));
1565    }
1566};
1567template <class _Tp>
1568struct _LIBCPP_TEMPLATE_VIS __enum_hash<_Tp, false> {
1569    __enum_hash() = delete;
1570    __enum_hash(__enum_hash const&) = delete;
1571    __enum_hash& operator=(__enum_hash const&) = delete;
1572};
1573
1574template <class _Tp>
1575struct _LIBCPP_TEMPLATE_VIS hash : public __enum_hash<_Tp>
1576{
1577};
1578#endif
1579
1580#if _LIBCPP_STD_VER > 14
1581
1582template <>
1583struct _LIBCPP_TEMPLATE_VIS hash<nullptr_t>
1584  : public unary_function<nullptr_t, size_t>
1585{
1586  _LIBCPP_INLINE_VISIBILITY
1587  size_t operator()(nullptr_t) const _NOEXCEPT {
1588    return 662607004ull;
1589  }
1590};
1591#endif
1592
1593#ifndef _LIBCPP_CXX03_LANG
1594template <class _Key, class _Hash>
1595using __check_hash_requirements = integral_constant<bool,
1596    is_copy_constructible<_Hash>::value &&
1597    is_move_constructible<_Hash>::value &&
1598    __invokable_r<size_t, _Hash, _Key const&>::value
1599>;
1600
1601template <class _Key, class _Hash = std::hash<_Key> >
1602using __has_enabled_hash = integral_constant<bool,
1603    __check_hash_requirements<_Key, _Hash>::value &&
1604    is_default_constructible<_Hash>::value
1605>;
1606
1607#if _LIBCPP_STD_VER > 14
1608template <class _Type, class>
1609using __enable_hash_helper_imp = _Type;
1610
1611template <class _Type, class ..._Keys>
1612using __enable_hash_helper = __enable_hash_helper_imp<_Type,
1613  typename enable_if<__all<__has_enabled_hash<_Keys>::value...>::value>::type
1614>;
1615#else
1616template <class _Type, class ...>
1617using __enable_hash_helper = _Type;
1618#endif
1619
1620#endif // !_LIBCPP_CXX03_LANG
1621
1622_LIBCPP_END_NAMESPACE_STD
1623
1624#endif  // _LIBCPP_UTILITY
1625