1// -*- C++ -*-
2//===-------------------------- utility -----------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_UTILITY
12#define _LIBCPP_UTILITY
13
14/*
15    utility synopsis
16
17namespace std
18{
19
20template <class T>
21    void
22    swap(T& a, T& b);
23
24namespace rel_ops
25{
26    template<class T> bool operator!=(const T&, const T&);
27    template<class T> bool operator> (const T&, const T&);
28    template<class T> bool operator<=(const T&, const T&);
29    template<class T> bool operator>=(const T&, const T&);
30}
31
32template<class T>
33void
34swap(T& a, T& b) noexcept(is_nothrow_move_constructible<T>::value &&
35                          is_nothrow_move_assignable<T>::value);
36
37template <class T, size_t N>
38void
39swap(T (&a)[N], T (&b)[N]) noexcept(noexcept(swap(*a, *b)));
40
41template <class T> T&& forward(typename remove_reference<T>::type& t) noexcept;  // constexpr in C++14
42template <class T> T&& forward(typename remove_reference<T>::type&& t) noexcept; // constexpr in C++14
43
44template <class T> typename remove_reference<T>::type&& move(T&&) noexcept;      // constexpr in C++14
45
46template <class T>
47    typename conditional
48    <
49        !is_nothrow_move_constructible<T>::value && is_copy_constructible<T>::value,
50        const T&,
51        T&&
52    >::type
53    move_if_noexcept(T& x) noexcept; // constexpr in C++14
54
55template <class T> constexpr add_const<T>_t& as_const(T& t) noexcept;      // C++17
56template <class T>                      void as_const(const T&&) = delete; // C++17
57
58template <class T> typename add_rvalue_reference<T>::type declval() noexcept;
59
60template <class T1, class T2>
61struct pair
62{
63    typedef T1 first_type;
64    typedef T2 second_type;
65
66    T1 first;
67    T2 second;
68
69    pair(const pair&) = default;
70    pair(pair&&) = default;
71    constexpr pair();
72    pair(const T1& x, const T2& y);                          // constexpr in C++14
73    template <class U, class V> pair(U&& x, V&& y);          // constexpr in C++14
74    template <class U, class V> pair(const pair<U, V>& p);   // constexpr in C++14
75    template <class U, class V> pair(pair<U, V>&& p);        // constexpr in C++14
76    template <class... Args1, class... Args2>
77        pair(piecewise_construct_t, tuple<Args1...> first_args,
78             tuple<Args2...> second_args);
79
80    template <class U, class V> pair& operator=(const pair<U, V>& p);
81    pair& operator=(pair&& p) noexcept(is_nothrow_move_assignable<T1>::value &&
82                                       is_nothrow_move_assignable<T2>::value);
83    template <class U, class V> pair& operator=(pair<U, V>&& p);
84
85    void swap(pair& p) noexcept(is_nothrow_swappable_v<T1> &&
86                                is_nothrow_swappable_v<T2>);
87};
88
89template <class T1, class T2> bool operator==(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
90template <class T1, class T2> bool operator!=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
91template <class T1, class T2> bool operator< (const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
92template <class T1, class T2> bool operator> (const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
93template <class T1, class T2> bool operator>=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
94template <class T1, class T2> bool operator<=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
95
96template <class T1, class T2> pair<V1, V2> make_pair(T1&&, T2&&);   // constexpr in C++14
97template <class T1, class T2>
98void
99swap(pair<T1, T2>& x, pair<T1, T2>& y) noexcept(noexcept(x.swap(y)));
100
101struct piecewise_construct_t { };
102constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
103
104template <class T> class tuple_size;
105template <size_t I, class T> class tuple_element;
106
107template <class T1, class T2> struct tuple_size<pair<T1, T2> >;
108template <class T1, class T2> struct tuple_element<0, pair<T1, T2> >;
109template <class T1, class T2> struct tuple_element<1, pair<T1, T2> >;
110
111template<size_t I, class T1, class T2>
112    typename tuple_element<I, pair<T1, T2> >::type&
113    get(pair<T1, T2>&) noexcept; // constexpr in C++14
114
115template<size_t I, class T1, class T2>
116    const typename tuple_element<I, pair<T1, T2> >::type&
117    get(const pair<T1, T2>&) noexcept; // constexpr in C++14
118
119template<size_t I, class T1, class T2>
120    typename tuple_element<I, pair<T1, T2> >::type&&
121    get(pair<T1, T2>&&) noexcept; // constexpr in C++14
122
123template<size_t I, class T1, class T2>
124    const typename tuple_element<I, pair<T1, T2> >::type&&
125    get(const pair<T1, T2>&&) noexcept; // constexpr in C++14
126
127template<class T1, class T2>
128    constexpr T1& get(pair<T1, T2>&) noexcept; // C++14
129
130template<class T1, class T2>
131    constexpr const T1& get(const pair<T1, T2>&) noexcept; // C++14
132
133template<class T1, class T2>
134    constexpr T1&& get(pair<T1, T2>&&) noexcept; // C++14
135
136template<class T1, class T2>
137    constexpr const T1&& get(const pair<T1, T2>&&) noexcept; // C++14
138
139template<class T1, class T2>
140    constexpr T1& get(pair<T2, T1>&) noexcept; // C++14
141
142template<class T1, class T2>
143    constexpr const T1& get(const pair<T2, T1>&) noexcept; // C++14
144
145template<class T1, class T2>
146    constexpr T1&& get(pair<T2, T1>&&) noexcept; // C++14
147
148template<class T1, class T2>
149    constexpr const T1&& get(const pair<T2, T1>&&) noexcept; // C++14
150
151// C++14
152
153template<class T, T... I>
154struct integer_sequence
155{
156    typedef T value_type;
157
158    static constexpr size_t size() noexcept;
159};
160
161template<size_t... I>
162  using index_sequence = integer_sequence<size_t, I...>;
163
164template<class T, T N>
165  using make_integer_sequence = integer_sequence<T, 0, 1, ..., N-1>;
166template<size_t N>
167  using make_index_sequence = make_integer_sequence<size_t, N>;
168
169template<class... T>
170  using index_sequence_for = make_index_sequence<sizeof...(T)>;
171
172template<class T, class U=T>
173    T exchange(T& obj, U&& new_value);
174
175// 20.2.7, in-place construction // C++17
176struct in_place_tag { in_place_tag() = delete; }; // C++17
177using in_place_t = in_place_tag(&)(unspecified );
178template <class T>
179    using in_place_type_t = in_place_tag(&)(unspecified <T>);
180template <size_t I>
181    using in_place_index_t = in_place_tag(&)(unspecified <I>);
182in_place_tag in_place(unspecified );
183template <class T>
184    in_place_tag in_place(unspecified <T>);
185template <size_t I>
186    in_place_tag in_place(unspecified <I>);
187
188}  // std
189
190*/
191
192#include <__config>
193#include <__tuple>
194#include <type_traits>
195#include <initializer_list>
196#include <__debug>
197
198#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
199#pragma GCC system_header
200#endif
201
202_LIBCPP_BEGIN_NAMESPACE_STD
203
204namespace rel_ops
205{
206
207template<class _Tp>
208inline _LIBCPP_INLINE_VISIBILITY
209bool
210operator!=(const _Tp& __x, const _Tp& __y)
211{
212    return !(__x == __y);
213}
214
215template<class _Tp>
216inline _LIBCPP_INLINE_VISIBILITY
217bool
218operator> (const _Tp& __x, const _Tp& __y)
219{
220    return __y < __x;
221}
222
223template<class _Tp>
224inline _LIBCPP_INLINE_VISIBILITY
225bool
226operator<=(const _Tp& __x, const _Tp& __y)
227{
228    return !(__y < __x);
229}
230
231template<class _Tp>
232inline _LIBCPP_INLINE_VISIBILITY
233bool
234operator>=(const _Tp& __x, const _Tp& __y)
235{
236    return !(__x < __y);
237}
238
239}  // rel_ops
240
241// swap_ranges
242
243
244template <class _ForwardIterator1, class _ForwardIterator2>
245inline _LIBCPP_INLINE_VISIBILITY
246_ForwardIterator2
247swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2)
248{
249    for(; __first1 != __last1; ++__first1, (void) ++__first2)
250        swap(*__first1, *__first2);
251    return __first2;
252}
253
254// forward declared in <type_traits>
255template<class _Tp, size_t _Np>
256inline _LIBCPP_INLINE_VISIBILITY
257typename enable_if<
258    __is_swappable<_Tp>::value
259>::type
260swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value)
261{
262    _VSTD::swap_ranges(__a, __a + _Np, __b);
263}
264
265template <class _Tp>
266inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
267#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
268typename conditional
269<
270    !is_nothrow_move_constructible<_Tp>::value && is_copy_constructible<_Tp>::value,
271    const _Tp&,
272    _Tp&&
273>::type
274#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
275const _Tp&
276#endif
277move_if_noexcept(_Tp& __x) _NOEXCEPT
278{
279    return _VSTD::move(__x);
280}
281
282#if _LIBCPP_STD_VER > 14
283template <class _Tp> constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
284template <class _Tp>                        void as_const(const _Tp&&) = delete;
285#endif
286
287struct _LIBCPP_TYPE_VIS_ONLY piecewise_construct_t { };
288#if defined(_LIBCPP_HAS_NO_CONSTEXPR) || defined(_LIBCPP_BUILDING_UTILITY)
289extern const piecewise_construct_t piecewise_construct;// = piecewise_construct_t();
290#else
291constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
292#endif
293
294#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
295struct __non_trivially_copyable_base {
296  _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
297  __non_trivially_copyable_base() _NOEXCEPT {}
298  _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
299  __non_trivially_copyable_base(__non_trivially_copyable_base const&) _NOEXCEPT {}
300};
301#endif
302
303template <class _T1, class _T2>
304struct _LIBCPP_TYPE_VIS_ONLY pair
305#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
306: private __non_trivially_copyable_base
307#endif
308{
309    typedef _T1 first_type;
310    typedef _T2 second_type;
311
312    _T1 first;
313    _T2 second;
314
315#if !defined(_LIBCPP_CXX03_LANG)
316    pair(pair const&) = default;
317    pair(pair&&) = default;
318#else
319  // Use the implicitly declared copy constructor in C++03
320#endif
321
322#ifdef _LIBCPP_CXX03_LANG
323    _LIBCPP_INLINE_VISIBILITY
324    pair() : first(), second() {}
325
326    _LIBCPP_INLINE_VISIBILITY
327    pair(_T1 const& __t1, _T2 const& __t2) : first(__t1), second(__t2) {}
328
329    template <class _U1, class _U2>
330    _LIBCPP_INLINE_VISIBILITY
331    pair(const pair<_U1, _U2>& __p) : first(__p.first), second(__p.second) {}
332
333    _LIBCPP_INLINE_VISIBILITY
334    pair& operator=(pair const& __p) {
335        first = __p.first;
336        second = __p.second;
337        return *this;
338    }
339#else
340    template <bool _Val>
341    using _EnableB = typename enable_if<_Val, bool>::type;
342
343    struct _CheckArgs {
344      template <class _U1, class _U2>
345      static constexpr bool __enable_default() {
346          return is_default_constructible<_U1>::value
347              && is_default_constructible<_U2>::value;
348      }
349
350      template <class _U1, class _U2>
351      static constexpr bool __enable_explicit() {
352          return is_constructible<first_type, _U1>::value
353              && is_constructible<second_type, _U2>::value
354              && (!is_convertible<_U1, first_type>::value
355                  || !is_convertible<_U2, second_type>::value);
356      }
357
358      template <class _U1, class _U2>
359      static constexpr bool __enable_implicit() {
360          return is_constructible<first_type, _U1>::value
361              && is_constructible<second_type, _U2>::value
362              && is_convertible<_U1, first_type>::value
363              && is_convertible<_U2, second_type>::value;
364      }
365    };
366
367    template <bool _MaybeEnable>
368    using _CheckArgsDep = typename conditional<
369      _MaybeEnable, _CheckArgs, __check_tuple_constructor_fail>::type;
370
371    struct _CheckTupleLikeConstructor {
372        template <class _Tuple>
373        static constexpr bool __enable_implicit() {
374            return __tuple_convertible<_Tuple, pair>::value;
375        }
376
377        template <class _Tuple>
378        static constexpr bool __enable_explicit() {
379            return __tuple_constructible<_Tuple, pair>::value
380               && !__tuple_convertible<_Tuple, pair>::value;
381        }
382
383        template <class _Tuple>
384        static constexpr bool __enable_assign() {
385            return __tuple_assignable<_Tuple, pair>::value;
386        }
387    };
388
389    template <class _Tuple>
390    using _CheckTLC = typename conditional<
391        __tuple_like_with_size<_Tuple, 2>::value
392            && !is_same<typename decay<_Tuple>::type, pair>::value,
393        _CheckTupleLikeConstructor,
394        __check_tuple_constructor_fail
395    >::type;
396
397    template<bool _Dummy = true, _EnableB<
398            _CheckArgsDep<_Dummy>::template __enable_default<_T1, _T2>()
399    > = false>
400    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
401    pair() : first(), second() {}
402
403    template <bool _Dummy = true, _EnableB<
404             _CheckArgsDep<_Dummy>::template __enable_explicit<_T1 const&, _T2 const&>()
405    > = false>
406    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
407    explicit pair(_T1 const& __t1, _T2 const& __t2)
408        : first(__t1), second(__t2) {}
409
410    template<bool _Dummy = true, _EnableB<
411            _CheckArgsDep<_Dummy>::template __enable_implicit<_T1 const&, _T2 const&>()
412    > = false>
413    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
414    pair(_T1 const& __t1, _T2 const& __t2)
415        : first(__t1), second(__t2) {}
416
417    template<class _U1, class _U2, _EnableB<
418             _CheckArgs::template __enable_explicit<_U1, _U2>()
419    > = false>
420    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
421    explicit pair(_U1&& __u1, _U2&& __u2)
422        : first(_VSTD::forward<_U1>(__u1)), second(_VSTD::forward<_U2>(__u2)) {}
423
424    template<class _U1, class _U2, _EnableB<
425            _CheckArgs::template __enable_implicit<_U1, _U2>()
426    > = false>
427    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
428    pair(_U1&& __u1, _U2&& __u2)
429        : first(_VSTD::forward<_U1>(__u1)), second(_VSTD::forward<_U2>(__u2)) {}
430
431    template<class _U1, class _U2, _EnableB<
432            _CheckArgs::template __enable_explicit<_U1 const&, _U2 const&>()
433    > = false>
434    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
435    explicit pair(pair<_U1, _U2> const& __p)
436        : first(__p.first), second(__p.second) {}
437
438    template<class _U1, class _U2, _EnableB<
439            _CheckArgs::template __enable_implicit<_U1 const&, _U2 const&>()
440    > = false>
441    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
442    pair(pair<_U1, _U2> const& __p)
443        : first(__p.first), second(__p.second) {}
444
445    template<class _U1, class _U2, _EnableB<
446            _CheckArgs::template __enable_explicit<_U1, _U2>()
447    > = false>
448    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
449    explicit pair(pair<_U1, _U2>&&__p)
450        : first(_VSTD::forward<_U1>(__p.first)), second(_VSTD::forward<_U2>(__p.second)) {}
451
452    template<class _U1, class _U2, _EnableB<
453            _CheckArgs::template __enable_implicit<_U1, _U2>()
454    > = false>
455    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
456    pair(pair<_U1, _U2>&& __p)
457        : first(_VSTD::forward<_U1>(__p.first)), second(_VSTD::forward<_U2>(__p.second)) {}
458
459    template<class _Tuple, _EnableB<
460            _CheckTLC<_Tuple>::template __enable_explicit<_Tuple>()
461    > = false>
462    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
463    explicit pair(_Tuple&& __p)
464        : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
465          second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
466
467    template<class _Tuple, _EnableB<
468            _CheckTLC<_Tuple>::template __enable_implicit<_Tuple>()
469    > = false>
470    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
471    pair(_Tuple&& __p)
472        : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
473          second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
474
475    template <class... _Args1, class... _Args2>
476    _LIBCPP_INLINE_VISIBILITY
477    pair(piecewise_construct_t __pc,
478         tuple<_Args1...> __first_args, tuple<_Args2...> __second_args)
479        : pair(__pc, __first_args, __second_args,
480                typename __make_tuple_indices<sizeof...(_Args1)>::type(),
481                typename __make_tuple_indices<sizeof...(_Args2) >::type()) {}
482
483    _LIBCPP_INLINE_VISIBILITY
484    pair& operator=(typename conditional<
485                        is_copy_assignable<first_type>::value &&
486                        is_copy_assignable<second_type>::value,
487                    pair, __nat>::type const& __p)
488        _NOEXCEPT_(is_nothrow_copy_assignable<first_type>::value &&
489                   is_nothrow_copy_assignable<second_type>::value)
490    {
491        first = __p.first;
492        second = __p.second;
493        return *this;
494    }
495
496    _LIBCPP_INLINE_VISIBILITY
497    pair& operator=(typename conditional<
498                        is_move_assignable<first_type>::value &&
499                        is_move_assignable<second_type>::value,
500                    pair, __nat>::type&& __p)
501        _NOEXCEPT_(is_nothrow_move_assignable<first_type>::value &&
502                   is_nothrow_move_assignable<second_type>::value)
503    {
504        first = _VSTD::forward<first_type>(__p.first);
505        second = _VSTD::forward<second_type>(__p.second);
506        return *this;
507    }
508
509    template <class _Tuple, _EnableB<
510            _CheckTLC<_Tuple>::template __enable_assign<_Tuple>()
511     > = false>
512    _LIBCPP_INLINE_VISIBILITY
513    pair& operator=(_Tuple&& __p) {
514        first = _VSTD::get<0>(_VSTD::forward<_Tuple>(__p));
515        second = _VSTD::get<1>(_VSTD::forward<_Tuple>(__p));
516        return *this;
517    }
518#endif
519
520    _LIBCPP_INLINE_VISIBILITY
521    void
522    swap(pair& __p) _NOEXCEPT_(__is_nothrow_swappable<first_type>::value &&
523                               __is_nothrow_swappable<second_type>::value)
524    {
525        using _VSTD::swap;
526        swap(first,  __p.first);
527        swap(second, __p.second);
528    }
529private:
530
531#ifndef _LIBCPP_CXX03_LANG
532    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
533        _LIBCPP_INLINE_VISIBILITY
534        pair(piecewise_construct_t,
535             tuple<_Args1...>& __first_args, tuple<_Args2...>& __second_args,
536             __tuple_indices<_I1...>, __tuple_indices<_I2...>);
537#endif
538};
539
540template <class _T1, class _T2>
541inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
542bool
543operator==(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
544{
545    return __x.first == __y.first && __x.second == __y.second;
546}
547
548template <class _T1, class _T2>
549inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
550bool
551operator!=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
552{
553    return !(__x == __y);
554}
555
556template <class _T1, class _T2>
557inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
558bool
559operator< (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
560{
561    return __x.first < __y.first || (!(__y.first < __x.first) && __x.second < __y.second);
562}
563
564template <class _T1, class _T2>
565inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
566bool
567operator> (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
568{
569    return __y < __x;
570}
571
572template <class _T1, class _T2>
573inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
574bool
575operator>=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
576{
577    return !(__x < __y);
578}
579
580template <class _T1, class _T2>
581inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
582bool
583operator<=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
584{
585    return !(__y < __x);
586}
587
588template <class _T1, class _T2>
589inline _LIBCPP_INLINE_VISIBILITY
590typename enable_if
591<
592    __is_swappable<_T1>::value &&
593    __is_swappable<_T2>::value,
594    void
595>::type
596swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)
597                     _NOEXCEPT_((__is_nothrow_swappable<_T1>::value &&
598                                 __is_nothrow_swappable<_T2>::value))
599{
600    __x.swap(__y);
601}
602
603#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
604
605
606template <class _Tp>
607struct __make_pair_return_impl
608{
609    typedef _Tp type;
610};
611
612template <class _Tp>
613struct __make_pair_return_impl<reference_wrapper<_Tp>>
614{
615    typedef _Tp& type;
616};
617
618template <class _Tp>
619struct __make_pair_return
620{
621    typedef typename __make_pair_return_impl<typename decay<_Tp>::type>::type type;
622};
623
624template <class _T1, class _T2>
625inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
626pair<typename __make_pair_return<_T1>::type, typename __make_pair_return<_T2>::type>
627make_pair(_T1&& __t1, _T2&& __t2)
628{
629    return pair<typename __make_pair_return<_T1>::type, typename __make_pair_return<_T2>::type>
630               (_VSTD::forward<_T1>(__t1), _VSTD::forward<_T2>(__t2));
631}
632
633#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
634
635template <class _T1, class _T2>
636inline _LIBCPP_INLINE_VISIBILITY
637pair<_T1,_T2>
638make_pair(_T1 __x, _T2 __y)
639{
640    return pair<_T1, _T2>(__x, __y);
641}
642
643#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
644
645template <class _T1, class _T2>
646  class _LIBCPP_TYPE_VIS_ONLY tuple_size<pair<_T1, _T2> >
647    : public integral_constant<size_t, 2> {};
648
649template <class _T1, class _T2>
650class _LIBCPP_TYPE_VIS_ONLY tuple_element<0, pair<_T1, _T2> >
651{
652public:
653    typedef _T1 type;
654};
655
656template <class _T1, class _T2>
657class _LIBCPP_TYPE_VIS_ONLY tuple_element<1, pair<_T1, _T2> >
658{
659public:
660    typedef _T2 type;
661};
662
663template <size_t _Ip> struct __get_pair;
664
665template <>
666struct __get_pair<0>
667{
668    template <class _T1, class _T2>
669    static
670    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
671    _T1&
672    get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
673
674    template <class _T1, class _T2>
675    static
676    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
677    const _T1&
678    get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
679
680#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
681
682    template <class _T1, class _T2>
683    static
684    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
685    _T1&&
686    get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T1>(__p.first);}
687
688    template <class _T1, class _T2>
689    static
690    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
691    const _T1&&
692    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T1>(__p.first);}
693
694#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
695};
696
697template <>
698struct __get_pair<1>
699{
700    template <class _T1, class _T2>
701    static
702    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
703    _T2&
704    get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
705
706    template <class _T1, class _T2>
707    static
708    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
709    const _T2&
710    get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
711
712#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
713
714    template <class _T1, class _T2>
715    static
716    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
717    _T2&&
718    get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T2>(__p.second);}
719
720    template <class _T1, class _T2>
721    static
722    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
723    const _T2&&
724    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T2>(__p.second);}
725
726#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
727};
728
729template <size_t _Ip, class _T1, class _T2>
730inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
731typename tuple_element<_Ip, pair<_T1, _T2> >::type&
732get(pair<_T1, _T2>& __p) _NOEXCEPT
733{
734    return __get_pair<_Ip>::get(__p);
735}
736
737template <size_t _Ip, class _T1, class _T2>
738inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
739const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
740get(const pair<_T1, _T2>& __p) _NOEXCEPT
741{
742    return __get_pair<_Ip>::get(__p);
743}
744
745#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
746
747template <size_t _Ip, class _T1, class _T2>
748inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
749typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
750get(pair<_T1, _T2>&& __p) _NOEXCEPT
751{
752    return __get_pair<_Ip>::get(_VSTD::move(__p));
753}
754
755template <size_t _Ip, class _T1, class _T2>
756inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
757const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
758get(const pair<_T1, _T2>&& __p) _NOEXCEPT
759{
760    return __get_pair<_Ip>::get(_VSTD::move(__p));
761}
762
763#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
764
765#if _LIBCPP_STD_VER > 11
766template <class _T1, class _T2>
767inline _LIBCPP_INLINE_VISIBILITY
768constexpr _T1 & get(pair<_T1, _T2>& __p) _NOEXCEPT
769{
770    return __get_pair<0>::get(__p);
771}
772
773template <class _T1, class _T2>
774inline _LIBCPP_INLINE_VISIBILITY
775constexpr _T1 const & get(pair<_T1, _T2> const& __p) _NOEXCEPT
776{
777    return __get_pair<0>::get(__p);
778}
779
780template <class _T1, class _T2>
781inline _LIBCPP_INLINE_VISIBILITY
782constexpr _T1 && get(pair<_T1, _T2>&& __p) _NOEXCEPT
783{
784    return __get_pair<0>::get(_VSTD::move(__p));
785}
786
787template <class _T1, class _T2>
788inline _LIBCPP_INLINE_VISIBILITY
789constexpr _T1 const && get(pair<_T1, _T2> const&& __p) _NOEXCEPT
790{
791    return __get_pair<0>::get(_VSTD::move(__p));
792}
793
794template <class _T1, class _T2>
795inline _LIBCPP_INLINE_VISIBILITY
796constexpr _T1 & get(pair<_T2, _T1>& __p) _NOEXCEPT
797{
798    return __get_pair<1>::get(__p);
799}
800
801template <class _T1, class _T2>
802inline _LIBCPP_INLINE_VISIBILITY
803constexpr _T1 const & get(pair<_T2, _T1> const& __p) _NOEXCEPT
804{
805    return __get_pair<1>::get(__p);
806}
807
808template <class _T1, class _T2>
809inline _LIBCPP_INLINE_VISIBILITY
810constexpr _T1 && get(pair<_T2, _T1>&& __p) _NOEXCEPT
811{
812    return __get_pair<1>::get(_VSTD::move(__p));
813}
814
815template <class _T1, class _T2>
816inline _LIBCPP_INLINE_VISIBILITY
817constexpr _T1 const && get(pair<_T2, _T1> const&& __p) _NOEXCEPT
818{
819    return __get_pair<1>::get(_VSTD::move(__p));
820}
821
822#endif
823
824#if _LIBCPP_STD_VER > 11
825
826template<class _Tp, _Tp... _Ip>
827struct _LIBCPP_TYPE_VIS_ONLY integer_sequence
828{
829    typedef _Tp value_type;
830    static_assert( is_integral<_Tp>::value,
831                  "std::integer_sequence can only be instantiated with an integral type" );
832    static
833    _LIBCPP_INLINE_VISIBILITY
834    constexpr
835    size_t
836    size() noexcept { return sizeof...(_Ip); }
837};
838
839template<size_t... _Ip>
840    using index_sequence = integer_sequence<size_t, _Ip...>;
841
842#if __has_builtin(__make_integer_seq) && !defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)
843
844template <class _Tp, _Tp _Ep>
845using __make_integer_sequence = __make_integer_seq<integer_sequence, _Tp, _Ep>;
846
847#else
848
849template<typename _Tp, _Tp _Np> using __make_integer_sequence_unchecked =
850  typename __detail::__make<_Np>::type::template __convert<integer_sequence, _Tp>;
851
852template <class _Tp, _Tp _Ep>
853struct __make_integer_sequence_checked
854{
855    static_assert(is_integral<_Tp>::value,
856                  "std::make_integer_sequence can only be instantiated with an integral type" );
857    static_assert(0 <= _Ep, "std::make_integer_sequence must have a non-negative sequence length");
858    // Workaround GCC bug by preventing bad installations when 0 <= _Ep
859    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68929
860    typedef __make_integer_sequence_unchecked<_Tp, 0 <= _Ep ? _Ep : 0> type;
861};
862
863template <class _Tp, _Tp _Ep>
864using __make_integer_sequence = typename __make_integer_sequence_checked<_Tp, _Ep>::type;
865
866#endif
867
868template<class _Tp, _Tp _Np>
869    using make_integer_sequence = __make_integer_sequence<_Tp, _Np>;
870
871template<size_t _Np>
872    using make_index_sequence = make_integer_sequence<size_t, _Np>;
873
874template<class... _Tp>
875    using index_sequence_for = make_index_sequence<sizeof...(_Tp)>;
876
877#endif  // _LIBCPP_STD_VER > 11
878
879#if _LIBCPP_STD_VER > 11
880template<class _T1, class _T2 = _T1>
881inline _LIBCPP_INLINE_VISIBILITY
882_T1 exchange(_T1& __obj, _T2 && __new_value)
883{
884    _T1 __old_value = _VSTD::move(__obj);
885    __obj = _VSTD::forward<_T2>(__new_value);
886    return __old_value;
887}
888#endif  // _LIBCPP_STD_VER > 11
889
890#if _LIBCPP_STD_VER > 14
891
892struct _LIBCPP_TYPE_VIS_ONLY __in_place_tag {};
893template <class> struct _LIBCPP_TYPE_VIS_ONLY __in_place_type_tag {};
894template <size_t> struct _LIBCPP_TYPE_VIS_ONLY __in_place_index_tag {};
895
896struct _LIBCPP_TYPE_VIS_ONLY in_place_tag;
897
898using in_place_t = in_place_tag(&)(__in_place_tag);
899template <class _Tp>
900using in_place_type_t = in_place_tag(&)(__in_place_type_tag<_Tp>);
901template <size_t _Nx>
902using in_place_index_t = in_place_tag(&)(__in_place_index_tag<_Nx>);
903
904struct in_place_tag {
905  in_place_tag() = delete;
906private:
907  explicit in_place_tag(__in_place_tag) {}
908
909  friend inline in_place_tag in_place(__in_place_tag __t);
910  template <class _Tp>
911  friend inline in_place_tag in_place(__in_place_type_tag<_Tp>);
912  template <size_t _Nx>
913  friend inline in_place_tag in_place(__in_place_index_tag<_Nx>);
914};
915
916inline in_place_tag in_place(__in_place_tag __t) {
917    _LIBCPP_ASSERT(false, "The in_place function cannot be invoked");
918    return in_place_tag(__t);
919}
920template <class _Tp>
921inline in_place_tag in_place(__in_place_type_tag<_Tp>) {
922    _LIBCPP_ASSERT(false, "The in_place function cannot be invoked");
923    return in_place_tag(__in_place_tag{});
924}
925template <size_t _Nx>
926inline in_place_tag in_place(__in_place_index_tag<_Nx>) {
927    _LIBCPP_ASSERT(false, "The in_place function cannot be invoked");
928    return in_place_tag(__in_place_tag{});
929}
930
931template <class _Tp>   struct __is_inplace_type : false_type {};
932template <>            struct __is_inplace_type<in_place_t> : true_type {};
933template <class _Tp>   struct __is_inplace_type<in_place_type_t<_Tp>> : true_type {};
934template <size_t _Idx> struct __is_inplace_type<in_place_index_t<_Idx>> : true_type {};
935
936#endif // _LIBCPP_STD_VER > 14
937
938_LIBCPP_END_NAMESPACE_STD
939
940#endif  // _LIBCPP_UTILITY
941