aboutsummaryrefslogtreecommitdiffstats
path: root/include/__split_buffer
blob: 1daa4e5ada3dd4c0188a1582a42110222ff0ff8b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
// -*- C++ -*-
#ifndef _LIBCPP_SPLIT_BUFFER
#define _LIBCPP_SPLIT_BUFFER

#include <__config>
#include <type_traits>
#include <algorithm>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

_LIBCPP_PUSH_MACROS
#include <__undef_macros>


_LIBCPP_BEGIN_NAMESPACE_STD

template <bool>
class __split_buffer_common
{
protected:
    void __throw_length_error() const;
    void __throw_out_of_range() const;
};

template <class _Tp, class _Allocator = allocator<_Tp> >
struct __split_buffer
    : private __split_buffer_common<true>
{
private:
    __split_buffer(const __split_buffer&);
    __split_buffer& operator=(const __split_buffer&);
public:
    typedef _Tp                                             value_type;
    typedef _Allocator                                      allocator_type;
    typedef typename remove_reference<allocator_type>::type __alloc_rr;
    typedef allocator_traits<__alloc_rr>                    __alloc_traits;
    typedef value_type&                                     reference;
    typedef const value_type&                               const_reference;
    typedef typename __alloc_traits::size_type              size_type;
    typedef typename __alloc_traits::difference_type        difference_type;
    typedef typename __alloc_traits::pointer                pointer;
    typedef typename __alloc_traits::const_pointer          const_pointer;
    typedef pointer                                         iterator;
    typedef const_pointer                                   const_iterator;

    pointer                                         __first_;
    pointer                                         __begin_;
    pointer                                         __end_;
    __compressed_pair<pointer, allocator_type> __end_cap_;

    typedef typename add_lvalue_reference<allocator_type>::type __alloc_ref;
    typedef typename add_lvalue_reference<allocator_type>::type __alloc_const_ref;

    _LIBCPP_INLINE_VISIBILITY __alloc_rr&           __alloc() _NOEXCEPT         {return __end_cap_.second();}
    _LIBCPP_INLINE_VISIBILITY const __alloc_rr&     __alloc() const _NOEXCEPT   {return __end_cap_.second();}
    _LIBCPP_INLINE_VISIBILITY pointer&              __end_cap() _NOEXCEPT       {return __end_cap_.first();}
    _LIBCPP_INLINE_VISIBILITY const pointer&        __end_cap() const _NOEXCEPT {return __end_cap_.first();}

    _LIBCPP_INLINE_VISIBILITY
    __split_buffer()
        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
    _LIBCPP_INLINE_VISIBILITY
    explicit __split_buffer(__alloc_rr& __a);
    _LIBCPP_INLINE_VISIBILITY
    explicit __split_buffer(const __alloc_rr& __a);
    __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a);
    ~__split_buffer();

#ifndef _LIBCPP_CXX03_LANG
    __split_buffer(__split_buffer&& __c)
        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
    __split_buffer(__split_buffer&& __c, const __alloc_rr& __a);
    __split_buffer& operator=(__split_buffer&& __c)
        _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
                is_nothrow_move_assignable<allocator_type>::value) ||
               !__alloc_traits::propagate_on_container_move_assignment::value);
#endif  // _LIBCPP_CXX03_LANG

    _LIBCPP_INLINE_VISIBILITY       iterator begin() _NOEXCEPT       {return __begin_;}
    _LIBCPP_INLINE_VISIBILITY const_iterator begin() const _NOEXCEPT {return __begin_;}
    _LIBCPP_INLINE_VISIBILITY       iterator end() _NOEXCEPT         {return __end_;}
    _LIBCPP_INLINE_VISIBILITY const_iterator end() const _NOEXCEPT   {return __end_;}

    _LIBCPP_INLINE_VISIBILITY
    void clear() _NOEXCEPT
        {__destruct_at_end(__begin_);}
    _LIBCPP_INLINE_VISIBILITY size_type size() const {return static_cast<size_type>(__end_ - __begin_);}
    _LIBCPP_INLINE_VISIBILITY bool empty()     const {return __end_ == __begin_;}
    _LIBCPP_INLINE_VISIBILITY size_type capacity() const {return static_cast<size_type>(__end_cap() - __first_);}
    _LIBCPP_INLINE_VISIBILITY size_type __front_spare() const {return static_cast<size_type>(__begin_ - __first_);}
    _LIBCPP_INLINE_VISIBILITY size_type __back_spare() const {return static_cast<size_type>(__end_cap() - __end_);}

    _LIBCPP_INLINE_VISIBILITY       reference front()       {return *__begin_;}
    _LIBCPP_INLINE_VISIBILITY const_reference front() const {return *__begin_;}
    _LIBCPP_INLINE_VISIBILITY       reference back()        {return *(__end_ - 1);}
    _LIBCPP_INLINE_VISIBILITY const_reference back() const  {return *(__end_ - 1);}

    void reserve(size_type __n);
    void shrink_to_fit() _NOEXCEPT;
    void push_front(const_reference __x);
    _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
#ifndef _LIBCPP_CXX03_LANG
    void push_front(value_type&& __x);
    void push_back(value_type&& __x);
    template <class... _Args>
        void emplace_back(_Args&&... __args);
#endif  // !defined(_LIBCPP_CXX03_LANG)

    _LIBCPP_INLINE_VISIBILITY void pop_front() {__destruct_at_begin(__begin_+1);}
    _LIBCPP_INLINE_VISIBILITY void pop_back() {__destruct_at_end(__end_-1);}

    void __construct_at_end(size_type __n);
    void __construct_at_end(size_type __n, const_reference __x);
    template <class _InputIter>
        typename enable_if
        <
            __is_input_iterator<_InputIter>::value &&
           !__is_forward_iterator<_InputIter>::value,
            void
        >::type
        __construct_at_end(_InputIter __first, _InputIter __last);
    template <class _ForwardIterator>
        typename enable_if
        <
            __is_forward_iterator<_ForwardIterator>::value,
            void
        >::type
        __construct_at_end(_ForwardIterator __first, _ForwardIterator __last);

    _LIBCPP_INLINE_VISIBILITY void __destruct_at_begin(pointer __new_begin)
        {__destruct_at_begin(__new_begin, is_trivially_destructible<value_type>());}
        _LIBCPP_INLINE_VISIBILITY
        void __destruct_at_begin(pointer __new_begin, false_type);
        _LIBCPP_INLINE_VISIBILITY
        void __destruct_at_begin(pointer __new_begin, true_type);

    _LIBCPP_INLINE_VISIBILITY
    void __destruct_at_end(pointer __new_last) _NOEXCEPT
        {__destruct_at_end(__new_last, false_type());}
    _LIBCPP_INLINE_VISIBILITY
        void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT;
    _LIBCPP_INLINE_VISIBILITY
        void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT;

    void swap(__split_buffer& __x)
        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value||
                   __is_nothrow_swappable<__alloc_rr>::value);

    bool __invariants() const;

private:
    _LIBCPP_INLINE_VISIBILITY
    void __move_assign_alloc(__split_buffer& __c, true_type)
        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
        {
            __alloc() = _VSTD::move(__c.__alloc());
        }

    _LIBCPP_INLINE_VISIBILITY
    void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT
        {}
};

template <class _Tp, class _Allocator>
bool
__split_buffer<_Tp, _Allocator>::__invariants() const
{
    if (__first_ == nullptr)
    {
        if (__begin_ != nullptr)
            return false;
        if (__end_ != nullptr)
            return false;
        if (__end_cap() != nullptr)
            return false;
    }
    else
    {
        if (__begin_ < __first_)
            return false;
        if (__end_ < __begin_)
            return false;
        if (__end_cap() < __end_)
            return false;
    }
    return true;
}

//  Default constructs __n objects starting at __end_
//  throws if construction throws
//  Precondition:  __n > 0
//  Precondition:  size() + __n <= capacity()
//  Postcondition:  size() == size() + __n
template <class _Tp, class _Allocator>
void
__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n)
{
    __alloc_rr& __a = this->__alloc();
    do
    {
        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_));
        ++this->__end_;
        --__n;
    } while (__n > 0);
}

//  Copy constructs __n objects starting at __end_ from __x
//  throws if construction throws
//  Precondition:  __n > 0
//  Precondition:  size() + __n <= capacity()
//  Postcondition:  size() == old size() + __n
//  Postcondition:  [i] == __x for all i in [size() - __n, __n)
template <class _Tp, class _Allocator>
void
__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x)
{
    __alloc_rr& __a = this->__alloc();
    do
    {
        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_), __x);
        ++this->__end_;
        --__n;
    } while (__n > 0);
}

template <class _Tp, class _Allocator>
template <class _InputIter>
typename enable_if
<
     __is_input_iterator<_InputIter>::value &&
    !__is_forward_iterator<_InputIter>::value,
    void
>::type
__split_buffer<_Tp, _Allocator>::__construct_at_end(_InputIter __first, _InputIter __last)
{
    __alloc_rr& __a = this->__alloc();
    for (; __first != __last; ++__first)
    {
        if (__end_ == __end_cap())
        {
            size_type __old_cap = __end_cap() - __first_;
            size_type __new_cap = _VSTD::max<size_type>(2 * __old_cap, 8);
            __split_buffer __buf(__new_cap, 0, __a);
            for (pointer __p = __begin_; __p != __end_; ++__p, ++__buf.__end_)
                __alloc_traits::construct(__buf.__alloc(),
                        _VSTD::__to_raw_pointer(__buf.__end_), _VSTD::move(*__p));
            swap(__buf);
        }
        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_), *__first);
        ++this->__end_;
    }
}

template <class _Tp, class _Allocator>
template <class _ForwardIterator>
typename enable_if
<
    __is_forward_iterator<_ForwardIterator>::value,
    void
>::type
__split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last)
{
    __alloc_rr& __a = this->__alloc();
    for (; __first != __last; ++__first)
    {
        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_), *__first);
        ++this->__end_;
    }
}

template <class _Tp, class _Allocator>
inline
void
__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type)
{
    while (__begin_ != __new_begin)
        __alloc_traits::destroy(__alloc(), __to_raw_pointer(__begin_++));
}

template <class _Tp, class _Allocator>
inline
void
__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type)
{
    __begin_ = __new_begin;
}

template <class _Tp, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
void
__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT
{
    while (__new_last != __end_)
        __alloc_traits::destroy(__alloc(), __to_raw_pointer(--__end_));
}

template <class _Tp, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
void
__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT
{
    __end_ = __new_last;
}

template <class _Tp, class _Allocator>
__split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a)
    : __end_cap_(nullptr, __a)
{
    __first_ = __cap != 0 ? __alloc_traits::allocate(__alloc(), __cap) : nullptr;
    __begin_ = __end_ = __first_ + __start;
    __end_cap() = __first_ + __cap;
}

template <class _Tp, class _Allocator>
inline
__split_buffer<_Tp, _Allocator>::__split_buffer()
    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr)
{
}

template <class _Tp, class _Allocator>
inline
__split_buffer<_Tp, _Allocator>::__split_buffer(__alloc_rr& __a)
    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a)
{
}

template <class _Tp, class _Allocator>
inline
__split_buffer<_Tp, _Allocator>::__split_buffer(const __alloc_rr& __a)
    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a)
{
}

template <class _Tp, class _Allocator>
__split_buffer<_Tp, _Allocator>::~__split_buffer()
{
    clear();
    if (__first_)
        __alloc_traits::deallocate(__alloc(), __first_, capacity());
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Tp, class _Allocator>
__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c)
    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
    : __first_(_VSTD::move(__c.__first_)),
      __begin_(_VSTD::move(__c.__begin_)),
      __end_(_VSTD::move(__c.__end_)),
      __end_cap_(_VSTD::move(__c.__end_cap_))
{
    __c.__first_ = nullptr;
    __c.__begin_ = nullptr;
    __c.__end_ = nullptr;
    __c.__end_cap() = nullptr;
}

template <class _Tp, class _Allocator>
__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a)
    : __end_cap_(__second_tag(), __a)
{
    if (__a == __c.__alloc())
    {
        __first_ = __c.__first_;
        __begin_ = __c.__begin_;
        __end_ = __c.__end_;
        __end_cap() = __c.__end_cap();
        __c.__first_ = nullptr;
        __c.__begin_ = nullptr;
        __c.__end_ = nullptr;
        __c.__end_cap() = nullptr;
    }
    else
    {
        size_type __cap = __c.size();
        __first_ = __alloc_traits::allocate(__alloc(), __cap);
        __begin_ = __end_ = __first_;
        __end_cap() = __first_ + __cap;
        typedef move_iterator<iterator> _Ip;
        __construct_at_end(_Ip(__c.begin()), _Ip(__c.end()));
    }
}

template <class _Tp, class _Allocator>
__split_buffer<_Tp, _Allocator>&
__split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c)
    _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
                is_nothrow_move_assignable<allocator_type>::value) ||
               !__alloc_traits::propagate_on_container_move_assignment::value)
{
    clear();
    shrink_to_fit();
    __first_ = __c.__first_;
    __begin_ = __c.__begin_;
    __end_ = __c.__end_;
    __end_cap() = __c.__end_cap();
    __move_assign_alloc(__c,
        integral_constant<bool,
                          __alloc_traits::propagate_on_container_move_assignment::value>());
    __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr;
    return *this;
}

#endif  // _LIBCPP_CXX03_LANG

template <class _Tp, class _Allocator>
void
__split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x)
        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value||
                   __is_nothrow_swappable<__alloc_rr>::value)
{
    _VSTD::swap(__first_, __x.__first_);
    _VSTD::swap(__begin_, __x.__begin_);
    _VSTD::swap(__end_, __x.__end_);
    _VSTD::swap(__end_cap(), __x.__end_cap());
    __swap_allocator(__alloc(), __x.__alloc());
}

template <class _Tp, class _Allocator>
void
__split_buffer<_Tp, _Allocator>::reserve(size_type __n)
{
    if (__n < capacity())
    {
        __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc());
        __t.__construct_at_end(move_iterator<pointer>(__begin_),
                               move_iterator<pointer>(__end_));
        _VSTD::swap(__first_, __t.__first_);
        _VSTD::swap(__begin_, __t.__begin_);
        _VSTD::swap(__end_, __t.__end_);
        _VSTD::swap(__end_cap(), __t.__end_cap());
    }
}

template <class _Tp, class _Allocator>
void
__split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
{
    if (capacity() > size())
    {
#ifndef _LIBCPP_NO_EXCEPTIONS
        try
        {
#endif  // _LIBCPP_NO_EXCEPTIONS
            __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc());
            __t.__construct_at_end(move_iterator<pointer>(__begin_),
                                   move_iterator<pointer>(__end_));
            __t.__end_ = __t.__begin_ + (__end_ - __begin_);
            _VSTD::swap(__first_, __t.__first_);
            _VSTD::swap(__begin_, __t.__begin_);
            _VSTD::swap(__end_, __t.__end_);
            _VSTD::swap(__end_cap(), __t.__end_cap());
#ifndef _LIBCPP_NO_EXCEPTIONS
        }
        catch (...)
        {
        }
#endif  // _LIBCPP_NO_EXCEPTIONS
    }
}

template <class _Tp, class _Allocator>
void
__split_buffer<_Tp, _Allocator>::push_front(const_reference __x)
{
    if (__begin_ == __first_)
    {
        if (__end_ < __end_cap())
        {
            difference_type __d = __end_cap() - __end_;
            __d = (__d + 1) / 2;
            __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d);
            __end_ += __d;
        }
        else
        {
            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
            __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc());
            __t.__construct_at_end(move_iterator<pointer>(__begin_),
                                   move_iterator<pointer>(__end_));
            _VSTD::swap(__first_, __t.__first_);
            _VSTD::swap(__begin_, __t.__begin_);
            _VSTD::swap(__end_, __t.__end_);
            _VSTD::swap(__end_cap(), __t.__end_cap());
        }
    }
    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__begin_-1), __x);
    --__begin_;
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Tp, class _Allocator>
void
__split_buffer<_Tp, _Allocator>::push_front(value_type&& __x)
{
    if (__begin_ == __first_)
    {
        if (__end_ < __end_cap())
        {
            difference_type __d = __end_cap() - __end_;
            __d = (__d + 1) / 2;
            __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d);
            __end_ += __d;
        }
        else
        {
            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
            __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc());
            __t.__construct_at_end(move_iterator<pointer>(__begin_),
                                   move_iterator<pointer>(__end_));
            _VSTD::swap(__first_, __t.__first_);
            _VSTD::swap(__begin_, __t.__begin_);
            _VSTD::swap(__end_, __t.__end_);
            _VSTD::swap(__end_cap(), __t.__end_cap());
        }
    }
    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__begin_-1),
            _VSTD::move(__x));
    --__begin_;
}

#endif  // _LIBCPP_CXX03_LANG

template <class _Tp, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
void
__split_buffer<_Tp, _Allocator>::push_back(const_reference __x)
{
    if (__end_ == __end_cap())
    {
        if (__begin_ > __first_)
        {
            difference_type __d = __begin_ - __first_;
            __d = (__d + 1) / 2;
            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
            __begin_ -= __d;
        }
        else
        {
            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
            __t.__construct_at_end(move_iterator<pointer>(__begin_),
                                   move_iterator<pointer>(__end_));
            _VSTD::swap(__first_, __t.__first_);
            _VSTD::swap(__begin_, __t.__begin_);
            _VSTD::swap(__end_, __t.__end_);
            _VSTD::swap(__end_cap(), __t.__end_cap());
        }
    }
    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__end_), __x);
    ++__end_;
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Tp, class _Allocator>
void
__split_buffer<_Tp, _Allocator>::push_back(value_type&& __x)
{
    if (__end_ == __end_cap())
    {
        if (__begin_ > __first_)
        {
            difference_type __d = __begin_ - __first_;
            __d = (__d + 1) / 2;
            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
            __begin_ -= __d;
        }
        else
        {
            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
            __t.__construct_at_end(move_iterator<pointer>(__begin_),
                                   move_iterator<pointer>(__end_));
            _VSTD::swap(__first_, __t.__first_);
            _VSTD::swap(__begin_, __t.__begin_);
            _VSTD::swap(__end_, __t.__end_);
            _VSTD::swap(__end_cap(), __t.__end_cap());
        }
    }
    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__end_),
            _VSTD::move(__x));
    ++__end_;
}

template <class _Tp, class _Allocator>
template <class... _Args>
void
__split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args)
{
    if (__end_ == __end_cap())
    {
        if (__begin_ > __first_)
        {
            difference_type __d = __begin_ - __first_;
            __d = (__d + 1) / 2;
            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
            __begin_ -= __d;
        }
        else
        {
            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
            __t.__construct_at_end(move_iterator<pointer>(__begin_),
                                   move_iterator<pointer>(__end_));
            _VSTD::swap(__first_, __t.__first_);
            _VSTD::swap(__begin_, __t.__begin_);
            _VSTD::swap(__end_, __t.__end_);
            _VSTD::swap(__end_cap(), __t.__end_cap());
        }
    }
    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__end_),
                              _VSTD::forward<_Args>(__args)...);
    ++__end_;
}

#endif  // _LIBCPP_CXX03_LANG

template <class _Tp, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
void
swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y)
        _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
{
    __x.swap(__y);
}

_LIBCPP_END_NAMESPACE_STD

_LIBCPP_POP_MACROS

#endif  // _LIBCPP_SPLIT_BUFFER