xref: /freebsd/contrib/llvm-project/libcxx/include/__cxx03/deque (revision 700637cbb5e582861067a11aaca4d053546871d2)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP___CXX03_DEQUE
11#define _LIBCPP___CXX03_DEQUE
12
13/*
14    deque synopsis
15
16namespace std
17{
18
19template <class T, class Allocator = allocator<T> >
20class deque
21{
22public:
23    // types:
24    typedef T value_type;
25    typedef Allocator allocator_type;
26
27    typedef typename allocator_type::reference       reference;
28    typedef typename allocator_type::const_reference const_reference;
29    typedef implementation-defined                   iterator;
30    typedef implementation-defined                   const_iterator;
31    typedef typename allocator_type::size_type       size_type;
32    typedef typename allocator_type::difference_type difference_type;
33
34    typedef typename allocator_type::pointer         pointer;
35    typedef typename allocator_type::const_pointer   const_pointer;
36    typedef std::reverse_iterator<iterator>          reverse_iterator;
37    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
38
39    // construct/copy/destroy:
40    deque() noexcept(is_nothrow_default_constructible<allocator_type>::value);
41    explicit deque(const allocator_type& a);
42    explicit deque(size_type n);
43    explicit deque(size_type n, const allocator_type& a); // C++14
44    deque(size_type n, const value_type& v);
45    deque(size_type n, const value_type& v, const allocator_type& a);
46    template <class InputIterator>
47        deque(InputIterator f, InputIterator l);
48    template <class InputIterator>
49        deque(InputIterator f, InputIterator l, const allocator_type& a);
50    template<container-compatible-range<T> R>
51        deque(from_range_t, R&& rg, const Allocator& = Allocator()); // C++23
52    deque(const deque& c);
53    deque(deque&& c)
54        noexcept(is_nothrow_move_constructible<allocator_type>::value);
55    deque(initializer_list<value_type> il, const Allocator& a = allocator_type());
56    deque(const deque& c, const allocator_type& a);
57    deque(deque&& c, const allocator_type& a);
58    ~deque();
59
60    deque& operator=(const deque& c);
61    deque& operator=(deque&& c)
62        noexcept(
63             allocator_type::propagate_on_container_move_assignment::value &&
64             is_nothrow_move_assignable<allocator_type>::value);
65    deque& operator=(initializer_list<value_type> il);
66
67    template <class InputIterator>
68        void assign(InputIterator f, InputIterator l);
69    template<container-compatible-range<T> R>
70      void assign_range(R&& rg); // C++23
71    void assign(size_type n, const value_type& v);
72    void assign(initializer_list<value_type> il);
73
74    allocator_type get_allocator() const noexcept;
75
76    // iterators:
77
78    iterator       begin() noexcept;
79    const_iterator begin() const noexcept;
80    iterator       end() noexcept;
81    const_iterator end() const noexcept;
82
83    reverse_iterator       rbegin() noexcept;
84    const_reverse_iterator rbegin() const noexcept;
85    reverse_iterator       rend() noexcept;
86    const_reverse_iterator rend() const noexcept;
87
88    const_iterator         cbegin() const noexcept;
89    const_iterator         cend() const noexcept;
90    const_reverse_iterator crbegin() const noexcept;
91    const_reverse_iterator crend() const noexcept;
92
93    // capacity:
94    size_type size() const noexcept;
95    size_type max_size() const noexcept;
96    void resize(size_type n);
97    void resize(size_type n, const value_type& v);
98    void shrink_to_fit();
99    bool empty() const noexcept;
100
101    // element access:
102    reference operator[](size_type i);
103    const_reference operator[](size_type i) const;
104    reference at(size_type i);
105    const_reference at(size_type i) const;
106    reference front();
107    const_reference front() const;
108    reference back();
109    const_reference back() const;
110
111    // modifiers:
112    void push_front(const value_type& v);
113    void push_front(value_type&& v);
114    template<container-compatible-range<T> R>
115      void prepend_range(R&& rg); // C++23
116    void push_back(const value_type& v);
117    void push_back(value_type&& v);
118    template<container-compatible-range<T> R>
119      void append_range(R&& rg); // C++23
120    template <class... Args> reference emplace_front(Args&&... args);  // reference in C++17
121    template <class... Args> reference emplace_back(Args&&... args);   // reference in C++17
122    template <class... Args> iterator emplace(const_iterator p, Args&&... args);
123    iterator insert(const_iterator p, const value_type& v);
124    iterator insert(const_iterator p, value_type&& v);
125    iterator insert(const_iterator p, size_type n, const value_type& v);
126    template <class InputIterator>
127        iterator insert(const_iterator p, InputIterator f, InputIterator l);
128    template<container-compatible-range<T> R>
129      iterator insert_range(const_iterator position, R&& rg); // C++23
130    iterator insert(const_iterator p, initializer_list<value_type> il);
131    void pop_front();
132    void pop_back();
133    iterator erase(const_iterator p);
134    iterator erase(const_iterator f, const_iterator l);
135    void swap(deque& c)
136        noexcept(allocator_traits<allocator_type>::is_always_equal::value);  // C++17
137    void clear() noexcept;
138};
139
140template <class InputIterator, class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
141   deque(InputIterator, InputIterator, Allocator = Allocator())
142   -> deque<typename iterator_traits<InputIterator>::value_type, Allocator>; // C++17
143
144template<ranges::input_range R, class Allocator = allocator<ranges::range_value_t<R>>>
145  deque(from_range_t, R&&, Allocator = Allocator())
146    -> deque<ranges::range_value_t<R>, Allocator>; // C++23
147
148template <class T, class Allocator>
149    bool operator==(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
150template <class T, class Allocator>
151    bool operator< (const deque<T,Allocator>& x, const deque<T,Allocator>& y); // removed in C++20
152template <class T, class Allocator>
153    bool operator!=(const deque<T,Allocator>& x, const deque<T,Allocator>& y); // removed in C++20
154template <class T, class Allocator>
155    bool operator> (const deque<T,Allocator>& x, const deque<T,Allocator>& y); // removed in C++20
156template <class T, class Allocator>
157    bool operator>=(const deque<T,Allocator>& x, const deque<T,Allocator>& y); // removed in C++20
158template <class T, class Allocator>
159    bool operator<=(const deque<T,Allocator>& x, const deque<T,Allocator>& y); // removed in C++20
160template<class T, class Allocator>
161    synth-three-way-result<T> operator<=>(const deque<T, Allocator>& x,
162                                          const deque<T, Allocator>& y);       // since C++20
163
164// specialized algorithms:
165template <class T, class Allocator>
166    void swap(deque<T,Allocator>& x, deque<T,Allocator>& y)
167         noexcept(noexcept(x.swap(y)));
168
169template <class T, class Allocator, class U>
170    typename deque<T, Allocator>::size_type
171    erase(deque<T, Allocator>& c, const U& value);       // C++20
172template <class T, class Allocator, class Predicate>
173    typename deque<T, Allocator>::size_type
174    erase_if(deque<T, Allocator>& c, Predicate pred);    // C++20
175
176}  // std
177
178*/
179
180#include <__cxx03/__algorithm/copy.h>
181#include <__cxx03/__algorithm/copy_backward.h>
182#include <__cxx03/__algorithm/copy_n.h>
183#include <__cxx03/__algorithm/equal.h>
184#include <__cxx03/__algorithm/fill_n.h>
185#include <__cxx03/__algorithm/lexicographical_compare.h>
186#include <__cxx03/__algorithm/min.h>
187#include <__cxx03/__algorithm/remove.h>
188#include <__cxx03/__algorithm/remove_if.h>
189#include <__cxx03/__algorithm/unwrap_iter.h>
190#include <__cxx03/__assert>
191#include <__cxx03/__config>
192#include <__cxx03/__debug_utils/sanitizers.h>
193#include <__cxx03/__fwd/deque.h>
194#include <__cxx03/__iterator/distance.h>
195#include <__cxx03/__iterator/iterator_traits.h>
196#include <__cxx03/__iterator/next.h>
197#include <__cxx03/__iterator/prev.h>
198#include <__cxx03/__iterator/reverse_iterator.h>
199#include <__cxx03/__iterator/segmented_iterator.h>
200#include <__cxx03/__memory/addressof.h>
201#include <__cxx03/__memory/allocator_destructor.h>
202#include <__cxx03/__memory/pointer_traits.h>
203#include <__cxx03/__memory/temp_value.h>
204#include <__cxx03/__memory/unique_ptr.h>
205#include <__cxx03/__split_buffer>
206#include <__cxx03/__type_traits/is_allocator.h>
207#include <__cxx03/__type_traits/is_convertible.h>
208#include <__cxx03/__type_traits/is_same.h>
209#include <__cxx03/__type_traits/is_swappable.h>
210#include <__cxx03/__type_traits/type_identity.h>
211#include <__cxx03/__utility/forward.h>
212#include <__cxx03/__utility/move.h>
213#include <__cxx03/__utility/pair.h>
214#include <__cxx03/__utility/swap.h>
215#include <__cxx03/limits>
216#include <__cxx03/stdexcept>
217#include <__cxx03/version>
218
219// standard-mandated includes
220
221// [iterator.range]
222#include <__cxx03/__iterator/access.h>
223
224#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
225#  pragma GCC system_header
226#endif
227
228_LIBCPP_PUSH_MACROS
229#include <__cxx03/__undef_macros>
230
231_LIBCPP_BEGIN_NAMESPACE_STD
232
233template <class _ValueType, class _DiffType>
234struct __deque_block_size {
235  static const _DiffType value = sizeof(_ValueType) < 256 ? 4096 / sizeof(_ValueType) : 16;
236};
237
238template <class _ValueType,
239          class _Pointer,
240          class _Reference,
241          class _MapPointer,
242          class _DiffType,
243          _DiffType _BS =
244#ifdef _LIBCPP_ABI_INCOMPLETE_TYPES_IN_DEQUE
245              // Keep template parameter to avoid changing all template declarations thoughout
246              // this file.
247          0
248#else
249              __deque_block_size<_ValueType, _DiffType>::value
250#endif
251          >
252class _LIBCPP_TEMPLATE_VIS __deque_iterator {
253  typedef _MapPointer __map_iterator;
254
255public:
256  typedef _Pointer pointer;
257  typedef _DiffType difference_type;
258
259private:
260  __map_iterator __m_iter_;
261  pointer __ptr_;
262
263  static const difference_type __block_size;
264
265public:
266  typedef _ValueType value_type;
267  typedef random_access_iterator_tag iterator_category;
268  typedef _Reference reference;
269
270  _LIBCPP_HIDE_FROM_ABI __deque_iterator() _NOEXCEPT {}
271
272  template <class _Pp, class _Rp, class _MP, __enable_if_t<is_convertible<_Pp, pointer>::value, int> = 0>
273  _LIBCPP_HIDE_FROM_ABI
274  __deque_iterator(const __deque_iterator<value_type, _Pp, _Rp, _MP, difference_type, _BS>& __it) _NOEXCEPT
275      : __m_iter_(__it.__m_iter_),
276        __ptr_(__it.__ptr_) {}
277
278  _LIBCPP_HIDE_FROM_ABI reference operator*() const { return *__ptr_; }
279  _LIBCPP_HIDE_FROM_ABI pointer operator->() const { return __ptr_; }
280
281  _LIBCPP_HIDE_FROM_ABI __deque_iterator& operator++() {
282    if (++__ptr_ - *__m_iter_ == __block_size) {
283      ++__m_iter_;
284      __ptr_ = *__m_iter_;
285    }
286    return *this;
287  }
288
289  _LIBCPP_HIDE_FROM_ABI __deque_iterator operator++(int) {
290    __deque_iterator __tmp = *this;
291    ++(*this);
292    return __tmp;
293  }
294
295  _LIBCPP_HIDE_FROM_ABI __deque_iterator& operator--() {
296    if (__ptr_ == *__m_iter_) {
297      --__m_iter_;
298      __ptr_ = *__m_iter_ + __block_size;
299    }
300    --__ptr_;
301    return *this;
302  }
303
304  _LIBCPP_HIDE_FROM_ABI __deque_iterator operator--(int) {
305    __deque_iterator __tmp = *this;
306    --(*this);
307    return __tmp;
308  }
309
310  _LIBCPP_HIDE_FROM_ABI __deque_iterator& operator+=(difference_type __n) {
311    if (__n != 0) {
312      __n += __ptr_ - *__m_iter_;
313      if (__n > 0) {
314        __m_iter_ += __n / __block_size;
315        __ptr_ = *__m_iter_ + __n % __block_size;
316      } else // (__n < 0)
317      {
318        difference_type __z = __block_size - 1 - __n;
319        __m_iter_ -= __z / __block_size;
320        __ptr_ = *__m_iter_ + (__block_size - 1 - __z % __block_size);
321      }
322    }
323    return *this;
324  }
325
326  _LIBCPP_HIDE_FROM_ABI __deque_iterator& operator-=(difference_type __n) { return *this += -__n; }
327
328  _LIBCPP_HIDE_FROM_ABI __deque_iterator operator+(difference_type __n) const {
329    __deque_iterator __t(*this);
330    __t += __n;
331    return __t;
332  }
333
334  _LIBCPP_HIDE_FROM_ABI __deque_iterator operator-(difference_type __n) const {
335    __deque_iterator __t(*this);
336    __t -= __n;
337    return __t;
338  }
339
340  _LIBCPP_HIDE_FROM_ABI friend __deque_iterator operator+(difference_type __n, const __deque_iterator& __it) {
341    return __it + __n;
342  }
343
344  _LIBCPP_HIDE_FROM_ABI friend difference_type operator-(const __deque_iterator& __x, const __deque_iterator& __y) {
345    if (__x != __y)
346      return (__x.__m_iter_ - __y.__m_iter_) * __block_size + (__x.__ptr_ - *__x.__m_iter_) -
347             (__y.__ptr_ - *__y.__m_iter_);
348    return 0;
349  }
350
351  _LIBCPP_HIDE_FROM_ABI reference operator[](difference_type __n) const { return *(*this + __n); }
352
353  _LIBCPP_HIDE_FROM_ABI friend bool operator==(const __deque_iterator& __x, const __deque_iterator& __y) {
354    return __x.__ptr_ == __y.__ptr_;
355  }
356
357  _LIBCPP_HIDE_FROM_ABI friend bool operator!=(const __deque_iterator& __x, const __deque_iterator& __y) {
358    return !(__x == __y);
359  }
360
361  // TODO(mordante) disable these overloads in the LLVM 20 release.
362  _LIBCPP_HIDE_FROM_ABI friend bool operator<(const __deque_iterator& __x, const __deque_iterator& __y) {
363    return __x.__m_iter_ < __y.__m_iter_ || (__x.__m_iter_ == __y.__m_iter_ && __x.__ptr_ < __y.__ptr_);
364  }
365
366  _LIBCPP_HIDE_FROM_ABI friend bool operator>(const __deque_iterator& __x, const __deque_iterator& __y) {
367    return __y < __x;
368  }
369
370  _LIBCPP_HIDE_FROM_ABI friend bool operator<=(const __deque_iterator& __x, const __deque_iterator& __y) {
371    return !(__y < __x);
372  }
373
374  _LIBCPP_HIDE_FROM_ABI friend bool operator>=(const __deque_iterator& __x, const __deque_iterator& __y) {
375    return !(__x < __y);
376  }
377
378private:
379  _LIBCPP_HIDE_FROM_ABI explicit __deque_iterator(__map_iterator __m, pointer __p) _NOEXCEPT
380      : __m_iter_(__m),
381        __ptr_(__p) {}
382
383  template <class _Tp, class _Ap>
384  friend class _LIBCPP_TEMPLATE_VIS deque;
385  template <class _Vp, class _Pp, class _Rp, class _MP, class _Dp, _Dp>
386  friend class _LIBCPP_TEMPLATE_VIS __deque_iterator;
387
388  template <class>
389  friend struct __segmented_iterator_traits;
390};
391
392template <class _ValueType, class _Pointer, class _Reference, class _MapPointer, class _DiffType, _DiffType _BlockSize>
393struct __segmented_iterator_traits<
394    __deque_iterator<_ValueType, _Pointer, _Reference, _MapPointer, _DiffType, _BlockSize> > {
395private:
396  using _Iterator = __deque_iterator<_ValueType, _Pointer, _Reference, _MapPointer, _DiffType, _BlockSize>;
397
398public:
399  using __is_segmented_iterator = true_type;
400  using __segment_iterator      = _MapPointer;
401  using __local_iterator        = _Pointer;
402
403  static _LIBCPP_HIDE_FROM_ABI __segment_iterator __segment(_Iterator __iter) { return __iter.__m_iter_; }
404  static _LIBCPP_HIDE_FROM_ABI __local_iterator __local(_Iterator __iter) { return __iter.__ptr_; }
405  static _LIBCPP_HIDE_FROM_ABI __local_iterator __begin(__segment_iterator __iter) { return *__iter; }
406
407  static _LIBCPP_HIDE_FROM_ABI __local_iterator __end(__segment_iterator __iter) {
408    return *__iter + _Iterator::__block_size;
409  }
410
411  static _LIBCPP_HIDE_FROM_ABI _Iterator __compose(__segment_iterator __segment, __local_iterator __local) {
412    if (__segment && __local == __end(__segment)) {
413      ++__segment;
414      return _Iterator(__segment, *__segment);
415    }
416    return _Iterator(__segment, __local);
417  }
418};
419
420template <class _ValueType, class _Pointer, class _Reference, class _MapPointer, class _DiffType, _DiffType _BlockSize>
421const _DiffType __deque_iterator<_ValueType, _Pointer, _Reference, _MapPointer, _DiffType, _BlockSize>::__block_size =
422    __deque_block_size<_ValueType, _DiffType>::value;
423
424template <class _Tp, class _Allocator /*= allocator<_Tp>*/>
425class _LIBCPP_TEMPLATE_VIS deque {
426public:
427  // types:
428
429  using value_type = _Tp;
430
431  using allocator_type = _Allocator;
432  using __alloc_traits = allocator_traits<allocator_type>;
433  static_assert(__check_valid_allocator<allocator_type>::value, "");
434  static_assert(is_same<typename allocator_type::value_type, value_type>::value,
435                "Allocator::value_type must be same type as value_type");
436
437  using size_type       = typename __alloc_traits::size_type;
438  using difference_type = typename __alloc_traits::difference_type;
439
440  using pointer       = typename __alloc_traits::pointer;
441  using const_pointer = typename __alloc_traits::const_pointer;
442
443  using __pointer_allocator       = __rebind_alloc<__alloc_traits, pointer>;
444  using __const_pointer_allocator = __rebind_alloc<__alloc_traits, const_pointer>;
445  using __map                     = __split_buffer<pointer, __pointer_allocator>;
446  using __map_alloc_traits        = allocator_traits<__pointer_allocator>;
447  using __map_pointer             = typename __map_alloc_traits::pointer;
448  using __map_const_pointer       = typename allocator_traits<__const_pointer_allocator>::const_pointer;
449  using __map_const_iterator      = typename __map::const_iterator;
450
451  using reference       = value_type&;
452  using const_reference = const value_type&;
453
454  using iterator = __deque_iterator<value_type, pointer, reference, __map_pointer, difference_type>;
455  using const_iterator =
456      __deque_iterator<value_type, const_pointer, const_reference, __map_const_pointer, difference_type>;
457  using reverse_iterator       = std::reverse_iterator<iterator>;
458  using const_reverse_iterator = std::reverse_iterator<const_iterator>;
459
460  // A deque contains the following members which may be trivially relocatable:
461  // - __map: is a `__split_buffer`, see `__split_buffer` for more information on when it is trivially relocatable
462  // - size_type: is always trivially relocatable, since it is required to be an integral type
463  // - allocator_type: may not be trivially relocatable, so it's checked
464  // None of these are referencing the `deque` itself, so if all of them are trivially relocatable, `deque` is too.
465  using __trivially_relocatable = __conditional_t<
466      __libcpp_is_trivially_relocatable<__map>::value && __libcpp_is_trivially_relocatable<allocator_type>::value,
467      deque,
468      void>;
469
470  static_assert(is_nothrow_default_constructible<allocator_type>::value ==
471                    is_nothrow_default_constructible<__pointer_allocator>::value,
472                "rebinding an allocator should not change exception guarantees");
473  static_assert(is_nothrow_move_constructible<allocator_type>::value ==
474                    is_nothrow_move_constructible<typename __map::allocator_type>::value,
475                "rebinding an allocator should not change exception guarantees");
476
477private:
478  struct __deque_block_range {
479    explicit _LIBCPP_HIDE_FROM_ABI __deque_block_range(pointer __b, pointer __e) _NOEXCEPT
480        : __begin_(__b),
481          __end_(__e) {}
482    const pointer __begin_;
483    const pointer __end_;
484  };
485
486  struct __deque_range {
487    iterator __pos_;
488    const iterator __end_;
489
490    _LIBCPP_HIDE_FROM_ABI __deque_range(iterator __pos, iterator __e) _NOEXCEPT : __pos_(__pos), __end_(__e) {}
491
492    explicit _LIBCPP_HIDE_FROM_ABI operator bool() const _NOEXCEPT { return __pos_ != __end_; }
493
494    _LIBCPP_HIDE_FROM_ABI __deque_range begin() const { return *this; }
495
496    _LIBCPP_HIDE_FROM_ABI __deque_range end() const { return __deque_range(__end_, __end_); }
497    _LIBCPP_HIDE_FROM_ABI __deque_block_range operator*() const _NOEXCEPT {
498      if (__pos_.__m_iter_ == __end_.__m_iter_) {
499        return __deque_block_range(__pos_.__ptr_, __end_.__ptr_);
500      }
501      return __deque_block_range(__pos_.__ptr_, *__pos_.__m_iter_ + __block_size);
502    }
503
504    _LIBCPP_HIDE_FROM_ABI __deque_range& operator++() _NOEXCEPT {
505      if (__pos_.__m_iter_ == __end_.__m_iter_) {
506        __pos_ = __end_;
507      } else {
508        ++__pos_.__m_iter_;
509        __pos_.__ptr_ = *__pos_.__m_iter_;
510      }
511      return *this;
512    }
513
514    _LIBCPP_HIDE_FROM_ABI friend bool operator==(__deque_range const& __lhs, __deque_range const& __rhs) {
515      return __lhs.__pos_ == __rhs.__pos_;
516    }
517    _LIBCPP_HIDE_FROM_ABI friend bool operator!=(__deque_range const& __lhs, __deque_range const& __rhs) {
518      return !(__lhs == __rhs);
519    }
520  };
521
522  struct _ConstructTransaction {
523    _LIBCPP_HIDE_FROM_ABI _ConstructTransaction(deque* __db, __deque_block_range& __r)
524        : __pos_(__r.__begin_), __end_(__r.__end_), __begin_(__r.__begin_), __base_(__db) {}
525
526    _LIBCPP_HIDE_FROM_ABI ~_ConstructTransaction() { __base_->__size() += (__pos_ - __begin_); }
527
528    pointer __pos_;
529    const pointer __end_;
530
531  private:
532    const pointer __begin_;
533    deque* const __base_;
534  };
535
536  static const difference_type __block_size;
537
538  __map __map_;
539  size_type __start_;
540  __compressed_pair<size_type, allocator_type> __size_;
541
542public:
543  // construct/copy/destroy:
544  _LIBCPP_HIDE_FROM_ABI deque() : __start_(0), __size_(0, __default_init_tag()) { __annotate_new(0); }
545
546  _LIBCPP_HIDE_FROM_ABI ~deque() {
547    clear();
548    __annotate_delete();
549    typename __map::iterator __i = __map_.begin();
550    typename __map::iterator __e = __map_.end();
551    for (; __i != __e; ++__i)
552      __alloc_traits::deallocate(__alloc(), *__i, __block_size);
553  }
554
555  _LIBCPP_HIDE_FROM_ABI explicit deque(const allocator_type& __a)
556      : __map_(__pointer_allocator(__a)), __start_(0), __size_(0, __a) {
557    __annotate_new(0);
558  }
559
560  explicit _LIBCPP_HIDE_FROM_ABI deque(size_type __n);
561  _LIBCPP_HIDE_FROM_ABI deque(size_type __n, const value_type& __v);
562
563  template <__enable_if_t<__is_allocator<_Allocator>::value, int> = 0>
564  _LIBCPP_HIDE_FROM_ABI deque(size_type __n, const value_type& __v, const allocator_type& __a)
565      : __map_(__pointer_allocator(__a)), __start_(0), __size_(0, __a) {
566    __annotate_new(0);
567    if (__n > 0)
568      __append(__n, __v);
569  }
570
571  template <class _InputIter, __enable_if_t<__has_input_iterator_category<_InputIter>::value, int> = 0>
572  _LIBCPP_HIDE_FROM_ABI deque(_InputIter __f, _InputIter __l);
573  template <class _InputIter, __enable_if_t<__has_input_iterator_category<_InputIter>::value, int> = 0>
574  _LIBCPP_HIDE_FROM_ABI deque(_InputIter __f, _InputIter __l, const allocator_type& __a);
575
576  _LIBCPP_HIDE_FROM_ABI deque(const deque& __c);
577  _LIBCPP_HIDE_FROM_ABI deque(const deque& __c, const __type_identity_t<allocator_type>& __a);
578
579  _LIBCPP_HIDE_FROM_ABI deque& operator=(const deque& __c);
580
581  template <class _InputIter,
582            __enable_if_t<__has_input_iterator_category<_InputIter>::value &&
583                              !__has_random_access_iterator_category<_InputIter>::value,
584                          int> = 0>
585  _LIBCPP_HIDE_FROM_ABI void assign(_InputIter __f, _InputIter __l);
586  template <class _RAIter, __enable_if_t<__has_random_access_iterator_category<_RAIter>::value, int> = 0>
587  _LIBCPP_HIDE_FROM_ABI void assign(_RAIter __f, _RAIter __l);
588
589  _LIBCPP_HIDE_FROM_ABI void assign(size_type __n, const value_type& __v);
590
591  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const _NOEXCEPT;
592  _LIBCPP_HIDE_FROM_ABI allocator_type& __alloc() _NOEXCEPT { return __size_.second(); }
593  _LIBCPP_HIDE_FROM_ABI const allocator_type& __alloc() const _NOEXCEPT { return __size_.second(); }
594
595  // iterators:
596
597  _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT {
598    __map_pointer __mp = __map_.begin() + __start_ / __block_size;
599    return iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
600  }
601
602  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT {
603    __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __start_ / __block_size);
604    return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
605  }
606
607  _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT {
608    size_type __p      = size() + __start_;
609    __map_pointer __mp = __map_.begin() + __p / __block_size;
610    return iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
611  }
612
613  _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT {
614    size_type __p            = size() + __start_;
615    __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __p / __block_size);
616    return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
617  }
618
619  _LIBCPP_HIDE_FROM_ABI reverse_iterator rbegin() _NOEXCEPT { return reverse_iterator(end()); }
620  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rbegin() const _NOEXCEPT { return const_reverse_iterator(end()); }
621  _LIBCPP_HIDE_FROM_ABI reverse_iterator rend() _NOEXCEPT { return reverse_iterator(begin()); }
622  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rend() const _NOEXCEPT { return const_reverse_iterator(begin()); }
623
624  _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT { return begin(); }
625  _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT { return end(); }
626  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crbegin() const _NOEXCEPT { return const_reverse_iterator(end()); }
627  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crend() const _NOEXCEPT { return const_reverse_iterator(begin()); }
628
629  // capacity:
630  _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __size(); }
631
632  _LIBCPP_HIDE_FROM_ABI size_type& __size() _NOEXCEPT { return __size_.first(); }
633  _LIBCPP_HIDE_FROM_ABI const size_type& __size() const _NOEXCEPT { return __size_.first(); }
634
635  _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT {
636    return std::min<size_type>(__alloc_traits::max_size(__alloc()), numeric_limits<difference_type>::max());
637  }
638  _LIBCPP_HIDE_FROM_ABI void resize(size_type __n);
639  _LIBCPP_HIDE_FROM_ABI void resize(size_type __n, const value_type& __v);
640  _LIBCPP_HIDE_FROM_ABI void shrink_to_fit() _NOEXCEPT;
641  _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT { return size() == 0; }
642
643  // element access:
644  _LIBCPP_HIDE_FROM_ABI reference operator[](size_type __i) _NOEXCEPT;
645  _LIBCPP_HIDE_FROM_ABI const_reference operator[](size_type __i) const _NOEXCEPT;
646  _LIBCPP_HIDE_FROM_ABI reference at(size_type __i);
647  _LIBCPP_HIDE_FROM_ABI const_reference at(size_type __i) const;
648  _LIBCPP_HIDE_FROM_ABI reference front() _NOEXCEPT;
649  _LIBCPP_HIDE_FROM_ABI const_reference front() const _NOEXCEPT;
650  _LIBCPP_HIDE_FROM_ABI reference back() _NOEXCEPT;
651  _LIBCPP_HIDE_FROM_ABI const_reference back() const _NOEXCEPT;
652
653  // 23.2.2.3 modifiers:
654  _LIBCPP_HIDE_FROM_ABI void push_front(const value_type& __v);
655  _LIBCPP_HIDE_FROM_ABI void push_back(const value_type& __v);
656
657  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, const value_type& __v);
658  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, size_type __n, const value_type& __v);
659  template <class _InputIter, __enable_if_t<__has_exactly_input_iterator_category<_InputIter>::value, int> = 0>
660  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, _InputIter __f, _InputIter __l);
661  template <class _ForwardIterator,
662            __enable_if_t<__has_exactly_forward_iterator_category<_ForwardIterator>::value, int> = 0>
663  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, _ForwardIterator __f, _ForwardIterator __l);
664  template <class _BiIter, __enable_if_t<__has_bidirectional_iterator_category<_BiIter>::value, int> = 0>
665  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, _BiIter __f, _BiIter __l);
666
667  _LIBCPP_HIDE_FROM_ABI void pop_front();
668  _LIBCPP_HIDE_FROM_ABI void pop_back();
669  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __p);
670  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __f, const_iterator __l);
671
672  _LIBCPP_HIDE_FROM_ABI void swap(deque& __c);
673  _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT;
674
675  _LIBCPP_HIDE_FROM_ABI bool __invariants() const {
676    if (!__map_.__invariants())
677      return false;
678    if (__map_.size() >= size_type(-1) / __block_size)
679      return false;
680    for (__map_const_iterator __i = __map_.begin(), __e = __map_.end(); __i != __e; ++__i)
681      if (*__i == nullptr)
682        return false;
683    if (__map_.size() != 0) {
684      if (size() >= __map_.size() * __block_size)
685        return false;
686      if (__start_ >= __map_.size() * __block_size - size())
687        return false;
688    } else {
689      if (size() != 0)
690        return false;
691      if (__start_ != 0)
692        return false;
693    }
694    return true;
695  }
696
697  _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(deque& __c) {
698    __move_assign_alloc(__c, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());
699  }
700
701  _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(deque& __c, true_type) { __alloc() = std::move(__c.__alloc()); }
702  _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(deque&, false_type) _NOEXCEPT {}
703
704  _LIBCPP_HIDE_FROM_ABI void __move_assign(deque& __c) {
705    __map_   = std::move(__c.__map_);
706    __start_ = __c.__start_;
707    __size() = __c.size();
708    __move_assign_alloc(__c);
709    __c.__start_ = __c.__size() = 0;
710  }
711
712  _LIBCPP_HIDE_FROM_ABI static size_type __recommend_blocks(size_type __n) {
713    return __n / __block_size + (__n % __block_size != 0);
714  }
715  _LIBCPP_HIDE_FROM_ABI size_type __capacity() const {
716    return __map_.size() == 0 ? 0 : __map_.size() * __block_size - 1;
717  }
718  _LIBCPP_HIDE_FROM_ABI size_type __block_count() const { return __map_.size(); }
719
720  _LIBCPP_HIDE_FROM_ABI size_type __front_spare() const { return __start_; }
721  _LIBCPP_HIDE_FROM_ABI size_type __front_spare_blocks() const { return __front_spare() / __block_size; }
722  _LIBCPP_HIDE_FROM_ABI size_type __back_spare() const { return __capacity() - (__start_ + size()); }
723  _LIBCPP_HIDE_FROM_ABI size_type __back_spare_blocks() const { return __back_spare() / __block_size; }
724
725private:
726  enum __asan_annotation_type { __asan_unposion, __asan_poison };
727
728  enum __asan_annotation_place {
729    __asan_front_moved,
730    __asan_back_moved,
731  };
732
733  _LIBCPP_HIDE_FROM_ABI void __annotate_from_to(
734      size_type __beg,
735      size_type __end,
736      __asan_annotation_type __annotation_type,
737      __asan_annotation_place __place) const _NOEXCEPT {
738    (void)__beg;
739    (void)__end;
740    (void)__annotation_type;
741    (void)__place;
742#ifndef _LIBCPP_HAS_NO_ASAN
743    // __beg - index of the first item to annotate
744    // __end - index behind the last item to annotate (so last item + 1)
745    // __annotation_type - __asan_unposion or __asan_poison
746    // __place - __asan_front_moved or __asan_back_moved
747    // Note: All indexes in __map_
748    if (__beg == __end)
749      return;
750    // __annotations_beg_map - first chunk which annotations we want to modify
751    // __annotations_end_map - last chunk which annotations we want to modify
752    // NOTE: if __end % __block_size == 0, __annotations_end_map points at the next block, which may not exist
753    __map_const_iterator __annotations_beg_map = __map_.begin() + __beg / __block_size;
754    __map_const_iterator __annotations_end_map = __map_.begin() + __end / __block_size;
755
756    bool const __poisoning = __annotation_type == __asan_poison;
757    // __old_c_beg_index - index of the first element in old container
758    // __old_c_end_index - index of the end of old container (last + 1)
759    // Note: may be outside the area we are annotating
760    size_t __old_c_beg_index = (__poisoning && __place == __asan_front_moved) ? __beg : __start_;
761    size_t __old_c_end_index = (__poisoning && __place == __asan_back_moved) ? __end : __start_ + size();
762    bool const __front       = __place == __asan_front_moved;
763
764    if (__poisoning && empty()) {
765      // Special case: we shouldn't trust __start_
766      __old_c_beg_index = __beg;
767      __old_c_end_index = __end;
768    }
769    // __old_c_beg_map - memory block (chunk) with first element
770    // __old_c_end_map - memory block (chunk) with end of old container
771    // Note: if __old_c_end_index % __block_size == 0, __old_c_end_map points at the next block,
772    // which may not exist
773    __map_const_iterator __old_c_beg_map = __map_.begin() + __old_c_beg_index / __block_size;
774    __map_const_iterator __old_c_end_map = __map_.begin() + __old_c_end_index / __block_size;
775
776    // One edge (front/end) of the container was moved and one was not modified.
777    // __new_edge_index - index of new edge
778    // __new_edge_map    - memory block (chunk) with new edge, it always equals to
779    //                    __annotations_beg_map or __annotations_end_map
780    // __old_edge_map    - memory block (chunk) with old edge, it always equals to
781    //                    __old_c_beg_map or __old_c_end_map
782    size_t __new_edge_index             = (__poisoning ^ __front) ? __beg : __end;
783    __map_const_iterator __new_edge_map = __map_.begin() + __new_edge_index / __block_size;
784    __map_const_iterator __old_edge_map = __front ? __old_c_end_map : __old_c_beg_map;
785
786    // We iterate over map pointers (chunks) and fully poison all memory blocks between the first and the last.
787    // First and last chunk may be partially poisoned.
788    // __annotate_end_map may point at not existing chunk, therefore we have to have a check for it.
789    for (__map_const_iterator __map_it = __annotations_beg_map; __map_it <= __annotations_end_map; ++__map_it) {
790      if (__map_it == __annotations_end_map && __end % __block_size == 0)
791        // Chunk may not exist, but nothing to do here anyway
792        break;
793
794      // The beginning and the end of the current memory block
795      const void* __mem_beg = std::__to_address(*__map_it);
796      const void* __mem_end = std::__to_address(*__map_it + __block_size);
797
798      // The beginning of memory-in-use in the memory block before container modification
799      const void* __old_beg =
800          (__map_it == __old_c_beg_map) ? std::__to_address(*__map_it + (__old_c_beg_index % __block_size)) : __mem_beg;
801
802      // The end of memory-in-use in the memory block before container modification
803      const void* __old_end;
804      if (__map_it < __old_c_beg_map || __map_it > __old_c_end_map || (!__poisoning && empty()))
805        __old_end = __old_beg;
806      else
807        __old_end = (__map_it == __old_c_end_map)
808                      ? std::__to_address(*__map_it + (__old_c_end_index % __block_size))
809                      : __mem_end;
810
811      // New edge of the container in current memory block
812      // If the edge is in a different chunk it points on corresponding end of the memory block
813      const void* __new_edge;
814      if (__map_it == __new_edge_map)
815        __new_edge = std::__to_address(*__map_it + (__new_edge_index % __block_size));
816      else
817        __new_edge = (__poisoning ^ __front) ? __mem_beg : __mem_end;
818
819      // Not modified edge of the container
820      // If the edge is in a different chunk it points on corresponding end of the memory block
821      const void* __old_edge;
822      if (__map_it == __old_edge_map)
823        __old_edge = __front ? __old_end : __old_beg;
824      else
825        __old_edge = __front ? __mem_end : __mem_beg;
826
827      // __new_beg - the beginning of memory-in-use in the memory block after container modification
828      // __new_end - the end of memory-in-use in the memory block after container modification
829      const void* __new_beg = __front ? __new_edge : __old_edge;
830      const void* __new_end = __front ? __old_edge : __new_edge;
831
832      std::__annotate_double_ended_contiguous_container<_Allocator>(
833          __mem_beg, __mem_end, __old_beg, __old_end, __new_beg, __new_end);
834    }
835#endif // !_LIBCPP_HAS_NO_ASAN
836  }
837
838  _LIBCPP_HIDE_FROM_ABI void __annotate_new(size_type __current_size) const _NOEXCEPT {
839    (void)__current_size;
840#ifndef _LIBCPP_HAS_NO_ASAN
841    if (__current_size == 0)
842      __annotate_from_to(0, __map_.size() * __block_size, __asan_poison, __asan_back_moved);
843    else {
844      __annotate_from_to(0, __start_, __asan_poison, __asan_front_moved);
845      __annotate_from_to(__start_ + __current_size, __map_.size() * __block_size, __asan_poison, __asan_back_moved);
846    }
847#endif
848  }
849
850  _LIBCPP_HIDE_FROM_ABI void __annotate_delete() const _NOEXCEPT {
851#ifndef _LIBCPP_HAS_NO_ASAN
852    if (empty()) {
853      for (size_t __i = 0; __i < __map_.size(); ++__i) {
854        __annotate_whole_block(__i, __asan_unposion);
855      }
856    } else {
857      __annotate_from_to(0, __start_, __asan_unposion, __asan_front_moved);
858      __annotate_from_to(__start_ + size(), __map_.size() * __block_size, __asan_unposion, __asan_back_moved);
859    }
860#endif
861  }
862
863  _LIBCPP_HIDE_FROM_ABI void __annotate_increase_front(size_type __n) const _NOEXCEPT {
864    (void)__n;
865#ifndef _LIBCPP_HAS_NO_ASAN
866    __annotate_from_to(__start_ - __n, __start_, __asan_unposion, __asan_front_moved);
867#endif
868  }
869
870  _LIBCPP_HIDE_FROM_ABI void __annotate_increase_back(size_type __n) const _NOEXCEPT {
871    (void)__n;
872#ifndef _LIBCPP_HAS_NO_ASAN
873    __annotate_from_to(__start_ + size(), __start_ + size() + __n, __asan_unposion, __asan_back_moved);
874#endif
875  }
876
877  _LIBCPP_HIDE_FROM_ABI void __annotate_shrink_front(size_type __old_size, size_type __old_start) const _NOEXCEPT {
878    (void)__old_size;
879    (void)__old_start;
880#ifndef _LIBCPP_HAS_NO_ASAN
881    __annotate_from_to(__old_start, __old_start + (__old_size - size()), __asan_poison, __asan_front_moved);
882#endif
883  }
884
885  _LIBCPP_HIDE_FROM_ABI void __annotate_shrink_back(size_type __old_size, size_type __old_start) const _NOEXCEPT {
886    (void)__old_size;
887    (void)__old_start;
888#ifndef _LIBCPP_HAS_NO_ASAN
889    __annotate_from_to(__old_start + size(), __old_start + __old_size, __asan_poison, __asan_back_moved);
890#endif
891  }
892
893  _LIBCPP_HIDE_FROM_ABI void __annotate_poison_block(const void* __beginning, const void* __end) const _NOEXCEPT {
894    std::__annotate_double_ended_contiguous_container<_Allocator>(__beginning, __end, __beginning, __end, __end, __end);
895  }
896
897  _LIBCPP_HIDE_FROM_ABI void
898  __annotate_whole_block(size_t __block_index, __asan_annotation_type __annotation_type) const _NOEXCEPT {
899    (void)__block_index;
900    (void)__annotation_type;
901#ifndef _LIBCPP_HAS_NO_ASAN
902    __map_const_iterator __block_it = __map_.begin() + __block_index;
903    const void* __block_start       = std::__to_address(*__block_it);
904    const void* __block_end         = std::__to_address(*__block_it + __block_size);
905
906    if (__annotation_type == __asan_poison)
907      __annotate_poison_block(__block_start, __block_end);
908    else {
909      std::__annotate_double_ended_contiguous_container<_Allocator>(
910          __block_start, __block_end, __block_start, __block_start, __block_start, __block_end);
911    }
912#endif
913  }
914#if !defined(_LIBCPP_HAS_NO_ASAN)
915
916public:
917  _LIBCPP_HIDE_FROM_ABI bool __verify_asan_annotations() const _NOEXCEPT {
918    // This function tests deque object annotations.
919    if (empty()) {
920      for (__map_const_iterator __it = __map_.begin(); __it != __map_.end(); ++__it) {
921        if (!__sanitizer_verify_double_ended_contiguous_container(
922                std::__to_address(*__it),
923                std::__to_address(*__it),
924                std::__to_address(*__it),
925                std::__to_address(*__it + __block_size)))
926          return false;
927      }
928
929      return true;
930    }
931
932    size_type __end                 = __start_ + size();
933    __map_const_iterator __first_mp = __map_.begin() + __start_ / __block_size;
934    __map_const_iterator __last_mp  = __map_.begin() + (__end - 1) / __block_size;
935
936    // Pointers to first and after last elements
937    // Those can be in different deque blocks
938    const void* __p_beg = std::__to_address(*__first_mp + (__start_ % __block_size));
939    const void* __p_end =
940        std::__to_address(*__last_mp + ((__end % __block_size == 0) ? __block_size : __end % __block_size));
941
942    for (__map_const_iterator __it = __map_.begin(); __it != __map_.end(); ++__it) {
943      // Go over all blocks, find the place we are in and verify its annotations
944      // Note that __p_end points *behind* the last item.
945
946      // - blocks before the first block with container elements
947      // - first block with items
948      // - last block with items
949      // - blocks after last block with ciontainer elements
950
951      // Is the block before or after deque blocks that contain elements?
952      if (__it < __first_mp || __it > __last_mp) {
953        if (!__sanitizer_verify_double_ended_contiguous_container(
954                std::__to_address(*__it),
955                std::__to_address(*__it),
956                std::__to_address(*__it),
957                std::__to_address(*__it + __block_size)))
958          return false;
959      } else {
960        const void* __containers_buffer_beg = (__it == __first_mp) ? __p_beg : (const void*)std::__to_address(*__it);
961        const void* __containers_buffer_end =
962            (__it == __last_mp) ? __p_end : (const void*)std::__to_address(*__it + __block_size);
963        if (!__sanitizer_verify_double_ended_contiguous_container(
964                std::__to_address(*__it),
965                __containers_buffer_beg,
966                __containers_buffer_end,
967                std::__to_address(*__it + __block_size))) {
968          return false;
969        }
970      }
971    }
972    return true;
973  }
974
975private:
976#endif // _LIBCPP_VERIFY_ASAN_DEQUE_ANNOTATIONS
977  _LIBCPP_HIDE_FROM_ABI bool __maybe_remove_front_spare(bool __keep_one = true) {
978    if (__front_spare_blocks() >= 2 || (!__keep_one && __front_spare_blocks())) {
979      __annotate_whole_block(0, __asan_unposion);
980      __alloc_traits::deallocate(__alloc(), __map_.front(), __block_size);
981      __map_.pop_front();
982      __start_ -= __block_size;
983      return true;
984    }
985    return false;
986  }
987
988  _LIBCPP_HIDE_FROM_ABI bool __maybe_remove_back_spare(bool __keep_one = true) {
989    if (__back_spare_blocks() >= 2 || (!__keep_one && __back_spare_blocks())) {
990      __annotate_whole_block(__map_.size() - 1, __asan_unposion);
991      __alloc_traits::deallocate(__alloc(), __map_.back(), __block_size);
992      __map_.pop_back();
993      return true;
994    }
995    return false;
996  }
997
998  template <class _Iterator, class _Sentinel>
999  _LIBCPP_HIDE_FROM_ABI void __assign_with_sentinel(_Iterator __f, _Sentinel __l);
1000
1001  template <class _RandomAccessIterator>
1002  _LIBCPP_HIDE_FROM_ABI void __assign_with_size_random_access(_RandomAccessIterator __f, difference_type __n);
1003  template <class _Iterator>
1004  _LIBCPP_HIDE_FROM_ABI void __assign_with_size(_Iterator __f, difference_type __n);
1005
1006  template <class _Iterator, class _Sentinel>
1007  _LIBCPP_HIDE_FROM_ABI iterator __insert_with_sentinel(const_iterator __p, _Iterator __f, _Sentinel __l);
1008
1009  template <class _Iterator>
1010  _LIBCPP_HIDE_FROM_ABI iterator __insert_with_size(const_iterator __p, _Iterator __f, size_type __n);
1011
1012  template <class _BiIter, class _Sentinel>
1013  _LIBCPP_HIDE_FROM_ABI iterator
1014  __insert_bidirectional(const_iterator __p, _BiIter __f, _Sentinel __sent, size_type __n);
1015  template <class _BiIter>
1016  _LIBCPP_HIDE_FROM_ABI iterator __insert_bidirectional(const_iterator __p, _BiIter __f, _BiIter __l, size_type __n);
1017
1018  template <class _InpIter, __enable_if_t<__has_exactly_input_iterator_category<_InpIter>::value, int> = 0>
1019  _LIBCPP_HIDE_FROM_ABI void __append(_InpIter __f, _InpIter __l);
1020  template <class _ForIter, __enable_if_t<__has_forward_iterator_category<_ForIter>::value, int> = 0>
1021  _LIBCPP_HIDE_FROM_ABI void __append(_ForIter __f, _ForIter __l);
1022
1023  template <class _InputIterator>
1024  _LIBCPP_HIDE_FROM_ABI void __append_with_size(_InputIterator __from, size_type __n);
1025  template <class _InputIterator, class _Sentinel>
1026  _LIBCPP_HIDE_FROM_ABI void __append_with_sentinel(_InputIterator __f, _Sentinel __l);
1027
1028  _LIBCPP_HIDE_FROM_ABI void __append(size_type __n);
1029  _LIBCPP_HIDE_FROM_ABI void __append(size_type __n, const value_type& __v);
1030  _LIBCPP_HIDE_FROM_ABI void __erase_to_end(const_iterator __f);
1031  _LIBCPP_HIDE_FROM_ABI void __add_front_capacity();
1032  _LIBCPP_HIDE_FROM_ABI void __add_front_capacity(size_type __n);
1033  _LIBCPP_HIDE_FROM_ABI void __add_back_capacity();
1034  _LIBCPP_HIDE_FROM_ABI void __add_back_capacity(size_type __n);
1035  _LIBCPP_HIDE_FROM_ABI iterator __move_and_check(iterator __f, iterator __l, iterator __r, const_pointer& __vt);
1036  _LIBCPP_HIDE_FROM_ABI iterator
1037  __move_backward_and_check(iterator __f, iterator __l, iterator __r, const_pointer& __vt);
1038  _LIBCPP_HIDE_FROM_ABI void __move_construct_and_check(iterator __f, iterator __l, iterator __r, const_pointer& __vt);
1039  _LIBCPP_HIDE_FROM_ABI void
1040  __move_construct_backward_and_check(iterator __f, iterator __l, iterator __r, const_pointer& __vt);
1041
1042  _LIBCPP_HIDE_FROM_ABI void __copy_assign_alloc(const deque& __c) {
1043    __copy_assign_alloc(__c, integral_constant<bool, __alloc_traits::propagate_on_container_copy_assignment::value>());
1044  }
1045
1046  _LIBCPP_HIDE_FROM_ABI void __copy_assign_alloc(const deque& __c, true_type) {
1047    if (__alloc() != __c.__alloc()) {
1048      clear();
1049      shrink_to_fit();
1050    }
1051    __alloc()        = __c.__alloc();
1052    __map_.__alloc() = __c.__map_.__alloc();
1053  }
1054
1055  _LIBCPP_HIDE_FROM_ABI void __copy_assign_alloc(const deque&, false_type) {}
1056
1057  _LIBCPP_HIDE_FROM_ABI void __move_assign(deque& __c, true_type);
1058  _LIBCPP_HIDE_FROM_ABI void __move_assign(deque& __c, false_type);
1059};
1060
1061template <class _Tp, class _Alloc>
1062const typename allocator_traits<_Alloc>::difference_type deque<_Tp, _Alloc>::__block_size =
1063    __deque_block_size<value_type, difference_type>::value;
1064
1065template <class _Tp, class _Allocator>
1066deque<_Tp, _Allocator>::deque(size_type __n) : __start_(0), __size_(0, __default_init_tag()) {
1067  __annotate_new(0);
1068  if (__n > 0)
1069    __append(__n);
1070}
1071
1072template <class _Tp, class _Allocator>
1073deque<_Tp, _Allocator>::deque(size_type __n, const value_type& __v) : __start_(0), __size_(0, __default_init_tag()) {
1074  __annotate_new(0);
1075  if (__n > 0)
1076    __append(__n, __v);
1077}
1078
1079template <class _Tp, class _Allocator>
1080template <class _InputIter, __enable_if_t<__has_input_iterator_category<_InputIter>::value, int> >
1081deque<_Tp, _Allocator>::deque(_InputIter __f, _InputIter __l) : __start_(0), __size_(0, __default_init_tag()) {
1082  __annotate_new(0);
1083  __append(__f, __l);
1084}
1085
1086template <class _Tp, class _Allocator>
1087template <class _InputIter, __enable_if_t<__has_input_iterator_category<_InputIter>::value, int> >
1088deque<_Tp, _Allocator>::deque(_InputIter __f, _InputIter __l, const allocator_type& __a)
1089    : __map_(__pointer_allocator(__a)), __start_(0), __size_(0, __a) {
1090  __annotate_new(0);
1091  __append(__f, __l);
1092}
1093
1094template <class _Tp, class _Allocator>
1095deque<_Tp, _Allocator>::deque(const deque& __c)
1096    : __map_(__pointer_allocator(__alloc_traits::select_on_container_copy_construction(__c.__alloc()))),
1097      __start_(0),
1098      __size_(0, __map_.__alloc()) {
1099  __annotate_new(0);
1100  __append(__c.begin(), __c.end());
1101}
1102
1103template <class _Tp, class _Allocator>
1104deque<_Tp, _Allocator>::deque(const deque& __c, const __type_identity_t<allocator_type>& __a)
1105    : __map_(__pointer_allocator(__a)), __start_(0), __size_(0, __a) {
1106  __annotate_new(0);
1107  __append(__c.begin(), __c.end());
1108}
1109
1110template <class _Tp, class _Allocator>
1111deque<_Tp, _Allocator>& deque<_Tp, _Allocator>::operator=(const deque& __c) {
1112  if (this != std::addressof(__c)) {
1113    __copy_assign_alloc(__c);
1114    assign(__c.begin(), __c.end());
1115  }
1116  return *this;
1117}
1118
1119template <class _Tp, class _Allocator>
1120template <class _InputIter,
1121          __enable_if_t<__has_input_iterator_category<_InputIter>::value &&
1122                            !__has_random_access_iterator_category<_InputIter>::value,
1123                        int> >
1124void deque<_Tp, _Allocator>::assign(_InputIter __f, _InputIter __l) {
1125  __assign_with_sentinel(__f, __l);
1126}
1127
1128template <class _Tp, class _Allocator>
1129template <class _Iterator, class _Sentinel>
1130_LIBCPP_HIDE_FROM_ABI void deque<_Tp, _Allocator>::__assign_with_sentinel(_Iterator __f, _Sentinel __l) {
1131  iterator __i = begin();
1132  iterator __e = end();
1133  for (; __f != __l && __i != __e; ++__f, (void)++__i)
1134    *__i = *__f;
1135  if (__f != __l)
1136    __append_with_sentinel(std::move(__f), std::move(__l));
1137  else
1138    __erase_to_end(__i);
1139}
1140
1141template <class _Tp, class _Allocator>
1142template <class _RAIter, __enable_if_t<__has_random_access_iterator_category<_RAIter>::value, int> >
1143void deque<_Tp, _Allocator>::assign(_RAIter __f, _RAIter __l) {
1144  __assign_with_size_random_access(__f, __l - __f);
1145}
1146
1147template <class _Tp, class _Allocator>
1148template <class _RandomAccessIterator>
1149_LIBCPP_HIDE_FROM_ABI void
1150deque<_Tp, _Allocator>::__assign_with_size_random_access(_RandomAccessIterator __f, difference_type __n) {
1151  if (static_cast<size_type>(__n) > size()) {
1152    auto __l = __f + size();
1153    std::copy(__f, __l, begin());
1154    __append_with_size(__l, __n - size());
1155  } else
1156    __erase_to_end(std::copy_n(__f, __n, begin()));
1157}
1158
1159template <class _Tp, class _Allocator>
1160template <class _Iterator>
1161_LIBCPP_HIDE_FROM_ABI void deque<_Tp, _Allocator>::__assign_with_size(_Iterator __f, difference_type __n) {
1162  if (static_cast<size_type>(__n) > size()) {
1163    auto __added_size = __n - size();
1164
1165    auto __i = begin();
1166    for (auto __count = size(); __count != 0; --__count) {
1167      *__i++ = *__f++;
1168    }
1169
1170    __append_with_size(__f, __added_size);
1171
1172  } else {
1173    __erase_to_end(std::copy_n(__f, __n, begin()));
1174  }
1175}
1176
1177template <class _Tp, class _Allocator>
1178void deque<_Tp, _Allocator>::assign(size_type __n, const value_type& __v) {
1179  if (__n > size()) {
1180    std::fill_n(begin(), size(), __v);
1181    __n -= size();
1182    __append(__n, __v);
1183  } else
1184    __erase_to_end(std::fill_n(begin(), __n, __v));
1185}
1186
1187template <class _Tp, class _Allocator>
1188inline _Allocator deque<_Tp, _Allocator>::get_allocator() const _NOEXCEPT {
1189  return __alloc();
1190}
1191
1192template <class _Tp, class _Allocator>
1193void deque<_Tp, _Allocator>::resize(size_type __n) {
1194  if (__n > size())
1195    __append(__n - size());
1196  else if (__n < size())
1197    __erase_to_end(begin() + __n);
1198}
1199
1200template <class _Tp, class _Allocator>
1201void deque<_Tp, _Allocator>::resize(size_type __n, const value_type& __v) {
1202  if (__n > size())
1203    __append(__n - size(), __v);
1204  else if (__n < size())
1205    __erase_to_end(begin() + __n);
1206}
1207
1208template <class _Tp, class _Allocator>
1209void deque<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT {
1210  allocator_type& __a = __alloc();
1211  if (empty()) {
1212    __annotate_delete();
1213    while (__map_.size() > 0) {
1214      __alloc_traits::deallocate(__a, __map_.back(), __block_size);
1215      __map_.pop_back();
1216    }
1217    __start_ = 0;
1218  } else {
1219    __maybe_remove_front_spare(/*__keep_one=*/false);
1220    __maybe_remove_back_spare(/*__keep_one=*/false);
1221  }
1222  __map_.shrink_to_fit();
1223}
1224
1225template <class _Tp, class _Allocator>
1226inline typename deque<_Tp, _Allocator>::reference deque<_Tp, _Allocator>::operator[](size_type __i) _NOEXCEPT {
1227  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__i < size(), "deque::operator[] index out of bounds");
1228  size_type __p = __start_ + __i;
1229  return *(*(__map_.begin() + __p / __block_size) + __p % __block_size);
1230}
1231
1232template <class _Tp, class _Allocator>
1233inline typename deque<_Tp, _Allocator>::const_reference
1234deque<_Tp, _Allocator>::operator[](size_type __i) const _NOEXCEPT {
1235  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__i < size(), "deque::operator[] index out of bounds");
1236  size_type __p = __start_ + __i;
1237  return *(*(__map_.begin() + __p / __block_size) + __p % __block_size);
1238}
1239
1240template <class _Tp, class _Allocator>
1241inline typename deque<_Tp, _Allocator>::reference deque<_Tp, _Allocator>::at(size_type __i) {
1242  if (__i >= size())
1243    std::__throw_out_of_range("deque");
1244  size_type __p = __start_ + __i;
1245  return *(*(__map_.begin() + __p / __block_size) + __p % __block_size);
1246}
1247
1248template <class _Tp, class _Allocator>
1249inline typename deque<_Tp, _Allocator>::const_reference deque<_Tp, _Allocator>::at(size_type __i) const {
1250  if (__i >= size())
1251    std::__throw_out_of_range("deque");
1252  size_type __p = __start_ + __i;
1253  return *(*(__map_.begin() + __p / __block_size) + __p % __block_size);
1254}
1255
1256template <class _Tp, class _Allocator>
1257inline typename deque<_Tp, _Allocator>::reference deque<_Tp, _Allocator>::front() _NOEXCEPT {
1258  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "deque::front called on an empty deque");
1259  return *(*(__map_.begin() + __start_ / __block_size) + __start_ % __block_size);
1260}
1261
1262template <class _Tp, class _Allocator>
1263inline typename deque<_Tp, _Allocator>::const_reference deque<_Tp, _Allocator>::front() const _NOEXCEPT {
1264  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "deque::front called on an empty deque");
1265  return *(*(__map_.begin() + __start_ / __block_size) + __start_ % __block_size);
1266}
1267
1268template <class _Tp, class _Allocator>
1269inline typename deque<_Tp, _Allocator>::reference deque<_Tp, _Allocator>::back() _NOEXCEPT {
1270  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "deque::back called on an empty deque");
1271  size_type __p = size() + __start_ - 1;
1272  return *(*(__map_.begin() + __p / __block_size) + __p % __block_size);
1273}
1274
1275template <class _Tp, class _Allocator>
1276inline typename deque<_Tp, _Allocator>::const_reference deque<_Tp, _Allocator>::back() const _NOEXCEPT {
1277  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "deque::back called on an empty deque");
1278  size_type __p = size() + __start_ - 1;
1279  return *(*(__map_.begin() + __p / __block_size) + __p % __block_size);
1280}
1281
1282template <class _Tp, class _Allocator>
1283void deque<_Tp, _Allocator>::push_back(const value_type& __v) {
1284  allocator_type& __a = __alloc();
1285  if (__back_spare() == 0)
1286    __add_back_capacity();
1287  // __back_spare() >= 1
1288  __annotate_increase_back(1);
1289  __alloc_traits::construct(__a, std::addressof(*end()), __v);
1290  ++__size();
1291}
1292
1293template <class _Tp, class _Allocator>
1294void deque<_Tp, _Allocator>::push_front(const value_type& __v) {
1295  allocator_type& __a = __alloc();
1296  if (__front_spare() == 0)
1297    __add_front_capacity();
1298  // __front_spare() >= 1
1299  __annotate_increase_front(1);
1300  __alloc_traits::construct(__a, std::addressof(*--begin()), __v);
1301  --__start_;
1302  ++__size();
1303}
1304
1305template <class _Tp, class _Allocator>
1306typename deque<_Tp, _Allocator>::iterator deque<_Tp, _Allocator>::insert(const_iterator __p, const value_type& __v) {
1307  size_type __pos     = __p - begin();
1308  size_type __to_end  = size() - __pos;
1309  allocator_type& __a = __alloc();
1310  if (__pos < __to_end) { // insert by shifting things backward
1311    if (__front_spare() == 0)
1312      __add_front_capacity();
1313    // __front_spare() >= 1
1314    __annotate_increase_front(1);
1315    if (__pos == 0) {
1316      __alloc_traits::construct(__a, std::addressof(*--begin()), __v);
1317      --__start_;
1318      ++__size();
1319    } else {
1320      const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
1321      iterator __b       = begin();
1322      iterator __bm1     = std::prev(__b);
1323      if (__vt == pointer_traits<const_pointer>::pointer_to(*__b))
1324        __vt = pointer_traits<const_pointer>::pointer_to(*__bm1);
1325      __alloc_traits::construct(__a, std::addressof(*__bm1), std::move(*__b));
1326      --__start_;
1327      ++__size();
1328      if (__pos > 1)
1329        __b = __move_and_check(std::next(__b), __b + __pos, __b, __vt);
1330      *__b = *__vt;
1331    }
1332  } else { // insert by shifting things forward
1333    if (__back_spare() == 0)
1334      __add_back_capacity();
1335    // __back_capacity >= 1
1336    __annotate_increase_back(1);
1337    size_type __de = size() - __pos;
1338    if (__de == 0) {
1339      __alloc_traits::construct(__a, std::addressof(*end()), __v);
1340      ++__size();
1341    } else {
1342      const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
1343      iterator __e       = end();
1344      iterator __em1     = std::prev(__e);
1345      if (__vt == pointer_traits<const_pointer>::pointer_to(*__em1))
1346        __vt = pointer_traits<const_pointer>::pointer_to(*__e);
1347      __alloc_traits::construct(__a, std::addressof(*__e), std::move(*__em1));
1348      ++__size();
1349      if (__de > 1)
1350        __e = __move_backward_and_check(__e - __de, __em1, __e, __vt);
1351      *--__e = *__vt;
1352    }
1353  }
1354  return begin() + __pos;
1355}
1356
1357template <class _Tp, class _Allocator>
1358typename deque<_Tp, _Allocator>::iterator
1359deque<_Tp, _Allocator>::insert(const_iterator __p, size_type __n, const value_type& __v) {
1360  size_type __pos     = __p - begin();
1361  size_type __to_end  = __size() - __pos;
1362  allocator_type& __a = __alloc();
1363  if (__pos < __to_end) { // insert by shifting things backward
1364    if (__n > __front_spare())
1365      __add_front_capacity(__n - __front_spare());
1366    // __n <= __front_spare()
1367    __annotate_increase_front(__n);
1368    iterator __old_begin = begin();
1369    iterator __i         = __old_begin;
1370    if (__n > __pos) {
1371      for (size_type __m = __n - __pos; __m; --__m, --__start_, ++__size())
1372        __alloc_traits::construct(__a, std::addressof(*--__i), __v);
1373      __n = __pos;
1374    }
1375    if (__n > 0) {
1376      const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
1377      iterator __obn     = __old_begin + __n;
1378      __move_construct_backward_and_check(__old_begin, __obn, __i, __vt);
1379      if (__n < __pos)
1380        __old_begin = __move_and_check(__obn, __old_begin + __pos, __old_begin, __vt);
1381      std::fill_n(__old_begin, __n, *__vt);
1382    }
1383  } else { // insert by shifting things forward
1384    size_type __back_capacity = __back_spare();
1385    if (__n > __back_capacity)
1386      __add_back_capacity(__n - __back_capacity);
1387    // __n <= __back_capacity
1388    __annotate_increase_back(__n);
1389    iterator __old_end = end();
1390    iterator __i       = __old_end;
1391    size_type __de     = size() - __pos;
1392    if (__n > __de) {
1393      for (size_type __m = __n - __de; __m; --__m, (void)++__i, ++__size())
1394        __alloc_traits::construct(__a, std::addressof(*__i), __v);
1395      __n = __de;
1396    }
1397    if (__n > 0) {
1398      const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
1399      iterator __oen     = __old_end - __n;
1400      __move_construct_and_check(__oen, __old_end, __i, __vt);
1401      if (__n < __de)
1402        __old_end = __move_backward_and_check(__old_end - __de, __oen, __old_end, __vt);
1403      std::fill_n(__old_end - __n, __n, *__vt);
1404    }
1405  }
1406  return begin() + __pos;
1407}
1408
1409template <class _Tp, class _Allocator>
1410template <class _InputIter, __enable_if_t<__has_exactly_input_iterator_category<_InputIter>::value, int> >
1411typename deque<_Tp, _Allocator>::iterator
1412deque<_Tp, _Allocator>::insert(const_iterator __p, _InputIter __f, _InputIter __l) {
1413  return __insert_with_sentinel(__p, __f, __l);
1414}
1415
1416template <class _Tp, class _Allocator>
1417template <class _Iterator, class _Sentinel>
1418_LIBCPP_HIDE_FROM_ABI typename deque<_Tp, _Allocator>::iterator
1419deque<_Tp, _Allocator>::__insert_with_sentinel(const_iterator __p, _Iterator __f, _Sentinel __l) {
1420  __split_buffer<value_type, allocator_type&> __buf(__alloc());
1421  __buf.__construct_at_end_with_sentinel(std::move(__f), std::move(__l));
1422  typedef typename __split_buffer<value_type, allocator_type&>::iterator __bi;
1423  return insert(__p, move_iterator<__bi>(__buf.begin()), move_iterator<__bi>(__buf.end()));
1424}
1425
1426template <class _Tp, class _Allocator>
1427template <class _ForwardIterator, __enable_if_t<__has_exactly_forward_iterator_category<_ForwardIterator>::value, int> >
1428typename deque<_Tp, _Allocator>::iterator
1429deque<_Tp, _Allocator>::insert(const_iterator __p, _ForwardIterator __f, _ForwardIterator __l) {
1430  return __insert_with_size(__p, __f, std::distance(__f, __l));
1431}
1432
1433template <class _Tp, class _Allocator>
1434template <class _Iterator>
1435_LIBCPP_HIDE_FROM_ABI typename deque<_Tp, _Allocator>::iterator
1436deque<_Tp, _Allocator>::__insert_with_size(const_iterator __p, _Iterator __f, size_type __n) {
1437  __split_buffer<value_type, allocator_type&> __buf(__n, 0, __alloc());
1438  __buf.__construct_at_end_with_size(__f, __n);
1439  typedef typename __split_buffer<value_type, allocator_type&>::iterator __fwd;
1440  return insert(__p, move_iterator<__fwd>(__buf.begin()), move_iterator<__fwd>(__buf.end()));
1441}
1442
1443template <class _Tp, class _Allocator>
1444template <class _BiIter, __enable_if_t<__has_bidirectional_iterator_category<_BiIter>::value, int> >
1445typename deque<_Tp, _Allocator>::iterator deque<_Tp, _Allocator>::insert(const_iterator __p, _BiIter __f, _BiIter __l) {
1446  return __insert_bidirectional(__p, __f, __l, std::distance(__f, __l));
1447}
1448
1449template <class _Tp, class _Allocator>
1450template <class _BiIter, class _Sentinel>
1451_LIBCPP_HIDE_FROM_ABI typename deque<_Tp, _Allocator>::iterator
1452deque<_Tp, _Allocator>::__insert_bidirectional(const_iterator __p, _BiIter __f, _Sentinel, size_type __n) {
1453  return __insert_bidirectional(__p, __f, std::next(__f, __n), __n);
1454}
1455
1456template <class _Tp, class _Allocator>
1457template <class _BiIter>
1458_LIBCPP_HIDE_FROM_ABI typename deque<_Tp, _Allocator>::iterator
1459deque<_Tp, _Allocator>::__insert_bidirectional(const_iterator __p, _BiIter __f, _BiIter __l, size_type __n) {
1460  size_type __pos     = __p - begin();
1461  size_type __to_end  = size() - __pos;
1462  allocator_type& __a = __alloc();
1463  if (__pos < __to_end) { // insert by shifting things backward
1464    if (__n > __front_spare())
1465      __add_front_capacity(__n - __front_spare());
1466    // __n <= __front_spare()
1467    __annotate_increase_front(__n);
1468    iterator __old_begin = begin();
1469    iterator __i         = __old_begin;
1470    _BiIter __m          = __f;
1471    if (__n > __pos) {
1472      __m = __pos < __n / 2 ? std::prev(__l, __pos) : std::next(__f, __n - __pos);
1473      for (_BiIter __j = __m; __j != __f; --__start_, ++__size())
1474        __alloc_traits::construct(__a, std::addressof(*--__i), *--__j);
1475      __n = __pos;
1476    }
1477    if (__n > 0) {
1478      iterator __obn = __old_begin + __n;
1479      for (iterator __j = __obn; __j != __old_begin;) {
1480        __alloc_traits::construct(__a, std::addressof(*--__i), std::move(*--__j));
1481        --__start_;
1482        ++__size();
1483      }
1484      if (__n < __pos)
1485        __old_begin = std::move(__obn, __old_begin + __pos, __old_begin);
1486      std::copy(__m, __l, __old_begin);
1487    }
1488  } else { // insert by shifting things forward
1489    size_type __back_capacity = __back_spare();
1490    if (__n > __back_capacity)
1491      __add_back_capacity(__n - __back_capacity);
1492    // __n <= __back_capacity
1493    __annotate_increase_back(__n);
1494    iterator __old_end = end();
1495    iterator __i       = __old_end;
1496    _BiIter __m        = __l;
1497    size_type __de     = size() - __pos;
1498    if (__n > __de) {
1499      __m = __de < __n / 2 ? std::next(__f, __de) : std::prev(__l, __n - __de);
1500      for (_BiIter __j = __m; __j != __l; ++__i, (void)++__j, ++__size())
1501        __alloc_traits::construct(__a, std::addressof(*__i), *__j);
1502      __n = __de;
1503    }
1504    if (__n > 0) {
1505      iterator __oen = __old_end - __n;
1506      for (iterator __j = __oen; __j != __old_end; ++__i, (void)++__j, ++__size())
1507        __alloc_traits::construct(__a, std::addressof(*__i), std::move(*__j));
1508      if (__n < __de)
1509        __old_end = std::move_backward(__old_end - __de, __oen, __old_end);
1510      std::copy_backward(__f, __m, __old_end);
1511    }
1512  }
1513  return begin() + __pos;
1514}
1515
1516template <class _Tp, class _Allocator>
1517template <class _InpIter, __enable_if_t<__has_exactly_input_iterator_category<_InpIter>::value, int> >
1518void deque<_Tp, _Allocator>::__append(_InpIter __f, _InpIter __l) {
1519  __append_with_sentinel(__f, __l);
1520}
1521
1522template <class _Tp, class _Allocator>
1523template <class _InputIterator, class _Sentinel>
1524_LIBCPP_HIDE_FROM_ABI void deque<_Tp, _Allocator>::__append_with_sentinel(_InputIterator __f, _Sentinel __l) {
1525  for (; __f != __l; ++__f)
1526    push_back(*__f);
1527}
1528
1529template <class _Tp, class _Allocator>
1530template <class _ForIter, __enable_if_t<__has_forward_iterator_category<_ForIter>::value, int> >
1531void deque<_Tp, _Allocator>::__append(_ForIter __f, _ForIter __l) {
1532  __append_with_size(__f, std::distance(__f, __l));
1533}
1534
1535template <class _Tp, class _Allocator>
1536template <class _InputIterator>
1537_LIBCPP_HIDE_FROM_ABI void deque<_Tp, _Allocator>::__append_with_size(_InputIterator __f, size_type __n) {
1538  allocator_type& __a       = __alloc();
1539  size_type __back_capacity = __back_spare();
1540  if (__n > __back_capacity)
1541    __add_back_capacity(__n - __back_capacity);
1542
1543  // __n <= __back_capacity
1544  __annotate_increase_back(__n);
1545  for (__deque_block_range __br : __deque_range(end(), end() + __n)) {
1546    _ConstructTransaction __tx(this, __br);
1547    for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_, (void)++__f) {
1548      __alloc_traits::construct(__a, std::__to_address(__tx.__pos_), *__f);
1549    }
1550  }
1551}
1552
1553template <class _Tp, class _Allocator>
1554void deque<_Tp, _Allocator>::__append(size_type __n) {
1555  allocator_type& __a       = __alloc();
1556  size_type __back_capacity = __back_spare();
1557  if (__n > __back_capacity)
1558    __add_back_capacity(__n - __back_capacity);
1559  // __n <= __back_capacity
1560  __annotate_increase_back(__n);
1561  for (__deque_block_range __br : __deque_range(end(), end() + __n)) {
1562    _ConstructTransaction __tx(this, __br);
1563    for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) {
1564      __alloc_traits::construct(__a, std::__to_address(__tx.__pos_));
1565    }
1566  }
1567}
1568
1569template <class _Tp, class _Allocator>
1570void deque<_Tp, _Allocator>::__append(size_type __n, const value_type& __v) {
1571  allocator_type& __a       = __alloc();
1572  size_type __back_capacity = __back_spare();
1573  if (__n > __back_capacity)
1574    __add_back_capacity(__n - __back_capacity);
1575  // __n <= __back_capacity
1576  __annotate_increase_back(__n);
1577  for (__deque_block_range __br : __deque_range(end(), end() + __n)) {
1578    _ConstructTransaction __tx(this, __br);
1579    for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) {
1580      __alloc_traits::construct(__a, std::__to_address(__tx.__pos_), __v);
1581    }
1582  }
1583}
1584
1585// Create front capacity for one block of elements.
1586// Strong guarantee.  Either do it or don't touch anything.
1587template <class _Tp, class _Allocator>
1588void deque<_Tp, _Allocator>::__add_front_capacity() {
1589  allocator_type& __a = __alloc();
1590  if (__back_spare() >= __block_size) {
1591    __start_ += __block_size;
1592    pointer __pt = __map_.back();
1593    __map_.pop_back();
1594    __map_.push_front(__pt);
1595  }
1596  // Else if __map_.size() < __map_.capacity() then we need to allocate 1 buffer
1597  else if (__map_.size() < __map_.capacity()) { // we can put the new buffer into the map, but don't shift things around
1598    // until all buffers are allocated.  If we throw, we don't need to fix
1599    // anything up (any added buffers are undetectible)
1600    if (__map_.__front_spare() > 0)
1601      __map_.push_front(__alloc_traits::allocate(__a, __block_size));
1602    else {
1603      __map_.push_back(__alloc_traits::allocate(__a, __block_size));
1604      // Done allocating, reorder capacity
1605      pointer __pt = __map_.back();
1606      __map_.pop_back();
1607      __map_.push_front(__pt);
1608    }
1609    __start_ = __map_.size() == 1 ? __block_size / 2 : __start_ + __block_size;
1610  }
1611  // Else need to allocate 1 buffer, *and* we need to reallocate __map_.
1612  else {
1613    __split_buffer<pointer, __pointer_allocator&> __buf(
1614        std::max<size_type>(2 * __map_.capacity(), 1), 0, __map_.__alloc());
1615
1616    typedef __allocator_destructor<_Allocator> _Dp;
1617    unique_ptr<pointer, _Dp> __hold(__alloc_traits::allocate(__a, __block_size), _Dp(__a, __block_size));
1618    __buf.push_back(__hold.get());
1619    __hold.release();
1620
1621    for (__map_pointer __i = __map_.begin(); __i != __map_.end(); ++__i)
1622      __buf.push_back(*__i);
1623    std::swap(__map_.__first_, __buf.__first_);
1624    std::swap(__map_.__begin_, __buf.__begin_);
1625    std::swap(__map_.__end_, __buf.__end_);
1626    std::swap(__map_.__end_cap(), __buf.__end_cap());
1627    __start_ = __map_.size() == 1 ? __block_size / 2 : __start_ + __block_size;
1628  }
1629  __annotate_whole_block(0, __asan_poison);
1630}
1631
1632// Create front capacity for __n elements.
1633// Strong guarantee.  Either do it or don't touch anything.
1634template <class _Tp, class _Allocator>
1635void deque<_Tp, _Allocator>::__add_front_capacity(size_type __n) {
1636  allocator_type& __a = __alloc();
1637  size_type __nb      = __recommend_blocks(__n + __map_.empty());
1638  // Number of unused blocks at back:
1639  size_type __back_capacity = __back_spare() / __block_size;
1640  __back_capacity           = std::min(__back_capacity, __nb); // don't take more than you need
1641  __nb -= __back_capacity;                                     // number of blocks need to allocate
1642  // If __nb == 0, then we have sufficient capacity.
1643  if (__nb == 0) {
1644    __start_ += __block_size * __back_capacity;
1645    for (; __back_capacity > 0; --__back_capacity) {
1646      pointer __pt = __map_.back();
1647      __map_.pop_back();
1648      __map_.push_front(__pt);
1649    }
1650  }
1651  // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
1652  else if (__nb <= __map_.capacity() -
1653                       __map_.size()) { // we can put the new buffers into the map, but don't shift things around
1654    // until all buffers are allocated.  If we throw, we don't need to fix
1655    // anything up (any added buffers are undetectible)
1656    for (; __nb > 0; --__nb, __start_ += __block_size - (__map_.size() == 1)) {
1657      if (__map_.__front_spare() == 0)
1658        break;
1659      __map_.push_front(__alloc_traits::allocate(__a, __block_size));
1660      __annotate_whole_block(0, __asan_poison);
1661    }
1662    for (; __nb > 0; --__nb, ++__back_capacity)
1663      __map_.push_back(__alloc_traits::allocate(__a, __block_size));
1664    // Done allocating, reorder capacity
1665    __start_ += __back_capacity * __block_size;
1666    for (; __back_capacity > 0; --__back_capacity) {
1667      pointer __pt = __map_.back();
1668      __map_.pop_back();
1669      __map_.push_front(__pt);
1670      __annotate_whole_block(0, __asan_poison);
1671    }
1672  }
1673  // Else need to allocate __nb buffers, *and* we need to reallocate __map_.
1674  else {
1675    size_type __ds = (__nb + __back_capacity) * __block_size - __map_.empty();
1676    __split_buffer<pointer, __pointer_allocator&> __buf(
1677        std::max<size_type>(2 * __map_.capacity(), __nb + __map_.size()), 0, __map_.__alloc());
1678#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1679    try {
1680#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1681      for (; __nb > 0; --__nb) {
1682        __buf.push_back(__alloc_traits::allocate(__a, __block_size));
1683        // ASan: this is empty container, we have to poison whole block
1684        __annotate_poison_block(std::__to_address(__buf.back()), std::__to_address(__buf.back() + __block_size));
1685      }
1686#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1687    } catch (...) {
1688      __annotate_delete();
1689      for (__map_pointer __i = __buf.begin(); __i != __buf.end(); ++__i)
1690        __alloc_traits::deallocate(__a, *__i, __block_size);
1691      throw;
1692    }
1693#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1694    for (; __back_capacity > 0; --__back_capacity) {
1695      __buf.push_back(__map_.back());
1696      __map_.pop_back();
1697    }
1698    for (__map_pointer __i = __map_.begin(); __i != __map_.end(); ++__i)
1699      __buf.push_back(*__i);
1700    std::swap(__map_.__first_, __buf.__first_);
1701    std::swap(__map_.__begin_, __buf.__begin_);
1702    std::swap(__map_.__end_, __buf.__end_);
1703    std::swap(__map_.__end_cap(), __buf.__end_cap());
1704    __start_ += __ds;
1705  }
1706}
1707
1708// Create back capacity for one block of elements.
1709// Strong guarantee.  Either do it or don't touch anything.
1710template <class _Tp, class _Allocator>
1711void deque<_Tp, _Allocator>::__add_back_capacity() {
1712  allocator_type& __a = __alloc();
1713  if (__front_spare() >= __block_size) {
1714    __start_ -= __block_size;
1715    pointer __pt = __map_.front();
1716    __map_.pop_front();
1717    __map_.push_back(__pt);
1718  }
1719  // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
1720  else if (__map_.size() < __map_.capacity()) { // we can put the new buffer into the map, but don't shift things around
1721    // until it is allocated.  If we throw, we don't need to fix
1722    // anything up (any added buffers are undetectible)
1723    if (__map_.__back_spare() != 0)
1724      __map_.push_back(__alloc_traits::allocate(__a, __block_size));
1725    else {
1726      __map_.push_front(__alloc_traits::allocate(__a, __block_size));
1727      // Done allocating, reorder capacity
1728      pointer __pt = __map_.front();
1729      __map_.pop_front();
1730      __map_.push_back(__pt);
1731    }
1732    __annotate_whole_block(__map_.size() - 1, __asan_poison);
1733  }
1734  // Else need to allocate 1 buffer, *and* we need to reallocate __map_.
1735  else {
1736    __split_buffer<pointer, __pointer_allocator&> __buf(
1737        std::max<size_type>(2 * __map_.capacity(), 1), __map_.size(), __map_.__alloc());
1738
1739    typedef __allocator_destructor<_Allocator> _Dp;
1740    unique_ptr<pointer, _Dp> __hold(__alloc_traits::allocate(__a, __block_size), _Dp(__a, __block_size));
1741    __buf.push_back(__hold.get());
1742    __hold.release();
1743
1744    for (__map_pointer __i = __map_.end(); __i != __map_.begin();)
1745      __buf.push_front(*--__i);
1746    std::swap(__map_.__first_, __buf.__first_);
1747    std::swap(__map_.__begin_, __buf.__begin_);
1748    std::swap(__map_.__end_, __buf.__end_);
1749    std::swap(__map_.__end_cap(), __buf.__end_cap());
1750    __annotate_whole_block(__map_.size() - 1, __asan_poison);
1751  }
1752}
1753
1754// Create back capacity for __n elements.
1755// Strong guarantee.  Either do it or don't touch anything.
1756template <class _Tp, class _Allocator>
1757void deque<_Tp, _Allocator>::__add_back_capacity(size_type __n) {
1758  allocator_type& __a = __alloc();
1759  size_type __nb      = __recommend_blocks(__n + __map_.empty());
1760  // Number of unused blocks at front:
1761  size_type __front_capacity = __front_spare() / __block_size;
1762  __front_capacity           = std::min(__front_capacity, __nb); // don't take more than you need
1763  __nb -= __front_capacity;                                      // number of blocks need to allocate
1764  // If __nb == 0, then we have sufficient capacity.
1765  if (__nb == 0) {
1766    __start_ -= __block_size * __front_capacity;
1767    for (; __front_capacity > 0; --__front_capacity) {
1768      pointer __pt = __map_.front();
1769      __map_.pop_front();
1770      __map_.push_back(__pt);
1771    }
1772  }
1773  // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
1774  else if (__nb <= __map_.capacity() -
1775                       __map_.size()) { // we can put the new buffers into the map, but don't shift things around
1776    // until all buffers are allocated.  If we throw, we don't need to fix
1777    // anything up (any added buffers are undetectible)
1778    for (; __nb > 0; --__nb) {
1779      if (__map_.__back_spare() == 0)
1780        break;
1781      __map_.push_back(__alloc_traits::allocate(__a, __block_size));
1782      __annotate_whole_block(__map_.size() - 1, __asan_poison);
1783    }
1784    for (; __nb > 0; --__nb, ++__front_capacity, __start_ += __block_size - (__map_.size() == 1)) {
1785      __map_.push_front(__alloc_traits::allocate(__a, __block_size));
1786      __annotate_whole_block(0, __asan_poison);
1787    }
1788    // Done allocating, reorder capacity
1789    __start_ -= __block_size * __front_capacity;
1790    for (; __front_capacity > 0; --__front_capacity) {
1791      pointer __pt = __map_.front();
1792      __map_.pop_front();
1793      __map_.push_back(__pt);
1794    }
1795  }
1796  // Else need to allocate __nb buffers, *and* we need to reallocate __map_.
1797  else {
1798    size_type __ds = __front_capacity * __block_size;
1799    __split_buffer<pointer, __pointer_allocator&> __buf(
1800        std::max<size_type>(2 * __map_.capacity(), __nb + __map_.size()),
1801        __map_.size() - __front_capacity,
1802        __map_.__alloc());
1803#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1804    try {
1805#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1806      for (; __nb > 0; --__nb) {
1807        __buf.push_back(__alloc_traits::allocate(__a, __block_size));
1808        // ASan: this is an empty container, we have to poison the whole block
1809        __annotate_poison_block(std::__to_address(__buf.back()), std::__to_address(__buf.back() + __block_size));
1810      }
1811#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1812    } catch (...) {
1813      __annotate_delete();
1814      for (__map_pointer __i = __buf.begin(); __i != __buf.end(); ++__i)
1815        __alloc_traits::deallocate(__a, *__i, __block_size);
1816      throw;
1817    }
1818#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1819    for (; __front_capacity > 0; --__front_capacity) {
1820      __buf.push_back(__map_.front());
1821      __map_.pop_front();
1822    }
1823    for (__map_pointer __i = __map_.end(); __i != __map_.begin();)
1824      __buf.push_front(*--__i);
1825    std::swap(__map_.__first_, __buf.__first_);
1826    std::swap(__map_.__begin_, __buf.__begin_);
1827    std::swap(__map_.__end_, __buf.__end_);
1828    std::swap(__map_.__end_cap(), __buf.__end_cap());
1829    __start_ -= __ds;
1830  }
1831}
1832
1833template <class _Tp, class _Allocator>
1834void deque<_Tp, _Allocator>::pop_front() {
1835  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "deque::pop_front called on an empty deque");
1836  size_type __old_sz    = size();
1837  size_type __old_start = __start_;
1838  allocator_type& __a   = __alloc();
1839  __alloc_traits::destroy(
1840      __a, std::__to_address(*(__map_.begin() + __start_ / __block_size) + __start_ % __block_size));
1841  --__size();
1842  ++__start_;
1843  __annotate_shrink_front(__old_sz, __old_start);
1844  __maybe_remove_front_spare();
1845}
1846
1847template <class _Tp, class _Allocator>
1848void deque<_Tp, _Allocator>::pop_back() {
1849  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "deque::pop_back called on an empty deque");
1850  size_type __old_sz    = size();
1851  size_type __old_start = __start_;
1852  allocator_type& __a   = __alloc();
1853  size_type __p         = size() + __start_ - 1;
1854  __alloc_traits::destroy(__a, std::__to_address(*(__map_.begin() + __p / __block_size) + __p % __block_size));
1855  --__size();
1856  __annotate_shrink_back(__old_sz, __old_start);
1857  __maybe_remove_back_spare();
1858}
1859
1860// move assign [__f, __l) to [__r, __r + (__l-__f)).
1861// If __vt points into [__f, __l), then subtract (__f - __r) from __vt.
1862template <class _Tp, class _Allocator>
1863typename deque<_Tp, _Allocator>::iterator
1864deque<_Tp, _Allocator>::__move_and_check(iterator __f, iterator __l, iterator __r, const_pointer& __vt) {
1865  // as if
1866  //   for (; __f != __l; ++__f, ++__r)
1867  //       *__r = std::move(*__f);
1868  difference_type __n = __l - __f;
1869  while (__n > 0) {
1870    pointer __fb         = __f.__ptr_;
1871    pointer __fe         = *__f.__m_iter_ + __block_size;
1872    difference_type __bs = __fe - __fb;
1873    if (__bs > __n) {
1874      __bs = __n;
1875      __fe = __fb + __bs;
1876    }
1877    if (__fb <= __vt && __vt < __fe)
1878      __vt = (const_iterator(static_cast<__map_const_pointer>(__f.__m_iter_), __vt) -= __f - __r).__ptr_;
1879    __r = std::move(__fb, __fe, __r);
1880    __n -= __bs;
1881    __f += __bs;
1882  }
1883  return __r;
1884}
1885
1886// move assign [__f, __l) to [__r - (__l-__f), __r) backwards.
1887// If __vt points into [__f, __l), then add (__r - __l) to __vt.
1888template <class _Tp, class _Allocator>
1889typename deque<_Tp, _Allocator>::iterator
1890deque<_Tp, _Allocator>::__move_backward_and_check(iterator __f, iterator __l, iterator __r, const_pointer& __vt) {
1891  // as if
1892  //   while (__f != __l)
1893  //       *--__r = std::move(*--__l);
1894  difference_type __n = __l - __f;
1895  while (__n > 0) {
1896    --__l;
1897    pointer __lb         = *__l.__m_iter_;
1898    pointer __le         = __l.__ptr_ + 1;
1899    difference_type __bs = __le - __lb;
1900    if (__bs > __n) {
1901      __bs = __n;
1902      __lb = __le - __bs;
1903    }
1904    if (__lb <= __vt && __vt < __le)
1905      __vt = (const_iterator(static_cast<__map_const_pointer>(__l.__m_iter_), __vt) += __r - __l - 1).__ptr_;
1906    __r = std::move_backward(__lb, __le, __r);
1907    __n -= __bs;
1908    __l -= __bs - 1;
1909  }
1910  return __r;
1911}
1912
1913// move construct [__f, __l) to [__r, __r + (__l-__f)).
1914// If __vt points into [__f, __l), then add (__r - __f) to __vt.
1915template <class _Tp, class _Allocator>
1916void deque<_Tp, _Allocator>::__move_construct_and_check(iterator __f, iterator __l, iterator __r, const_pointer& __vt) {
1917  allocator_type& __a = __alloc();
1918  // as if
1919  //   for (; __f != __l; ++__r, ++__f, ++__size())
1920  //       __alloc_traits::construct(__a, std::addressof(*__r), std::move(*__f));
1921  difference_type __n = __l - __f;
1922  while (__n > 0) {
1923    pointer __fb         = __f.__ptr_;
1924    pointer __fe         = *__f.__m_iter_ + __block_size;
1925    difference_type __bs = __fe - __fb;
1926    if (__bs > __n) {
1927      __bs = __n;
1928      __fe = __fb + __bs;
1929    }
1930    if (__fb <= __vt && __vt < __fe)
1931      __vt = (const_iterator(static_cast<__map_const_pointer>(__f.__m_iter_), __vt) += __r - __f).__ptr_;
1932    for (; __fb != __fe; ++__fb, ++__r, ++__size())
1933      __alloc_traits::construct(__a, std::addressof(*__r), std::move(*__fb));
1934    __n -= __bs;
1935    __f += __bs;
1936  }
1937}
1938
1939// move construct [__f, __l) to [__r - (__l-__f), __r) backwards.
1940// If __vt points into [__f, __l), then subtract (__l - __r) from __vt.
1941template <class _Tp, class _Allocator>
1942void deque<_Tp, _Allocator>::__move_construct_backward_and_check(
1943    iterator __f, iterator __l, iterator __r, const_pointer& __vt) {
1944  allocator_type& __a = __alloc();
1945  // as if
1946  //   for (iterator __j = __l; __j != __f;)
1947  //   {
1948  //       __alloc_traitsconstruct(__a, std::addressof(*--__r), std::move(*--__j));
1949  //       --__start_;
1950  //       ++__size();
1951  //   }
1952  difference_type __n = __l - __f;
1953  while (__n > 0) {
1954    --__l;
1955    pointer __lb         = *__l.__m_iter_;
1956    pointer __le         = __l.__ptr_ + 1;
1957    difference_type __bs = __le - __lb;
1958    if (__bs > __n) {
1959      __bs = __n;
1960      __lb = __le - __bs;
1961    }
1962    if (__lb <= __vt && __vt < __le)
1963      __vt = (const_iterator(static_cast<__map_const_pointer>(__l.__m_iter_), __vt) -= __l - __r + 1).__ptr_;
1964    while (__le != __lb) {
1965      __alloc_traits::construct(__a, std::addressof(*--__r), std::move(*--__le));
1966      --__start_;
1967      ++__size();
1968    }
1969    __n -= __bs;
1970    __l -= __bs - 1;
1971  }
1972}
1973
1974template <class _Tp, class _Allocator>
1975typename deque<_Tp, _Allocator>::iterator deque<_Tp, _Allocator>::erase(const_iterator __f) {
1976  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
1977      __f != end(), "deque::erase(iterator) called with a non-dereferenceable iterator");
1978  size_type __old_sz    = size();
1979  size_type __old_start = __start_;
1980  iterator __b          = begin();
1981  difference_type __pos = __f - __b;
1982  iterator __p          = __b + __pos;
1983  allocator_type& __a   = __alloc();
1984  if (static_cast<size_t>(__pos) <= (size() - 1) / 2) { // erase from front
1985    std::move_backward(__b, __p, std::next(__p));
1986    __alloc_traits::destroy(__a, std::addressof(*__b));
1987    --__size();
1988    ++__start_;
1989    __annotate_shrink_front(__old_sz, __old_start);
1990    __maybe_remove_front_spare();
1991  } else { // erase from back
1992    iterator __i = std::move(std::next(__p), end(), __p);
1993    __alloc_traits::destroy(__a, std::addressof(*__i));
1994    --__size();
1995    __annotate_shrink_back(__old_sz, __old_start);
1996    __maybe_remove_back_spare();
1997  }
1998  return begin() + __pos;
1999}
2000
2001template <class _Tp, class _Allocator>
2002typename deque<_Tp, _Allocator>::iterator deque<_Tp, _Allocator>::erase(const_iterator __f, const_iterator __l) {
2003  _LIBCPP_ASSERT_VALID_INPUT_RANGE(__f <= __l, "deque::erase(first, last) called with an invalid range");
2004  size_type __old_sz    = size();
2005  size_type __old_start = __start_;
2006  difference_type __n   = __l - __f;
2007  iterator __b          = begin();
2008  difference_type __pos = __f - __b;
2009  iterator __p          = __b + __pos;
2010  if (__n > 0) {
2011    allocator_type& __a = __alloc();
2012    if (static_cast<size_t>(__pos) <= (size() - __n) / 2) { // erase from front
2013      iterator __i = std::move_backward(__b, __p, __p + __n);
2014      for (; __b != __i; ++__b)
2015        __alloc_traits::destroy(__a, std::addressof(*__b));
2016      __size() -= __n;
2017      __start_ += __n;
2018      __annotate_shrink_front(__old_sz, __old_start);
2019      while (__maybe_remove_front_spare()) {
2020      }
2021    } else { // erase from back
2022      iterator __i = std::move(__p + __n, end(), __p);
2023      for (iterator __e = end(); __i != __e; ++__i)
2024        __alloc_traits::destroy(__a, std::addressof(*__i));
2025      __size() -= __n;
2026      __annotate_shrink_back(__old_sz, __old_start);
2027      while (__maybe_remove_back_spare()) {
2028      }
2029    }
2030  }
2031  return begin() + __pos;
2032}
2033
2034template <class _Tp, class _Allocator>
2035void deque<_Tp, _Allocator>::__erase_to_end(const_iterator __f) {
2036  size_type __old_sz    = size();
2037  size_type __old_start = __start_;
2038  iterator __e          = end();
2039  difference_type __n   = __e - __f;
2040  if (__n > 0) {
2041    allocator_type& __a   = __alloc();
2042    iterator __b          = begin();
2043    difference_type __pos = __f - __b;
2044    for (iterator __p = __b + __pos; __p != __e; ++__p)
2045      __alloc_traits::destroy(__a, std::addressof(*__p));
2046    __size() -= __n;
2047    __annotate_shrink_back(__old_sz, __old_start);
2048    while (__maybe_remove_back_spare()) {
2049    }
2050  }
2051}
2052
2053template <class _Tp, class _Allocator>
2054inline void deque<_Tp, _Allocator>::swap(deque& __c) {
2055  __map_.swap(__c.__map_);
2056  std::swap(__start_, __c.__start_);
2057  std::swap(__size(), __c.__size());
2058  std::__swap_allocator(__alloc(), __c.__alloc());
2059}
2060
2061template <class _Tp, class _Allocator>
2062inline void deque<_Tp, _Allocator>::clear() _NOEXCEPT {
2063  __annotate_delete();
2064  allocator_type& __a = __alloc();
2065  for (iterator __i = begin(), __e = end(); __i != __e; ++__i)
2066    __alloc_traits::destroy(__a, std::addressof(*__i));
2067  __size() = 0;
2068  while (__map_.size() > 2) {
2069    __alloc_traits::deallocate(__a, __map_.front(), __block_size);
2070    __map_.pop_front();
2071  }
2072  switch (__map_.size()) {
2073  case 1:
2074    __start_ = __block_size / 2;
2075    break;
2076  case 2:
2077    __start_ = __block_size;
2078    break;
2079  }
2080  __annotate_new(0);
2081}
2082
2083template <class _Tp, class _Allocator>
2084inline _LIBCPP_HIDE_FROM_ABI bool operator==(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y) {
2085  const typename deque<_Tp, _Allocator>::size_type __sz = __x.size();
2086  return __sz == __y.size() && std::equal(__x.begin(), __x.end(), __y.begin());
2087}
2088
2089template <class _Tp, class _Allocator>
2090inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y) {
2091  return !(__x == __y);
2092}
2093
2094template <class _Tp, class _Allocator>
2095inline _LIBCPP_HIDE_FROM_ABI bool operator<(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y) {
2096  return std::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
2097}
2098
2099template <class _Tp, class _Allocator>
2100inline _LIBCPP_HIDE_FROM_ABI bool operator>(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y) {
2101  return __y < __x;
2102}
2103
2104template <class _Tp, class _Allocator>
2105inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y) {
2106  return !(__x < __y);
2107}
2108
2109template <class _Tp, class _Allocator>
2110inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y) {
2111  return !(__y < __x);
2112}
2113
2114template <class _Tp, class _Allocator>
2115inline _LIBCPP_HIDE_FROM_ABI void swap(deque<_Tp, _Allocator>& __x, deque<_Tp, _Allocator>& __y) {
2116  __x.swap(__y);
2117}
2118
2119_LIBCPP_END_NAMESPACE_STD
2120
2121_LIBCPP_POP_MACROS
2122
2123#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES)
2124#  include <__cxx03/algorithm>
2125#  include <__cxx03/atomic>
2126#  include <__cxx03/cstdlib>
2127#  include <__cxx03/functional>
2128#  include <__cxx03/iosfwd>
2129#  include <__cxx03/iterator>
2130#  include <__cxx03/type_traits>
2131#  include <__cxx03/typeinfo>
2132#endif
2133
2134#endif // _LIBCPP___CXX03_DEQUE
2135