xref: /llvm-project-15.0.7/libcxx/include/string (revision 2bb3a906)
1// -*- C++ -*-
2//===--------------------------- string -----------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is distributed under the University of Illinois Open Source
7// License. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_STRING
12#define _LIBCPP_STRING
13
14/*
15    string synopsis
16
17namespace std
18{
19
20template <class stateT>
21class fpos
22{
23private:
24    stateT st;
25public:
26    fpos(streamoff = streamoff());
27
28    operator streamoff() const;
29
30    stateT state() const;
31    void state(stateT);
32
33    fpos& operator+=(streamoff);
34    fpos  operator+ (streamoff) const;
35    fpos& operator-=(streamoff);
36    fpos  operator- (streamoff) const;
37};
38
39template <class stateT> streamoff operator-(const fpos<stateT>& x, const fpos<stateT>& y);
40
41template <class stateT> bool operator==(const fpos<stateT>& x, const fpos<stateT>& y);
42template <class stateT> bool operator!=(const fpos<stateT>& x, const fpos<stateT>& y);
43
44template <class charT>
45struct char_traits
46{
47    typedef charT     char_type;
48    typedef ...       int_type;
49    typedef streamoff off_type;
50    typedef streampos pos_type;
51    typedef mbstate_t state_type;
52
53    static void assign(char_type& c1, const char_type& c2) noexcept;
54    static constexpr bool eq(char_type c1, char_type c2) noexcept;
55    static constexpr bool lt(char_type c1, char_type c2) noexcept;
56
57    static int              compare(const char_type* s1, const char_type* s2, size_t n);
58    static size_t           length(const char_type* s);
59    static const char_type* find(const char_type* s, size_t n, const char_type& a);
60    static char_type*       move(char_type* s1, const char_type* s2, size_t n);
61    static char_type*       copy(char_type* s1, const char_type* s2, size_t n);
62    static char_type*       assign(char_type* s, size_t n, char_type a);
63
64    static constexpr int_type  not_eof(int_type c) noexcept;
65    static constexpr char_type to_char_type(int_type c) noexcept;
66    static constexpr int_type  to_int_type(char_type c) noexcept;
67    static constexpr bool      eq_int_type(int_type c1, int_type c2) noexcept;
68    static constexpr int_type  eof() noexcept;
69};
70
71template <> struct char_traits<char>;
72template <> struct char_traits<wchar_t>;
73
74template<class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
75class basic_string
76{
77public:
78// types:
79    typedef traits traits_type;
80    typedef typename traits_type::char_type value_type;
81    typedef Allocator allocator_type;
82    typedef typename allocator_type::size_type size_type;
83    typedef typename allocator_type::difference_type difference_type;
84    typedef typename allocator_type::reference reference;
85    typedef typename allocator_type::const_reference const_reference;
86    typedef typename allocator_type::pointer pointer;
87    typedef typename allocator_type::const_pointer const_pointer;
88    typedef implementation-defined iterator;
89    typedef implementation-defined const_iterator;
90    typedef std::reverse_iterator<iterator> reverse_iterator;
91    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
92
93    static const size_type npos = -1;
94
95    basic_string()
96        noexcept(is_nothrow_default_constructible<allocator_type>::value);
97    explicit basic_string(const allocator_type& a);
98    basic_string(const basic_string& str);
99    basic_string(basic_string&& str)
100        noexcept(is_nothrow_move_constructible<allocator_type>::value);
101    basic_string(const basic_string& str, size_type pos, size_type n = npos,
102                 const allocator_type& a = allocator_type());
103    basic_string(const value_type* s, const allocator_type& a = allocator_type());
104    basic_string(const value_type* s, size_type n, const allocator_type& a = allocator_type());
105    basic_string(size_type n, value_type c, const allocator_type& a = allocator_type());
106    template<class InputIterator>
107        basic_string(InputIterator begin, InputIterator end,
108                     const allocator_type& a = allocator_type());
109    basic_string(initializer_list<value_type>, const Allocator& = Allocator());
110    basic_string(const basic_string&, const Allocator&);
111    basic_string(basic_string&&, const Allocator&);
112
113    ~basic_string();
114
115    basic_string& operator=(const basic_string& str);
116    basic_string& operator=(basic_string&& str)
117        noexcept(
118             allocator_type::propagate_on_container_move_assignment::value &&
119             is_nothrow_move_assignable<allocator_type>::value);
120    basic_string& operator=(const value_type* s);
121    basic_string& operator=(value_type c);
122    basic_string& operator=(initializer_list<value_type>);
123
124    iterator       begin() noexcept;
125    const_iterator begin() const noexcept;
126    iterator       end() noexcept;
127    const_iterator end() const noexcept;
128
129    reverse_iterator       rbegin() noexcept;
130    const_reverse_iterator rbegin() const noexcept;
131    reverse_iterator       rend() noexcept;
132    const_reverse_iterator rend() const noexcept;
133
134    const_iterator         cbegin() const noexcept;
135    const_iterator         cend() const noexcept;
136    const_reverse_iterator crbegin() const noexcept;
137    const_reverse_iterator crend() const noexcept;
138
139    size_type size() const noexcept;
140    size_type length() const noexcept;
141    size_type max_size() const noexcept;
142    size_type capacity() const noexcept;
143
144    void resize(size_type n, value_type c);
145    void resize(size_type n);
146
147    void reserve(size_type res_arg = 0);
148    void shrink_to_fit();
149    void clear() noexcept;
150    bool empty() const noexcept;
151
152    const_reference operator[](size_type pos) const;
153    reference       operator[](size_type pos);
154
155    const_reference at(size_type n) const;
156    reference       at(size_type n);
157
158    basic_string& operator+=(const basic_string& str);
159    basic_string& operator+=(const value_type* s);
160    basic_string& operator+=(value_type c);
161    basic_string& operator+=(initializer_list<value_type>);
162
163    basic_string& append(const basic_string& str);
164    basic_string& append(const basic_string& str, size_type pos, size_type n=npos); //C++14
165    basic_string& append(const value_type* s, size_type n);
166    basic_string& append(const value_type* s);
167    basic_string& append(size_type n, value_type c);
168    template<class InputIterator>
169        basic_string& append(InputIterator first, InputIterator last);
170    basic_string& append(initializer_list<value_type>);
171
172    void push_back(value_type c);
173    void pop_back();
174    reference       front();
175    const_reference front() const;
176    reference       back();
177    const_reference back() const;
178
179    basic_string& assign(const basic_string& str);
180    basic_string& assign(basic_string&& str);
181    basic_string& assign(const basic_string& str, size_type pos, size_type n=npos); // C++14
182    basic_string& assign(const value_type* s, size_type n);
183    basic_string& assign(const value_type* s);
184    basic_string& assign(size_type n, value_type c);
185    template<class InputIterator>
186        basic_string& assign(InputIterator first, InputIterator last);
187    basic_string& assign(initializer_list<value_type>);
188
189    basic_string& insert(size_type pos1, const basic_string& str);
190    basic_string& insert(size_type pos1, const basic_string& str,
191                         size_type pos2, size_type n);
192    basic_string& insert(size_type pos, const value_type* s, size_type n=npos); //C++14
193    basic_string& insert(size_type pos, const value_type* s);
194    basic_string& insert(size_type pos, size_type n, value_type c);
195    iterator      insert(const_iterator p, value_type c);
196    iterator      insert(const_iterator p, size_type n, value_type c);
197    template<class InputIterator>
198        iterator insert(const_iterator p, InputIterator first, InputIterator last);
199    iterator      insert(const_iterator p, initializer_list<value_type>);
200
201    basic_string& erase(size_type pos = 0, size_type n = npos);
202    iterator      erase(const_iterator position);
203    iterator      erase(const_iterator first, const_iterator last);
204
205    basic_string& replace(size_type pos1, size_type n1, const basic_string& str);
206    basic_string& replace(size_type pos1, size_type n1, const basic_string& str,
207                          size_type pos2, size_type n2=npos); // C++14
208    basic_string& replace(size_type pos, size_type n1, const value_type* s, size_type n2);
209    basic_string& replace(size_type pos, size_type n1, const value_type* s);
210    basic_string& replace(size_type pos, size_type n1, size_type n2, value_type c);
211    basic_string& replace(const_iterator i1, const_iterator i2, const basic_string& str);
212    basic_string& replace(const_iterator i1, const_iterator i2, const value_type* s, size_type n);
213    basic_string& replace(const_iterator i1, const_iterator i2, const value_type* s);
214    basic_string& replace(const_iterator i1, const_iterator i2, size_type n, value_type c);
215    template<class InputIterator>
216        basic_string& replace(const_iterator i1, const_iterator i2, InputIterator j1, InputIterator j2);
217    basic_string& replace(const_iterator i1, const_iterator i2, initializer_list<value_type>);
218
219    size_type copy(value_type* s, size_type n, size_type pos = 0) const;
220    basic_string substr(size_type pos = 0, size_type n = npos) const;
221
222    void swap(basic_string& str)
223        noexcept(!allocator_type::propagate_on_container_swap::value ||
224                 __is_nothrow_swappable<allocator_type>::value)
225
226    const value_type* c_str() const noexcept;
227    const value_type* data() const noexcept;
228
229    allocator_type get_allocator() const noexcept;
230
231    size_type find(const basic_string& str, size_type pos = 0) const noexcept;
232    size_type find(const value_type* s, size_type pos, size_type n) const noexcept;
233    size_type find(const value_type* s, size_type pos = 0) const noexcept;
234    size_type find(value_type c, size_type pos = 0) const noexcept;
235
236    size_type rfind(const basic_string& str, size_type pos = npos) const noexcept;
237    size_type rfind(const value_type* s, size_type pos, size_type n) const noexcept;
238    size_type rfind(const value_type* s, size_type pos = npos) const noexcept;
239    size_type rfind(value_type c, size_type pos = npos) const noexcept;
240
241    size_type find_first_of(const basic_string& str, size_type pos = 0) const noexcept;
242    size_type find_first_of(const value_type* s, size_type pos, size_type n) const noexcept;
243    size_type find_first_of(const value_type* s, size_type pos = 0) const noexcept;
244    size_type find_first_of(value_type c, size_type pos = 0) const noexcept;
245
246    size_type find_last_of(const basic_string& str, size_type pos = npos) const noexcept;
247    size_type find_last_of(const value_type* s, size_type pos, size_type n) const noexcept;
248    size_type find_last_of(const value_type* s, size_type pos = npos) const noexcept;
249    size_type find_last_of(value_type c, size_type pos = npos) const noexcept;
250
251    size_type find_first_not_of(const basic_string& str, size_type pos = 0) const noexcept;
252    size_type find_first_not_of(const value_type* s, size_type pos, size_type n) const noexcept;
253    size_type find_first_not_of(const value_type* s, size_type pos = 0) const noexcept;
254    size_type find_first_not_of(value_type c, size_type pos = 0) const noexcept;
255
256    size_type find_last_not_of(const basic_string& str, size_type pos = npos) const noexcept;
257    size_type find_last_not_of(const value_type* s, size_type pos, size_type n) const noexcept;
258    size_type find_last_not_of(const value_type* s, size_type pos = npos) const noexcept;
259    size_type find_last_not_of(value_type c, size_type pos = npos) const noexcept;
260
261    int compare(const basic_string& str) const noexcept;
262    int compare(size_type pos1, size_type n1, const basic_string& str) const;
263    int compare(size_type pos1, size_type n1, const basic_string& str,
264                size_type pos2, size_type n2=npos) const; // C++14
265    int compare(const value_type* s) const noexcept;
266    int compare(size_type pos1, size_type n1, const value_type* s) const;
267    int compare(size_type pos1, size_type n1, const value_type* s, size_type n2) const;
268
269    bool __invariants() const;
270};
271
272template<class charT, class traits, class Allocator>
273basic_string<charT, traits, Allocator>
274operator+(const basic_string<charT, traits, Allocator>& lhs,
275          const basic_string<charT, traits, Allocator>& rhs);
276
277template<class charT, class traits, class Allocator>
278basic_string<charT, traits, Allocator>
279operator+(const charT* lhs , const basic_string<charT,traits,Allocator>&rhs);
280
281template<class charT, class traits, class Allocator>
282basic_string<charT, traits, Allocator>
283operator+(charT lhs, const basic_string<charT,traits,Allocator>& rhs);
284
285template<class charT, class traits, class Allocator>
286basic_string<charT, traits, Allocator>
287operator+(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs);
288
289template<class charT, class traits, class Allocator>
290basic_string<charT, traits, Allocator>
291operator+(const basic_string<charT, traits, Allocator>& lhs, charT rhs);
292
293template<class charT, class traits, class Allocator>
294bool operator==(const basic_string<charT, traits, Allocator>& lhs,
295                const basic_string<charT, traits, Allocator>& rhs) noexcept;
296
297template<class charT, class traits, class Allocator>
298bool operator==(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
299
300template<class charT, class traits, class Allocator>
301bool operator==(const basic_string<charT,traits,Allocator>& lhs, const charT* rhs) noexcept;
302
303template<class charT, class traits, class Allocator>
304bool operator!=(const basic_string<charT,traits,Allocator>& lhs,
305                const basic_string<charT, traits, Allocator>& rhs) noexcept;
306
307template<class charT, class traits, class Allocator>
308bool operator!=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
309
310template<class charT, class traits, class Allocator>
311bool operator!=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;
312
313template<class charT, class traits, class Allocator>
314bool operator< (const basic_string<charT, traits, Allocator>& lhs,
315                const basic_string<charT, traits, Allocator>& rhs) noexcept;
316
317template<class charT, class traits, class Allocator>
318bool operator< (const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;
319
320template<class charT, class traits, class Allocator>
321bool operator< (const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
322
323template<class charT, class traits, class Allocator>
324bool operator> (const basic_string<charT, traits, Allocator>& lhs,
325                const basic_string<charT, traits, Allocator>& rhs) noexcept;
326
327template<class charT, class traits, class Allocator>
328bool operator> (const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;
329
330template<class charT, class traits, class Allocator>
331bool operator> (const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
332
333template<class charT, class traits, class Allocator>
334bool operator<=(const basic_string<charT, traits, Allocator>& lhs,
335                const basic_string<charT, traits, Allocator>& rhs) noexcept;
336
337template<class charT, class traits, class Allocator>
338bool operator<=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;
339
340template<class charT, class traits, class Allocator>
341bool operator<=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
342
343template<class charT, class traits, class Allocator>
344bool operator>=(const basic_string<charT, traits, Allocator>& lhs,
345                const basic_string<charT, traits, Allocator>& rhs) noexcept;
346
347template<class charT, class traits, class Allocator>
348bool operator>=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;
349
350template<class charT, class traits, class Allocator>
351bool operator>=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
352
353template<class charT, class traits, class Allocator>
354void swap(basic_string<charT, traits, Allocator>& lhs,
355          basic_string<charT, traits, Allocator>& rhs)
356            noexcept(noexcept(lhs.swap(rhs)));
357
358template<class charT, class traits, class Allocator>
359basic_istream<charT, traits>&
360operator>>(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str);
361
362template<class charT, class traits, class Allocator>
363basic_ostream<charT, traits>&
364operator<<(basic_ostream<charT, traits>& os, const basic_string<charT, traits, Allocator>& str);
365
366template<class charT, class traits, class Allocator>
367basic_istream<charT, traits>&
368getline(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str,
369        charT delim);
370
371template<class charT, class traits, class Allocator>
372basic_istream<charT, traits>&
373getline(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str);
374
375typedef basic_string<char>    string;
376typedef basic_string<wchar_t> wstring;
377typedef basic_string<char16_t> u16string;
378typedef basic_string<char32_t> u32string;
379
380int                stoi  (const string& str, size_t* idx = 0, int base = 10);
381long               stol  (const string& str, size_t* idx = 0, int base = 10);
382unsigned long      stoul (const string& str, size_t* idx = 0, int base = 10);
383long long          stoll (const string& str, size_t* idx = 0, int base = 10);
384unsigned long long stoull(const string& str, size_t* idx = 0, int base = 10);
385
386float       stof (const string& str, size_t* idx = 0);
387double      stod (const string& str, size_t* idx = 0);
388long double stold(const string& str, size_t* idx = 0);
389
390string to_string(int val);
391string to_string(unsigned val);
392string to_string(long val);
393string to_string(unsigned long val);
394string to_string(long long val);
395string to_string(unsigned long long val);
396string to_string(float val);
397string to_string(double val);
398string to_string(long double val);
399
400int                stoi  (const wstring& str, size_t* idx = 0, int base = 10);
401long               stol  (const wstring& str, size_t* idx = 0, int base = 10);
402unsigned long      stoul (const wstring& str, size_t* idx = 0, int base = 10);
403long long          stoll (const wstring& str, size_t* idx = 0, int base = 10);
404unsigned long long stoull(const wstring& str, size_t* idx = 0, int base = 10);
405
406float       stof (const wstring& str, size_t* idx = 0);
407double      stod (const wstring& str, size_t* idx = 0);
408long double stold(const wstring& str, size_t* idx = 0);
409
410wstring to_wstring(int val);
411wstring to_wstring(unsigned val);
412wstring to_wstring(long val);
413wstring to_wstring(unsigned long val);
414wstring to_wstring(long long val);
415wstring to_wstring(unsigned long long val);
416wstring to_wstring(float val);
417wstring to_wstring(double val);
418wstring to_wstring(long double val);
419
420template <> struct hash<string>;
421template <> struct hash<u16string>;
422template <> struct hash<u32string>;
423template <> struct hash<wstring>;
424
425basic_string<char>     operator "" s( const char *str,     size_t len ); // C++14
426basic_string<wchar_t>  operator "" s( const wchar_t *str,  size_t len ); // C++14
427basic_string<char16_t> operator "" s( const char16_t *str, size_t len ); // C++14
428basic_string<char32_t> operator "" s( const char32_t *str, size_t len ); // C++14
429
430}  // std
431
432*/
433
434#include <__config>
435#include <iosfwd>
436#include <cstring>
437#include <cstdio>  // For EOF.
438#include <cwchar>
439#include <algorithm>
440#include <iterator>
441#include <utility>
442#include <memory>
443#include <stdexcept>
444#include <type_traits>
445#include <initializer_list>
446#include <__functional_base>
447#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
448#include <cstdint>
449#endif
450#if defined(_LIBCPP_NO_EXCEPTIONS)
451#include <cassert>
452#endif
453
454#include <__undef_min_max>
455
456#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
457#pragma GCC system_header
458#endif
459
460_LIBCPP_BEGIN_NAMESPACE_STD
461
462// fpos
463
464template <class _StateT>
465class _LIBCPP_TYPE_VIS_ONLY fpos
466{
467private:
468    _StateT __st_;
469    streamoff __off_;
470public:
471    _LIBCPP_INLINE_VISIBILITY fpos(streamoff __off = streamoff()) : __st_(), __off_(__off) {}
472
473    _LIBCPP_INLINE_VISIBILITY operator streamoff() const {return __off_;}
474
475    _LIBCPP_INLINE_VISIBILITY _StateT state() const {return __st_;}
476    _LIBCPP_INLINE_VISIBILITY void state(_StateT __st) {__st_ = __st;}
477
478    _LIBCPP_INLINE_VISIBILITY fpos& operator+=(streamoff __off) {__off_ += __off; return *this;}
479    _LIBCPP_INLINE_VISIBILITY fpos  operator+ (streamoff __off) const {fpos __t(*this); __t += __off; return __t;}
480    _LIBCPP_INLINE_VISIBILITY fpos& operator-=(streamoff __off) {__off_ -= __off; return *this;}
481    _LIBCPP_INLINE_VISIBILITY fpos  operator- (streamoff __off) const {fpos __t(*this); __t -= __off; return __t;}
482};
483
484template <class _StateT>
485inline _LIBCPP_INLINE_VISIBILITY
486streamoff operator-(const fpos<_StateT>& __x, const fpos<_StateT>& __y)
487    {return streamoff(__x) - streamoff(__y);}
488
489template <class _StateT>
490inline _LIBCPP_INLINE_VISIBILITY
491bool operator==(const fpos<_StateT>& __x, const fpos<_StateT>& __y)
492    {return streamoff(__x) == streamoff(__y);}
493
494template <class _StateT>
495inline _LIBCPP_INLINE_VISIBILITY
496bool operator!=(const fpos<_StateT>& __x, const fpos<_StateT>& __y)
497    {return streamoff(__x) != streamoff(__y);}
498
499// char_traits
500
501template <class _CharT>
502struct _LIBCPP_TYPE_VIS_ONLY char_traits
503{
504    typedef _CharT    char_type;
505    typedef int       int_type;
506    typedef streamoff off_type;
507    typedef streampos pos_type;
508    typedef mbstate_t state_type;
509
510    _LIBCPP_INLINE_VISIBILITY
511    static void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
512        {__c1 = __c2;}
513    _LIBCPP_INLINE_VISIBILITY
514    static _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
515        {return __c1 == __c2;}
516    _LIBCPP_INLINE_VISIBILITY
517    static _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
518        {return __c1 < __c2;}
519
520    static int              compare(const char_type* __s1, const char_type* __s2, size_t __n);
521    static size_t           length(const char_type* __s);
522    static const char_type* find(const char_type* __s, size_t __n, const char_type& __a);
523    static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n);
524    static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n);
525    static char_type*       assign(char_type* __s, size_t __n, char_type __a);
526
527    _LIBCPP_INLINE_VISIBILITY
528    static _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
529        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
530    _LIBCPP_INLINE_VISIBILITY
531    static _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
532        {return char_type(__c);}
533    _LIBCPP_INLINE_VISIBILITY
534    static _LIBCPP_CONSTEXPR int_type  to_int_type(char_type __c) _NOEXCEPT
535        {return int_type(__c);}
536    _LIBCPP_INLINE_VISIBILITY
537    static _LIBCPP_CONSTEXPR bool      eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
538        {return __c1 == __c2;}
539    _LIBCPP_INLINE_VISIBILITY
540    static _LIBCPP_CONSTEXPR int_type  eof() _NOEXCEPT
541        {return int_type(EOF);}
542};
543
544template <class _CharT>
545int
546char_traits<_CharT>::compare(const char_type* __s1, const char_type* __s2, size_t __n)
547{
548    for (; __n; --__n, ++__s1, ++__s2)
549    {
550        if (lt(*__s1, *__s2))
551            return -1;
552        if (lt(*__s2, *__s1))
553            return 1;
554    }
555    return 0;
556}
557
558template <class _CharT>
559inline _LIBCPP_INLINE_VISIBILITY
560size_t
561char_traits<_CharT>::length(const char_type* __s)
562{
563    size_t __len = 0;
564    for (; !eq(*__s, char_type(0)); ++__s)
565        ++__len;
566    return __len;
567}
568
569template <class _CharT>
570inline _LIBCPP_INLINE_VISIBILITY
571const _CharT*
572char_traits<_CharT>::find(const char_type* __s, size_t __n, const char_type& __a)
573{
574    for (; __n; --__n)
575    {
576        if (eq(*__s, __a))
577            return __s;
578        ++__s;
579    }
580    return 0;
581}
582
583template <class _CharT>
584_CharT*
585char_traits<_CharT>::move(char_type* __s1, const char_type* __s2, size_t __n)
586{
587    char_type* __r = __s1;
588    if (__s1 < __s2)
589    {
590        for (; __n; --__n, ++__s1, ++__s2)
591            assign(*__s1, *__s2);
592    }
593    else if (__s2 < __s1)
594    {
595        __s1 += __n;
596        __s2 += __n;
597        for (; __n; --__n)
598            assign(*--__s1, *--__s2);
599    }
600    return __r;
601}
602
603template <class _CharT>
604inline _LIBCPP_INLINE_VISIBILITY
605_CharT*
606char_traits<_CharT>::copy(char_type* __s1, const char_type* __s2, size_t __n)
607{
608    _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
609    char_type* __r = __s1;
610    for (; __n; --__n, ++__s1, ++__s2)
611        assign(*__s1, *__s2);
612    return __r;
613}
614
615template <class _CharT>
616inline _LIBCPP_INLINE_VISIBILITY
617_CharT*
618char_traits<_CharT>::assign(char_type* __s, size_t __n, char_type __a)
619{
620    char_type* __r = __s;
621    for (; __n; --__n, ++__s)
622        assign(*__s, __a);
623    return __r;
624}
625
626// char_traits<char>
627
628template <>
629struct _LIBCPP_TYPE_VIS_ONLY char_traits<char>
630{
631    typedef char      char_type;
632    typedef int       int_type;
633    typedef streamoff off_type;
634    typedef streampos pos_type;
635    typedef mbstate_t state_type;
636
637    _LIBCPP_INLINE_VISIBILITY
638    static void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
639        {__c1 = __c2;}
640    _LIBCPP_INLINE_VISIBILITY
641    static _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
642            {return __c1 == __c2;}
643    _LIBCPP_INLINE_VISIBILITY
644    static _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
645        {return (unsigned char)__c1 < (unsigned char)__c2;}
646
647    _LIBCPP_INLINE_VISIBILITY
648    static int compare(const char_type* __s1, const char_type* __s2, size_t __n)
649        {return memcmp(__s1, __s2, __n);}
650    _LIBCPP_INLINE_VISIBILITY
651    static size_t length(const char_type* __s) {return strlen(__s);}
652    _LIBCPP_INLINE_VISIBILITY
653    static const char_type* find(const char_type* __s, size_t __n, const char_type& __a)
654        {return (const char_type*)memchr(__s, to_int_type(__a), __n);}
655    _LIBCPP_INLINE_VISIBILITY
656    static char_type* move(char_type* __s1, const char_type* __s2, size_t __n)
657        {return (char_type*)memmove(__s1, __s2, __n);}
658    _LIBCPP_INLINE_VISIBILITY
659    static char_type* copy(char_type* __s1, const char_type* __s2, size_t __n)
660        {
661            _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
662            return (char_type*)memcpy(__s1, __s2, __n);
663        }
664    _LIBCPP_INLINE_VISIBILITY
665    static char_type* assign(char_type* __s, size_t __n, char_type __a)
666        {return (char_type*)memset(__s, to_int_type(__a), __n);}
667
668    _LIBCPP_INLINE_VISIBILITY
669    static _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
670        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
671    _LIBCPP_INLINE_VISIBILITY
672    static _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
673        {return char_type(__c);}
674    _LIBCPP_INLINE_VISIBILITY
675    static _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT
676        {return int_type((unsigned char)__c);}
677    _LIBCPP_INLINE_VISIBILITY
678    static _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
679        {return __c1 == __c2;}
680    _LIBCPP_INLINE_VISIBILITY
681    static _LIBCPP_CONSTEXPR int_type  eof() _NOEXCEPT
682        {return int_type(EOF);}
683};
684
685// char_traits<wchar_t>
686
687template <>
688struct _LIBCPP_TYPE_VIS_ONLY char_traits<wchar_t>
689{
690    typedef wchar_t   char_type;
691    typedef wint_t    int_type;
692    typedef streamoff off_type;
693    typedef streampos pos_type;
694    typedef mbstate_t state_type;
695
696    _LIBCPP_INLINE_VISIBILITY
697    static void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
698        {__c1 = __c2;}
699    _LIBCPP_INLINE_VISIBILITY
700    static _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
701        {return __c1 == __c2;}
702    _LIBCPP_INLINE_VISIBILITY
703    static _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
704        {return __c1 < __c2;}
705
706    _LIBCPP_INLINE_VISIBILITY
707    static int compare(const char_type* __s1, const char_type* __s2, size_t __n)
708        {return wmemcmp(__s1, __s2, __n);}
709    _LIBCPP_INLINE_VISIBILITY
710    static size_t length(const char_type* __s)
711        {return wcslen(__s);}
712    _LIBCPP_INLINE_VISIBILITY
713    static const char_type* find(const char_type* __s, size_t __n, const char_type& __a)
714        {return (const char_type*)wmemchr(__s, __a, __n);}
715    _LIBCPP_INLINE_VISIBILITY
716    static char_type* move(char_type* __s1, const char_type* __s2, size_t __n)
717        {return (char_type*)wmemmove(__s1, __s2, __n);}
718    _LIBCPP_INLINE_VISIBILITY
719    static char_type* copy(char_type* __s1, const char_type* __s2, size_t __n)
720        {
721            _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
722            return (char_type*)wmemcpy(__s1, __s2, __n);
723        }
724    _LIBCPP_INLINE_VISIBILITY
725    static char_type* assign(char_type* __s, size_t __n, char_type __a)
726        {return (char_type*)wmemset(__s, __a, __n);}
727
728    _LIBCPP_INLINE_VISIBILITY
729    static _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
730        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
731    _LIBCPP_INLINE_VISIBILITY
732    static _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
733        {return char_type(__c);}
734    _LIBCPP_INLINE_VISIBILITY
735    static _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT
736        {return int_type(__c);}
737    _LIBCPP_INLINE_VISIBILITY
738    static _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
739        {return __c1 == __c2;}
740    _LIBCPP_INLINE_VISIBILITY
741    static _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT
742        {return int_type(WEOF);}
743};
744
745#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
746
747template <>
748struct _LIBCPP_TYPE_VIS_ONLY char_traits<char16_t>
749{
750    typedef char16_t       char_type;
751    typedef uint_least16_t int_type;
752    typedef streamoff      off_type;
753    typedef u16streampos   pos_type;
754    typedef mbstate_t      state_type;
755
756    _LIBCPP_INLINE_VISIBILITY
757    static void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
758        {__c1 = __c2;}
759    _LIBCPP_INLINE_VISIBILITY
760    static _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
761        {return __c1 == __c2;}
762    _LIBCPP_INLINE_VISIBILITY
763    static _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
764        {return __c1 < __c2;}
765
766    static int              compare(const char_type* __s1, const char_type* __s2, size_t __n);
767    static size_t           length(const char_type* __s);
768    static const char_type* find(const char_type* __s, size_t __n, const char_type& __a);
769    static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n);
770    static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n);
771    static char_type*       assign(char_type* __s, size_t __n, char_type __a);
772
773    _LIBCPP_INLINE_VISIBILITY
774    static _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
775        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
776    _LIBCPP_INLINE_VISIBILITY
777    static _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
778        {return char_type(__c);}
779    _LIBCPP_INLINE_VISIBILITY
780    static _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT
781        {return int_type(__c);}
782    _LIBCPP_INLINE_VISIBILITY
783    static _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
784        {return __c1 == __c2;}
785    _LIBCPP_INLINE_VISIBILITY
786    static _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT
787        {return int_type(0xDFFF);}
788};
789
790inline _LIBCPP_INLINE_VISIBILITY
791int
792char_traits<char16_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n)
793{
794    for (; __n; --__n, ++__s1, ++__s2)
795    {
796        if (lt(*__s1, *__s2))
797            return -1;
798        if (lt(*__s2, *__s1))
799            return 1;
800    }
801    return 0;
802}
803
804inline _LIBCPP_INLINE_VISIBILITY
805size_t
806char_traits<char16_t>::length(const char_type* __s)
807{
808    size_t __len = 0;
809    for (; !eq(*__s, char_type(0)); ++__s)
810        ++__len;
811    return __len;
812}
813
814inline _LIBCPP_INLINE_VISIBILITY
815const char16_t*
816char_traits<char16_t>::find(const char_type* __s, size_t __n, const char_type& __a)
817{
818    for (; __n; --__n)
819    {
820        if (eq(*__s, __a))
821            return __s;
822        ++__s;
823    }
824    return 0;
825}
826
827inline _LIBCPP_INLINE_VISIBILITY
828char16_t*
829char_traits<char16_t>::move(char_type* __s1, const char_type* __s2, size_t __n)
830{
831    char_type* __r = __s1;
832    if (__s1 < __s2)
833    {
834        for (; __n; --__n, ++__s1, ++__s2)
835            assign(*__s1, *__s2);
836    }
837    else if (__s2 < __s1)
838    {
839        __s1 += __n;
840        __s2 += __n;
841        for (; __n; --__n)
842            assign(*--__s1, *--__s2);
843    }
844    return __r;
845}
846
847inline _LIBCPP_INLINE_VISIBILITY
848char16_t*
849char_traits<char16_t>::copy(char_type* __s1, const char_type* __s2, size_t __n)
850{
851    _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
852    char_type* __r = __s1;
853    for (; __n; --__n, ++__s1, ++__s2)
854        assign(*__s1, *__s2);
855    return __r;
856}
857
858inline _LIBCPP_INLINE_VISIBILITY
859char16_t*
860char_traits<char16_t>::assign(char_type* __s, size_t __n, char_type __a)
861{
862    char_type* __r = __s;
863    for (; __n; --__n, ++__s)
864        assign(*__s, __a);
865    return __r;
866}
867
868template <>
869struct _LIBCPP_TYPE_VIS_ONLY char_traits<char32_t>
870{
871    typedef char32_t       char_type;
872    typedef uint_least32_t int_type;
873    typedef streamoff      off_type;
874    typedef u32streampos   pos_type;
875    typedef mbstate_t      state_type;
876
877    _LIBCPP_INLINE_VISIBILITY
878    static void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
879        {__c1 = __c2;}
880    _LIBCPP_INLINE_VISIBILITY
881    static _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
882        {return __c1 == __c2;}
883    _LIBCPP_INLINE_VISIBILITY
884    static _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
885        {return __c1 < __c2;}
886
887    static int              compare(const char_type* __s1, const char_type* __s2, size_t __n);
888    static size_t           length(const char_type* __s);
889    static const char_type* find(const char_type* __s, size_t __n, const char_type& __a);
890    static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n);
891    static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n);
892    static char_type*       assign(char_type* __s, size_t __n, char_type __a);
893
894    _LIBCPP_INLINE_VISIBILITY
895    static _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
896        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
897    _LIBCPP_INLINE_VISIBILITY
898    static _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
899        {return char_type(__c);}
900    _LIBCPP_INLINE_VISIBILITY
901    static _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT
902        {return int_type(__c);}
903    _LIBCPP_INLINE_VISIBILITY
904    static _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
905        {return __c1 == __c2;}
906    _LIBCPP_INLINE_VISIBILITY
907    static _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT
908        {return int_type(0xFFFFFFFF);}
909};
910
911inline _LIBCPP_INLINE_VISIBILITY
912int
913char_traits<char32_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n)
914{
915    for (; __n; --__n, ++__s1, ++__s2)
916    {
917        if (lt(*__s1, *__s2))
918            return -1;
919        if (lt(*__s2, *__s1))
920            return 1;
921    }
922    return 0;
923}
924
925inline _LIBCPP_INLINE_VISIBILITY
926size_t
927char_traits<char32_t>::length(const char_type* __s)
928{
929    size_t __len = 0;
930    for (; !eq(*__s, char_type(0)); ++__s)
931        ++__len;
932    return __len;
933}
934
935inline _LIBCPP_INLINE_VISIBILITY
936const char32_t*
937char_traits<char32_t>::find(const char_type* __s, size_t __n, const char_type& __a)
938{
939    for (; __n; --__n)
940    {
941        if (eq(*__s, __a))
942            return __s;
943        ++__s;
944    }
945    return 0;
946}
947
948inline _LIBCPP_INLINE_VISIBILITY
949char32_t*
950char_traits<char32_t>::move(char_type* __s1, const char_type* __s2, size_t __n)
951{
952    char_type* __r = __s1;
953    if (__s1 < __s2)
954    {
955        for (; __n; --__n, ++__s1, ++__s2)
956            assign(*__s1, *__s2);
957    }
958    else if (__s2 < __s1)
959    {
960        __s1 += __n;
961        __s2 += __n;
962        for (; __n; --__n)
963            assign(*--__s1, *--__s2);
964    }
965    return __r;
966}
967
968inline _LIBCPP_INLINE_VISIBILITY
969char32_t*
970char_traits<char32_t>::copy(char_type* __s1, const char_type* __s2, size_t __n)
971{
972    _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
973    char_type* __r = __s1;
974    for (; __n; --__n, ++__s1, ++__s2)
975        assign(*__s1, *__s2);
976    return __r;
977}
978
979inline _LIBCPP_INLINE_VISIBILITY
980char32_t*
981char_traits<char32_t>::assign(char_type* __s, size_t __n, char_type __a)
982{
983    char_type* __r = __s;
984    for (; __n; --__n, ++__s)
985        assign(*__s, __a);
986    return __r;
987}
988
989#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
990
991// helper fns for basic_string
992
993// __str_find
994template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
995_SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
996__str_find(const _CharT *__p, _SizeT __sz,
997             _CharT __c, _SizeT __pos) _NOEXCEPT
998{
999    if (__pos >= __sz)
1000        return __npos;
1001    const _CharT* __r = _Traits::find(__p + __pos, __sz - __pos, __c);
1002    if (__r == 0)
1003        return __npos;
1004    return static_cast<_SizeT>(__r - __p);
1005}
1006
1007template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
1008_SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1009__str_find(const _CharT *__p, _SizeT __sz,
1010       const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
1011{
1012    if (__pos > __sz || __sz - __pos < __n)
1013        return __npos;
1014    if (__n == 0)
1015        return __pos;
1016    const _CharT* __r =
1017        _VSTD::__search(__p + __pos, __p + __sz,
1018                        __s, __s + __n, _Traits::eq,
1019                        random_access_iterator_tag(), random_access_iterator_tag());
1020    if (__r == __p + __sz)
1021        return __npos;
1022    return static_cast<_SizeT>(__r - __p);
1023}
1024
1025
1026// __str_rfind
1027
1028template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
1029_SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1030__str_rfind(const _CharT *__p, _SizeT __sz,
1031              _CharT __c, _SizeT __pos) _NOEXCEPT
1032{
1033    if (__sz < 1)
1034        return __npos;
1035    if (__pos < __sz)
1036        ++__pos;
1037    else
1038        __pos = __sz;
1039    for (const _CharT* __ps = __p + __pos; __ps != __p;)
1040    {
1041        if (_Traits::eq(*--__ps, __c))
1042            return static_cast<_SizeT>(__ps - __p);
1043    }
1044    return __npos;
1045}
1046
1047template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
1048_SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1049__str_rfind(const _CharT *__p, _SizeT __sz,
1050        const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
1051{
1052    __pos = _VSTD::min(__pos, __sz);
1053    if (__n < __sz - __pos)
1054        __pos += __n;
1055    else
1056        __pos = __sz;
1057    const _CharT* __r = _VSTD::__find_end(
1058                  __p, __p + __pos, __s, __s + __n, _Traits::eq,
1059                        random_access_iterator_tag(), random_access_iterator_tag());
1060    if (__n > 0 && __r == __p + __pos)
1061        return __npos;
1062    return static_cast<_SizeT>(__r - __p);
1063}
1064
1065// __str_find_first_of
1066template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
1067_SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1068__str_find_first_of(const _CharT *__p, _SizeT __sz,
1069                const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
1070{
1071    if (__pos >= __sz || __n == 0)
1072        return __npos;
1073    const _CharT* __r = _VSTD::__find_first_of_ce
1074        (__p + __pos, __p + __sz, __s, __s + __n, _Traits::eq );
1075    if (__r == __p + __sz)
1076        return __npos;
1077    return static_cast<_SizeT>(__r - __p);
1078}
1079
1080
1081// __str_find_last_of
1082template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
1083_SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1084__str_find_last_of(const _CharT *__p, _SizeT __sz,
1085               const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
1086    {
1087    if (__n != 0)
1088    {
1089        if (__pos < __sz)
1090            ++__pos;
1091        else
1092            __pos = __sz;
1093        for (const _CharT* __ps = __p + __pos; __ps != __p;)
1094        {
1095            const _CharT* __r = _Traits::find(__s, __n, *--__ps);
1096            if (__r)
1097                return static_cast<_SizeT>(__ps - __p);
1098        }
1099    }
1100    return __npos;
1101}
1102
1103
1104// __str_find_first_not_of
1105template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
1106_SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1107__str_find_first_not_of(const _CharT *__p, _SizeT __sz,
1108                    const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
1109{
1110    if (__pos < __sz)
1111    {
1112        const _CharT* __pe = __p + __sz;
1113        for (const _CharT* __ps = __p + __pos; __ps != __pe; ++__ps)
1114            if (_Traits::find(__s, __n, *__ps) == 0)
1115                return static_cast<_SizeT>(__ps - __p);
1116    }
1117    return __npos;
1118}
1119
1120
1121template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
1122_SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1123__str_find_first_not_of(const _CharT *__p, _SizeT __sz,
1124                          _CharT __c, _SizeT __pos) _NOEXCEPT
1125{
1126    if (__pos < __sz)
1127    {
1128        const _CharT* __pe = __p + __sz;
1129        for (const _CharT* __ps = __p + __pos; __ps != __pe; ++__ps)
1130            if (!_Traits::eq(*__ps, __c))
1131                return static_cast<_SizeT>(__ps - __p);
1132    }
1133    return __npos;
1134}
1135
1136
1137// __str_find_last_not_of
1138template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
1139_SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1140__str_find_last_not_of(const _CharT *__p, _SizeT __sz,
1141                   const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
1142{
1143    if (__pos < __sz)
1144        ++__pos;
1145    else
1146        __pos = __sz;
1147    for (const _CharT* __ps = __p + __pos; __ps != __p;)
1148        if (_Traits::find(__s, __n, *--__ps) == 0)
1149            return static_cast<_SizeT>(__ps - __p);
1150    return __npos;
1151}
1152
1153
1154template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
1155_SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1156__str_find_last_not_of(const _CharT *__p, _SizeT __sz,
1157                         _CharT __c, _SizeT __pos) _NOEXCEPT
1158{
1159    if (__pos < __sz)
1160        ++__pos;
1161    else
1162        __pos = __sz;
1163    for (const _CharT* __ps = __p + __pos; __ps != __p;)
1164        if (!_Traits::eq(*--__ps, __c))
1165            return static_cast<_SizeT>(__ps - __p);
1166    return __npos;
1167}
1168
1169template<class _Ptr>
1170size_t _LIBCPP_INLINE_VISIBILITY __do_string_hash(_Ptr __p, _Ptr __e)
1171{
1172    typedef typename iterator_traits<_Ptr>::value_type value_type;
1173    return __murmur2_or_cityhash<size_t>()(__p, (__e-__p)*sizeof(value_type));
1174}
1175
1176// basic_string
1177
1178template<class _CharT, class _Traits, class _Allocator>
1179basic_string<_CharT, _Traits, _Allocator>
1180operator+(const basic_string<_CharT, _Traits, _Allocator>& __x,
1181          const basic_string<_CharT, _Traits, _Allocator>& __y);
1182
1183template<class _CharT, class _Traits, class _Allocator>
1184basic_string<_CharT, _Traits, _Allocator>
1185operator+(const _CharT* __x, const basic_string<_CharT,_Traits,_Allocator>& __y);
1186
1187template<class _CharT, class _Traits, class _Allocator>
1188basic_string<_CharT, _Traits, _Allocator>
1189operator+(_CharT __x, const basic_string<_CharT,_Traits,_Allocator>& __y);
1190
1191template<class _CharT, class _Traits, class _Allocator>
1192basic_string<_CharT, _Traits, _Allocator>
1193operator+(const basic_string<_CharT, _Traits, _Allocator>& __x, const _CharT* __y);
1194
1195template<class _CharT, class _Traits, class _Allocator>
1196basic_string<_CharT, _Traits, _Allocator>
1197operator+(const basic_string<_CharT, _Traits, _Allocator>& __x, _CharT __y);
1198
1199template <bool>
1200class _LIBCPP_TYPE_VIS_ONLY __basic_string_common
1201{
1202protected:
1203    void __throw_length_error() const;
1204    void __throw_out_of_range() const;
1205};
1206
1207template <bool __b>
1208void
1209__basic_string_common<__b>::__throw_length_error() const
1210{
1211#ifndef _LIBCPP_NO_EXCEPTIONS
1212    throw length_error("basic_string");
1213#else
1214    assert(!"basic_string length_error");
1215#endif
1216}
1217
1218template <bool __b>
1219void
1220__basic_string_common<__b>::__throw_out_of_range() const
1221{
1222#ifndef _LIBCPP_NO_EXCEPTIONS
1223    throw out_of_range("basic_string");
1224#else
1225    assert(!"basic_string out_of_range");
1226#endif
1227}
1228
1229#ifdef _LIBCPP_MSVC
1230#pragma warning( push )
1231#pragma warning( disable: 4231 )
1232#endif // _LIBCPP_MSVC
1233_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_TYPE_VIS __basic_string_common<true>)
1234#ifdef _LIBCPP_MSVC
1235#pragma warning( pop )
1236#endif // _LIBCPP_MSVC
1237
1238#ifdef _LIBCPP_ALTERNATE_STRING_LAYOUT
1239
1240template <class _CharT, size_t = sizeof(_CharT)>
1241struct __padding
1242{
1243    unsigned char __xx[sizeof(_CharT)-1];
1244};
1245
1246template <class _CharT>
1247struct __padding<_CharT, 1>
1248{
1249};
1250
1251#endif  // _LIBCPP_ALTERNATE_STRING_LAYOUT
1252
1253template<class _CharT, class _Traits, class _Allocator>
1254class _LIBCPP_TYPE_VIS_ONLY basic_string
1255    : private __basic_string_common<true>
1256{
1257public:
1258    typedef basic_string                                 __self;
1259    typedef _Traits                                      traits_type;
1260    typedef typename traits_type::char_type              value_type;
1261    typedef _Allocator                                   allocator_type;
1262    typedef allocator_traits<allocator_type>             __alloc_traits;
1263    typedef typename __alloc_traits::size_type           size_type;
1264    typedef typename __alloc_traits::difference_type     difference_type;
1265    typedef value_type&                                  reference;
1266    typedef const value_type&                            const_reference;
1267    typedef typename __alloc_traits::pointer             pointer;
1268    typedef typename __alloc_traits::const_pointer       const_pointer;
1269
1270    static_assert(is_pod<value_type>::value, "Character type of basic_string must be a POD");
1271    static_assert((is_same<_CharT, value_type>::value),
1272                  "traits_type::char_type must be the same type as CharT");
1273    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
1274                  "Allocator::value_type must be same type as value_type");
1275#if defined(_LIBCPP_RAW_ITERATORS)
1276    typedef pointer                                      iterator;
1277    typedef const_pointer                                const_iterator;
1278#else  // defined(_LIBCPP_RAW_ITERATORS)
1279    typedef __wrap_iter<pointer>                         iterator;
1280    typedef __wrap_iter<const_pointer>                   const_iterator;
1281#endif  // defined(_LIBCPP_RAW_ITERATORS)
1282    typedef _VSTD::reverse_iterator<iterator>             reverse_iterator;
1283    typedef _VSTD::reverse_iterator<const_iterator>       const_reverse_iterator;
1284
1285private:
1286
1287#ifdef _LIBCPP_ALTERNATE_STRING_LAYOUT
1288
1289    struct __long
1290    {
1291        pointer   __data_;
1292        size_type __size_;
1293        size_type __cap_;
1294    };
1295
1296#if _LIBCPP_BIG_ENDIAN
1297    enum {__short_mask = 0x01};
1298    enum {__long_mask  = 0x1ul};
1299#else  // _LIBCPP_BIG_ENDIAN
1300    enum {__short_mask = 0x80};
1301    enum {__long_mask  = ~(size_type(~0) >> 1)};
1302#endif  // _LIBCPP_BIG_ENDIAN
1303
1304    enum {__min_cap = (sizeof(__long) - 1)/sizeof(value_type) > 2 ?
1305                      (sizeof(__long) - 1)/sizeof(value_type) : 2};
1306
1307    struct __short
1308    {
1309        value_type __data_[__min_cap];
1310        struct
1311            : __padding<value_type>
1312        {
1313            unsigned char __size_;
1314        };
1315    };
1316
1317#else
1318
1319    struct __long
1320    {
1321        size_type __cap_;
1322        size_type __size_;
1323        pointer   __data_;
1324    };
1325
1326#if _LIBCPP_BIG_ENDIAN
1327    enum {__short_mask = 0x80};
1328    enum {__long_mask  = ~(size_type(~0) >> 1)};
1329#else  // _LIBCPP_BIG_ENDIAN
1330    enum {__short_mask = 0x01};
1331    enum {__long_mask  = 0x1ul};
1332#endif  // _LIBCPP_BIG_ENDIAN
1333
1334    enum {__min_cap = (sizeof(__long) - 1)/sizeof(value_type) > 2 ?
1335                      (sizeof(__long) - 1)/sizeof(value_type) : 2};
1336
1337    struct __short
1338    {
1339        union
1340        {
1341            unsigned char __size_;
1342            value_type __lx;
1343        };
1344        value_type __data_[__min_cap];
1345    };
1346
1347#endif  // _LIBCPP_ALTERNATE_STRING_LAYOUT
1348
1349    union __ulx{__long __lx; __short __lxx;};
1350
1351    enum {__n_words = sizeof(__ulx) / sizeof(size_type)};
1352
1353    struct __raw
1354    {
1355        size_type __words[__n_words];
1356    };
1357
1358    struct __rep
1359    {
1360        union
1361        {
1362            __long  __l;
1363            __short __s;
1364            __raw   __r;
1365        };
1366    };
1367
1368    __compressed_pair<__rep, allocator_type> __r_;
1369
1370public:
1371    static const size_type npos = -1;
1372
1373    _LIBCPP_INLINE_VISIBILITY basic_string()
1374        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
1375    _LIBCPP_INLINE_VISIBILITY explicit basic_string(const allocator_type& __a);
1376    basic_string(const basic_string& __str);
1377    basic_string(const basic_string& __str, const allocator_type& __a);
1378#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1379    _LIBCPP_INLINE_VISIBILITY
1380    basic_string(basic_string&& __str)
1381        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
1382    _LIBCPP_INLINE_VISIBILITY
1383    basic_string(basic_string&& __str, const allocator_type& __a);
1384#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1385    _LIBCPP_INLINE_VISIBILITY basic_string(const value_type* __s);
1386    _LIBCPP_INLINE_VISIBILITY
1387    basic_string(const value_type* __s, const allocator_type& __a);
1388    _LIBCPP_INLINE_VISIBILITY
1389    basic_string(const value_type* __s, size_type __n);
1390    _LIBCPP_INLINE_VISIBILITY
1391    basic_string(const value_type* __s, size_type __n, const allocator_type& __a);
1392    _LIBCPP_INLINE_VISIBILITY
1393    basic_string(size_type __n, value_type __c);
1394    _LIBCPP_INLINE_VISIBILITY
1395    basic_string(size_type __n, value_type __c, const allocator_type& __a);
1396    basic_string(const basic_string& __str, size_type __pos, size_type __n = npos,
1397                 const allocator_type& __a = allocator_type());
1398    template<class _InputIterator>
1399        _LIBCPP_INLINE_VISIBILITY
1400        basic_string(_InputIterator __first, _InputIterator __last);
1401    template<class _InputIterator>
1402        _LIBCPP_INLINE_VISIBILITY
1403        basic_string(_InputIterator __first, _InputIterator __last, const allocator_type& __a);
1404#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1405    _LIBCPP_INLINE_VISIBILITY
1406    basic_string(initializer_list<value_type> __il);
1407    _LIBCPP_INLINE_VISIBILITY
1408    basic_string(initializer_list<value_type> __il, const allocator_type& __a);
1409#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1410
1411    ~basic_string();
1412
1413    basic_string& operator=(const basic_string& __str);
1414#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1415    _LIBCPP_INLINE_VISIBILITY
1416    basic_string& operator=(basic_string&& __str)
1417        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
1418                   is_nothrow_move_assignable<allocator_type>::value);
1419#endif
1420    _LIBCPP_INLINE_VISIBILITY basic_string& operator=(const value_type* __s) {return assign(__s);}
1421    basic_string& operator=(value_type __c);
1422#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1423    _LIBCPP_INLINE_VISIBILITY
1424    basic_string& operator=(initializer_list<value_type> __il) {return assign(__il.begin(), __il.size());}
1425#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1426
1427#if _LIBCPP_DEBUG_LEVEL >= 2
1428    _LIBCPP_INLINE_VISIBILITY
1429    iterator begin() _NOEXCEPT
1430        {return iterator(this, __get_pointer());}
1431    _LIBCPP_INLINE_VISIBILITY
1432    const_iterator begin() const _NOEXCEPT
1433        {return const_iterator(this, __get_pointer());}
1434    _LIBCPP_INLINE_VISIBILITY
1435    iterator end() _NOEXCEPT
1436        {return iterator(this, __get_pointer() + size());}
1437    _LIBCPP_INLINE_VISIBILITY
1438    const_iterator end() const _NOEXCEPT
1439        {return const_iterator(this, __get_pointer() + size());}
1440#else
1441    _LIBCPP_INLINE_VISIBILITY
1442    iterator begin() _NOEXCEPT
1443        {return iterator(__get_pointer());}
1444    _LIBCPP_INLINE_VISIBILITY
1445    const_iterator begin() const _NOEXCEPT
1446        {return const_iterator(__get_pointer());}
1447    _LIBCPP_INLINE_VISIBILITY
1448    iterator end() _NOEXCEPT
1449        {return iterator(__get_pointer() + size());}
1450    _LIBCPP_INLINE_VISIBILITY
1451    const_iterator end() const _NOEXCEPT
1452        {return const_iterator(__get_pointer() + size());}
1453#endif  // _LIBCPP_DEBUG_LEVEL >= 2
1454    _LIBCPP_INLINE_VISIBILITY
1455    reverse_iterator rbegin() _NOEXCEPT
1456        {return reverse_iterator(end());}
1457    _LIBCPP_INLINE_VISIBILITY
1458    const_reverse_iterator rbegin() const _NOEXCEPT
1459        {return const_reverse_iterator(end());}
1460    _LIBCPP_INLINE_VISIBILITY
1461    reverse_iterator rend() _NOEXCEPT
1462        {return reverse_iterator(begin());}
1463    _LIBCPP_INLINE_VISIBILITY
1464    const_reverse_iterator rend() const _NOEXCEPT
1465        {return const_reverse_iterator(begin());}
1466
1467    _LIBCPP_INLINE_VISIBILITY
1468    const_iterator cbegin() const _NOEXCEPT
1469        {return begin();}
1470    _LIBCPP_INLINE_VISIBILITY
1471    const_iterator cend() const _NOEXCEPT
1472        {return end();}
1473    _LIBCPP_INLINE_VISIBILITY
1474    const_reverse_iterator crbegin() const _NOEXCEPT
1475        {return rbegin();}
1476    _LIBCPP_INLINE_VISIBILITY
1477    const_reverse_iterator crend() const _NOEXCEPT
1478        {return rend();}
1479
1480    _LIBCPP_INLINE_VISIBILITY size_type size() const _NOEXCEPT
1481        {return __is_long() ? __get_long_size() : __get_short_size();}
1482    _LIBCPP_INLINE_VISIBILITY size_type length() const _NOEXCEPT {return size();}
1483    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT;
1484    _LIBCPP_INLINE_VISIBILITY size_type capacity() const _NOEXCEPT
1485        {return (__is_long() ? __get_long_cap() : __min_cap) - 1;}
1486
1487    void resize(size_type __n, value_type __c);
1488    _LIBCPP_INLINE_VISIBILITY void resize(size_type __n) {resize(__n, value_type());}
1489
1490    void reserve(size_type res_arg = 0);
1491    _LIBCPP_INLINE_VISIBILITY
1492    void shrink_to_fit() _NOEXCEPT {reserve();}
1493    _LIBCPP_INLINE_VISIBILITY
1494    void clear() _NOEXCEPT;
1495    _LIBCPP_INLINE_VISIBILITY bool empty() const _NOEXCEPT {return size() == 0;}
1496
1497    _LIBCPP_INLINE_VISIBILITY const_reference operator[](size_type __pos) const;
1498    _LIBCPP_INLINE_VISIBILITY reference       operator[](size_type __pos);
1499
1500    const_reference at(size_type __n) const;
1501    reference       at(size_type __n);
1502
1503    _LIBCPP_INLINE_VISIBILITY basic_string& operator+=(const basic_string& __str) {return append(__str);}
1504    _LIBCPP_INLINE_VISIBILITY basic_string& operator+=(const value_type* __s)         {return append(__s);}
1505    _LIBCPP_INLINE_VISIBILITY basic_string& operator+=(value_type __c)            {push_back(__c); return *this;}
1506#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1507    _LIBCPP_INLINE_VISIBILITY basic_string& operator+=(initializer_list<value_type> __il) {return append(__il);}
1508#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1509
1510    _LIBCPP_INLINE_VISIBILITY
1511    basic_string& append(const basic_string& __str);
1512    basic_string& append(const basic_string& __str, size_type __pos, size_type __n=npos);
1513    basic_string& append(const value_type* __s, size_type __n);
1514    basic_string& append(const value_type* __s);
1515    basic_string& append(size_type __n, value_type __c);
1516    template<class _InputIterator>
1517        typename enable_if
1518        <
1519             __is_input_iterator  <_InputIterator>::value &&
1520            !__is_forward_iterator<_InputIterator>::value,
1521            basic_string&
1522        >::type
1523        append(_InputIterator __first, _InputIterator __last);
1524    template<class _ForwardIterator>
1525        typename enable_if
1526        <
1527            __is_forward_iterator<_ForwardIterator>::value,
1528            basic_string&
1529        >::type
1530        append(_ForwardIterator __first, _ForwardIterator __last);
1531#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1532    _LIBCPP_INLINE_VISIBILITY
1533    basic_string& append(initializer_list<value_type> __il) {return append(__il.begin(), __il.size());}
1534#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1535
1536    void push_back(value_type __c);
1537    _LIBCPP_INLINE_VISIBILITY
1538    void pop_back();
1539    _LIBCPP_INLINE_VISIBILITY reference       front();
1540    _LIBCPP_INLINE_VISIBILITY const_reference front() const;
1541    _LIBCPP_INLINE_VISIBILITY reference       back();
1542    _LIBCPP_INLINE_VISIBILITY const_reference back() const;
1543
1544    _LIBCPP_INLINE_VISIBILITY
1545    basic_string& assign(const basic_string& __str);
1546#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1547    _LIBCPP_INLINE_VISIBILITY
1548    basic_string& assign(basic_string&& str)
1549        {*this = _VSTD::move(str); return *this;}
1550#endif
1551    basic_string& assign(const basic_string& __str, size_type __pos, size_type __n=npos);
1552    basic_string& assign(const value_type* __s, size_type __n);
1553    basic_string& assign(const value_type* __s);
1554    basic_string& assign(size_type __n, value_type __c);
1555    template<class _InputIterator>
1556        typename enable_if
1557        <
1558             __is_input_iterator  <_InputIterator>::value &&
1559            !__is_forward_iterator<_InputIterator>::value,
1560            basic_string&
1561        >::type
1562        assign(_InputIterator __first, _InputIterator __last);
1563    template<class _ForwardIterator>
1564        typename enable_if
1565        <
1566            __is_forward_iterator<_ForwardIterator>::value,
1567            basic_string&
1568        >::type
1569        assign(_ForwardIterator __first, _ForwardIterator __last);
1570#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1571    _LIBCPP_INLINE_VISIBILITY
1572    basic_string& assign(initializer_list<value_type> __il) {return assign(__il.begin(), __il.size());}
1573#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1574
1575    _LIBCPP_INLINE_VISIBILITY
1576    basic_string& insert(size_type __pos1, const basic_string& __str);
1577    basic_string& insert(size_type __pos1, const basic_string& __str, size_type __pos2, size_type __n=npos);
1578    basic_string& insert(size_type __pos, const value_type* __s, size_type __n);
1579    basic_string& insert(size_type __pos, const value_type* __s);
1580    basic_string& insert(size_type __pos, size_type __n, value_type __c);
1581    iterator      insert(const_iterator __pos, value_type __c);
1582    _LIBCPP_INLINE_VISIBILITY
1583    iterator      insert(const_iterator __pos, size_type __n, value_type __c);
1584    template<class _InputIterator>
1585        typename enable_if
1586        <
1587             __is_input_iterator  <_InputIterator>::value &&
1588            !__is_forward_iterator<_InputIterator>::value,
1589            iterator
1590        >::type
1591        insert(const_iterator __pos, _InputIterator __first, _InputIterator __last);
1592    template<class _ForwardIterator>
1593        typename enable_if
1594        <
1595            __is_forward_iterator<_ForwardIterator>::value,
1596            iterator
1597        >::type
1598        insert(const_iterator __pos, _ForwardIterator __first, _ForwardIterator __last);
1599#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1600    _LIBCPP_INLINE_VISIBILITY
1601    iterator insert(const_iterator __pos, initializer_list<value_type> __il)
1602                    {return insert(__pos, __il.begin(), __il.end());}
1603#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1604
1605    basic_string& erase(size_type __pos = 0, size_type __n = npos);
1606    _LIBCPP_INLINE_VISIBILITY
1607    iterator      erase(const_iterator __pos);
1608    _LIBCPP_INLINE_VISIBILITY
1609    iterator      erase(const_iterator __first, const_iterator __last);
1610
1611    _LIBCPP_INLINE_VISIBILITY
1612    basic_string& replace(size_type __pos1, size_type __n1, const basic_string& __str);
1613    basic_string& replace(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2=npos);
1614    basic_string& replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2);
1615    basic_string& replace(size_type __pos, size_type __n1, const value_type* __s);
1616    basic_string& replace(size_type __pos, size_type __n1, size_type __n2, value_type __c);
1617    _LIBCPP_INLINE_VISIBILITY
1618    basic_string& replace(const_iterator __i1, const_iterator __i2, const basic_string& __str);
1619    _LIBCPP_INLINE_VISIBILITY
1620    basic_string& replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n);
1621    _LIBCPP_INLINE_VISIBILITY
1622    basic_string& replace(const_iterator __i1, const_iterator __i2, const value_type* __s);
1623    _LIBCPP_INLINE_VISIBILITY
1624    basic_string& replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c);
1625    template<class _InputIterator>
1626        typename enable_if
1627        <
1628            __is_input_iterator<_InputIterator>::value,
1629            basic_string&
1630        >::type
1631        replace(const_iterator __i1, const_iterator __i2, _InputIterator __j1, _InputIterator __j2);
1632#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1633    _LIBCPP_INLINE_VISIBILITY
1634    basic_string& replace(const_iterator __i1, const_iterator __i2, initializer_list<value_type> __il)
1635        {return replace(__i1, __i2, __il.begin(), __il.end());}
1636#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1637
1638    size_type copy(value_type* __s, size_type __n, size_type __pos = 0) const;
1639    _LIBCPP_INLINE_VISIBILITY
1640    basic_string substr(size_type __pos = 0, size_type __n = npos) const;
1641
1642    _LIBCPP_INLINE_VISIBILITY
1643    void swap(basic_string& __str)
1644        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
1645                   __is_nothrow_swappable<allocator_type>::value);
1646
1647    _LIBCPP_INLINE_VISIBILITY
1648    const value_type* c_str() const _NOEXCEPT {return data();}
1649    _LIBCPP_INLINE_VISIBILITY
1650    const value_type* data() const _NOEXCEPT  {return _VSTD::__to_raw_pointer(__get_pointer());}
1651
1652    _LIBCPP_INLINE_VISIBILITY
1653    allocator_type get_allocator() const _NOEXCEPT {return __alloc();}
1654
1655    _LIBCPP_INLINE_VISIBILITY
1656    size_type find(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT;
1657    size_type find(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
1658    _LIBCPP_INLINE_VISIBILITY
1659    size_type find(const value_type* __s, size_type __pos = 0) const _NOEXCEPT;
1660    size_type find(value_type __c, size_type __pos = 0) const _NOEXCEPT;
1661
1662    _LIBCPP_INLINE_VISIBILITY
1663    size_type rfind(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT;
1664    size_type rfind(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
1665    _LIBCPP_INLINE_VISIBILITY
1666    size_type rfind(const value_type* __s, size_type __pos = npos) const _NOEXCEPT;
1667    size_type rfind(value_type __c, size_type __pos = npos) const _NOEXCEPT;
1668
1669    _LIBCPP_INLINE_VISIBILITY
1670    size_type find_first_of(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT;
1671    size_type find_first_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
1672    _LIBCPP_INLINE_VISIBILITY
1673    size_type find_first_of(const value_type* __s, size_type __pos = 0) const _NOEXCEPT;
1674    _LIBCPP_INLINE_VISIBILITY
1675    size_type find_first_of(value_type __c, size_type __pos = 0) const _NOEXCEPT;
1676
1677    _LIBCPP_INLINE_VISIBILITY
1678    size_type find_last_of(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT;
1679    size_type find_last_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
1680    _LIBCPP_INLINE_VISIBILITY
1681    size_type find_last_of(const value_type* __s, size_type __pos = npos) const _NOEXCEPT;
1682    _LIBCPP_INLINE_VISIBILITY
1683    size_type find_last_of(value_type __c, size_type __pos = npos) const _NOEXCEPT;
1684
1685    _LIBCPP_INLINE_VISIBILITY
1686    size_type find_first_not_of(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT;
1687    size_type find_first_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
1688    _LIBCPP_INLINE_VISIBILITY
1689    size_type find_first_not_of(const value_type* __s, size_type __pos = 0) const _NOEXCEPT;
1690    _LIBCPP_INLINE_VISIBILITY
1691    size_type find_first_not_of(value_type __c, size_type __pos = 0) const _NOEXCEPT;
1692
1693    _LIBCPP_INLINE_VISIBILITY
1694    size_type find_last_not_of(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT;
1695    size_type find_last_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
1696    _LIBCPP_INLINE_VISIBILITY
1697    size_type find_last_not_of(const value_type* __s, size_type __pos = npos) const _NOEXCEPT;
1698    _LIBCPP_INLINE_VISIBILITY
1699    size_type find_last_not_of(value_type __c, size_type __pos = npos) const _NOEXCEPT;
1700
1701    _LIBCPP_INLINE_VISIBILITY
1702    int compare(const basic_string& __str) const _NOEXCEPT;
1703    _LIBCPP_INLINE_VISIBILITY
1704    int compare(size_type __pos1, size_type __n1, const basic_string& __str) const;
1705    int compare(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2=npos) const;
1706    int compare(const value_type* __s) const _NOEXCEPT;
1707    int compare(size_type __pos1, size_type __n1, const value_type* __s) const;
1708    int compare(size_type __pos1, size_type __n1, const value_type* __s, size_type __n2) const;
1709
1710    _LIBCPP_INLINE_VISIBILITY bool __invariants() const;
1711
1712    _LIBCPP_INLINE_VISIBILITY
1713    bool __is_long() const _NOEXCEPT
1714        {return bool(__r_.first().__s.__size_ & __short_mask);}
1715
1716#if _LIBCPP_DEBUG_LEVEL >= 2
1717
1718    bool __dereferenceable(const const_iterator* __i) const;
1719    bool __decrementable(const const_iterator* __i) const;
1720    bool __addable(const const_iterator* __i, ptrdiff_t __n) const;
1721    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const;
1722
1723#endif  // _LIBCPP_DEBUG_LEVEL >= 2
1724
1725private:
1726    _LIBCPP_INLINE_VISIBILITY
1727    allocator_type& __alloc() _NOEXCEPT
1728        {return __r_.second();}
1729    _LIBCPP_INLINE_VISIBILITY
1730    const allocator_type& __alloc() const _NOEXCEPT
1731        {return __r_.second();}
1732
1733#ifdef _LIBCPP_ALTERNATE_STRING_LAYOUT
1734
1735    _LIBCPP_INLINE_VISIBILITY
1736    void __set_short_size(size_type __s) _NOEXCEPT
1737#   if _LIBCPP_BIG_ENDIAN
1738        {__r_.first().__s.__size_ = (unsigned char)(__s << 1);}
1739#   else
1740        {__r_.first().__s.__size_ = (unsigned char)(__s);}
1741#   endif
1742
1743    _LIBCPP_INLINE_VISIBILITY
1744    size_type __get_short_size() const _NOEXCEPT
1745#   if _LIBCPP_BIG_ENDIAN
1746        {return __r_.first().__s.__size_ >> 1;}
1747#   else
1748        {return __r_.first().__s.__size_;}
1749#   endif
1750
1751#else  // _LIBCPP_ALTERNATE_STRING_LAYOUT
1752
1753    _LIBCPP_INLINE_VISIBILITY
1754    void __set_short_size(size_type __s) _NOEXCEPT
1755#   if _LIBCPP_BIG_ENDIAN
1756        {__r_.first().__s.__size_ = (unsigned char)(__s);}
1757#   else
1758        {__r_.first().__s.__size_ = (unsigned char)(__s << 1);}
1759#   endif
1760
1761    _LIBCPP_INLINE_VISIBILITY
1762    size_type __get_short_size() const _NOEXCEPT
1763#   if _LIBCPP_BIG_ENDIAN
1764        {return __r_.first().__s.__size_;}
1765#   else
1766        {return __r_.first().__s.__size_ >> 1;}
1767#   endif
1768
1769#endif  // _LIBCPP_ALTERNATE_STRING_LAYOUT
1770
1771    _LIBCPP_INLINE_VISIBILITY
1772    void __set_long_size(size_type __s) _NOEXCEPT
1773        {__r_.first().__l.__size_ = __s;}
1774    _LIBCPP_INLINE_VISIBILITY
1775    size_type __get_long_size() const _NOEXCEPT
1776        {return __r_.first().__l.__size_;}
1777    _LIBCPP_INLINE_VISIBILITY
1778    void __set_size(size_type __s) _NOEXCEPT
1779        {if (__is_long()) __set_long_size(__s); else __set_short_size(__s);}
1780
1781    _LIBCPP_INLINE_VISIBILITY
1782    void __set_long_cap(size_type __s) _NOEXCEPT
1783        {__r_.first().__l.__cap_  = __long_mask | __s;}
1784    _LIBCPP_INLINE_VISIBILITY
1785    size_type __get_long_cap() const _NOEXCEPT
1786        {return __r_.first().__l.__cap_ & size_type(~__long_mask);}
1787
1788    _LIBCPP_INLINE_VISIBILITY
1789    void __set_long_pointer(pointer __p) _NOEXCEPT
1790        {__r_.first().__l.__data_ = __p;}
1791    _LIBCPP_INLINE_VISIBILITY
1792    pointer __get_long_pointer() _NOEXCEPT
1793        {return __r_.first().__l.__data_;}
1794    _LIBCPP_INLINE_VISIBILITY
1795    const_pointer __get_long_pointer() const _NOEXCEPT
1796        {return __r_.first().__l.__data_;}
1797    _LIBCPP_INLINE_VISIBILITY
1798    pointer __get_short_pointer() _NOEXCEPT
1799        {return pointer_traits<pointer>::pointer_to(__r_.first().__s.__data_[0]);}
1800    _LIBCPP_INLINE_VISIBILITY
1801    const_pointer __get_short_pointer() const _NOEXCEPT
1802        {return pointer_traits<const_pointer>::pointer_to(__r_.first().__s.__data_[0]);}
1803    _LIBCPP_INLINE_VISIBILITY
1804    pointer __get_pointer() _NOEXCEPT
1805        {return __is_long() ? __get_long_pointer() : __get_short_pointer();}
1806    _LIBCPP_INLINE_VISIBILITY
1807    const_pointer __get_pointer() const _NOEXCEPT
1808        {return __is_long() ? __get_long_pointer() : __get_short_pointer();}
1809
1810    _LIBCPP_INLINE_VISIBILITY
1811    void __zero() _NOEXCEPT
1812        {
1813            size_type (&__a)[__n_words] = __r_.first().__r.__words;
1814            for (unsigned __i = 0; __i < __n_words; ++__i)
1815                __a[__i] = 0;
1816        }
1817
1818    template <size_type __a> static
1819        _LIBCPP_INLINE_VISIBILITY
1820        size_type __align_it(size_type __s) _NOEXCEPT
1821            {return __s + (__a-1) & ~(__a-1);}
1822    enum {__alignment = 16};
1823    static _LIBCPP_INLINE_VISIBILITY
1824    size_type __recommend(size_type __s) _NOEXCEPT
1825        {return (__s < __min_cap ? __min_cap :
1826                 __align_it<sizeof(value_type) < __alignment ?
1827                            __alignment/sizeof(value_type) : 1 > (__s+1)) - 1;}
1828
1829    void __init(const value_type* __s, size_type __sz, size_type __reserve);
1830    void __init(const value_type* __s, size_type __sz);
1831    void __init(size_type __n, value_type __c);
1832
1833    template <class _InputIterator>
1834    typename enable_if
1835    <
1836         __is_input_iterator  <_InputIterator>::value &&
1837        !__is_forward_iterator<_InputIterator>::value,
1838        void
1839    >::type
1840    __init(_InputIterator __first, _InputIterator __last);
1841
1842    template <class _ForwardIterator>
1843    typename enable_if
1844    <
1845        __is_forward_iterator<_ForwardIterator>::value,
1846        void
1847    >::type
1848    __init(_ForwardIterator __first, _ForwardIterator __last);
1849
1850    void __grow_by(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
1851                   size_type __n_copy,  size_type __n_del,     size_type __n_add = 0);
1852    void __grow_by_and_replace(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
1853                               size_type __n_copy,  size_type __n_del,
1854                               size_type __n_add, const value_type* __p_new_stuff);
1855
1856    _LIBCPP_INLINE_VISIBILITY
1857    void __erase_to_end(size_type __pos);
1858
1859    _LIBCPP_INLINE_VISIBILITY
1860    void __copy_assign_alloc(const basic_string& __str)
1861        {__copy_assign_alloc(__str, integral_constant<bool,
1862                      __alloc_traits::propagate_on_container_copy_assignment::value>());}
1863
1864    _LIBCPP_INLINE_VISIBILITY
1865    void __copy_assign_alloc(const basic_string& __str, true_type)
1866        {
1867            if (__alloc() != __str.__alloc())
1868            {
1869                clear();
1870                shrink_to_fit();
1871            }
1872            __alloc() = __str.__alloc();
1873        }
1874
1875    _LIBCPP_INLINE_VISIBILITY
1876    void __copy_assign_alloc(const basic_string&, false_type) _NOEXCEPT
1877        {}
1878
1879#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1880    _LIBCPP_INLINE_VISIBILITY
1881    void __move_assign(basic_string& __str, false_type);
1882    _LIBCPP_INLINE_VISIBILITY
1883    void __move_assign(basic_string& __str, true_type)
1884        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
1885#endif
1886
1887    _LIBCPP_INLINE_VISIBILITY
1888    void
1889    __move_assign_alloc(basic_string& __str)
1890        _NOEXCEPT_(
1891            !__alloc_traits::propagate_on_container_move_assignment::value ||
1892            is_nothrow_move_assignable<allocator_type>::value)
1893    {__move_assign_alloc(__str, integral_constant<bool,
1894                      __alloc_traits::propagate_on_container_move_assignment::value>());}
1895
1896    _LIBCPP_INLINE_VISIBILITY
1897    void __move_assign_alloc(basic_string& __c, true_type)
1898        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
1899        {
1900            __alloc() = _VSTD::move(__c.__alloc());
1901        }
1902
1903    _LIBCPP_INLINE_VISIBILITY
1904    void __move_assign_alloc(basic_string&, false_type)
1905        _NOEXCEPT
1906        {}
1907
1908    _LIBCPP_INLINE_VISIBILITY
1909    static void __swap_alloc(allocator_type& __x, allocator_type& __y)
1910        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
1911                   __is_nothrow_swappable<allocator_type>::value)
1912        {__swap_alloc(__x, __y, integral_constant<bool,
1913                      __alloc_traits::propagate_on_container_swap::value>());}
1914
1915    _LIBCPP_INLINE_VISIBILITY
1916    static void __swap_alloc(allocator_type& __x, allocator_type& __y, true_type)
1917        _NOEXCEPT_(__is_nothrow_swappable<allocator_type>::value)
1918        {
1919            using _VSTD::swap;
1920            swap(__x, __y);
1921        }
1922    _LIBCPP_INLINE_VISIBILITY
1923    static void __swap_alloc(allocator_type&, allocator_type&, false_type) _NOEXCEPT
1924        {}
1925
1926    _LIBCPP_INLINE_VISIBILITY void __invalidate_all_iterators();
1927    _LIBCPP_INLINE_VISIBILITY void __invalidate_iterators_past(size_type);
1928
1929    friend basic_string operator+<>(const basic_string&, const basic_string&);
1930    friend basic_string operator+<>(const value_type*, const basic_string&);
1931    friend basic_string operator+<>(value_type, const basic_string&);
1932    friend basic_string operator+<>(const basic_string&, const value_type*);
1933    friend basic_string operator+<>(const basic_string&, value_type);
1934};
1935
1936template <class _CharT, class _Traits, class _Allocator>
1937inline _LIBCPP_INLINE_VISIBILITY
1938void
1939basic_string<_CharT, _Traits, _Allocator>::__invalidate_all_iterators()
1940{
1941#if _LIBCPP_DEBUG_LEVEL >= 2
1942    __get_db()->__invalidate_all(this);
1943#endif  // _LIBCPP_DEBUG_LEVEL >= 2
1944}
1945
1946template <class _CharT, class _Traits, class _Allocator>
1947inline _LIBCPP_INLINE_VISIBILITY
1948void
1949basic_string<_CharT, _Traits, _Allocator>::__invalidate_iterators_past(size_type
1950#if _LIBCPP_DEBUG_LEVEL >= 2
1951                                                                        __pos
1952#endif
1953                                                                      )
1954{
1955#if _LIBCPP_DEBUG_LEVEL >= 2
1956    __c_node* __c = __get_db()->__find_c_and_lock(this);
1957    if (__c)
1958    {
1959        const_pointer __new_last = __get_pointer() + __pos;
1960        for (__i_node** __p = __c->end_; __p != __c->beg_; )
1961        {
1962            --__p;
1963            const_iterator* __i = static_cast<const_iterator*>((*__p)->__i_);
1964            if (__i->base() > __new_last)
1965            {
1966                (*__p)->__c_ = nullptr;
1967                if (--__c->end_ != __p)
1968                    memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
1969            }
1970        }
1971        __get_db()->unlock();
1972    }
1973#endif  // _LIBCPP_DEBUG_LEVEL >= 2
1974}
1975
1976template <class _CharT, class _Traits, class _Allocator>
1977inline _LIBCPP_INLINE_VISIBILITY
1978basic_string<_CharT, _Traits, _Allocator>::basic_string()
1979    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
1980{
1981#if _LIBCPP_DEBUG_LEVEL >= 2
1982    __get_db()->__insert_c(this);
1983#endif
1984    __zero();
1985}
1986
1987template <class _CharT, class _Traits, class _Allocator>
1988inline _LIBCPP_INLINE_VISIBILITY
1989basic_string<_CharT, _Traits, _Allocator>::basic_string(const allocator_type& __a)
1990    : __r_(__a)
1991{
1992#if _LIBCPP_DEBUG_LEVEL >= 2
1993    __get_db()->__insert_c(this);
1994#endif
1995    __zero();
1996}
1997
1998template <class _CharT, class _Traits, class _Allocator>
1999void
2000basic_string<_CharT, _Traits, _Allocator>::__init(const value_type* __s, size_type __sz, size_type __reserve)
2001{
2002    if (__reserve > max_size())
2003        this->__throw_length_error();
2004    pointer __p;
2005    if (__reserve < __min_cap)
2006    {
2007        __set_short_size(__sz);
2008        __p = __get_short_pointer();
2009    }
2010    else
2011    {
2012        size_type __cap = __recommend(__reserve);
2013        __p = __alloc_traits::allocate(__alloc(), __cap+1);
2014        __set_long_pointer(__p);
2015        __set_long_cap(__cap+1);
2016        __set_long_size(__sz);
2017    }
2018    traits_type::copy(_VSTD::__to_raw_pointer(__p), __s, __sz);
2019    traits_type::assign(__p[__sz], value_type());
2020}
2021
2022template <class _CharT, class _Traits, class _Allocator>
2023void
2024basic_string<_CharT, _Traits, _Allocator>::__init(const value_type* __s, size_type __sz)
2025{
2026    if (__sz > max_size())
2027        this->__throw_length_error();
2028    pointer __p;
2029    if (__sz < __min_cap)
2030    {
2031        __set_short_size(__sz);
2032        __p = __get_short_pointer();
2033    }
2034    else
2035    {
2036        size_type __cap = __recommend(__sz);
2037        __p = __alloc_traits::allocate(__alloc(), __cap+1);
2038        __set_long_pointer(__p);
2039        __set_long_cap(__cap+1);
2040        __set_long_size(__sz);
2041    }
2042    traits_type::copy(_VSTD::__to_raw_pointer(__p), __s, __sz);
2043    traits_type::assign(__p[__sz], value_type());
2044}
2045
2046template <class _CharT, class _Traits, class _Allocator>
2047inline _LIBCPP_INLINE_VISIBILITY
2048basic_string<_CharT, _Traits, _Allocator>::basic_string(const value_type* __s)
2049{
2050    _LIBCPP_ASSERT(__s != nullptr, "basic_string(const char*) detected nullptr");
2051    __init(__s, traits_type::length(__s));
2052#if _LIBCPP_DEBUG_LEVEL >= 2
2053    __get_db()->__insert_c(this);
2054#endif
2055}
2056
2057template <class _CharT, class _Traits, class _Allocator>
2058inline _LIBCPP_INLINE_VISIBILITY
2059basic_string<_CharT, _Traits, _Allocator>::basic_string(const value_type* __s, const allocator_type& __a)
2060    : __r_(__a)
2061{
2062    _LIBCPP_ASSERT(__s != nullptr, "basic_string(const char*, allocator) detected nullptr");
2063    __init(__s, traits_type::length(__s));
2064#if _LIBCPP_DEBUG_LEVEL >= 2
2065    __get_db()->__insert_c(this);
2066#endif
2067}
2068
2069template <class _CharT, class _Traits, class _Allocator>
2070inline _LIBCPP_INLINE_VISIBILITY
2071basic_string<_CharT, _Traits, _Allocator>::basic_string(const value_type* __s, size_type __n)
2072{
2073    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "basic_string(const char*, n) detected nullptr");
2074    __init(__s, __n);
2075#if _LIBCPP_DEBUG_LEVEL >= 2
2076    __get_db()->__insert_c(this);
2077#endif
2078}
2079
2080template <class _CharT, class _Traits, class _Allocator>
2081inline _LIBCPP_INLINE_VISIBILITY
2082basic_string<_CharT, _Traits, _Allocator>::basic_string(const value_type* __s, size_type __n, const allocator_type& __a)
2083    : __r_(__a)
2084{
2085    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "basic_string(const char*, n, allocator) detected nullptr");
2086    __init(__s, __n);
2087#if _LIBCPP_DEBUG_LEVEL >= 2
2088    __get_db()->__insert_c(this);
2089#endif
2090}
2091
2092template <class _CharT, class _Traits, class _Allocator>
2093basic_string<_CharT, _Traits, _Allocator>::basic_string(const basic_string& __str)
2094    : __r_(__alloc_traits::select_on_container_copy_construction(__str.__alloc()))
2095{
2096    if (!__str.__is_long())
2097        __r_.first().__r = __str.__r_.first().__r;
2098    else
2099        __init(_VSTD::__to_raw_pointer(__str.__get_long_pointer()), __str.__get_long_size());
2100#if _LIBCPP_DEBUG_LEVEL >= 2
2101    __get_db()->__insert_c(this);
2102#endif
2103}
2104
2105template <class _CharT, class _Traits, class _Allocator>
2106basic_string<_CharT, _Traits, _Allocator>::basic_string(const basic_string& __str, const allocator_type& __a)
2107    : __r_(__a)
2108{
2109    if (!__str.__is_long())
2110        __r_.first().__r = __str.__r_.first().__r;
2111    else
2112        __init(_VSTD::__to_raw_pointer(__str.__get_long_pointer()), __str.__get_long_size());
2113#if _LIBCPP_DEBUG_LEVEL >= 2
2114    __get_db()->__insert_c(this);
2115#endif
2116}
2117
2118#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2119
2120template <class _CharT, class _Traits, class _Allocator>
2121inline _LIBCPP_INLINE_VISIBILITY
2122basic_string<_CharT, _Traits, _Allocator>::basic_string(basic_string&& __str)
2123        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
2124    : __r_(_VSTD::move(__str.__r_))
2125{
2126    __str.__zero();
2127#if _LIBCPP_DEBUG_LEVEL >= 2
2128    __get_db()->__insert_c(this);
2129    if (__is_long())
2130        __get_db()->swap(this, &__str);
2131#endif
2132}
2133
2134template <class _CharT, class _Traits, class _Allocator>
2135inline _LIBCPP_INLINE_VISIBILITY
2136basic_string<_CharT, _Traits, _Allocator>::basic_string(basic_string&& __str, const allocator_type& __a)
2137    : __r_(__a)
2138{
2139    if (__str.__is_long() && __a != __str.__alloc()) // copy, not move
2140        __init(_VSTD::__to_raw_pointer(__str.__get_long_pointer()), __str.__get_long_size());
2141    else
2142    {
2143        __r_.first().__r = __str.__r_.first().__r;
2144        __str.__zero();
2145    }
2146#if _LIBCPP_DEBUG_LEVEL >= 2
2147    __get_db()->__insert_c(this);
2148    if (__is_long())
2149        __get_db()->swap(this, &__str);
2150#endif
2151}
2152
2153#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2154
2155template <class _CharT, class _Traits, class _Allocator>
2156void
2157basic_string<_CharT, _Traits, _Allocator>::__init(size_type __n, value_type __c)
2158{
2159    if (__n > max_size())
2160        this->__throw_length_error();
2161    pointer __p;
2162    if (__n < __min_cap)
2163    {
2164        __set_short_size(__n);
2165        __p = __get_short_pointer();
2166    }
2167    else
2168    {
2169        size_type __cap = __recommend(__n);
2170        __p = __alloc_traits::allocate(__alloc(), __cap+1);
2171        __set_long_pointer(__p);
2172        __set_long_cap(__cap+1);
2173        __set_long_size(__n);
2174    }
2175    traits_type::assign(_VSTD::__to_raw_pointer(__p), __n, __c);
2176    traits_type::assign(__p[__n], value_type());
2177}
2178
2179template <class _CharT, class _Traits, class _Allocator>
2180inline _LIBCPP_INLINE_VISIBILITY
2181basic_string<_CharT, _Traits, _Allocator>::basic_string(size_type __n, value_type __c)
2182{
2183    __init(__n, __c);
2184#if _LIBCPP_DEBUG_LEVEL >= 2
2185    __get_db()->__insert_c(this);
2186#endif
2187}
2188
2189template <class _CharT, class _Traits, class _Allocator>
2190inline _LIBCPP_INLINE_VISIBILITY
2191basic_string<_CharT, _Traits, _Allocator>::basic_string(size_type __n, value_type __c, const allocator_type& __a)
2192    : __r_(__a)
2193{
2194    __init(__n, __c);
2195#if _LIBCPP_DEBUG_LEVEL >= 2
2196    __get_db()->__insert_c(this);
2197#endif
2198}
2199
2200template <class _CharT, class _Traits, class _Allocator>
2201basic_string<_CharT, _Traits, _Allocator>::basic_string(const basic_string& __str, size_type __pos, size_type __n,
2202                                                        const allocator_type& __a)
2203    : __r_(__a)
2204{
2205    size_type __str_sz = __str.size();
2206    if (__pos > __str_sz)
2207        this->__throw_out_of_range();
2208    __init(__str.data() + __pos, _VSTD::min(__n, __str_sz - __pos));
2209#if _LIBCPP_DEBUG_LEVEL >= 2
2210    __get_db()->__insert_c(this);
2211#endif
2212}
2213
2214template <class _CharT, class _Traits, class _Allocator>
2215template <class _InputIterator>
2216typename enable_if
2217<
2218     __is_input_iterator  <_InputIterator>::value &&
2219    !__is_forward_iterator<_InputIterator>::value,
2220    void
2221>::type
2222basic_string<_CharT, _Traits, _Allocator>::__init(_InputIterator __first, _InputIterator __last)
2223{
2224    __zero();
2225#ifndef _LIBCPP_NO_EXCEPTIONS
2226    try
2227    {
2228#endif  // _LIBCPP_NO_EXCEPTIONS
2229    for (; __first != __last; ++__first)
2230        push_back(*__first);
2231#ifndef _LIBCPP_NO_EXCEPTIONS
2232    }
2233    catch (...)
2234    {
2235        if (__is_long())
2236            __alloc_traits::deallocate(__alloc(), __get_long_pointer(), __get_long_cap());
2237        throw;
2238    }
2239#endif  // _LIBCPP_NO_EXCEPTIONS
2240}
2241
2242template <class _CharT, class _Traits, class _Allocator>
2243template <class _ForwardIterator>
2244typename enable_if
2245<
2246    __is_forward_iterator<_ForwardIterator>::value,
2247    void
2248>::type
2249basic_string<_CharT, _Traits, _Allocator>::__init(_ForwardIterator __first, _ForwardIterator __last)
2250{
2251    size_type __sz = static_cast<size_type>(_VSTD::distance(__first, __last));
2252    if (__sz > max_size())
2253        this->__throw_length_error();
2254    pointer __p;
2255    if (__sz < __min_cap)
2256    {
2257        __set_short_size(__sz);
2258        __p = __get_short_pointer();
2259    }
2260    else
2261    {
2262        size_type __cap = __recommend(__sz);
2263        __p = __alloc_traits::allocate(__alloc(), __cap+1);
2264        __set_long_pointer(__p);
2265        __set_long_cap(__cap+1);
2266        __set_long_size(__sz);
2267    }
2268    for (; __first != __last; ++__first, ++__p)
2269        traits_type::assign(*__p, *__first);
2270    traits_type::assign(*__p, value_type());
2271}
2272
2273template <class _CharT, class _Traits, class _Allocator>
2274template<class _InputIterator>
2275inline _LIBCPP_INLINE_VISIBILITY
2276basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator __first, _InputIterator __last)
2277{
2278    __init(__first, __last);
2279#if _LIBCPP_DEBUG_LEVEL >= 2
2280    __get_db()->__insert_c(this);
2281#endif
2282}
2283
2284template <class _CharT, class _Traits, class _Allocator>
2285template<class _InputIterator>
2286inline _LIBCPP_INLINE_VISIBILITY
2287basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator __first, _InputIterator __last,
2288                                                        const allocator_type& __a)
2289    : __r_(__a)
2290{
2291    __init(__first, __last);
2292#if _LIBCPP_DEBUG_LEVEL >= 2
2293    __get_db()->__insert_c(this);
2294#endif
2295}
2296
2297#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
2298
2299template <class _CharT, class _Traits, class _Allocator>
2300inline _LIBCPP_INLINE_VISIBILITY
2301basic_string<_CharT, _Traits, _Allocator>::basic_string(initializer_list<value_type> __il)
2302{
2303    __init(__il.begin(), __il.end());
2304#if _LIBCPP_DEBUG_LEVEL >= 2
2305    __get_db()->__insert_c(this);
2306#endif
2307}
2308
2309template <class _CharT, class _Traits, class _Allocator>
2310inline _LIBCPP_INLINE_VISIBILITY
2311basic_string<_CharT, _Traits, _Allocator>::basic_string(initializer_list<value_type> __il, const allocator_type& __a)
2312    : __r_(__a)
2313{
2314    __init(__il.begin(), __il.end());
2315#if _LIBCPP_DEBUG_LEVEL >= 2
2316    __get_db()->__insert_c(this);
2317#endif
2318}
2319
2320#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
2321
2322template <class _CharT, class _Traits, class _Allocator>
2323basic_string<_CharT, _Traits, _Allocator>::~basic_string()
2324{
2325#if _LIBCPP_DEBUG_LEVEL >= 2
2326    __get_db()->__erase_c(this);
2327#endif
2328    if (__is_long())
2329        __alloc_traits::deallocate(__alloc(), __get_long_pointer(), __get_long_cap());
2330}
2331
2332template <class _CharT, class _Traits, class _Allocator>
2333void
2334basic_string<_CharT, _Traits, _Allocator>::__grow_by_and_replace
2335    (size_type __old_cap, size_type __delta_cap, size_type __old_sz,
2336     size_type __n_copy,  size_type __n_del,     size_type __n_add, const value_type* __p_new_stuff)
2337{
2338    size_type __ms = max_size();
2339    if (__delta_cap > __ms - __old_cap - 1)
2340        this->__throw_length_error();
2341    pointer __old_p = __get_pointer();
2342    size_type __cap = __old_cap < __ms / 2 - __alignment ?
2343                          __recommend(_VSTD::max(__old_cap + __delta_cap, 2 * __old_cap)) :
2344                          __ms - 1;
2345    pointer __p = __alloc_traits::allocate(__alloc(), __cap+1);
2346    __invalidate_all_iterators();
2347    if (__n_copy != 0)
2348        traits_type::copy(_VSTD::__to_raw_pointer(__p),
2349                          _VSTD::__to_raw_pointer(__old_p), __n_copy);
2350    if (__n_add != 0)
2351        traits_type::copy(_VSTD::__to_raw_pointer(__p) + __n_copy, __p_new_stuff, __n_add);
2352    size_type __sec_cp_sz = __old_sz - __n_del - __n_copy;
2353    if (__sec_cp_sz != 0)
2354        traits_type::copy(_VSTD::__to_raw_pointer(__p) + __n_copy + __n_add,
2355                          _VSTD::__to_raw_pointer(__old_p) + __n_copy + __n_del, __sec_cp_sz);
2356    if (__old_cap+1 != __min_cap)
2357        __alloc_traits::deallocate(__alloc(), __old_p, __old_cap+1);
2358    __set_long_pointer(__p);
2359    __set_long_cap(__cap+1);
2360    __old_sz = __n_copy + __n_add + __sec_cp_sz;
2361    __set_long_size(__old_sz);
2362    traits_type::assign(__p[__old_sz], value_type());
2363}
2364
2365template <class _CharT, class _Traits, class _Allocator>
2366void
2367basic_string<_CharT, _Traits, _Allocator>::__grow_by(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
2368                                                     size_type __n_copy,  size_type __n_del,     size_type __n_add)
2369{
2370    size_type __ms = max_size();
2371    if (__delta_cap > __ms - __old_cap)
2372        this->__throw_length_error();
2373    pointer __old_p = __get_pointer();
2374    size_type __cap = __old_cap < __ms / 2 - __alignment ?
2375                          __recommend(_VSTD::max(__old_cap + __delta_cap, 2 * __old_cap)) :
2376                          __ms - 1;
2377    pointer __p = __alloc_traits::allocate(__alloc(), __cap+1);
2378    __invalidate_all_iterators();
2379    if (__n_copy != 0)
2380        traits_type::copy(_VSTD::__to_raw_pointer(__p),
2381                          _VSTD::__to_raw_pointer(__old_p), __n_copy);
2382    size_type __sec_cp_sz = __old_sz - __n_del - __n_copy;
2383    if (__sec_cp_sz != 0)
2384        traits_type::copy(_VSTD::__to_raw_pointer(__p) + __n_copy + __n_add,
2385                          _VSTD::__to_raw_pointer(__old_p) + __n_copy + __n_del,
2386                          __sec_cp_sz);
2387    if (__old_cap+1 != __min_cap)
2388        __alloc_traits::deallocate(__alloc(), __old_p, __old_cap+1);
2389    __set_long_pointer(__p);
2390    __set_long_cap(__cap+1);
2391}
2392
2393// assign
2394
2395template <class _CharT, class _Traits, class _Allocator>
2396basic_string<_CharT, _Traits, _Allocator>&
2397basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s, size_type __n)
2398{
2399    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::assign received nullptr");
2400    size_type __cap = capacity();
2401    if (__cap >= __n)
2402    {
2403        value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
2404        traits_type::move(__p, __s, __n);
2405        traits_type::assign(__p[__n], value_type());
2406        __set_size(__n);
2407        __invalidate_iterators_past(__n);
2408    }
2409    else
2410    {
2411        size_type __sz = size();
2412        __grow_by_and_replace(__cap, __n - __cap, __sz, 0, __sz, __n, __s);
2413    }
2414    return *this;
2415}
2416
2417template <class _CharT, class _Traits, class _Allocator>
2418basic_string<_CharT, _Traits, _Allocator>&
2419basic_string<_CharT, _Traits, _Allocator>::assign(size_type __n, value_type __c)
2420{
2421    size_type __cap = capacity();
2422    if (__cap < __n)
2423    {
2424        size_type __sz = size();
2425        __grow_by(__cap, __n - __cap, __sz, 0, __sz);
2426    }
2427    else
2428        __invalidate_iterators_past(__n);
2429    value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
2430    traits_type::assign(__p, __n, __c);
2431    traits_type::assign(__p[__n], value_type());
2432    __set_size(__n);
2433    return *this;
2434}
2435
2436template <class _CharT, class _Traits, class _Allocator>
2437basic_string<_CharT, _Traits, _Allocator>&
2438basic_string<_CharT, _Traits, _Allocator>::operator=(value_type __c)
2439{
2440    pointer __p;
2441    if (__is_long())
2442    {
2443        __p = __get_long_pointer();
2444        __set_long_size(1);
2445    }
2446    else
2447    {
2448        __p = __get_short_pointer();
2449        __set_short_size(1);
2450    }
2451    traits_type::assign(*__p, __c);
2452    traits_type::assign(*++__p, value_type());
2453    __invalidate_iterators_past(1);
2454    return *this;
2455}
2456
2457template <class _CharT, class _Traits, class _Allocator>
2458basic_string<_CharT, _Traits, _Allocator>&
2459basic_string<_CharT, _Traits, _Allocator>::operator=(const basic_string& __str)
2460{
2461    if (this != &__str)
2462    {
2463        __copy_assign_alloc(__str);
2464        assign(__str);
2465    }
2466    return *this;
2467}
2468
2469#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2470
2471template <class _CharT, class _Traits, class _Allocator>
2472inline _LIBCPP_INLINE_VISIBILITY
2473void
2474basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, false_type)
2475{
2476    if (__alloc() != __str.__alloc())
2477        assign(__str);
2478    else
2479        __move_assign(__str, true_type());
2480}
2481
2482template <class _CharT, class _Traits, class _Allocator>
2483inline _LIBCPP_INLINE_VISIBILITY
2484void
2485basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, true_type)
2486    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
2487{
2488    clear();
2489    shrink_to_fit();
2490    __r_.first() = __str.__r_.first();
2491    __move_assign_alloc(__str);
2492    __str.__zero();
2493}
2494
2495template <class _CharT, class _Traits, class _Allocator>
2496inline _LIBCPP_INLINE_VISIBILITY
2497basic_string<_CharT, _Traits, _Allocator>&
2498basic_string<_CharT, _Traits, _Allocator>::operator=(basic_string&& __str)
2499    _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
2500               is_nothrow_move_assignable<allocator_type>::value)
2501{
2502    __move_assign(__str, integral_constant<bool,
2503          __alloc_traits::propagate_on_container_move_assignment::value>());
2504    return *this;
2505}
2506
2507#endif
2508
2509template <class _CharT, class _Traits, class _Allocator>
2510template<class _InputIterator>
2511typename enable_if
2512<
2513     __is_input_iterator  <_InputIterator>::value &&
2514    !__is_forward_iterator<_InputIterator>::value,
2515    basic_string<_CharT, _Traits, _Allocator>&
2516>::type
2517basic_string<_CharT, _Traits, _Allocator>::assign(_InputIterator __first, _InputIterator __last)
2518{
2519    clear();
2520    for (; __first != __last; ++__first)
2521        push_back(*__first);
2522    return *this;
2523}
2524
2525template <class _CharT, class _Traits, class _Allocator>
2526template<class _ForwardIterator>
2527typename enable_if
2528<
2529    __is_forward_iterator<_ForwardIterator>::value,
2530    basic_string<_CharT, _Traits, _Allocator>&
2531>::type
2532basic_string<_CharT, _Traits, _Allocator>::assign(_ForwardIterator __first, _ForwardIterator __last)
2533{
2534    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
2535    size_type __cap = capacity();
2536    if (__cap < __n)
2537    {
2538        size_type __sz = size();
2539        __grow_by(__cap, __n - __cap, __sz, 0, __sz);
2540    }
2541    else
2542        __invalidate_iterators_past(__n);
2543    pointer __p = __get_pointer();
2544    for (; __first != __last; ++__first, ++__p)
2545        traits_type::assign(*__p, *__first);
2546    traits_type::assign(*__p, value_type());
2547    __set_size(__n);
2548    return *this;
2549}
2550
2551template <class _CharT, class _Traits, class _Allocator>
2552inline _LIBCPP_INLINE_VISIBILITY
2553basic_string<_CharT, _Traits, _Allocator>&
2554basic_string<_CharT, _Traits, _Allocator>::assign(const basic_string& __str)
2555{
2556    return assign(__str.data(), __str.size());
2557}
2558
2559template <class _CharT, class _Traits, class _Allocator>
2560basic_string<_CharT, _Traits, _Allocator>&
2561basic_string<_CharT, _Traits, _Allocator>::assign(const basic_string& __str, size_type __pos, size_type __n)
2562{
2563    size_type __sz = __str.size();
2564    if (__pos > __sz)
2565        this->__throw_out_of_range();
2566    return assign(__str.data() + __pos, _VSTD::min(__n, __sz - __pos));
2567}
2568
2569template <class _CharT, class _Traits, class _Allocator>
2570basic_string<_CharT, _Traits, _Allocator>&
2571basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s)
2572{
2573    _LIBCPP_ASSERT(__s != nullptr, "string::assign received nullptr");
2574    return assign(__s, traits_type::length(__s));
2575}
2576
2577// append
2578
2579template <class _CharT, class _Traits, class _Allocator>
2580basic_string<_CharT, _Traits, _Allocator>&
2581basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s, size_type __n)
2582{
2583    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::append received nullptr");
2584    size_type __cap = capacity();
2585    size_type __sz = size();
2586    if (__cap - __sz >= __n)
2587    {
2588        if (__n)
2589        {
2590            value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
2591            traits_type::copy(__p + __sz, __s, __n);
2592            __sz += __n;
2593            __set_size(__sz);
2594            traits_type::assign(__p[__sz], value_type());
2595        }
2596    }
2597    else
2598        __grow_by_and_replace(__cap, __sz + __n - __cap, __sz, __sz, 0, __n, __s);
2599    return *this;
2600}
2601
2602template <class _CharT, class _Traits, class _Allocator>
2603basic_string<_CharT, _Traits, _Allocator>&
2604basic_string<_CharT, _Traits, _Allocator>::append(size_type __n, value_type __c)
2605{
2606    if (__n)
2607    {
2608        size_type __cap = capacity();
2609        size_type __sz = size();
2610        if (__cap - __sz < __n)
2611            __grow_by(__cap, __sz + __n - __cap, __sz, __sz, 0);
2612        pointer __p = __get_pointer();
2613        traits_type::assign(_VSTD::__to_raw_pointer(__p) + __sz, __n, __c);
2614        __sz += __n;
2615        __set_size(__sz);
2616        traits_type::assign(__p[__sz], value_type());
2617    }
2618    return *this;
2619}
2620
2621template <class _CharT, class _Traits, class _Allocator>
2622void
2623basic_string<_CharT, _Traits, _Allocator>::push_back(value_type __c)
2624{
2625    bool __is_short = !__is_long();
2626    size_type __cap;
2627    size_type __sz;
2628    if (__is_short)
2629    {
2630        __cap = __min_cap - 1;
2631        __sz = __get_short_size();
2632    }
2633    else
2634    {
2635        __cap = __get_long_cap() - 1;
2636        __sz = __get_long_size();
2637    }
2638    if (__sz == __cap)
2639    {
2640        __grow_by(__cap, 1, __sz, __sz, 0);
2641        __is_short = !__is_long();
2642    }
2643    pointer __p;
2644    if (__is_short)
2645    {
2646        __p = __get_short_pointer() + __sz;
2647        __set_short_size(__sz+1);
2648    }
2649    else
2650    {
2651        __p = __get_long_pointer() + __sz;
2652        __set_long_size(__sz+1);
2653    }
2654    traits_type::assign(*__p, __c);
2655    traits_type::assign(*++__p, value_type());
2656}
2657
2658template <class _CharT, class _Traits, class _Allocator>
2659template<class _InputIterator>
2660typename enable_if
2661<
2662     __is_input_iterator  <_InputIterator>::value &&
2663    !__is_forward_iterator<_InputIterator>::value,
2664    basic_string<_CharT, _Traits, _Allocator>&
2665>::type
2666basic_string<_CharT, _Traits, _Allocator>::append(_InputIterator __first, _InputIterator __last)
2667{
2668    for (; __first != __last; ++__first)
2669        push_back(*__first);
2670    return *this;
2671}
2672
2673template <class _CharT, class _Traits, class _Allocator>
2674template<class _ForwardIterator>
2675typename enable_if
2676<
2677    __is_forward_iterator<_ForwardIterator>::value,
2678    basic_string<_CharT, _Traits, _Allocator>&
2679>::type
2680basic_string<_CharT, _Traits, _Allocator>::append(_ForwardIterator __first, _ForwardIterator __last)
2681{
2682    size_type __sz = size();
2683    size_type __cap = capacity();
2684    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
2685    if (__n)
2686    {
2687        if (__cap - __sz < __n)
2688            __grow_by(__cap, __sz + __n - __cap, __sz, __sz, 0);
2689        pointer __p = __get_pointer() + __sz;
2690        for (; __first != __last; ++__p, ++__first)
2691            traits_type::assign(*__p, *__first);
2692        traits_type::assign(*__p, value_type());
2693        __set_size(__sz + __n);
2694    }
2695    return *this;
2696}
2697
2698template <class _CharT, class _Traits, class _Allocator>
2699inline _LIBCPP_INLINE_VISIBILITY
2700basic_string<_CharT, _Traits, _Allocator>&
2701basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str)
2702{
2703    return append(__str.data(), __str.size());
2704}
2705
2706template <class _CharT, class _Traits, class _Allocator>
2707basic_string<_CharT, _Traits, _Allocator>&
2708basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str, size_type __pos, size_type __n)
2709{
2710    size_type __sz = __str.size();
2711    if (__pos > __sz)
2712        this->__throw_out_of_range();
2713    return append(__str.data() + __pos, _VSTD::min(__n, __sz - __pos));
2714}
2715
2716template <class _CharT, class _Traits, class _Allocator>
2717basic_string<_CharT, _Traits, _Allocator>&
2718basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s)
2719{
2720    _LIBCPP_ASSERT(__s != nullptr, "string::append received nullptr");
2721    return append(__s, traits_type::length(__s));
2722}
2723
2724// insert
2725
2726template <class _CharT, class _Traits, class _Allocator>
2727basic_string<_CharT, _Traits, _Allocator>&
2728basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s, size_type __n)
2729{
2730    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::insert received nullptr");
2731    size_type __sz = size();
2732    if (__pos > __sz)
2733        this->__throw_out_of_range();
2734    size_type __cap = capacity();
2735    if (__cap - __sz >= __n)
2736    {
2737        if (__n)
2738        {
2739            value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
2740            size_type __n_move = __sz - __pos;
2741            if (__n_move != 0)
2742            {
2743                if (__p + __pos <= __s && __s < __p + __sz)
2744                    __s += __n;
2745                traits_type::move(__p + __pos + __n, __p + __pos, __n_move);
2746            }
2747            traits_type::move(__p + __pos, __s, __n);
2748            __sz += __n;
2749            __set_size(__sz);
2750            traits_type::assign(__p[__sz], value_type());
2751        }
2752    }
2753    else
2754        __grow_by_and_replace(__cap, __sz + __n - __cap, __sz, __pos, 0, __n, __s);
2755    return *this;
2756}
2757
2758template <class _CharT, class _Traits, class _Allocator>
2759basic_string<_CharT, _Traits, _Allocator>&
2760basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, size_type __n, value_type __c)
2761{
2762    size_type __sz = size();
2763    if (__pos > __sz)
2764        this->__throw_out_of_range();
2765    if (__n)
2766    {
2767        size_type __cap = capacity();
2768        value_type* __p;
2769        if (__cap - __sz >= __n)
2770        {
2771            __p = _VSTD::__to_raw_pointer(__get_pointer());
2772            size_type __n_move = __sz - __pos;
2773            if (__n_move != 0)
2774                traits_type::move(__p + __pos + __n, __p + __pos, __n_move);
2775        }
2776        else
2777        {
2778            __grow_by(__cap, __sz + __n - __cap, __sz, __pos, 0, __n);
2779            __p = _VSTD::__to_raw_pointer(__get_long_pointer());
2780        }
2781        traits_type::assign(__p + __pos, __n, __c);
2782        __sz += __n;
2783        __set_size(__sz);
2784        traits_type::assign(__p[__sz], value_type());
2785    }
2786    return *this;
2787}
2788
2789template <class _CharT, class _Traits, class _Allocator>
2790template<class _InputIterator>
2791typename enable_if
2792<
2793     __is_input_iterator  <_InputIterator>::value &&
2794    !__is_forward_iterator<_InputIterator>::value,
2795    typename basic_string<_CharT, _Traits, _Allocator>::iterator
2796>::type
2797basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, _InputIterator __first, _InputIterator __last)
2798{
2799#if _LIBCPP_DEBUG_LEVEL >= 2
2800    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
2801        "string::insert(iterator, range) called with an iterator not"
2802        " referring to this string");
2803#endif
2804    size_type __old_sz = size();
2805    difference_type __ip = __pos - begin();
2806    for (; __first != __last; ++__first)
2807        push_back(*__first);
2808    pointer __p = __get_pointer();
2809    _VSTD::rotate(__p + __ip, __p + __old_sz, __p + size());
2810#if _LIBCPP_DEBUG_LEVEL >= 2
2811    return iterator(this, __p + __ip);
2812#else
2813    return iterator(__p + __ip);
2814#endif
2815}
2816
2817template <class _CharT, class _Traits, class _Allocator>
2818template<class _ForwardIterator>
2819typename enable_if
2820<
2821    __is_forward_iterator<_ForwardIterator>::value,
2822    typename basic_string<_CharT, _Traits, _Allocator>::iterator
2823>::type
2824basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, _ForwardIterator __first, _ForwardIterator __last)
2825{
2826#if _LIBCPP_DEBUG_LEVEL >= 2
2827    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
2828        "string::insert(iterator, range) called with an iterator not"
2829        " referring to this string");
2830#endif
2831    size_type __ip = static_cast<size_type>(__pos - begin());
2832    size_type __sz = size();
2833    size_type __cap = capacity();
2834    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
2835    if (__n)
2836    {
2837        value_type* __p;
2838        if (__cap - __sz >= __n)
2839        {
2840            __p = _VSTD::__to_raw_pointer(__get_pointer());
2841            size_type __n_move = __sz - __ip;
2842            if (__n_move != 0)
2843                traits_type::move(__p + __ip + __n, __p + __ip, __n_move);
2844        }
2845        else
2846        {
2847            __grow_by(__cap, __sz + __n - __cap, __sz, __ip, 0, __n);
2848            __p = _VSTD::__to_raw_pointer(__get_long_pointer());
2849        }
2850        __sz += __n;
2851        __set_size(__sz);
2852        traits_type::assign(__p[__sz], value_type());
2853        for (__p += __ip; __first != __last; ++__p, ++__first)
2854            traits_type::assign(*__p, *__first);
2855    }
2856    return begin() + __ip;
2857}
2858
2859template <class _CharT, class _Traits, class _Allocator>
2860inline _LIBCPP_INLINE_VISIBILITY
2861basic_string<_CharT, _Traits, _Allocator>&
2862basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const basic_string& __str)
2863{
2864    return insert(__pos1, __str.data(), __str.size());
2865}
2866
2867template <class _CharT, class _Traits, class _Allocator>
2868basic_string<_CharT, _Traits, _Allocator>&
2869basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const basic_string& __str,
2870                                                  size_type __pos2, size_type __n)
2871{
2872    size_type __str_sz = __str.size();
2873    if (__pos2 > __str_sz)
2874        this->__throw_out_of_range();
2875    return insert(__pos1, __str.data() + __pos2, _VSTD::min(__n, __str_sz - __pos2));
2876}
2877
2878template <class _CharT, class _Traits, class _Allocator>
2879basic_string<_CharT, _Traits, _Allocator>&
2880basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s)
2881{
2882    _LIBCPP_ASSERT(__s != nullptr, "string::insert received nullptr");
2883    return insert(__pos, __s, traits_type::length(__s));
2884}
2885
2886template <class _CharT, class _Traits, class _Allocator>
2887typename basic_string<_CharT, _Traits, _Allocator>::iterator
2888basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, value_type __c)
2889{
2890    size_type __ip = static_cast<size_type>(__pos - begin());
2891    size_type __sz = size();
2892    size_type __cap = capacity();
2893    value_type* __p;
2894    if (__cap == __sz)
2895    {
2896        __grow_by(__cap, 1, __sz, __ip, 0, 1);
2897        __p = _VSTD::__to_raw_pointer(__get_long_pointer());
2898    }
2899    else
2900    {
2901        __p = _VSTD::__to_raw_pointer(__get_pointer());
2902        size_type __n_move = __sz - __ip;
2903        if (__n_move != 0)
2904            traits_type::move(__p + __ip + 1, __p + __ip, __n_move);
2905    }
2906    traits_type::assign(__p[__ip], __c);
2907    traits_type::assign(__p[++__sz], value_type());
2908    __set_size(__sz);
2909    return begin() + static_cast<difference_type>(__ip);
2910}
2911
2912template <class _CharT, class _Traits, class _Allocator>
2913inline _LIBCPP_INLINE_VISIBILITY
2914typename basic_string<_CharT, _Traits, _Allocator>::iterator
2915basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, size_type __n, value_type __c)
2916{
2917#if _LIBCPP_DEBUG_LEVEL >= 2
2918    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
2919        "string::insert(iterator, n, value) called with an iterator not"
2920        " referring to this string");
2921#endif
2922    difference_type __p = __pos - begin();
2923    insert(static_cast<size_type>(__p), __n, __c);
2924    return begin() + __p;
2925}
2926
2927// replace
2928
2929template <class _CharT, class _Traits, class _Allocator>
2930basic_string<_CharT, _Traits, _Allocator>&
2931basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2)
2932{
2933    _LIBCPP_ASSERT(__n2 == 0 || __s != nullptr, "string::replace received nullptr");
2934    size_type __sz = size();
2935    if (__pos > __sz)
2936        this->__throw_out_of_range();
2937    __n1 = _VSTD::min(__n1, __sz - __pos);
2938    size_type __cap = capacity();
2939    if (__cap - __sz + __n1 >= __n2)
2940    {
2941        value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
2942        if (__n1 != __n2)
2943        {
2944            size_type __n_move = __sz - __pos - __n1;
2945            if (__n_move != 0)
2946            {
2947                if (__n1 > __n2)
2948                {
2949                    traits_type::move(__p + __pos, __s, __n2);
2950                    traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
2951                    goto __finish;
2952                }
2953                if (__p + __pos < __s && __s < __p + __sz)
2954                {
2955                    if (__p + __pos + __n1 <= __s)
2956                        __s += __n2 - __n1;
2957                    else // __p + __pos < __s < __p + __pos + __n1
2958                    {
2959                        traits_type::move(__p + __pos, __s, __n1);
2960                        __pos += __n1;
2961                        __s += __n2;
2962                        __n2 -= __n1;
2963                        __n1 = 0;
2964                    }
2965                }
2966                traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
2967            }
2968        }
2969        traits_type::move(__p + __pos, __s, __n2);
2970__finish:
2971        __sz += __n2 - __n1;
2972        __set_size(__sz);
2973        __invalidate_iterators_past(__sz);
2974        traits_type::assign(__p[__sz], value_type());
2975    }
2976    else
2977        __grow_by_and_replace(__cap, __sz - __n1 + __n2 - __cap, __sz, __pos, __n1, __n2, __s);
2978    return *this;
2979}
2980
2981template <class _CharT, class _Traits, class _Allocator>
2982basic_string<_CharT, _Traits, _Allocator>&
2983basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, size_type __n2, value_type __c)
2984{
2985    size_type __sz = size();
2986    if (__pos > __sz)
2987        this->__throw_out_of_range();
2988    __n1 = _VSTD::min(__n1, __sz - __pos);
2989    size_type __cap = capacity();
2990    value_type* __p;
2991    if (__cap - __sz + __n1 >= __n2)
2992    {
2993        __p = _VSTD::__to_raw_pointer(__get_pointer());
2994        if (__n1 != __n2)
2995        {
2996            size_type __n_move = __sz - __pos - __n1;
2997            if (__n_move != 0)
2998                traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
2999        }
3000    }
3001    else
3002    {
3003        __grow_by(__cap, __sz - __n1 + __n2 - __cap, __sz, __pos, __n1, __n2);
3004        __p = _VSTD::__to_raw_pointer(__get_long_pointer());
3005    }
3006    traits_type::assign(__p + __pos, __n2, __c);
3007    __sz += __n2 - __n1;
3008    __set_size(__sz);
3009    __invalidate_iterators_past(__sz);
3010    traits_type::assign(__p[__sz], value_type());
3011    return *this;
3012}
3013
3014template <class _CharT, class _Traits, class _Allocator>
3015template<class _InputIterator>
3016typename enable_if
3017<
3018    __is_input_iterator<_InputIterator>::value,
3019    basic_string<_CharT, _Traits, _Allocator>&
3020>::type
3021basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2,
3022                                                   _InputIterator __j1, _InputIterator __j2)
3023{
3024    for (; true; ++__i1, ++__j1)
3025    {
3026        if (__i1 == __i2)
3027        {
3028            if (__j1 != __j2)
3029                insert(__i1, __j1, __j2);
3030            break;
3031        }
3032        if (__j1 == __j2)
3033        {
3034            erase(__i1, __i2);
3035            break;
3036        }
3037        traits_type::assign(const_cast<value_type&>(*__i1), *__j1);
3038    }
3039    return *this;
3040}
3041
3042template <class _CharT, class _Traits, class _Allocator>
3043inline _LIBCPP_INLINE_VISIBILITY
3044basic_string<_CharT, _Traits, _Allocator>&
3045basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const basic_string& __str)
3046{
3047    return replace(__pos1, __n1, __str.data(), __str.size());
3048}
3049
3050template <class _CharT, class _Traits, class _Allocator>
3051basic_string<_CharT, _Traits, _Allocator>&
3052basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const basic_string& __str,
3053                                                   size_type __pos2, size_type __n2)
3054{
3055    size_type __str_sz = __str.size();
3056    if (__pos2 > __str_sz)
3057        this->__throw_out_of_range();
3058    return replace(__pos1, __n1, __str.data() + __pos2, _VSTD::min(__n2, __str_sz - __pos2));
3059}
3060
3061template <class _CharT, class _Traits, class _Allocator>
3062basic_string<_CharT, _Traits, _Allocator>&
3063basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s)
3064{
3065    _LIBCPP_ASSERT(__s != nullptr, "string::replace received nullptr");
3066    return replace(__pos, __n1, __s, traits_type::length(__s));
3067}
3068
3069template <class _CharT, class _Traits, class _Allocator>
3070inline _LIBCPP_INLINE_VISIBILITY
3071basic_string<_CharT, _Traits, _Allocator>&
3072basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const basic_string& __str)
3073{
3074    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1),
3075                   __str.data(), __str.size());
3076}
3077
3078template <class _CharT, class _Traits, class _Allocator>
3079inline _LIBCPP_INLINE_VISIBILITY
3080basic_string<_CharT, _Traits, _Allocator>&
3081basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n)
3082{
3083    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s, __n);
3084}
3085
3086template <class _CharT, class _Traits, class _Allocator>
3087inline _LIBCPP_INLINE_VISIBILITY
3088basic_string<_CharT, _Traits, _Allocator>&
3089basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const value_type* __s)
3090{
3091    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s);
3092}
3093
3094template <class _CharT, class _Traits, class _Allocator>
3095inline _LIBCPP_INLINE_VISIBILITY
3096basic_string<_CharT, _Traits, _Allocator>&
3097basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c)
3098{
3099    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __n, __c);
3100}
3101
3102// erase
3103
3104template <class _CharT, class _Traits, class _Allocator>
3105basic_string<_CharT, _Traits, _Allocator>&
3106basic_string<_CharT, _Traits, _Allocator>::erase(size_type __pos, size_type __n)
3107{
3108    size_type __sz = size();
3109    if (__pos > __sz)
3110        this->__throw_out_of_range();
3111    if (__n)
3112    {
3113        value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
3114        __n = _VSTD::min(__n, __sz - __pos);
3115        size_type __n_move = __sz - __pos - __n;
3116        if (__n_move != 0)
3117            traits_type::move(__p + __pos, __p + __pos + __n, __n_move);
3118        __sz -= __n;
3119        __set_size(__sz);
3120        __invalidate_iterators_past(__sz);
3121        traits_type::assign(__p[__sz], value_type());
3122    }
3123    return *this;
3124}
3125
3126template <class _CharT, class _Traits, class _Allocator>
3127inline _LIBCPP_INLINE_VISIBILITY
3128typename basic_string<_CharT, _Traits, _Allocator>::iterator
3129basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __pos)
3130{
3131#if _LIBCPP_DEBUG_LEVEL >= 2
3132    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
3133        "string::erase(iterator) called with an iterator not"
3134        " referring to this string");
3135#endif
3136    _LIBCPP_ASSERT(__pos != end(),
3137        "string::erase(iterator) called with a non-dereferenceable iterator");
3138    iterator __b = begin();
3139    size_type __r = static_cast<size_type>(__pos - __b);
3140    erase(__r, 1);
3141    return __b + static_cast<difference_type>(__r);
3142}
3143
3144template <class _CharT, class _Traits, class _Allocator>
3145inline _LIBCPP_INLINE_VISIBILITY
3146typename basic_string<_CharT, _Traits, _Allocator>::iterator
3147basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __first, const_iterator __last)
3148{
3149#if _LIBCPP_DEBUG_LEVEL >= 2
3150    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
3151        "string::erase(iterator,  iterator) called with an iterator not"
3152        " referring to this string");
3153#endif
3154    _LIBCPP_ASSERT(__first <= __last, "string::erase(first, last) called with invalid range");
3155    iterator __b = begin();
3156    size_type __r = static_cast<size_type>(__first - __b);
3157    erase(__r, static_cast<size_type>(__last - __first));
3158    return __b + static_cast<difference_type>(__r);
3159}
3160
3161template <class _CharT, class _Traits, class _Allocator>
3162inline _LIBCPP_INLINE_VISIBILITY
3163void
3164basic_string<_CharT, _Traits, _Allocator>::pop_back()
3165{
3166    _LIBCPP_ASSERT(!empty(), "string::pop_back(): string is already empty");
3167    size_type __sz;
3168    if (__is_long())
3169    {
3170        __sz = __get_long_size() - 1;
3171        __set_long_size(__sz);
3172        traits_type::assign(*(__get_long_pointer() + __sz), value_type());
3173    }
3174    else
3175    {
3176        __sz = __get_short_size() - 1;
3177        __set_short_size(__sz);
3178        traits_type::assign(*(__get_short_pointer() + __sz), value_type());
3179    }
3180    __invalidate_iterators_past(__sz);
3181}
3182
3183template <class _CharT, class _Traits, class _Allocator>
3184inline _LIBCPP_INLINE_VISIBILITY
3185void
3186basic_string<_CharT, _Traits, _Allocator>::clear() _NOEXCEPT
3187{
3188    __invalidate_all_iterators();
3189    if (__is_long())
3190    {
3191        traits_type::assign(*__get_long_pointer(), value_type());
3192        __set_long_size(0);
3193    }
3194    else
3195    {
3196        traits_type::assign(*__get_short_pointer(), value_type());
3197        __set_short_size(0);
3198    }
3199}
3200
3201template <class _CharT, class _Traits, class _Allocator>
3202inline _LIBCPP_INLINE_VISIBILITY
3203void
3204basic_string<_CharT, _Traits, _Allocator>::__erase_to_end(size_type __pos)
3205{
3206    if (__is_long())
3207    {
3208        traits_type::assign(*(__get_long_pointer() + __pos), value_type());
3209        __set_long_size(__pos);
3210    }
3211    else
3212    {
3213        traits_type::assign(*(__get_short_pointer() + __pos), value_type());
3214        __set_short_size(__pos);
3215    }
3216    __invalidate_iterators_past(__pos);
3217}
3218
3219template <class _CharT, class _Traits, class _Allocator>
3220void
3221basic_string<_CharT, _Traits, _Allocator>::resize(size_type __n, value_type __c)
3222{
3223    size_type __sz = size();
3224    if (__n > __sz)
3225        append(__n - __sz, __c);
3226    else
3227        __erase_to_end(__n);
3228}
3229
3230template <class _CharT, class _Traits, class _Allocator>
3231inline _LIBCPP_INLINE_VISIBILITY
3232typename basic_string<_CharT, _Traits, _Allocator>::size_type
3233basic_string<_CharT, _Traits, _Allocator>::max_size() const _NOEXCEPT
3234{
3235    size_type __m = __alloc_traits::max_size(__alloc());
3236#if _LIBCPP_BIG_ENDIAN
3237    return (__m <= ~__long_mask ? __m : __m/2) - __alignment;
3238#else
3239    return __m - __alignment;
3240#endif
3241}
3242
3243template <class _CharT, class _Traits, class _Allocator>
3244void
3245basic_string<_CharT, _Traits, _Allocator>::reserve(size_type __res_arg)
3246{
3247    if (__res_arg > max_size())
3248        this->__throw_length_error();
3249    size_type __cap = capacity();
3250    size_type __sz = size();
3251    __res_arg = _VSTD::max(__res_arg, __sz);
3252    __res_arg = __recommend(__res_arg);
3253    if (__res_arg != __cap)
3254    {
3255        pointer __new_data, __p;
3256        bool __was_long, __now_long;
3257        if (__res_arg == __min_cap - 1)
3258        {
3259            __was_long = true;
3260            __now_long = false;
3261            __new_data = __get_short_pointer();
3262            __p = __get_long_pointer();
3263        }
3264        else
3265        {
3266            if (__res_arg > __cap)
3267                __new_data = __alloc_traits::allocate(__alloc(), __res_arg+1);
3268            else
3269            {
3270            #ifndef _LIBCPP_NO_EXCEPTIONS
3271                try
3272                {
3273            #endif  // _LIBCPP_NO_EXCEPTIONS
3274                    __new_data = __alloc_traits::allocate(__alloc(), __res_arg+1);
3275            #ifndef _LIBCPP_NO_EXCEPTIONS
3276                }
3277                catch (...)
3278                {
3279                    return;
3280                }
3281            #else  // _LIBCPP_NO_EXCEPTIONS
3282                if (__new_data == nullptr)
3283                    return;
3284            #endif  // _LIBCPP_NO_EXCEPTIONS
3285            }
3286            __now_long = true;
3287            __was_long = __is_long();
3288            __p = __get_pointer();
3289        }
3290        traits_type::copy(_VSTD::__to_raw_pointer(__new_data),
3291                          _VSTD::__to_raw_pointer(__p), size()+1);
3292        if (__was_long)
3293            __alloc_traits::deallocate(__alloc(), __p, __cap+1);
3294        if (__now_long)
3295        {
3296            __set_long_cap(__res_arg+1);
3297            __set_long_size(__sz);
3298            __set_long_pointer(__new_data);
3299        }
3300        else
3301            __set_short_size(__sz);
3302        __invalidate_all_iterators();
3303    }
3304}
3305
3306template <class _CharT, class _Traits, class _Allocator>
3307inline _LIBCPP_INLINE_VISIBILITY
3308typename basic_string<_CharT, _Traits, _Allocator>::const_reference
3309basic_string<_CharT, _Traits, _Allocator>::operator[](size_type __pos) const
3310{
3311    _LIBCPP_ASSERT(__pos <= size(), "string index out of bounds");
3312    return *(data() + __pos);
3313}
3314
3315template <class _CharT, class _Traits, class _Allocator>
3316inline _LIBCPP_INLINE_VISIBILITY
3317typename basic_string<_CharT, _Traits, _Allocator>::reference
3318basic_string<_CharT, _Traits, _Allocator>::operator[](size_type __pos)
3319{
3320    _LIBCPP_ASSERT(__pos <= size(), "string index out of bounds");
3321    return *(__get_pointer() + __pos);
3322}
3323
3324template <class _CharT, class _Traits, class _Allocator>
3325typename basic_string<_CharT, _Traits, _Allocator>::const_reference
3326basic_string<_CharT, _Traits, _Allocator>::at(size_type __n) const
3327{
3328    if (__n >= size())
3329        this->__throw_out_of_range();
3330    return (*this)[__n];
3331}
3332
3333template <class _CharT, class _Traits, class _Allocator>
3334typename basic_string<_CharT, _Traits, _Allocator>::reference
3335basic_string<_CharT, _Traits, _Allocator>::at(size_type __n)
3336{
3337    if (__n >= size())
3338        this->__throw_out_of_range();
3339    return (*this)[__n];
3340}
3341
3342template <class _CharT, class _Traits, class _Allocator>
3343inline _LIBCPP_INLINE_VISIBILITY
3344typename basic_string<_CharT, _Traits, _Allocator>::reference
3345basic_string<_CharT, _Traits, _Allocator>::front()
3346{
3347    _LIBCPP_ASSERT(!empty(), "string::front(): string is empty");
3348    return *__get_pointer();
3349}
3350
3351template <class _CharT, class _Traits, class _Allocator>
3352inline _LIBCPP_INLINE_VISIBILITY
3353typename basic_string<_CharT, _Traits, _Allocator>::const_reference
3354basic_string<_CharT, _Traits, _Allocator>::front() const
3355{
3356    _LIBCPP_ASSERT(!empty(), "string::front(): string is empty");
3357    return *data();
3358}
3359
3360template <class _CharT, class _Traits, class _Allocator>
3361inline _LIBCPP_INLINE_VISIBILITY
3362typename basic_string<_CharT, _Traits, _Allocator>::reference
3363basic_string<_CharT, _Traits, _Allocator>::back()
3364{
3365    _LIBCPP_ASSERT(!empty(), "string::back(): string is empty");
3366    return *(__get_pointer() + size() - 1);
3367}
3368
3369template <class _CharT, class _Traits, class _Allocator>
3370inline _LIBCPP_INLINE_VISIBILITY
3371typename basic_string<_CharT, _Traits, _Allocator>::const_reference
3372basic_string<_CharT, _Traits, _Allocator>::back() const
3373{
3374    _LIBCPP_ASSERT(!empty(), "string::back(): string is empty");
3375    return *(data() + size() - 1);
3376}
3377
3378template <class _CharT, class _Traits, class _Allocator>
3379typename basic_string<_CharT, _Traits, _Allocator>::size_type
3380basic_string<_CharT, _Traits, _Allocator>::copy(value_type* __s, size_type __n, size_type __pos) const
3381{
3382    size_type __sz = size();
3383    if (__pos > __sz)
3384        this->__throw_out_of_range();
3385    size_type __rlen = _VSTD::min(__n, __sz - __pos);
3386    traits_type::copy(__s, data() + __pos, __rlen);
3387    return __rlen;
3388}
3389
3390template <class _CharT, class _Traits, class _Allocator>
3391inline _LIBCPP_INLINE_VISIBILITY
3392basic_string<_CharT, _Traits, _Allocator>
3393basic_string<_CharT, _Traits, _Allocator>::substr(size_type __pos, size_type __n) const
3394{
3395    return basic_string(*this, __pos, __n, __alloc());
3396}
3397
3398template <class _CharT, class _Traits, class _Allocator>
3399inline _LIBCPP_INLINE_VISIBILITY
3400void
3401basic_string<_CharT, _Traits, _Allocator>::swap(basic_string& __str)
3402        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
3403                   __is_nothrow_swappable<allocator_type>::value)
3404{
3405#if _LIBCPP_DEBUG_LEVEL >= 2
3406    if (!__is_long())
3407        __get_db()->__invalidate_all(this);
3408    if (!__str.__is_long())
3409        __get_db()->__invalidate_all(&__str);
3410    __get_db()->swap(this, &__str);
3411#endif
3412    _VSTD::swap(__r_.first(), __str.__r_.first());
3413    __swap_alloc(__alloc(), __str.__alloc());
3414}
3415
3416// find
3417
3418template <class _Traits>
3419struct _LIBCPP_HIDDEN __traits_eq
3420{
3421    typedef typename _Traits::char_type char_type;
3422    _LIBCPP_INLINE_VISIBILITY
3423    bool operator()(const char_type& __x, const char_type& __y) _NOEXCEPT
3424        {return _Traits::eq(__x, __y);}
3425};
3426
3427template<class _CharT, class _Traits, class _Allocator>
3428typename basic_string<_CharT, _Traits, _Allocator>::size_type
3429basic_string<_CharT, _Traits, _Allocator>::find(const value_type* __s,
3430                                                size_type __pos,
3431                                                size_type __n) const _NOEXCEPT
3432{
3433    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find(): received nullptr");
3434    return _VSTD::__str_find<value_type, size_type, traits_type, npos>
3435        (data(), size(), __s, __pos, __n);
3436}
3437
3438template<class _CharT, class _Traits, class _Allocator>
3439inline _LIBCPP_INLINE_VISIBILITY
3440typename basic_string<_CharT, _Traits, _Allocator>::size_type
3441basic_string<_CharT, _Traits, _Allocator>::find(const basic_string& __str,
3442                                                size_type __pos) const _NOEXCEPT
3443{
3444    return _VSTD::__str_find<value_type, size_type, traits_type, npos>
3445        (data(), size(), __str.data(), __pos, __str.size());
3446}
3447
3448template<class _CharT, class _Traits, class _Allocator>
3449inline _LIBCPP_INLINE_VISIBILITY
3450typename basic_string<_CharT, _Traits, _Allocator>::size_type
3451basic_string<_CharT, _Traits, _Allocator>::find(const value_type* __s,
3452                                                size_type __pos) const _NOEXCEPT
3453{
3454    _LIBCPP_ASSERT(__s != nullptr, "string::find(): received nullptr");
3455    return _VSTD::__str_find<value_type, size_type, traits_type, npos>
3456        (data(), size(), __s, __pos, traits_type::length(__s));
3457}
3458
3459template<class _CharT, class _Traits, class _Allocator>
3460typename basic_string<_CharT, _Traits, _Allocator>::size_type
3461basic_string<_CharT, _Traits, _Allocator>::find(value_type __c,
3462                                                size_type __pos) const _NOEXCEPT
3463{
3464    return _VSTD::__str_find<value_type, size_type, traits_type, npos>
3465        (data(), size(), __c, __pos);
3466}
3467
3468// rfind
3469
3470template<class _CharT, class _Traits, class _Allocator>
3471typename basic_string<_CharT, _Traits, _Allocator>::size_type
3472basic_string<_CharT, _Traits, _Allocator>::rfind(const value_type* __s,
3473                                                 size_type __pos,
3474                                                 size_type __n) const _NOEXCEPT
3475{
3476    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::rfind(): received nullptr");
3477    return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
3478        (data(), size(), __s, __pos, __n);
3479}
3480
3481template<class _CharT, class _Traits, class _Allocator>
3482inline _LIBCPP_INLINE_VISIBILITY
3483typename basic_string<_CharT, _Traits, _Allocator>::size_type
3484basic_string<_CharT, _Traits, _Allocator>::rfind(const basic_string& __str,
3485                                                 size_type __pos) const _NOEXCEPT
3486{
3487    return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
3488        (data(), size(), __str.data(), __pos, __str.size());
3489}
3490
3491template<class _CharT, class _Traits, class _Allocator>
3492inline _LIBCPP_INLINE_VISIBILITY
3493typename basic_string<_CharT, _Traits, _Allocator>::size_type
3494basic_string<_CharT, _Traits, _Allocator>::rfind(const value_type* __s,
3495                                                 size_type __pos) const _NOEXCEPT
3496{
3497    _LIBCPP_ASSERT(__s != nullptr, "string::rfind(): received nullptr");
3498    return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
3499        (data(), size(), __s, __pos, traits_type::length(__s));
3500}
3501
3502template<class _CharT, class _Traits, class _Allocator>
3503typename basic_string<_CharT, _Traits, _Allocator>::size_type
3504basic_string<_CharT, _Traits, _Allocator>::rfind(value_type __c,
3505                                                 size_type __pos) const _NOEXCEPT
3506{
3507    return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
3508        (data(), size(), __c, __pos);
3509}
3510
3511// find_first_of
3512
3513template<class _CharT, class _Traits, class _Allocator>
3514typename basic_string<_CharT, _Traits, _Allocator>::size_type
3515basic_string<_CharT, _Traits, _Allocator>::find_first_of(const value_type* __s,
3516                                                         size_type __pos,
3517                                                         size_type __n) const _NOEXCEPT
3518{
3519    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_first_of(): received nullptr");
3520    return _VSTD::__str_find_first_of<value_type, size_type, traits_type, npos>
3521        (data(), size(), __s, __pos, __n);
3522}
3523
3524template<class _CharT, class _Traits, class _Allocator>
3525inline _LIBCPP_INLINE_VISIBILITY
3526typename basic_string<_CharT, _Traits, _Allocator>::size_type
3527basic_string<_CharT, _Traits, _Allocator>::find_first_of(const basic_string& __str,
3528                                                         size_type __pos) const _NOEXCEPT
3529{
3530    return _VSTD::__str_find_first_of<value_type, size_type, traits_type, npos>
3531        (data(), size(), __str.data(), __pos, __str.size());
3532}
3533
3534template<class _CharT, class _Traits, class _Allocator>
3535inline _LIBCPP_INLINE_VISIBILITY
3536typename basic_string<_CharT, _Traits, _Allocator>::size_type
3537basic_string<_CharT, _Traits, _Allocator>::find_first_of(const value_type* __s,
3538                                                         size_type __pos) const _NOEXCEPT
3539{
3540    _LIBCPP_ASSERT(__s != nullptr, "string::find_first_of(): received nullptr");
3541    return _VSTD::__str_find_first_of<value_type, size_type, traits_type, npos>
3542        (data(), size(), __s, __pos, traits_type::length(__s));
3543}
3544
3545template<class _CharT, class _Traits, class _Allocator>
3546inline _LIBCPP_INLINE_VISIBILITY
3547typename basic_string<_CharT, _Traits, _Allocator>::size_type
3548basic_string<_CharT, _Traits, _Allocator>::find_first_of(value_type __c,
3549                                                         size_type __pos) const _NOEXCEPT
3550{
3551    return find(__c, __pos);
3552}
3553
3554// find_last_of
3555
3556template<class _CharT, class _Traits, class _Allocator>
3557typename basic_string<_CharT, _Traits, _Allocator>::size_type
3558basic_string<_CharT, _Traits, _Allocator>::find_last_of(const value_type* __s,
3559                                                        size_type __pos,
3560                                                        size_type __n) const _NOEXCEPT
3561{
3562    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_last_of(): received nullptr");
3563    return _VSTD::__str_find_last_of<value_type, size_type, traits_type, npos>
3564        (data(), size(), __s, __pos, __n);
3565}
3566
3567template<class _CharT, class _Traits, class _Allocator>
3568inline _LIBCPP_INLINE_VISIBILITY
3569typename basic_string<_CharT, _Traits, _Allocator>::size_type
3570basic_string<_CharT, _Traits, _Allocator>::find_last_of(const basic_string& __str,
3571                                                        size_type __pos) const _NOEXCEPT
3572{
3573    return _VSTD::__str_find_last_of<value_type, size_type, traits_type, npos>
3574        (data(), size(), __str.data(), __pos, __str.size());
3575}
3576
3577template<class _CharT, class _Traits, class _Allocator>
3578inline _LIBCPP_INLINE_VISIBILITY
3579typename basic_string<_CharT, _Traits, _Allocator>::size_type
3580basic_string<_CharT, _Traits, _Allocator>::find_last_of(const value_type* __s,
3581                                                        size_type __pos) const _NOEXCEPT
3582{
3583    _LIBCPP_ASSERT(__s != nullptr, "string::find_last_of(): received nullptr");
3584    return _VSTD::__str_find_last_of<value_type, size_type, traits_type, npos>
3585        (data(), size(), __s, __pos, traits_type::length(__s));
3586}
3587
3588template<class _CharT, class _Traits, class _Allocator>
3589inline _LIBCPP_INLINE_VISIBILITY
3590typename basic_string<_CharT, _Traits, _Allocator>::size_type
3591basic_string<_CharT, _Traits, _Allocator>::find_last_of(value_type __c,
3592                                                        size_type __pos) const _NOEXCEPT
3593{
3594    return rfind(__c, __pos);
3595}
3596
3597// find_first_not_of
3598
3599template<class _CharT, class _Traits, class _Allocator>
3600typename basic_string<_CharT, _Traits, _Allocator>::size_type
3601basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const value_type* __s,
3602                                                             size_type __pos,
3603                                                             size_type __n) const _NOEXCEPT
3604{
3605    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_first_not_of(): received nullptr");
3606    return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
3607        (data(), size(), __s, __pos, __n);
3608}
3609
3610template<class _CharT, class _Traits, class _Allocator>
3611inline _LIBCPP_INLINE_VISIBILITY
3612typename basic_string<_CharT, _Traits, _Allocator>::size_type
3613basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const basic_string& __str,
3614                                                             size_type __pos) const _NOEXCEPT
3615{
3616    return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
3617        (data(), size(), __str.data(), __pos, __str.size());
3618}
3619
3620template<class _CharT, class _Traits, class _Allocator>
3621inline _LIBCPP_INLINE_VISIBILITY
3622typename basic_string<_CharT, _Traits, _Allocator>::size_type
3623basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const value_type* __s,
3624                                                             size_type __pos) const _NOEXCEPT
3625{
3626    _LIBCPP_ASSERT(__s != nullptr, "string::find_first_not_of(): received nullptr");
3627    return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
3628        (data(), size(), __s, __pos, traits_type::length(__s));
3629}
3630
3631template<class _CharT, class _Traits, class _Allocator>
3632inline _LIBCPP_INLINE_VISIBILITY
3633typename basic_string<_CharT, _Traits, _Allocator>::size_type
3634basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(value_type __c,
3635                                                             size_type __pos) const _NOEXCEPT
3636{
3637    return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
3638        (data(), size(), __c, __pos);
3639}
3640
3641// find_last_not_of
3642
3643template<class _CharT, class _Traits, class _Allocator>
3644typename basic_string<_CharT, _Traits, _Allocator>::size_type
3645basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const value_type* __s,
3646                                                            size_type __pos,
3647                                                            size_type __n) const _NOEXCEPT
3648{
3649    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_last_not_of(): received nullptr");
3650    return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
3651        (data(), size(), __s, __pos, __n);
3652}
3653
3654template<class _CharT, class _Traits, class _Allocator>
3655inline _LIBCPP_INLINE_VISIBILITY
3656typename basic_string<_CharT, _Traits, _Allocator>::size_type
3657basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const basic_string& __str,
3658                                                            size_type __pos) const _NOEXCEPT
3659{
3660    return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
3661        (data(), size(), __str.data(), __pos, __str.size());
3662}
3663
3664template<class _CharT, class _Traits, class _Allocator>
3665inline _LIBCPP_INLINE_VISIBILITY
3666typename basic_string<_CharT, _Traits, _Allocator>::size_type
3667basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const value_type* __s,
3668                                                            size_type __pos) const _NOEXCEPT
3669{
3670    _LIBCPP_ASSERT(__s != nullptr, "string::find_last_not_of(): received nullptr");
3671    return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
3672        (data(), size(), __s, __pos, traits_type::length(__s));
3673}
3674
3675template<class _CharT, class _Traits, class _Allocator>
3676inline _LIBCPP_INLINE_VISIBILITY
3677typename basic_string<_CharT, _Traits, _Allocator>::size_type
3678basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(value_type __c,
3679                                                            size_type __pos) const _NOEXCEPT
3680{
3681    return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
3682        (data(), size(), __c, __pos);
3683}
3684
3685// compare
3686
3687template <class _CharT, class _Traits, class _Allocator>
3688inline _LIBCPP_INLINE_VISIBILITY
3689int
3690basic_string<_CharT, _Traits, _Allocator>::compare(const basic_string& __str) const _NOEXCEPT
3691{
3692    size_t __lhs_sz = size();
3693    size_t __rhs_sz = __str.size();
3694    int __result = traits_type::compare(data(), __str.data(),
3695                                        _VSTD::min(__lhs_sz, __rhs_sz));
3696    if (__result != 0)
3697        return __result;
3698    if (__lhs_sz < __rhs_sz)
3699        return -1;
3700    if (__lhs_sz > __rhs_sz)
3701        return 1;
3702    return 0;
3703}
3704
3705template <class _CharT, class _Traits, class _Allocator>
3706inline _LIBCPP_INLINE_VISIBILITY
3707int
3708basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
3709                                                   size_type __n1,
3710                                                   const basic_string& __str) const
3711{
3712    return compare(__pos1, __n1, __str.data(), __str.size());
3713}
3714
3715template <class _CharT, class _Traits, class _Allocator>
3716int
3717basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
3718                                                   size_type __n1,
3719                                                   const basic_string& __str,
3720                                                   size_type __pos2,
3721                                                   size_type __n2) const
3722{
3723    size_type __sz = __str.size();
3724    if (__pos2 > __sz)
3725        this->__throw_out_of_range();
3726    return compare(__pos1, __n1, __str.data() + __pos2, _VSTD::min(__n2,
3727                                                                  __sz - __pos2));
3728}
3729
3730template <class _CharT, class _Traits, class _Allocator>
3731int
3732basic_string<_CharT, _Traits, _Allocator>::compare(const value_type* __s) const _NOEXCEPT
3733{
3734    _LIBCPP_ASSERT(__s != nullptr, "string::compare(): received nullptr");
3735    return compare(0, npos, __s, traits_type::length(__s));
3736}
3737
3738template <class _CharT, class _Traits, class _Allocator>
3739int
3740basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
3741                                                   size_type __n1,
3742                                                   const value_type* __s) const
3743{
3744    _LIBCPP_ASSERT(__s != nullptr, "string::compare(): received nullptr");
3745    return compare(__pos1, __n1, __s, traits_type::length(__s));
3746}
3747
3748template <class _CharT, class _Traits, class _Allocator>
3749int
3750basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
3751                                                   size_type __n1,
3752                                                   const value_type* __s,
3753                                                   size_type __n2) const
3754{
3755    _LIBCPP_ASSERT(__n2 == 0 || __s != nullptr, "string::compare(): received nullptr");
3756    size_type __sz = size();
3757    if (__pos1 > __sz || __n2 == npos)
3758        this->__throw_out_of_range();
3759    size_type __rlen = _VSTD::min(__n1, __sz - __pos1);
3760    int __r = traits_type::compare(data() + __pos1, __s, _VSTD::min(__rlen, __n2));
3761    if (__r == 0)
3762    {
3763        if (__rlen < __n2)
3764            __r = -1;
3765        else if (__rlen > __n2)
3766            __r = 1;
3767    }
3768    return __r;
3769}
3770
3771// __invariants
3772
3773template<class _CharT, class _Traits, class _Allocator>
3774inline _LIBCPP_INLINE_VISIBILITY
3775bool
3776basic_string<_CharT, _Traits, _Allocator>::__invariants() const
3777{
3778    if (size() > capacity())
3779        return false;
3780    if (capacity() < __min_cap - 1)
3781        return false;
3782    if (data() == 0)
3783        return false;
3784    if (data()[size()] != value_type(0))
3785        return false;
3786    return true;
3787}
3788
3789// operator==
3790
3791template<class _CharT, class _Traits, class _Allocator>
3792inline _LIBCPP_INLINE_VISIBILITY
3793bool
3794operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3795           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3796{
3797    size_t __lhs_sz = __lhs.size();
3798    return __lhs_sz == __rhs.size() && _Traits::compare(__lhs.data(),
3799                                                        __rhs.data(),
3800                                                        __lhs_sz) == 0;
3801}
3802
3803template<class _Allocator>
3804inline _LIBCPP_INLINE_VISIBILITY
3805bool
3806operator==(const basic_string<char, char_traits<char>, _Allocator>& __lhs,
3807           const basic_string<char, char_traits<char>, _Allocator>& __rhs) _NOEXCEPT
3808{
3809    size_t __lhs_sz = __lhs.size();
3810    if (__lhs_sz != __rhs.size())
3811        return false;
3812    const char* __lp = __lhs.data();
3813    const char* __rp = __rhs.data();
3814    if (__lhs.__is_long())
3815        return char_traits<char>::compare(__lp, __rp, __lhs_sz) == 0;
3816    for (; __lhs_sz != 0; --__lhs_sz, ++__lp, ++__rp)
3817        if (*__lp != *__rp)
3818            return false;
3819    return true;
3820}
3821
3822template<class _CharT, class _Traits, class _Allocator>
3823inline _LIBCPP_INLINE_VISIBILITY
3824bool
3825operator==(const _CharT* __lhs,
3826           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3827{
3828    return __rhs.compare(__lhs) == 0;
3829}
3830
3831template<class _CharT, class _Traits, class _Allocator>
3832inline _LIBCPP_INLINE_VISIBILITY
3833bool
3834operator==(const basic_string<_CharT,_Traits,_Allocator>& __lhs,
3835           const _CharT* __rhs) _NOEXCEPT
3836{
3837    return __lhs.compare(__rhs) == 0;
3838}
3839
3840// operator!=
3841
3842template<class _CharT, class _Traits, class _Allocator>
3843inline _LIBCPP_INLINE_VISIBILITY
3844bool
3845operator!=(const basic_string<_CharT,_Traits,_Allocator>& __lhs,
3846           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3847{
3848    return !(__lhs == __rhs);
3849}
3850
3851template<class _CharT, class _Traits, class _Allocator>
3852inline _LIBCPP_INLINE_VISIBILITY
3853bool
3854operator!=(const _CharT* __lhs,
3855           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3856{
3857    return !(__lhs == __rhs);
3858}
3859
3860template<class _CharT, class _Traits, class _Allocator>
3861inline _LIBCPP_INLINE_VISIBILITY
3862bool
3863operator!=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3864           const _CharT* __rhs) _NOEXCEPT
3865{
3866    return !(__lhs == __rhs);
3867}
3868
3869// operator<
3870
3871template<class _CharT, class _Traits, class _Allocator>
3872inline _LIBCPP_INLINE_VISIBILITY
3873bool
3874operator< (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3875           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3876{
3877    return __lhs.compare(__rhs) < 0;
3878}
3879
3880template<class _CharT, class _Traits, class _Allocator>
3881inline _LIBCPP_INLINE_VISIBILITY
3882bool
3883operator< (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3884           const _CharT* __rhs) _NOEXCEPT
3885{
3886    return __lhs.compare(__rhs) < 0;
3887}
3888
3889template<class _CharT, class _Traits, class _Allocator>
3890inline _LIBCPP_INLINE_VISIBILITY
3891bool
3892operator< (const _CharT* __lhs,
3893           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3894{
3895    return __rhs.compare(__lhs) > 0;
3896}
3897
3898// operator>
3899
3900template<class _CharT, class _Traits, class _Allocator>
3901inline _LIBCPP_INLINE_VISIBILITY
3902bool
3903operator> (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3904           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3905{
3906    return __rhs < __lhs;
3907}
3908
3909template<class _CharT, class _Traits, class _Allocator>
3910inline _LIBCPP_INLINE_VISIBILITY
3911bool
3912operator> (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3913           const _CharT* __rhs) _NOEXCEPT
3914{
3915    return __rhs < __lhs;
3916}
3917
3918template<class _CharT, class _Traits, class _Allocator>
3919inline _LIBCPP_INLINE_VISIBILITY
3920bool
3921operator> (const _CharT* __lhs,
3922           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3923{
3924    return __rhs < __lhs;
3925}
3926
3927// operator<=
3928
3929template<class _CharT, class _Traits, class _Allocator>
3930inline _LIBCPP_INLINE_VISIBILITY
3931bool
3932operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3933           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3934{
3935    return !(__rhs < __lhs);
3936}
3937
3938template<class _CharT, class _Traits, class _Allocator>
3939inline _LIBCPP_INLINE_VISIBILITY
3940bool
3941operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3942           const _CharT* __rhs) _NOEXCEPT
3943{
3944    return !(__rhs < __lhs);
3945}
3946
3947template<class _CharT, class _Traits, class _Allocator>
3948inline _LIBCPP_INLINE_VISIBILITY
3949bool
3950operator<=(const _CharT* __lhs,
3951           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3952{
3953    return !(__rhs < __lhs);
3954}
3955
3956// operator>=
3957
3958template<class _CharT, class _Traits, class _Allocator>
3959inline _LIBCPP_INLINE_VISIBILITY
3960bool
3961operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3962           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3963{
3964    return !(__lhs < __rhs);
3965}
3966
3967template<class _CharT, class _Traits, class _Allocator>
3968inline _LIBCPP_INLINE_VISIBILITY
3969bool
3970operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3971           const _CharT* __rhs) _NOEXCEPT
3972{
3973    return !(__lhs < __rhs);
3974}
3975
3976template<class _CharT, class _Traits, class _Allocator>
3977inline _LIBCPP_INLINE_VISIBILITY
3978bool
3979operator>=(const _CharT* __lhs,
3980           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3981{
3982    return !(__lhs < __rhs);
3983}
3984
3985// operator +
3986
3987template<class _CharT, class _Traits, class _Allocator>
3988basic_string<_CharT, _Traits, _Allocator>
3989operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3990          const basic_string<_CharT, _Traits, _Allocator>& __rhs)
3991{
3992    basic_string<_CharT, _Traits, _Allocator> __r(__lhs.get_allocator());
3993    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = __lhs.size();
3994    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = __rhs.size();
3995    __r.__init(__lhs.data(), __lhs_sz, __lhs_sz + __rhs_sz);
3996    __r.append(__rhs.data(), __rhs_sz);
3997    return __r;
3998}
3999
4000template<class _CharT, class _Traits, class _Allocator>
4001basic_string<_CharT, _Traits, _Allocator>
4002operator+(const _CharT* __lhs , const basic_string<_CharT,_Traits,_Allocator>& __rhs)
4003{
4004    basic_string<_CharT, _Traits, _Allocator> __r(__rhs.get_allocator());
4005    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = _Traits::length(__lhs);
4006    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = __rhs.size();
4007    __r.__init(__lhs, __lhs_sz, __lhs_sz + __rhs_sz);
4008    __r.append(__rhs.data(), __rhs_sz);
4009    return __r;
4010}
4011
4012template<class _CharT, class _Traits, class _Allocator>
4013basic_string<_CharT, _Traits, _Allocator>
4014operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Allocator>& __rhs)
4015{
4016    basic_string<_CharT, _Traits, _Allocator> __r(__rhs.get_allocator());
4017    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = __rhs.size();
4018    __r.__init(&__lhs, 1, 1 + __rhs_sz);
4019    __r.append(__rhs.data(), __rhs_sz);
4020    return __r;
4021}
4022
4023template<class _CharT, class _Traits, class _Allocator>
4024basic_string<_CharT, _Traits, _Allocator>
4025operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs)
4026{
4027    basic_string<_CharT, _Traits, _Allocator> __r(__lhs.get_allocator());
4028    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = __lhs.size();
4029    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = _Traits::length(__rhs);
4030    __r.__init(__lhs.data(), __lhs_sz, __lhs_sz + __rhs_sz);
4031    __r.append(__rhs, __rhs_sz);
4032    return __r;
4033}
4034
4035template<class _CharT, class _Traits, class _Allocator>
4036basic_string<_CharT, _Traits, _Allocator>
4037operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, _CharT __rhs)
4038{
4039    basic_string<_CharT, _Traits, _Allocator> __r(__lhs.get_allocator());
4040    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = __lhs.size();
4041    __r.__init(__lhs.data(), __lhs_sz, __lhs_sz + 1);
4042    __r.push_back(__rhs);
4043    return __r;
4044}
4045
4046#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4047
4048template<class _CharT, class _Traits, class _Allocator>
4049inline _LIBCPP_INLINE_VISIBILITY
4050basic_string<_CharT, _Traits, _Allocator>
4051operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs)
4052{
4053    return _VSTD::move(__lhs.append(__rhs));
4054}
4055
4056template<class _CharT, class _Traits, class _Allocator>
4057inline _LIBCPP_INLINE_VISIBILITY
4058basic_string<_CharT, _Traits, _Allocator>
4059operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs)
4060{
4061    return _VSTD::move(__rhs.insert(0, __lhs));
4062}
4063
4064template<class _CharT, class _Traits, class _Allocator>
4065inline _LIBCPP_INLINE_VISIBILITY
4066basic_string<_CharT, _Traits, _Allocator>
4067operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs)
4068{
4069    return _VSTD::move(__lhs.append(__rhs));
4070}
4071
4072template<class _CharT, class _Traits, class _Allocator>
4073inline _LIBCPP_INLINE_VISIBILITY
4074basic_string<_CharT, _Traits, _Allocator>
4075operator+(const _CharT* __lhs , basic_string<_CharT,_Traits,_Allocator>&& __rhs)
4076{
4077    return _VSTD::move(__rhs.insert(0, __lhs));
4078}
4079
4080template<class _CharT, class _Traits, class _Allocator>
4081inline _LIBCPP_INLINE_VISIBILITY
4082basic_string<_CharT, _Traits, _Allocator>
4083operator+(_CharT __lhs, basic_string<_CharT,_Traits,_Allocator>&& __rhs)
4084{
4085    __rhs.insert(__rhs.begin(), __lhs);
4086    return _VSTD::move(__rhs);
4087}
4088
4089template<class _CharT, class _Traits, class _Allocator>
4090inline _LIBCPP_INLINE_VISIBILITY
4091basic_string<_CharT, _Traits, _Allocator>
4092operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const _CharT* __rhs)
4093{
4094    return _VSTD::move(__lhs.append(__rhs));
4095}
4096
4097template<class _CharT, class _Traits, class _Allocator>
4098inline _LIBCPP_INLINE_VISIBILITY
4099basic_string<_CharT, _Traits, _Allocator>
4100operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, _CharT __rhs)
4101{
4102    __lhs.push_back(__rhs);
4103    return _VSTD::move(__lhs);
4104}
4105
4106#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4107
4108// swap
4109
4110template<class _CharT, class _Traits, class _Allocator>
4111inline _LIBCPP_INLINE_VISIBILITY
4112void
4113swap(basic_string<_CharT, _Traits, _Allocator>& __lhs,
4114     basic_string<_CharT, _Traits, _Allocator>& __rhs)
4115     _NOEXCEPT_(_NOEXCEPT_(__lhs.swap(__rhs)))
4116{
4117    __lhs.swap(__rhs);
4118}
4119
4120#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
4121
4122typedef basic_string<char16_t> u16string;
4123typedef basic_string<char32_t> u32string;
4124
4125#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
4126
4127_LIBCPP_FUNC_VIS int                stoi  (const string& __str, size_t* __idx = 0, int __base = 10);
4128_LIBCPP_FUNC_VIS long               stol  (const string& __str, size_t* __idx = 0, int __base = 10);
4129_LIBCPP_FUNC_VIS unsigned long      stoul (const string& __str, size_t* __idx = 0, int __base = 10);
4130_LIBCPP_FUNC_VIS long long          stoll (const string& __str, size_t* __idx = 0, int __base = 10);
4131_LIBCPP_FUNC_VIS unsigned long long stoull(const string& __str, size_t* __idx = 0, int __base = 10);
4132
4133_LIBCPP_FUNC_VIS float       stof (const string& __str, size_t* __idx = 0);
4134_LIBCPP_FUNC_VIS double      stod (const string& __str, size_t* __idx = 0);
4135_LIBCPP_FUNC_VIS long double stold(const string& __str, size_t* __idx = 0);
4136
4137_LIBCPP_FUNC_VIS string to_string(int __val);
4138_LIBCPP_FUNC_VIS string to_string(unsigned __val);
4139_LIBCPP_FUNC_VIS string to_string(long __val);
4140_LIBCPP_FUNC_VIS string to_string(unsigned long __val);
4141_LIBCPP_FUNC_VIS string to_string(long long __val);
4142_LIBCPP_FUNC_VIS string to_string(unsigned long long __val);
4143_LIBCPP_FUNC_VIS string to_string(float __val);
4144_LIBCPP_FUNC_VIS string to_string(double __val);
4145_LIBCPP_FUNC_VIS string to_string(long double __val);
4146
4147_LIBCPP_FUNC_VIS int                stoi  (const wstring& __str, size_t* __idx = 0, int __base = 10);
4148_LIBCPP_FUNC_VIS long               stol  (const wstring& __str, size_t* __idx = 0, int __base = 10);
4149_LIBCPP_FUNC_VIS unsigned long      stoul (const wstring& __str, size_t* __idx = 0, int __base = 10);
4150_LIBCPP_FUNC_VIS long long          stoll (const wstring& __str, size_t* __idx = 0, int __base = 10);
4151_LIBCPP_FUNC_VIS unsigned long long stoull(const wstring& __str, size_t* __idx = 0, int __base = 10);
4152
4153_LIBCPP_FUNC_VIS float       stof (const wstring& __str, size_t* __idx = 0);
4154_LIBCPP_FUNC_VIS double      stod (const wstring& __str, size_t* __idx = 0);
4155_LIBCPP_FUNC_VIS long double stold(const wstring& __str, size_t* __idx = 0);
4156
4157_LIBCPP_FUNC_VIS wstring to_wstring(int __val);
4158_LIBCPP_FUNC_VIS wstring to_wstring(unsigned __val);
4159_LIBCPP_FUNC_VIS wstring to_wstring(long __val);
4160_LIBCPP_FUNC_VIS wstring to_wstring(unsigned long __val);
4161_LIBCPP_FUNC_VIS wstring to_wstring(long long __val);
4162_LIBCPP_FUNC_VIS wstring to_wstring(unsigned long long __val);
4163_LIBCPP_FUNC_VIS wstring to_wstring(float __val);
4164_LIBCPP_FUNC_VIS wstring to_wstring(double __val);
4165_LIBCPP_FUNC_VIS wstring to_wstring(long double __val);
4166
4167template<class _CharT, class _Traits, class _Allocator>
4168    const typename basic_string<_CharT, _Traits, _Allocator>::size_type
4169                   basic_string<_CharT, _Traits, _Allocator>::npos;
4170
4171template<class _CharT, class _Traits, class _Allocator>
4172struct _LIBCPP_TYPE_VIS_ONLY hash<basic_string<_CharT, _Traits, _Allocator> >
4173    : public unary_function<basic_string<_CharT, _Traits, _Allocator>, size_t>
4174{
4175    size_t
4176        operator()(const basic_string<_CharT, _Traits, _Allocator>& __val) const _NOEXCEPT;
4177};
4178
4179template<class _CharT, class _Traits, class _Allocator>
4180size_t
4181hash<basic_string<_CharT, _Traits, _Allocator> >::operator()(
4182        const basic_string<_CharT, _Traits, _Allocator>& __val) const _NOEXCEPT
4183{
4184    return __do_string_hash(__val.data(), __val.data() + __val.size());
4185}
4186
4187template<class _CharT, class _Traits, class _Allocator>
4188basic_ostream<_CharT, _Traits>&
4189operator<<(basic_ostream<_CharT, _Traits>& __os,
4190           const basic_string<_CharT, _Traits, _Allocator>& __str);
4191
4192template<class _CharT, class _Traits, class _Allocator>
4193basic_istream<_CharT, _Traits>&
4194operator>>(basic_istream<_CharT, _Traits>& __is,
4195           basic_string<_CharT, _Traits, _Allocator>& __str);
4196
4197template<class _CharT, class _Traits, class _Allocator>
4198basic_istream<_CharT, _Traits>&
4199getline(basic_istream<_CharT, _Traits>& __is,
4200        basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm);
4201
4202template<class _CharT, class _Traits, class _Allocator>
4203inline _LIBCPP_INLINE_VISIBILITY
4204basic_istream<_CharT, _Traits>&
4205getline(basic_istream<_CharT, _Traits>& __is,
4206        basic_string<_CharT, _Traits, _Allocator>& __str);
4207
4208#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4209
4210template<class _CharT, class _Traits, class _Allocator>
4211inline _LIBCPP_INLINE_VISIBILITY
4212basic_istream<_CharT, _Traits>&
4213getline(basic_istream<_CharT, _Traits>&& __is,
4214        basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm);
4215
4216template<class _CharT, class _Traits, class _Allocator>
4217inline _LIBCPP_INLINE_VISIBILITY
4218basic_istream<_CharT, _Traits>&
4219getline(basic_istream<_CharT, _Traits>&& __is,
4220        basic_string<_CharT, _Traits, _Allocator>& __str);
4221
4222#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4223
4224#if _LIBCPP_DEBUG_LEVEL >= 2
4225
4226template<class _CharT, class _Traits, class _Allocator>
4227bool
4228basic_string<_CharT, _Traits, _Allocator>::__dereferenceable(const const_iterator* __i) const
4229{
4230    return this->data() <= _VSTD::__to_raw_pointer(__i->base()) &&
4231           _VSTD::__to_raw_pointer(__i->base()) < this->data() + this->size();
4232}
4233
4234template<class _CharT, class _Traits, class _Allocator>
4235bool
4236basic_string<_CharT, _Traits, _Allocator>::__decrementable(const const_iterator* __i) const
4237{
4238    return this->data() < _VSTD::__to_raw_pointer(__i->base()) &&
4239           _VSTD::__to_raw_pointer(__i->base()) <= this->data() + this->size();
4240}
4241
4242template<class _CharT, class _Traits, class _Allocator>
4243bool
4244basic_string<_CharT, _Traits, _Allocator>::__addable(const const_iterator* __i, ptrdiff_t __n) const
4245{
4246    const value_type* __p = _VSTD::__to_raw_pointer(__i->base()) + __n;
4247    return this->data() <= __p && __p <= this->data() + this->size();
4248}
4249
4250template<class _CharT, class _Traits, class _Allocator>
4251bool
4252basic_string<_CharT, _Traits, _Allocator>::__subscriptable(const const_iterator* __i, ptrdiff_t __n) const
4253{
4254    const value_type* __p = _VSTD::__to_raw_pointer(__i->base()) + __n;
4255    return this->data() <= __p && __p < this->data() + this->size();
4256}
4257
4258#endif  // _LIBCPP_DEBUG_LEVEL >= 2
4259
4260#if _LIBCPP_STD_VER > 11
4261// Literal suffixes for basic_string [basic.string.literals]
4262inline namespace literals
4263{
4264  inline namespace string_literals
4265  {
4266    inline _LIBCPP_INLINE_VISIBILITY
4267    basic_string<char> operator "" s( const char *__str, size_t __len )
4268    {
4269        return basic_string<char> (__str, __len);
4270    }
4271
4272    inline _LIBCPP_INLINE_VISIBILITY
4273    basic_string<wchar_t> operator "" s( const wchar_t *__str, size_t __len )
4274    {
4275        return basic_string<wchar_t> (__str, __len);
4276    }
4277
4278    inline _LIBCPP_INLINE_VISIBILITY
4279    basic_string<char16_t> operator "" s( const char16_t *__str, size_t __len )
4280    {
4281        return basic_string<char16_t> (__str, __len);
4282    }
4283
4284    inline _LIBCPP_INLINE_VISIBILITY
4285    basic_string<char32_t> operator "" s( const char32_t *__str, size_t __len )
4286    {
4287        return basic_string<char32_t> (__str, __len);
4288    }
4289  }
4290}
4291#endif
4292
4293_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_TYPE_VIS basic_string<char>)
4294_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_TYPE_VIS basic_string<wchar_t>)
4295_LIBCPP_EXTERN_TEMPLATE(string operator+<char, char_traits<char>, allocator<char> >(char const*, string const&))
4296
4297_LIBCPP_END_NAMESPACE_STD
4298
4299#endif  // _LIBCPP_STRING
4300