xref: /llvm-project-15.0.7/libcxx/include/string (revision f3bd08ae)
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 (__a == __str.__alloc() || !__str.__is_long())
2140        __r_.first().__r = __str.__r_.first().__r;
2141    else
2142        __init(_VSTD::__to_raw_pointer(__str.__get_long_pointer()), __str.__get_long_size());
2143    __str.__zero();
2144#if _LIBCPP_DEBUG_LEVEL >= 2
2145    __get_db()->__insert_c(this);
2146    if (__is_long())
2147        __get_db()->swap(this, &__str);
2148#endif
2149}
2150
2151#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2152
2153template <class _CharT, class _Traits, class _Allocator>
2154void
2155basic_string<_CharT, _Traits, _Allocator>::__init(size_type __n, value_type __c)
2156{
2157    if (__n > max_size())
2158        this->__throw_length_error();
2159    pointer __p;
2160    if (__n < __min_cap)
2161    {
2162        __set_short_size(__n);
2163        __p = __get_short_pointer();
2164    }
2165    else
2166    {
2167        size_type __cap = __recommend(__n);
2168        __p = __alloc_traits::allocate(__alloc(), __cap+1);
2169        __set_long_pointer(__p);
2170        __set_long_cap(__cap+1);
2171        __set_long_size(__n);
2172    }
2173    traits_type::assign(_VSTD::__to_raw_pointer(__p), __n, __c);
2174    traits_type::assign(__p[__n], value_type());
2175}
2176
2177template <class _CharT, class _Traits, class _Allocator>
2178inline _LIBCPP_INLINE_VISIBILITY
2179basic_string<_CharT, _Traits, _Allocator>::basic_string(size_type __n, value_type __c)
2180{
2181    __init(__n, __c);
2182#if _LIBCPP_DEBUG_LEVEL >= 2
2183    __get_db()->__insert_c(this);
2184#endif
2185}
2186
2187template <class _CharT, class _Traits, class _Allocator>
2188inline _LIBCPP_INLINE_VISIBILITY
2189basic_string<_CharT, _Traits, _Allocator>::basic_string(size_type __n, value_type __c, const allocator_type& __a)
2190    : __r_(__a)
2191{
2192    __init(__n, __c);
2193#if _LIBCPP_DEBUG_LEVEL >= 2
2194    __get_db()->__insert_c(this);
2195#endif
2196}
2197
2198template <class _CharT, class _Traits, class _Allocator>
2199basic_string<_CharT, _Traits, _Allocator>::basic_string(const basic_string& __str, size_type __pos, size_type __n,
2200                                                        const allocator_type& __a)
2201    : __r_(__a)
2202{
2203    size_type __str_sz = __str.size();
2204    if (__pos > __str_sz)
2205        this->__throw_out_of_range();
2206    __init(__str.data() + __pos, _VSTD::min(__n, __str_sz - __pos));
2207#if _LIBCPP_DEBUG_LEVEL >= 2
2208    __get_db()->__insert_c(this);
2209#endif
2210}
2211
2212template <class _CharT, class _Traits, class _Allocator>
2213template <class _InputIterator>
2214typename enable_if
2215<
2216     __is_input_iterator  <_InputIterator>::value &&
2217    !__is_forward_iterator<_InputIterator>::value,
2218    void
2219>::type
2220basic_string<_CharT, _Traits, _Allocator>::__init(_InputIterator __first, _InputIterator __last)
2221{
2222    __zero();
2223#ifndef _LIBCPP_NO_EXCEPTIONS
2224    try
2225    {
2226#endif  // _LIBCPP_NO_EXCEPTIONS
2227    for (; __first != __last; ++__first)
2228        push_back(*__first);
2229#ifndef _LIBCPP_NO_EXCEPTIONS
2230    }
2231    catch (...)
2232    {
2233        if (__is_long())
2234            __alloc_traits::deallocate(__alloc(), __get_long_pointer(), __get_long_cap());
2235        throw;
2236    }
2237#endif  // _LIBCPP_NO_EXCEPTIONS
2238}
2239
2240template <class _CharT, class _Traits, class _Allocator>
2241template <class _ForwardIterator>
2242typename enable_if
2243<
2244    __is_forward_iterator<_ForwardIterator>::value,
2245    void
2246>::type
2247basic_string<_CharT, _Traits, _Allocator>::__init(_ForwardIterator __first, _ForwardIterator __last)
2248{
2249    size_type __sz = static_cast<size_type>(_VSTD::distance(__first, __last));
2250    if (__sz > max_size())
2251        this->__throw_length_error();
2252    pointer __p;
2253    if (__sz < __min_cap)
2254    {
2255        __set_short_size(__sz);
2256        __p = __get_short_pointer();
2257    }
2258    else
2259    {
2260        size_type __cap = __recommend(__sz);
2261        __p = __alloc_traits::allocate(__alloc(), __cap+1);
2262        __set_long_pointer(__p);
2263        __set_long_cap(__cap+1);
2264        __set_long_size(__sz);
2265    }
2266    for (; __first != __last; ++__first, ++__p)
2267        traits_type::assign(*__p, *__first);
2268    traits_type::assign(*__p, value_type());
2269}
2270
2271template <class _CharT, class _Traits, class _Allocator>
2272template<class _InputIterator>
2273inline _LIBCPP_INLINE_VISIBILITY
2274basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator __first, _InputIterator __last)
2275{
2276    __init(__first, __last);
2277#if _LIBCPP_DEBUG_LEVEL >= 2
2278    __get_db()->__insert_c(this);
2279#endif
2280}
2281
2282template <class _CharT, class _Traits, class _Allocator>
2283template<class _InputIterator>
2284inline _LIBCPP_INLINE_VISIBILITY
2285basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator __first, _InputIterator __last,
2286                                                        const allocator_type& __a)
2287    : __r_(__a)
2288{
2289    __init(__first, __last);
2290#if _LIBCPP_DEBUG_LEVEL >= 2
2291    __get_db()->__insert_c(this);
2292#endif
2293}
2294
2295#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
2296
2297template <class _CharT, class _Traits, class _Allocator>
2298inline _LIBCPP_INLINE_VISIBILITY
2299basic_string<_CharT, _Traits, _Allocator>::basic_string(initializer_list<value_type> __il)
2300{
2301    __init(__il.begin(), __il.end());
2302#if _LIBCPP_DEBUG_LEVEL >= 2
2303    __get_db()->__insert_c(this);
2304#endif
2305}
2306
2307template <class _CharT, class _Traits, class _Allocator>
2308inline _LIBCPP_INLINE_VISIBILITY
2309basic_string<_CharT, _Traits, _Allocator>::basic_string(initializer_list<value_type> __il, const allocator_type& __a)
2310    : __r_(__a)
2311{
2312    __init(__il.begin(), __il.end());
2313#if _LIBCPP_DEBUG_LEVEL >= 2
2314    __get_db()->__insert_c(this);
2315#endif
2316}
2317
2318#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
2319
2320template <class _CharT, class _Traits, class _Allocator>
2321basic_string<_CharT, _Traits, _Allocator>::~basic_string()
2322{
2323#if _LIBCPP_DEBUG_LEVEL >= 2
2324    __get_db()->__erase_c(this);
2325#endif
2326    if (__is_long())
2327        __alloc_traits::deallocate(__alloc(), __get_long_pointer(), __get_long_cap());
2328}
2329
2330template <class _CharT, class _Traits, class _Allocator>
2331void
2332basic_string<_CharT, _Traits, _Allocator>::__grow_by_and_replace
2333    (size_type __old_cap, size_type __delta_cap, size_type __old_sz,
2334     size_type __n_copy,  size_type __n_del,     size_type __n_add, const value_type* __p_new_stuff)
2335{
2336    size_type __ms = max_size();
2337    if (__delta_cap > __ms - __old_cap - 1)
2338        this->__throw_length_error();
2339    pointer __old_p = __get_pointer();
2340    size_type __cap = __old_cap < __ms / 2 - __alignment ?
2341                          __recommend(_VSTD::max(__old_cap + __delta_cap, 2 * __old_cap)) :
2342                          __ms - 1;
2343    pointer __p = __alloc_traits::allocate(__alloc(), __cap+1);
2344    __invalidate_all_iterators();
2345    if (__n_copy != 0)
2346        traits_type::copy(_VSTD::__to_raw_pointer(__p),
2347                          _VSTD::__to_raw_pointer(__old_p), __n_copy);
2348    if (__n_add != 0)
2349        traits_type::copy(_VSTD::__to_raw_pointer(__p) + __n_copy, __p_new_stuff, __n_add);
2350    size_type __sec_cp_sz = __old_sz - __n_del - __n_copy;
2351    if (__sec_cp_sz != 0)
2352        traits_type::copy(_VSTD::__to_raw_pointer(__p) + __n_copy + __n_add,
2353                          _VSTD::__to_raw_pointer(__old_p) + __n_copy + __n_del, __sec_cp_sz);
2354    if (__old_cap+1 != __min_cap)
2355        __alloc_traits::deallocate(__alloc(), __old_p, __old_cap+1);
2356    __set_long_pointer(__p);
2357    __set_long_cap(__cap+1);
2358    __old_sz = __n_copy + __n_add + __sec_cp_sz;
2359    __set_long_size(__old_sz);
2360    traits_type::assign(__p[__old_sz], value_type());
2361}
2362
2363template <class _CharT, class _Traits, class _Allocator>
2364void
2365basic_string<_CharT, _Traits, _Allocator>::__grow_by(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
2366                                                     size_type __n_copy,  size_type __n_del,     size_type __n_add)
2367{
2368    size_type __ms = max_size();
2369    if (__delta_cap > __ms - __old_cap)
2370        this->__throw_length_error();
2371    pointer __old_p = __get_pointer();
2372    size_type __cap = __old_cap < __ms / 2 - __alignment ?
2373                          __recommend(_VSTD::max(__old_cap + __delta_cap, 2 * __old_cap)) :
2374                          __ms - 1;
2375    pointer __p = __alloc_traits::allocate(__alloc(), __cap+1);
2376    __invalidate_all_iterators();
2377    if (__n_copy != 0)
2378        traits_type::copy(_VSTD::__to_raw_pointer(__p),
2379                          _VSTD::__to_raw_pointer(__old_p), __n_copy);
2380    size_type __sec_cp_sz = __old_sz - __n_del - __n_copy;
2381    if (__sec_cp_sz != 0)
2382        traits_type::copy(_VSTD::__to_raw_pointer(__p) + __n_copy + __n_add,
2383                          _VSTD::__to_raw_pointer(__old_p) + __n_copy + __n_del,
2384                          __sec_cp_sz);
2385    if (__old_cap+1 != __min_cap)
2386        __alloc_traits::deallocate(__alloc(), __old_p, __old_cap+1);
2387    __set_long_pointer(__p);
2388    __set_long_cap(__cap+1);
2389}
2390
2391// assign
2392
2393template <class _CharT, class _Traits, class _Allocator>
2394basic_string<_CharT, _Traits, _Allocator>&
2395basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s, size_type __n)
2396{
2397    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::assign received nullptr");
2398    size_type __cap = capacity();
2399    if (__cap >= __n)
2400    {
2401        value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
2402        traits_type::move(__p, __s, __n);
2403        traits_type::assign(__p[__n], value_type());
2404        __set_size(__n);
2405        __invalidate_iterators_past(__n);
2406    }
2407    else
2408    {
2409        size_type __sz = size();
2410        __grow_by_and_replace(__cap, __n - __cap, __sz, 0, __sz, __n, __s);
2411    }
2412    return *this;
2413}
2414
2415template <class _CharT, class _Traits, class _Allocator>
2416basic_string<_CharT, _Traits, _Allocator>&
2417basic_string<_CharT, _Traits, _Allocator>::assign(size_type __n, value_type __c)
2418{
2419    size_type __cap = capacity();
2420    if (__cap < __n)
2421    {
2422        size_type __sz = size();
2423        __grow_by(__cap, __n - __cap, __sz, 0, __sz);
2424    }
2425    else
2426        __invalidate_iterators_past(__n);
2427    value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
2428    traits_type::assign(__p, __n, __c);
2429    traits_type::assign(__p[__n], value_type());
2430    __set_size(__n);
2431    return *this;
2432}
2433
2434template <class _CharT, class _Traits, class _Allocator>
2435basic_string<_CharT, _Traits, _Allocator>&
2436basic_string<_CharT, _Traits, _Allocator>::operator=(value_type __c)
2437{
2438    pointer __p;
2439    if (__is_long())
2440    {
2441        __p = __get_long_pointer();
2442        __set_long_size(1);
2443    }
2444    else
2445    {
2446        __p = __get_short_pointer();
2447        __set_short_size(1);
2448    }
2449    traits_type::assign(*__p, __c);
2450    traits_type::assign(*++__p, value_type());
2451    __invalidate_iterators_past(1);
2452    return *this;
2453}
2454
2455template <class _CharT, class _Traits, class _Allocator>
2456basic_string<_CharT, _Traits, _Allocator>&
2457basic_string<_CharT, _Traits, _Allocator>::operator=(const basic_string& __str)
2458{
2459    if (this != &__str)
2460    {
2461        __copy_assign_alloc(__str);
2462        assign(__str);
2463    }
2464    return *this;
2465}
2466
2467#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2468
2469template <class _CharT, class _Traits, class _Allocator>
2470inline _LIBCPP_INLINE_VISIBILITY
2471void
2472basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, false_type)
2473{
2474    if (__alloc() != __str.__alloc())
2475        assign(__str);
2476    else
2477        __move_assign(__str, true_type());
2478}
2479
2480template <class _CharT, class _Traits, class _Allocator>
2481inline _LIBCPP_INLINE_VISIBILITY
2482void
2483basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, true_type)
2484    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
2485{
2486    clear();
2487    shrink_to_fit();
2488    __r_.first() = __str.__r_.first();
2489    __move_assign_alloc(__str);
2490    __str.__zero();
2491}
2492
2493template <class _CharT, class _Traits, class _Allocator>
2494inline _LIBCPP_INLINE_VISIBILITY
2495basic_string<_CharT, _Traits, _Allocator>&
2496basic_string<_CharT, _Traits, _Allocator>::operator=(basic_string&& __str)
2497    _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
2498               is_nothrow_move_assignable<allocator_type>::value)
2499{
2500    __move_assign(__str, integral_constant<bool,
2501          __alloc_traits::propagate_on_container_move_assignment::value>());
2502    return *this;
2503}
2504
2505#endif
2506
2507template <class _CharT, class _Traits, class _Allocator>
2508template<class _InputIterator>
2509typename enable_if
2510<
2511     __is_input_iterator  <_InputIterator>::value &&
2512    !__is_forward_iterator<_InputIterator>::value,
2513    basic_string<_CharT, _Traits, _Allocator>&
2514>::type
2515basic_string<_CharT, _Traits, _Allocator>::assign(_InputIterator __first, _InputIterator __last)
2516{
2517    clear();
2518    for (; __first != __last; ++__first)
2519        push_back(*__first);
2520    return *this;
2521}
2522
2523template <class _CharT, class _Traits, class _Allocator>
2524template<class _ForwardIterator>
2525typename enable_if
2526<
2527    __is_forward_iterator<_ForwardIterator>::value,
2528    basic_string<_CharT, _Traits, _Allocator>&
2529>::type
2530basic_string<_CharT, _Traits, _Allocator>::assign(_ForwardIterator __first, _ForwardIterator __last)
2531{
2532    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
2533    size_type __cap = capacity();
2534    if (__cap < __n)
2535    {
2536        size_type __sz = size();
2537        __grow_by(__cap, __n - __cap, __sz, 0, __sz);
2538    }
2539    else
2540        __invalidate_iterators_past(__n);
2541    pointer __p = __get_pointer();
2542    for (; __first != __last; ++__first, ++__p)
2543        traits_type::assign(*__p, *__first);
2544    traits_type::assign(*__p, value_type());
2545    __set_size(__n);
2546    return *this;
2547}
2548
2549template <class _CharT, class _Traits, class _Allocator>
2550inline _LIBCPP_INLINE_VISIBILITY
2551basic_string<_CharT, _Traits, _Allocator>&
2552basic_string<_CharT, _Traits, _Allocator>::assign(const basic_string& __str)
2553{
2554    return assign(__str.data(), __str.size());
2555}
2556
2557template <class _CharT, class _Traits, class _Allocator>
2558basic_string<_CharT, _Traits, _Allocator>&
2559basic_string<_CharT, _Traits, _Allocator>::assign(const basic_string& __str, size_type __pos, size_type __n)
2560{
2561    size_type __sz = __str.size();
2562    if (__pos > __sz)
2563        this->__throw_out_of_range();
2564    return assign(__str.data() + __pos, _VSTD::min(__n, __sz - __pos));
2565}
2566
2567template <class _CharT, class _Traits, class _Allocator>
2568basic_string<_CharT, _Traits, _Allocator>&
2569basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s)
2570{
2571    _LIBCPP_ASSERT(__s != nullptr, "string::assign received nullptr");
2572    return assign(__s, traits_type::length(__s));
2573}
2574
2575// append
2576
2577template <class _CharT, class _Traits, class _Allocator>
2578basic_string<_CharT, _Traits, _Allocator>&
2579basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s, size_type __n)
2580{
2581    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::append received nullptr");
2582    size_type __cap = capacity();
2583    size_type __sz = size();
2584    if (__cap - __sz >= __n)
2585    {
2586        if (__n)
2587        {
2588            value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
2589            traits_type::copy(__p + __sz, __s, __n);
2590            __sz += __n;
2591            __set_size(__sz);
2592            traits_type::assign(__p[__sz], value_type());
2593        }
2594    }
2595    else
2596        __grow_by_and_replace(__cap, __sz + __n - __cap, __sz, __sz, 0, __n, __s);
2597    return *this;
2598}
2599
2600template <class _CharT, class _Traits, class _Allocator>
2601basic_string<_CharT, _Traits, _Allocator>&
2602basic_string<_CharT, _Traits, _Allocator>::append(size_type __n, value_type __c)
2603{
2604    if (__n)
2605    {
2606        size_type __cap = capacity();
2607        size_type __sz = size();
2608        if (__cap - __sz < __n)
2609            __grow_by(__cap, __sz + __n - __cap, __sz, __sz, 0);
2610        pointer __p = __get_pointer();
2611        traits_type::assign(_VSTD::__to_raw_pointer(__p) + __sz, __n, __c);
2612        __sz += __n;
2613        __set_size(__sz);
2614        traits_type::assign(__p[__sz], value_type());
2615    }
2616    return *this;
2617}
2618
2619template <class _CharT, class _Traits, class _Allocator>
2620void
2621basic_string<_CharT, _Traits, _Allocator>::push_back(value_type __c)
2622{
2623    bool __is_short = !__is_long();
2624    size_type __cap;
2625    size_type __sz;
2626    if (__is_short)
2627    {
2628        __cap = __min_cap - 1;
2629        __sz = __get_short_size();
2630    }
2631    else
2632    {
2633        __cap = __get_long_cap() - 1;
2634        __sz = __get_long_size();
2635    }
2636    if (__sz == __cap)
2637    {
2638        __grow_by(__cap, 1, __sz, __sz, 0);
2639        __is_short = !__is_long();
2640    }
2641    pointer __p;
2642    if (__is_short)
2643    {
2644        __p = __get_short_pointer() + __sz;
2645        __set_short_size(__sz+1);
2646    }
2647    else
2648    {
2649        __p = __get_long_pointer() + __sz;
2650        __set_long_size(__sz+1);
2651    }
2652    traits_type::assign(*__p, __c);
2653    traits_type::assign(*++__p, value_type());
2654}
2655
2656template <class _CharT, class _Traits, class _Allocator>
2657template<class _InputIterator>
2658typename enable_if
2659<
2660     __is_input_iterator  <_InputIterator>::value &&
2661    !__is_forward_iterator<_InputIterator>::value,
2662    basic_string<_CharT, _Traits, _Allocator>&
2663>::type
2664basic_string<_CharT, _Traits, _Allocator>::append(_InputIterator __first, _InputIterator __last)
2665{
2666    for (; __first != __last; ++__first)
2667        push_back(*__first);
2668    return *this;
2669}
2670
2671template <class _CharT, class _Traits, class _Allocator>
2672template<class _ForwardIterator>
2673typename enable_if
2674<
2675    __is_forward_iterator<_ForwardIterator>::value,
2676    basic_string<_CharT, _Traits, _Allocator>&
2677>::type
2678basic_string<_CharT, _Traits, _Allocator>::append(_ForwardIterator __first, _ForwardIterator __last)
2679{
2680    size_type __sz = size();
2681    size_type __cap = capacity();
2682    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
2683    if (__n)
2684    {
2685        if (__cap - __sz < __n)
2686            __grow_by(__cap, __sz + __n - __cap, __sz, __sz, 0);
2687        pointer __p = __get_pointer() + __sz;
2688        for (; __first != __last; ++__p, ++__first)
2689            traits_type::assign(*__p, *__first);
2690        traits_type::assign(*__p, value_type());
2691        __set_size(__sz + __n);
2692    }
2693    return *this;
2694}
2695
2696template <class _CharT, class _Traits, class _Allocator>
2697inline _LIBCPP_INLINE_VISIBILITY
2698basic_string<_CharT, _Traits, _Allocator>&
2699basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str)
2700{
2701    return append(__str.data(), __str.size());
2702}
2703
2704template <class _CharT, class _Traits, class _Allocator>
2705basic_string<_CharT, _Traits, _Allocator>&
2706basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str, size_type __pos, size_type __n)
2707{
2708    size_type __sz = __str.size();
2709    if (__pos > __sz)
2710        this->__throw_out_of_range();
2711    return append(__str.data() + __pos, _VSTD::min(__n, __sz - __pos));
2712}
2713
2714template <class _CharT, class _Traits, class _Allocator>
2715basic_string<_CharT, _Traits, _Allocator>&
2716basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s)
2717{
2718    _LIBCPP_ASSERT(__s != nullptr, "string::append received nullptr");
2719    return append(__s, traits_type::length(__s));
2720}
2721
2722// insert
2723
2724template <class _CharT, class _Traits, class _Allocator>
2725basic_string<_CharT, _Traits, _Allocator>&
2726basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s, size_type __n)
2727{
2728    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::insert received nullptr");
2729    size_type __sz = size();
2730    if (__pos > __sz)
2731        this->__throw_out_of_range();
2732    size_type __cap = capacity();
2733    if (__cap - __sz >= __n)
2734    {
2735        if (__n)
2736        {
2737            value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
2738            size_type __n_move = __sz - __pos;
2739            if (__n_move != 0)
2740            {
2741                if (__p + __pos <= __s && __s < __p + __sz)
2742                    __s += __n;
2743                traits_type::move(__p + __pos + __n, __p + __pos, __n_move);
2744            }
2745            traits_type::move(__p + __pos, __s, __n);
2746            __sz += __n;
2747            __set_size(__sz);
2748            traits_type::assign(__p[__sz], value_type());
2749        }
2750    }
2751    else
2752        __grow_by_and_replace(__cap, __sz + __n - __cap, __sz, __pos, 0, __n, __s);
2753    return *this;
2754}
2755
2756template <class _CharT, class _Traits, class _Allocator>
2757basic_string<_CharT, _Traits, _Allocator>&
2758basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, size_type __n, value_type __c)
2759{
2760    size_type __sz = size();
2761    if (__pos > __sz)
2762        this->__throw_out_of_range();
2763    if (__n)
2764    {
2765        size_type __cap = capacity();
2766        value_type* __p;
2767        if (__cap - __sz >= __n)
2768        {
2769            __p = _VSTD::__to_raw_pointer(__get_pointer());
2770            size_type __n_move = __sz - __pos;
2771            if (__n_move != 0)
2772                traits_type::move(__p + __pos + __n, __p + __pos, __n_move);
2773        }
2774        else
2775        {
2776            __grow_by(__cap, __sz + __n - __cap, __sz, __pos, 0, __n);
2777            __p = _VSTD::__to_raw_pointer(__get_long_pointer());
2778        }
2779        traits_type::assign(__p + __pos, __n, __c);
2780        __sz += __n;
2781        __set_size(__sz);
2782        traits_type::assign(__p[__sz], value_type());
2783    }
2784    return *this;
2785}
2786
2787template <class _CharT, class _Traits, class _Allocator>
2788template<class _InputIterator>
2789typename enable_if
2790<
2791     __is_input_iterator  <_InputIterator>::value &&
2792    !__is_forward_iterator<_InputIterator>::value,
2793    typename basic_string<_CharT, _Traits, _Allocator>::iterator
2794>::type
2795basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, _InputIterator __first, _InputIterator __last)
2796{
2797#if _LIBCPP_DEBUG_LEVEL >= 2
2798    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
2799        "string::insert(iterator, range) called with an iterator not"
2800        " referring to this string");
2801#endif
2802    size_type __old_sz = size();
2803    difference_type __ip = __pos - begin();
2804    for (; __first != __last; ++__first)
2805        push_back(*__first);
2806    pointer __p = __get_pointer();
2807    _VSTD::rotate(__p + __ip, __p + __old_sz, __p + size());
2808#if _LIBCPP_DEBUG_LEVEL >= 2
2809    return iterator(this, __p + __ip);
2810#else
2811    return iterator(__p + __ip);
2812#endif
2813}
2814
2815template <class _CharT, class _Traits, class _Allocator>
2816template<class _ForwardIterator>
2817typename enable_if
2818<
2819    __is_forward_iterator<_ForwardIterator>::value,
2820    typename basic_string<_CharT, _Traits, _Allocator>::iterator
2821>::type
2822basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, _ForwardIterator __first, _ForwardIterator __last)
2823{
2824#if _LIBCPP_DEBUG_LEVEL >= 2
2825    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
2826        "string::insert(iterator, range) called with an iterator not"
2827        " referring to this string");
2828#endif
2829    size_type __ip = static_cast<size_type>(__pos - begin());
2830    size_type __sz = size();
2831    size_type __cap = capacity();
2832    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
2833    if (__n)
2834    {
2835        value_type* __p;
2836        if (__cap - __sz >= __n)
2837        {
2838            __p = _VSTD::__to_raw_pointer(__get_pointer());
2839            size_type __n_move = __sz - __ip;
2840            if (__n_move != 0)
2841                traits_type::move(__p + __ip + __n, __p + __ip, __n_move);
2842        }
2843        else
2844        {
2845            __grow_by(__cap, __sz + __n - __cap, __sz, __ip, 0, __n);
2846            __p = _VSTD::__to_raw_pointer(__get_long_pointer());
2847        }
2848        __sz += __n;
2849        __set_size(__sz);
2850        traits_type::assign(__p[__sz], value_type());
2851        for (__p += __ip; __first != __last; ++__p, ++__first)
2852            traits_type::assign(*__p, *__first);
2853    }
2854    return begin() + __ip;
2855}
2856
2857template <class _CharT, class _Traits, class _Allocator>
2858inline _LIBCPP_INLINE_VISIBILITY
2859basic_string<_CharT, _Traits, _Allocator>&
2860basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const basic_string& __str)
2861{
2862    return insert(__pos1, __str.data(), __str.size());
2863}
2864
2865template <class _CharT, class _Traits, class _Allocator>
2866basic_string<_CharT, _Traits, _Allocator>&
2867basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const basic_string& __str,
2868                                                  size_type __pos2, size_type __n)
2869{
2870    size_type __str_sz = __str.size();
2871    if (__pos2 > __str_sz)
2872        this->__throw_out_of_range();
2873    return insert(__pos1, __str.data() + __pos2, _VSTD::min(__n, __str_sz - __pos2));
2874}
2875
2876template <class _CharT, class _Traits, class _Allocator>
2877basic_string<_CharT, _Traits, _Allocator>&
2878basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s)
2879{
2880    _LIBCPP_ASSERT(__s != nullptr, "string::insert received nullptr");
2881    return insert(__pos, __s, traits_type::length(__s));
2882}
2883
2884template <class _CharT, class _Traits, class _Allocator>
2885typename basic_string<_CharT, _Traits, _Allocator>::iterator
2886basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, value_type __c)
2887{
2888    size_type __ip = static_cast<size_type>(__pos - begin());
2889    size_type __sz = size();
2890    size_type __cap = capacity();
2891    value_type* __p;
2892    if (__cap == __sz)
2893    {
2894        __grow_by(__cap, 1, __sz, __ip, 0, 1);
2895        __p = _VSTD::__to_raw_pointer(__get_long_pointer());
2896    }
2897    else
2898    {
2899        __p = _VSTD::__to_raw_pointer(__get_pointer());
2900        size_type __n_move = __sz - __ip;
2901        if (__n_move != 0)
2902            traits_type::move(__p + __ip + 1, __p + __ip, __n_move);
2903    }
2904    traits_type::assign(__p[__ip], __c);
2905    traits_type::assign(__p[++__sz], value_type());
2906    __set_size(__sz);
2907    return begin() + static_cast<difference_type>(__ip);
2908}
2909
2910template <class _CharT, class _Traits, class _Allocator>
2911inline _LIBCPP_INLINE_VISIBILITY
2912typename basic_string<_CharT, _Traits, _Allocator>::iterator
2913basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, size_type __n, value_type __c)
2914{
2915#if _LIBCPP_DEBUG_LEVEL >= 2
2916    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
2917        "string::insert(iterator, n, value) called with an iterator not"
2918        " referring to this string");
2919#endif
2920    difference_type __p = __pos - begin();
2921    insert(static_cast<size_type>(__p), __n, __c);
2922    return begin() + __p;
2923}
2924
2925// replace
2926
2927template <class _CharT, class _Traits, class _Allocator>
2928basic_string<_CharT, _Traits, _Allocator>&
2929basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2)
2930{
2931    _LIBCPP_ASSERT(__n2 == 0 || __s != nullptr, "string::replace received nullptr");
2932    size_type __sz = size();
2933    if (__pos > __sz)
2934        this->__throw_out_of_range();
2935    __n1 = _VSTD::min(__n1, __sz - __pos);
2936    size_type __cap = capacity();
2937    if (__cap - __sz + __n1 >= __n2)
2938    {
2939        value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
2940        if (__n1 != __n2)
2941        {
2942            size_type __n_move = __sz - __pos - __n1;
2943            if (__n_move != 0)
2944            {
2945                if (__n1 > __n2)
2946                {
2947                    traits_type::move(__p + __pos, __s, __n2);
2948                    traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
2949                    goto __finish;
2950                }
2951                if (__p + __pos < __s && __s < __p + __sz)
2952                {
2953                    if (__p + __pos + __n1 <= __s)
2954                        __s += __n2 - __n1;
2955                    else // __p + __pos < __s < __p + __pos + __n1
2956                    {
2957                        traits_type::move(__p + __pos, __s, __n1);
2958                        __pos += __n1;
2959                        __s += __n2;
2960                        __n2 -= __n1;
2961                        __n1 = 0;
2962                    }
2963                }
2964                traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
2965            }
2966        }
2967        traits_type::move(__p + __pos, __s, __n2);
2968__finish:
2969        __sz += __n2 - __n1;
2970        __set_size(__sz);
2971        __invalidate_iterators_past(__sz);
2972        traits_type::assign(__p[__sz], value_type());
2973    }
2974    else
2975        __grow_by_and_replace(__cap, __sz - __n1 + __n2 - __cap, __sz, __pos, __n1, __n2, __s);
2976    return *this;
2977}
2978
2979template <class _CharT, class _Traits, class _Allocator>
2980basic_string<_CharT, _Traits, _Allocator>&
2981basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, size_type __n2, value_type __c)
2982{
2983    size_type __sz = size();
2984    if (__pos > __sz)
2985        this->__throw_out_of_range();
2986    __n1 = _VSTD::min(__n1, __sz - __pos);
2987    size_type __cap = capacity();
2988    value_type* __p;
2989    if (__cap - __sz + __n1 >= __n2)
2990    {
2991        __p = _VSTD::__to_raw_pointer(__get_pointer());
2992        if (__n1 != __n2)
2993        {
2994            size_type __n_move = __sz - __pos - __n1;
2995            if (__n_move != 0)
2996                traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
2997        }
2998    }
2999    else
3000    {
3001        __grow_by(__cap, __sz - __n1 + __n2 - __cap, __sz, __pos, __n1, __n2);
3002        __p = _VSTD::__to_raw_pointer(__get_long_pointer());
3003    }
3004    traits_type::assign(__p + __pos, __n2, __c);
3005    __sz += __n2 - __n1;
3006    __set_size(__sz);
3007    __invalidate_iterators_past(__sz);
3008    traits_type::assign(__p[__sz], value_type());
3009    return *this;
3010}
3011
3012template <class _CharT, class _Traits, class _Allocator>
3013template<class _InputIterator>
3014typename enable_if
3015<
3016    __is_input_iterator<_InputIterator>::value,
3017    basic_string<_CharT, _Traits, _Allocator>&
3018>::type
3019basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2,
3020                                                   _InputIterator __j1, _InputIterator __j2)
3021{
3022    for (; true; ++__i1, ++__j1)
3023    {
3024        if (__i1 == __i2)
3025        {
3026            if (__j1 != __j2)
3027                insert(__i1, __j1, __j2);
3028            break;
3029        }
3030        if (__j1 == __j2)
3031        {
3032            erase(__i1, __i2);
3033            break;
3034        }
3035        traits_type::assign(const_cast<value_type&>(*__i1), *__j1);
3036    }
3037    return *this;
3038}
3039
3040template <class _CharT, class _Traits, class _Allocator>
3041inline _LIBCPP_INLINE_VISIBILITY
3042basic_string<_CharT, _Traits, _Allocator>&
3043basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const basic_string& __str)
3044{
3045    return replace(__pos1, __n1, __str.data(), __str.size());
3046}
3047
3048template <class _CharT, class _Traits, class _Allocator>
3049basic_string<_CharT, _Traits, _Allocator>&
3050basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const basic_string& __str,
3051                                                   size_type __pos2, size_type __n2)
3052{
3053    size_type __str_sz = __str.size();
3054    if (__pos2 > __str_sz)
3055        this->__throw_out_of_range();
3056    return replace(__pos1, __n1, __str.data() + __pos2, _VSTD::min(__n2, __str_sz - __pos2));
3057}
3058
3059template <class _CharT, class _Traits, class _Allocator>
3060basic_string<_CharT, _Traits, _Allocator>&
3061basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s)
3062{
3063    _LIBCPP_ASSERT(__s != nullptr, "string::replace received nullptr");
3064    return replace(__pos, __n1, __s, traits_type::length(__s));
3065}
3066
3067template <class _CharT, class _Traits, class _Allocator>
3068inline _LIBCPP_INLINE_VISIBILITY
3069basic_string<_CharT, _Traits, _Allocator>&
3070basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const basic_string& __str)
3071{
3072    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1),
3073                   __str.data(), __str.size());
3074}
3075
3076template <class _CharT, class _Traits, class _Allocator>
3077inline _LIBCPP_INLINE_VISIBILITY
3078basic_string<_CharT, _Traits, _Allocator>&
3079basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n)
3080{
3081    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s, __n);
3082}
3083
3084template <class _CharT, class _Traits, class _Allocator>
3085inline _LIBCPP_INLINE_VISIBILITY
3086basic_string<_CharT, _Traits, _Allocator>&
3087basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const value_type* __s)
3088{
3089    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s);
3090}
3091
3092template <class _CharT, class _Traits, class _Allocator>
3093inline _LIBCPP_INLINE_VISIBILITY
3094basic_string<_CharT, _Traits, _Allocator>&
3095basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c)
3096{
3097    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __n, __c);
3098}
3099
3100// erase
3101
3102template <class _CharT, class _Traits, class _Allocator>
3103basic_string<_CharT, _Traits, _Allocator>&
3104basic_string<_CharT, _Traits, _Allocator>::erase(size_type __pos, size_type __n)
3105{
3106    size_type __sz = size();
3107    if (__pos > __sz)
3108        this->__throw_out_of_range();
3109    if (__n)
3110    {
3111        value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
3112        __n = _VSTD::min(__n, __sz - __pos);
3113        size_type __n_move = __sz - __pos - __n;
3114        if (__n_move != 0)
3115            traits_type::move(__p + __pos, __p + __pos + __n, __n_move);
3116        __sz -= __n;
3117        __set_size(__sz);
3118        __invalidate_iterators_past(__sz);
3119        traits_type::assign(__p[__sz], value_type());
3120    }
3121    return *this;
3122}
3123
3124template <class _CharT, class _Traits, class _Allocator>
3125inline _LIBCPP_INLINE_VISIBILITY
3126typename basic_string<_CharT, _Traits, _Allocator>::iterator
3127basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __pos)
3128{
3129#if _LIBCPP_DEBUG_LEVEL >= 2
3130    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
3131        "string::erase(iterator) called with an iterator not"
3132        " referring to this string");
3133#endif
3134    _LIBCPP_ASSERT(__pos != end(),
3135        "string::erase(iterator) called with a non-dereferenceable iterator");
3136    iterator __b = begin();
3137    size_type __r = static_cast<size_type>(__pos - __b);
3138    erase(__r, 1);
3139    return __b + static_cast<difference_type>(__r);
3140}
3141
3142template <class _CharT, class _Traits, class _Allocator>
3143inline _LIBCPP_INLINE_VISIBILITY
3144typename basic_string<_CharT, _Traits, _Allocator>::iterator
3145basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __first, const_iterator __last)
3146{
3147#if _LIBCPP_DEBUG_LEVEL >= 2
3148    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
3149        "string::erase(iterator,  iterator) called with an iterator not"
3150        " referring to this string");
3151#endif
3152    _LIBCPP_ASSERT(__first <= __last, "string::erase(first, last) called with invalid range");
3153    iterator __b = begin();
3154    size_type __r = static_cast<size_type>(__first - __b);
3155    erase(__r, static_cast<size_type>(__last - __first));
3156    return __b + static_cast<difference_type>(__r);
3157}
3158
3159template <class _CharT, class _Traits, class _Allocator>
3160inline _LIBCPP_INLINE_VISIBILITY
3161void
3162basic_string<_CharT, _Traits, _Allocator>::pop_back()
3163{
3164    _LIBCPP_ASSERT(!empty(), "string::pop_back(): string is already empty");
3165    size_type __sz;
3166    if (__is_long())
3167    {
3168        __sz = __get_long_size() - 1;
3169        __set_long_size(__sz);
3170        traits_type::assign(*(__get_long_pointer() + __sz), value_type());
3171    }
3172    else
3173    {
3174        __sz = __get_short_size() - 1;
3175        __set_short_size(__sz);
3176        traits_type::assign(*(__get_short_pointer() + __sz), value_type());
3177    }
3178    __invalidate_iterators_past(__sz);
3179}
3180
3181template <class _CharT, class _Traits, class _Allocator>
3182inline _LIBCPP_INLINE_VISIBILITY
3183void
3184basic_string<_CharT, _Traits, _Allocator>::clear() _NOEXCEPT
3185{
3186    __invalidate_all_iterators();
3187    if (__is_long())
3188    {
3189        traits_type::assign(*__get_long_pointer(), value_type());
3190        __set_long_size(0);
3191    }
3192    else
3193    {
3194        traits_type::assign(*__get_short_pointer(), value_type());
3195        __set_short_size(0);
3196    }
3197}
3198
3199template <class _CharT, class _Traits, class _Allocator>
3200inline _LIBCPP_INLINE_VISIBILITY
3201void
3202basic_string<_CharT, _Traits, _Allocator>::__erase_to_end(size_type __pos)
3203{
3204    if (__is_long())
3205    {
3206        traits_type::assign(*(__get_long_pointer() + __pos), value_type());
3207        __set_long_size(__pos);
3208    }
3209    else
3210    {
3211        traits_type::assign(*(__get_short_pointer() + __pos), value_type());
3212        __set_short_size(__pos);
3213    }
3214    __invalidate_iterators_past(__pos);
3215}
3216
3217template <class _CharT, class _Traits, class _Allocator>
3218void
3219basic_string<_CharT, _Traits, _Allocator>::resize(size_type __n, value_type __c)
3220{
3221    size_type __sz = size();
3222    if (__n > __sz)
3223        append(__n - __sz, __c);
3224    else
3225        __erase_to_end(__n);
3226}
3227
3228template <class _CharT, class _Traits, class _Allocator>
3229inline _LIBCPP_INLINE_VISIBILITY
3230typename basic_string<_CharT, _Traits, _Allocator>::size_type
3231basic_string<_CharT, _Traits, _Allocator>::max_size() const _NOEXCEPT
3232{
3233    size_type __m = __alloc_traits::max_size(__alloc());
3234#if _LIBCPP_BIG_ENDIAN
3235    return (__m <= ~__long_mask ? __m : __m/2) - __alignment;
3236#else
3237    return __m - __alignment;
3238#endif
3239}
3240
3241template <class _CharT, class _Traits, class _Allocator>
3242void
3243basic_string<_CharT, _Traits, _Allocator>::reserve(size_type __res_arg)
3244{
3245    if (__res_arg > max_size())
3246        this->__throw_length_error();
3247    size_type __cap = capacity();
3248    size_type __sz = size();
3249    __res_arg = _VSTD::max(__res_arg, __sz);
3250    __res_arg = __recommend(__res_arg);
3251    if (__res_arg != __cap)
3252    {
3253        pointer __new_data, __p;
3254        bool __was_long, __now_long;
3255        if (__res_arg == __min_cap - 1)
3256        {
3257            __was_long = true;
3258            __now_long = false;
3259            __new_data = __get_short_pointer();
3260            __p = __get_long_pointer();
3261        }
3262        else
3263        {
3264            if (__res_arg > __cap)
3265                __new_data = __alloc_traits::allocate(__alloc(), __res_arg+1);
3266            else
3267            {
3268            #ifndef _LIBCPP_NO_EXCEPTIONS
3269                try
3270                {
3271            #endif  // _LIBCPP_NO_EXCEPTIONS
3272                    __new_data = __alloc_traits::allocate(__alloc(), __res_arg+1);
3273            #ifndef _LIBCPP_NO_EXCEPTIONS
3274                }
3275                catch (...)
3276                {
3277                    return;
3278                }
3279            #else  // _LIBCPP_NO_EXCEPTIONS
3280                if (__new_data == nullptr)
3281                    return;
3282            #endif  // _LIBCPP_NO_EXCEPTIONS
3283            }
3284            __now_long = true;
3285            __was_long = __is_long();
3286            __p = __get_pointer();
3287        }
3288        traits_type::copy(_VSTD::__to_raw_pointer(__new_data),
3289                          _VSTD::__to_raw_pointer(__p), size()+1);
3290        if (__was_long)
3291            __alloc_traits::deallocate(__alloc(), __p, __cap+1);
3292        if (__now_long)
3293        {
3294            __set_long_cap(__res_arg+1);
3295            __set_long_size(__sz);
3296            __set_long_pointer(__new_data);
3297        }
3298        else
3299            __set_short_size(__sz);
3300        __invalidate_all_iterators();
3301    }
3302}
3303
3304template <class _CharT, class _Traits, class _Allocator>
3305inline _LIBCPP_INLINE_VISIBILITY
3306typename basic_string<_CharT, _Traits, _Allocator>::const_reference
3307basic_string<_CharT, _Traits, _Allocator>::operator[](size_type __pos) const
3308{
3309    _LIBCPP_ASSERT(__pos <= size(), "string index out of bounds");
3310    return *(data() + __pos);
3311}
3312
3313template <class _CharT, class _Traits, class _Allocator>
3314inline _LIBCPP_INLINE_VISIBILITY
3315typename basic_string<_CharT, _Traits, _Allocator>::reference
3316basic_string<_CharT, _Traits, _Allocator>::operator[](size_type __pos)
3317{
3318    _LIBCPP_ASSERT(__pos <= size(), "string index out of bounds");
3319    return *(__get_pointer() + __pos);
3320}
3321
3322template <class _CharT, class _Traits, class _Allocator>
3323typename basic_string<_CharT, _Traits, _Allocator>::const_reference
3324basic_string<_CharT, _Traits, _Allocator>::at(size_type __n) const
3325{
3326    if (__n >= size())
3327        this->__throw_out_of_range();
3328    return (*this)[__n];
3329}
3330
3331template <class _CharT, class _Traits, class _Allocator>
3332typename basic_string<_CharT, _Traits, _Allocator>::reference
3333basic_string<_CharT, _Traits, _Allocator>::at(size_type __n)
3334{
3335    if (__n >= size())
3336        this->__throw_out_of_range();
3337    return (*this)[__n];
3338}
3339
3340template <class _CharT, class _Traits, class _Allocator>
3341inline _LIBCPP_INLINE_VISIBILITY
3342typename basic_string<_CharT, _Traits, _Allocator>::reference
3343basic_string<_CharT, _Traits, _Allocator>::front()
3344{
3345    _LIBCPP_ASSERT(!empty(), "string::front(): string is empty");
3346    return *__get_pointer();
3347}
3348
3349template <class _CharT, class _Traits, class _Allocator>
3350inline _LIBCPP_INLINE_VISIBILITY
3351typename basic_string<_CharT, _Traits, _Allocator>::const_reference
3352basic_string<_CharT, _Traits, _Allocator>::front() const
3353{
3354    _LIBCPP_ASSERT(!empty(), "string::front(): string is empty");
3355    return *data();
3356}
3357
3358template <class _CharT, class _Traits, class _Allocator>
3359inline _LIBCPP_INLINE_VISIBILITY
3360typename basic_string<_CharT, _Traits, _Allocator>::reference
3361basic_string<_CharT, _Traits, _Allocator>::back()
3362{
3363    _LIBCPP_ASSERT(!empty(), "string::back(): string is empty");
3364    return *(__get_pointer() + size() - 1);
3365}
3366
3367template <class _CharT, class _Traits, class _Allocator>
3368inline _LIBCPP_INLINE_VISIBILITY
3369typename basic_string<_CharT, _Traits, _Allocator>::const_reference
3370basic_string<_CharT, _Traits, _Allocator>::back() const
3371{
3372    _LIBCPP_ASSERT(!empty(), "string::back(): string is empty");
3373    return *(data() + size() - 1);
3374}
3375
3376template <class _CharT, class _Traits, class _Allocator>
3377typename basic_string<_CharT, _Traits, _Allocator>::size_type
3378basic_string<_CharT, _Traits, _Allocator>::copy(value_type* __s, size_type __n, size_type __pos) const
3379{
3380    size_type __sz = size();
3381    if (__pos > __sz)
3382        this->__throw_out_of_range();
3383    size_type __rlen = _VSTD::min(__n, __sz - __pos);
3384    traits_type::copy(__s, data() + __pos, __rlen);
3385    return __rlen;
3386}
3387
3388template <class _CharT, class _Traits, class _Allocator>
3389inline _LIBCPP_INLINE_VISIBILITY
3390basic_string<_CharT, _Traits, _Allocator>
3391basic_string<_CharT, _Traits, _Allocator>::substr(size_type __pos, size_type __n) const
3392{
3393    return basic_string(*this, __pos, __n, __alloc());
3394}
3395
3396template <class _CharT, class _Traits, class _Allocator>
3397inline _LIBCPP_INLINE_VISIBILITY
3398void
3399basic_string<_CharT, _Traits, _Allocator>::swap(basic_string& __str)
3400        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
3401                   __is_nothrow_swappable<allocator_type>::value)
3402{
3403#if _LIBCPP_DEBUG_LEVEL >= 2
3404    if (!__is_long())
3405        __get_db()->__invalidate_all(this);
3406    if (!__str.__is_long())
3407        __get_db()->__invalidate_all(&__str);
3408    __get_db()->swap(this, &__str);
3409#endif
3410    _VSTD::swap(__r_.first(), __str.__r_.first());
3411    __swap_alloc(__alloc(), __str.__alloc());
3412}
3413
3414// find
3415
3416template <class _Traits>
3417struct _LIBCPP_HIDDEN __traits_eq
3418{
3419    typedef typename _Traits::char_type char_type;
3420    _LIBCPP_INLINE_VISIBILITY
3421    bool operator()(const char_type& __x, const char_type& __y) _NOEXCEPT
3422        {return _Traits::eq(__x, __y);}
3423};
3424
3425template<class _CharT, class _Traits, class _Allocator>
3426typename basic_string<_CharT, _Traits, _Allocator>::size_type
3427basic_string<_CharT, _Traits, _Allocator>::find(const value_type* __s,
3428                                                size_type __pos,
3429                                                size_type __n) const _NOEXCEPT
3430{
3431    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find(): received nullptr");
3432    return _VSTD::__str_find<value_type, size_type, traits_type, npos>
3433        (data(), size(), __s, __pos, __n);
3434}
3435
3436template<class _CharT, class _Traits, class _Allocator>
3437inline _LIBCPP_INLINE_VISIBILITY
3438typename basic_string<_CharT, _Traits, _Allocator>::size_type
3439basic_string<_CharT, _Traits, _Allocator>::find(const basic_string& __str,
3440                                                size_type __pos) const _NOEXCEPT
3441{
3442    return _VSTD::__str_find<value_type, size_type, traits_type, npos>
3443        (data(), size(), __str.data(), __pos, __str.size());
3444}
3445
3446template<class _CharT, class _Traits, class _Allocator>
3447inline _LIBCPP_INLINE_VISIBILITY
3448typename basic_string<_CharT, _Traits, _Allocator>::size_type
3449basic_string<_CharT, _Traits, _Allocator>::find(const value_type* __s,
3450                                                size_type __pos) const _NOEXCEPT
3451{
3452    _LIBCPP_ASSERT(__s != nullptr, "string::find(): received nullptr");
3453    return _VSTD::__str_find<value_type, size_type, traits_type, npos>
3454        (data(), size(), __s, __pos, traits_type::length(__s));
3455}
3456
3457template<class _CharT, class _Traits, class _Allocator>
3458typename basic_string<_CharT, _Traits, _Allocator>::size_type
3459basic_string<_CharT, _Traits, _Allocator>::find(value_type __c,
3460                                                size_type __pos) const _NOEXCEPT
3461{
3462    return _VSTD::__str_find<value_type, size_type, traits_type, npos>
3463        (data(), size(), __c, __pos);
3464}
3465
3466// rfind
3467
3468template<class _CharT, class _Traits, class _Allocator>
3469typename basic_string<_CharT, _Traits, _Allocator>::size_type
3470basic_string<_CharT, _Traits, _Allocator>::rfind(const value_type* __s,
3471                                                 size_type __pos,
3472                                                 size_type __n) const _NOEXCEPT
3473{
3474    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::rfind(): received nullptr");
3475    return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
3476        (data(), size(), __s, __pos, __n);
3477}
3478
3479template<class _CharT, class _Traits, class _Allocator>
3480inline _LIBCPP_INLINE_VISIBILITY
3481typename basic_string<_CharT, _Traits, _Allocator>::size_type
3482basic_string<_CharT, _Traits, _Allocator>::rfind(const basic_string& __str,
3483                                                 size_type __pos) const _NOEXCEPT
3484{
3485    return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
3486        (data(), size(), __str.data(), __pos, __str.size());
3487}
3488
3489template<class _CharT, class _Traits, class _Allocator>
3490inline _LIBCPP_INLINE_VISIBILITY
3491typename basic_string<_CharT, _Traits, _Allocator>::size_type
3492basic_string<_CharT, _Traits, _Allocator>::rfind(const value_type* __s,
3493                                                 size_type __pos) const _NOEXCEPT
3494{
3495    _LIBCPP_ASSERT(__s != nullptr, "string::rfind(): received nullptr");
3496    return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
3497        (data(), size(), __s, __pos, traits_type::length(__s));
3498}
3499
3500template<class _CharT, class _Traits, class _Allocator>
3501typename basic_string<_CharT, _Traits, _Allocator>::size_type
3502basic_string<_CharT, _Traits, _Allocator>::rfind(value_type __c,
3503                                                 size_type __pos) const _NOEXCEPT
3504{
3505    return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
3506        (data(), size(), __c, __pos);
3507}
3508
3509// find_first_of
3510
3511template<class _CharT, class _Traits, class _Allocator>
3512typename basic_string<_CharT, _Traits, _Allocator>::size_type
3513basic_string<_CharT, _Traits, _Allocator>::find_first_of(const value_type* __s,
3514                                                         size_type __pos,
3515                                                         size_type __n) const _NOEXCEPT
3516{
3517    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_first_of(): received nullptr");
3518    return _VSTD::__str_find_first_of<value_type, size_type, traits_type, npos>
3519        (data(), size(), __s, __pos, __n);
3520}
3521
3522template<class _CharT, class _Traits, class _Allocator>
3523inline _LIBCPP_INLINE_VISIBILITY
3524typename basic_string<_CharT, _Traits, _Allocator>::size_type
3525basic_string<_CharT, _Traits, _Allocator>::find_first_of(const basic_string& __str,
3526                                                         size_type __pos) const _NOEXCEPT
3527{
3528    return _VSTD::__str_find_first_of<value_type, size_type, traits_type, npos>
3529        (data(), size(), __str.data(), __pos, __str.size());
3530}
3531
3532template<class _CharT, class _Traits, class _Allocator>
3533inline _LIBCPP_INLINE_VISIBILITY
3534typename basic_string<_CharT, _Traits, _Allocator>::size_type
3535basic_string<_CharT, _Traits, _Allocator>::find_first_of(const value_type* __s,
3536                                                         size_type __pos) const _NOEXCEPT
3537{
3538    _LIBCPP_ASSERT(__s != nullptr, "string::find_first_of(): received nullptr");
3539    return _VSTD::__str_find_first_of<value_type, size_type, traits_type, npos>
3540        (data(), size(), __s, __pos, traits_type::length(__s));
3541}
3542
3543template<class _CharT, class _Traits, class _Allocator>
3544inline _LIBCPP_INLINE_VISIBILITY
3545typename basic_string<_CharT, _Traits, _Allocator>::size_type
3546basic_string<_CharT, _Traits, _Allocator>::find_first_of(value_type __c,
3547                                                         size_type __pos) const _NOEXCEPT
3548{
3549    return find(__c, __pos);
3550}
3551
3552// find_last_of
3553
3554template<class _CharT, class _Traits, class _Allocator>
3555typename basic_string<_CharT, _Traits, _Allocator>::size_type
3556basic_string<_CharT, _Traits, _Allocator>::find_last_of(const value_type* __s,
3557                                                        size_type __pos,
3558                                                        size_type __n) const _NOEXCEPT
3559{
3560    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_last_of(): received nullptr");
3561    return _VSTD::__str_find_last_of<value_type, size_type, traits_type, npos>
3562        (data(), size(), __s, __pos, __n);
3563}
3564
3565template<class _CharT, class _Traits, class _Allocator>
3566inline _LIBCPP_INLINE_VISIBILITY
3567typename basic_string<_CharT, _Traits, _Allocator>::size_type
3568basic_string<_CharT, _Traits, _Allocator>::find_last_of(const basic_string& __str,
3569                                                        size_type __pos) const _NOEXCEPT
3570{
3571    return _VSTD::__str_find_last_of<value_type, size_type, traits_type, npos>
3572        (data(), size(), __str.data(), __pos, __str.size());
3573}
3574
3575template<class _CharT, class _Traits, class _Allocator>
3576inline _LIBCPP_INLINE_VISIBILITY
3577typename basic_string<_CharT, _Traits, _Allocator>::size_type
3578basic_string<_CharT, _Traits, _Allocator>::find_last_of(const value_type* __s,
3579                                                        size_type __pos) const _NOEXCEPT
3580{
3581    _LIBCPP_ASSERT(__s != nullptr, "string::find_last_of(): received nullptr");
3582    return _VSTD::__str_find_last_of<value_type, size_type, traits_type, npos>
3583        (data(), size(), __s, __pos, traits_type::length(__s));
3584}
3585
3586template<class _CharT, class _Traits, class _Allocator>
3587inline _LIBCPP_INLINE_VISIBILITY
3588typename basic_string<_CharT, _Traits, _Allocator>::size_type
3589basic_string<_CharT, _Traits, _Allocator>::find_last_of(value_type __c,
3590                                                        size_type __pos) const _NOEXCEPT
3591{
3592    return rfind(__c, __pos);
3593}
3594
3595// find_first_not_of
3596
3597template<class _CharT, class _Traits, class _Allocator>
3598typename basic_string<_CharT, _Traits, _Allocator>::size_type
3599basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const value_type* __s,
3600                                                             size_type __pos,
3601                                                             size_type __n) const _NOEXCEPT
3602{
3603    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_first_not_of(): received nullptr");
3604    return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
3605        (data(), size(), __s, __pos, __n);
3606}
3607
3608template<class _CharT, class _Traits, class _Allocator>
3609inline _LIBCPP_INLINE_VISIBILITY
3610typename basic_string<_CharT, _Traits, _Allocator>::size_type
3611basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const basic_string& __str,
3612                                                             size_type __pos) const _NOEXCEPT
3613{
3614    return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
3615        (data(), size(), __str.data(), __pos, __str.size());
3616}
3617
3618template<class _CharT, class _Traits, class _Allocator>
3619inline _LIBCPP_INLINE_VISIBILITY
3620typename basic_string<_CharT, _Traits, _Allocator>::size_type
3621basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const value_type* __s,
3622                                                             size_type __pos) const _NOEXCEPT
3623{
3624    _LIBCPP_ASSERT(__s != nullptr, "string::find_first_not_of(): received nullptr");
3625    return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
3626        (data(), size(), __s, __pos, traits_type::length(__s));
3627}
3628
3629template<class _CharT, class _Traits, class _Allocator>
3630inline _LIBCPP_INLINE_VISIBILITY
3631typename basic_string<_CharT, _Traits, _Allocator>::size_type
3632basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(value_type __c,
3633                                                             size_type __pos) const _NOEXCEPT
3634{
3635    return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
3636        (data(), size(), __c, __pos);
3637}
3638
3639// find_last_not_of
3640
3641template<class _CharT, class _Traits, class _Allocator>
3642typename basic_string<_CharT, _Traits, _Allocator>::size_type
3643basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const value_type* __s,
3644                                                            size_type __pos,
3645                                                            size_type __n) const _NOEXCEPT
3646{
3647    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_last_not_of(): received nullptr");
3648    return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
3649        (data(), size(), __s, __pos, __n);
3650}
3651
3652template<class _CharT, class _Traits, class _Allocator>
3653inline _LIBCPP_INLINE_VISIBILITY
3654typename basic_string<_CharT, _Traits, _Allocator>::size_type
3655basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const basic_string& __str,
3656                                                            size_type __pos) const _NOEXCEPT
3657{
3658    return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
3659        (data(), size(), __str.data(), __pos, __str.size());
3660}
3661
3662template<class _CharT, class _Traits, class _Allocator>
3663inline _LIBCPP_INLINE_VISIBILITY
3664typename basic_string<_CharT, _Traits, _Allocator>::size_type
3665basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const value_type* __s,
3666                                                            size_type __pos) const _NOEXCEPT
3667{
3668    _LIBCPP_ASSERT(__s != nullptr, "string::find_last_not_of(): received nullptr");
3669    return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
3670        (data(), size(), __s, __pos, traits_type::length(__s));
3671}
3672
3673template<class _CharT, class _Traits, class _Allocator>
3674inline _LIBCPP_INLINE_VISIBILITY
3675typename basic_string<_CharT, _Traits, _Allocator>::size_type
3676basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(value_type __c,
3677                                                            size_type __pos) const _NOEXCEPT
3678{
3679    return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
3680        (data(), size(), __c, __pos);
3681}
3682
3683// compare
3684
3685template <class _CharT, class _Traits, class _Allocator>
3686inline _LIBCPP_INLINE_VISIBILITY
3687int
3688basic_string<_CharT, _Traits, _Allocator>::compare(const basic_string& __str) const _NOEXCEPT
3689{
3690    size_t __lhs_sz = size();
3691    size_t __rhs_sz = __str.size();
3692    int __result = traits_type::compare(data(), __str.data(),
3693                                        _VSTD::min(__lhs_sz, __rhs_sz));
3694    if (__result != 0)
3695        return __result;
3696    if (__lhs_sz < __rhs_sz)
3697        return -1;
3698    if (__lhs_sz > __rhs_sz)
3699        return 1;
3700    return 0;
3701}
3702
3703template <class _CharT, class _Traits, class _Allocator>
3704inline _LIBCPP_INLINE_VISIBILITY
3705int
3706basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
3707                                                   size_type __n1,
3708                                                   const basic_string& __str) const
3709{
3710    return compare(__pos1, __n1, __str.data(), __str.size());
3711}
3712
3713template <class _CharT, class _Traits, class _Allocator>
3714int
3715basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
3716                                                   size_type __n1,
3717                                                   const basic_string& __str,
3718                                                   size_type __pos2,
3719                                                   size_type __n2) const
3720{
3721    size_type __sz = __str.size();
3722    if (__pos2 > __sz)
3723        this->__throw_out_of_range();
3724    return compare(__pos1, __n1, __str.data() + __pos2, _VSTD::min(__n2,
3725                                                                  __sz - __pos2));
3726}
3727
3728template <class _CharT, class _Traits, class _Allocator>
3729int
3730basic_string<_CharT, _Traits, _Allocator>::compare(const value_type* __s) const _NOEXCEPT
3731{
3732    _LIBCPP_ASSERT(__s != nullptr, "string::compare(): received nullptr");
3733    return compare(0, npos, __s, traits_type::length(__s));
3734}
3735
3736template <class _CharT, class _Traits, class _Allocator>
3737int
3738basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
3739                                                   size_type __n1,
3740                                                   const value_type* __s) const
3741{
3742    _LIBCPP_ASSERT(__s != nullptr, "string::compare(): received nullptr");
3743    return compare(__pos1, __n1, __s, traits_type::length(__s));
3744}
3745
3746template <class _CharT, class _Traits, class _Allocator>
3747int
3748basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
3749                                                   size_type __n1,
3750                                                   const value_type* __s,
3751                                                   size_type __n2) const
3752{
3753    _LIBCPP_ASSERT(__n2 == 0 || __s != nullptr, "string::compare(): received nullptr");
3754    size_type __sz = size();
3755    if (__pos1 > __sz || __n2 == npos)
3756        this->__throw_out_of_range();
3757    size_type __rlen = _VSTD::min(__n1, __sz - __pos1);
3758    int __r = traits_type::compare(data() + __pos1, __s, _VSTD::min(__rlen, __n2));
3759    if (__r == 0)
3760    {
3761        if (__rlen < __n2)
3762            __r = -1;
3763        else if (__rlen > __n2)
3764            __r = 1;
3765    }
3766    return __r;
3767}
3768
3769// __invariants
3770
3771template<class _CharT, class _Traits, class _Allocator>
3772inline _LIBCPP_INLINE_VISIBILITY
3773bool
3774basic_string<_CharT, _Traits, _Allocator>::__invariants() const
3775{
3776    if (size() > capacity())
3777        return false;
3778    if (capacity() < __min_cap - 1)
3779        return false;
3780    if (data() == 0)
3781        return false;
3782    if (data()[size()] != value_type(0))
3783        return false;
3784    return true;
3785}
3786
3787// operator==
3788
3789template<class _CharT, class _Traits, class _Allocator>
3790inline _LIBCPP_INLINE_VISIBILITY
3791bool
3792operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3793           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3794{
3795    size_t __lhs_sz = __lhs.size();
3796    return __lhs_sz == __rhs.size() && _Traits::compare(__lhs.data(),
3797                                                        __rhs.data(),
3798                                                        __lhs_sz) == 0;
3799}
3800
3801template<class _Allocator>
3802inline _LIBCPP_INLINE_VISIBILITY
3803bool
3804operator==(const basic_string<char, char_traits<char>, _Allocator>& __lhs,
3805           const basic_string<char, char_traits<char>, _Allocator>& __rhs) _NOEXCEPT
3806{
3807    size_t __lhs_sz = __lhs.size();
3808    if (__lhs_sz != __rhs.size())
3809        return false;
3810    const char* __lp = __lhs.data();
3811    const char* __rp = __rhs.data();
3812    if (__lhs.__is_long())
3813        return char_traits<char>::compare(__lp, __rp, __lhs_sz) == 0;
3814    for (; __lhs_sz != 0; --__lhs_sz, ++__lp, ++__rp)
3815        if (*__lp != *__rp)
3816            return false;
3817    return true;
3818}
3819
3820template<class _CharT, class _Traits, class _Allocator>
3821inline _LIBCPP_INLINE_VISIBILITY
3822bool
3823operator==(const _CharT* __lhs,
3824           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3825{
3826    return __rhs.compare(__lhs) == 0;
3827}
3828
3829template<class _CharT, class _Traits, class _Allocator>
3830inline _LIBCPP_INLINE_VISIBILITY
3831bool
3832operator==(const basic_string<_CharT,_Traits,_Allocator>& __lhs,
3833           const _CharT* __rhs) _NOEXCEPT
3834{
3835    return __lhs.compare(__rhs) == 0;
3836}
3837
3838// operator!=
3839
3840template<class _CharT, class _Traits, class _Allocator>
3841inline _LIBCPP_INLINE_VISIBILITY
3842bool
3843operator!=(const basic_string<_CharT,_Traits,_Allocator>& __lhs,
3844           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3845{
3846    return !(__lhs == __rhs);
3847}
3848
3849template<class _CharT, class _Traits, class _Allocator>
3850inline _LIBCPP_INLINE_VISIBILITY
3851bool
3852operator!=(const _CharT* __lhs,
3853           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3854{
3855    return !(__lhs == __rhs);
3856}
3857
3858template<class _CharT, class _Traits, class _Allocator>
3859inline _LIBCPP_INLINE_VISIBILITY
3860bool
3861operator!=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3862           const _CharT* __rhs) _NOEXCEPT
3863{
3864    return !(__lhs == __rhs);
3865}
3866
3867// operator<
3868
3869template<class _CharT, class _Traits, class _Allocator>
3870inline _LIBCPP_INLINE_VISIBILITY
3871bool
3872operator< (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3873           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3874{
3875    return __lhs.compare(__rhs) < 0;
3876}
3877
3878template<class _CharT, class _Traits, class _Allocator>
3879inline _LIBCPP_INLINE_VISIBILITY
3880bool
3881operator< (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3882           const _CharT* __rhs) _NOEXCEPT
3883{
3884    return __lhs.compare(__rhs) < 0;
3885}
3886
3887template<class _CharT, class _Traits, class _Allocator>
3888inline _LIBCPP_INLINE_VISIBILITY
3889bool
3890operator< (const _CharT* __lhs,
3891           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3892{
3893    return __rhs.compare(__lhs) > 0;
3894}
3895
3896// operator>
3897
3898template<class _CharT, class _Traits, class _Allocator>
3899inline _LIBCPP_INLINE_VISIBILITY
3900bool
3901operator> (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3902           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3903{
3904    return __rhs < __lhs;
3905}
3906
3907template<class _CharT, class _Traits, class _Allocator>
3908inline _LIBCPP_INLINE_VISIBILITY
3909bool
3910operator> (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3911           const _CharT* __rhs) _NOEXCEPT
3912{
3913    return __rhs < __lhs;
3914}
3915
3916template<class _CharT, class _Traits, class _Allocator>
3917inline _LIBCPP_INLINE_VISIBILITY
3918bool
3919operator> (const _CharT* __lhs,
3920           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3921{
3922    return __rhs < __lhs;
3923}
3924
3925// operator<=
3926
3927template<class _CharT, class _Traits, class _Allocator>
3928inline _LIBCPP_INLINE_VISIBILITY
3929bool
3930operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3931           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3932{
3933    return !(__rhs < __lhs);
3934}
3935
3936template<class _CharT, class _Traits, class _Allocator>
3937inline _LIBCPP_INLINE_VISIBILITY
3938bool
3939operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3940           const _CharT* __rhs) _NOEXCEPT
3941{
3942    return !(__rhs < __lhs);
3943}
3944
3945template<class _CharT, class _Traits, class _Allocator>
3946inline _LIBCPP_INLINE_VISIBILITY
3947bool
3948operator<=(const _CharT* __lhs,
3949           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3950{
3951    return !(__rhs < __lhs);
3952}
3953
3954// operator>=
3955
3956template<class _CharT, class _Traits, class _Allocator>
3957inline _LIBCPP_INLINE_VISIBILITY
3958bool
3959operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3960           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3961{
3962    return !(__lhs < __rhs);
3963}
3964
3965template<class _CharT, class _Traits, class _Allocator>
3966inline _LIBCPP_INLINE_VISIBILITY
3967bool
3968operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3969           const _CharT* __rhs) _NOEXCEPT
3970{
3971    return !(__lhs < __rhs);
3972}
3973
3974template<class _CharT, class _Traits, class _Allocator>
3975inline _LIBCPP_INLINE_VISIBILITY
3976bool
3977operator>=(const _CharT* __lhs,
3978           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
3979{
3980    return !(__lhs < __rhs);
3981}
3982
3983// operator +
3984
3985template<class _CharT, class _Traits, class _Allocator>
3986basic_string<_CharT, _Traits, _Allocator>
3987operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3988          const basic_string<_CharT, _Traits, _Allocator>& __rhs)
3989{
3990    basic_string<_CharT, _Traits, _Allocator> __r(__lhs.get_allocator());
3991    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = __lhs.size();
3992    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = __rhs.size();
3993    __r.__init(__lhs.data(), __lhs_sz, __lhs_sz + __rhs_sz);
3994    __r.append(__rhs.data(), __rhs_sz);
3995    return __r;
3996}
3997
3998template<class _CharT, class _Traits, class _Allocator>
3999basic_string<_CharT, _Traits, _Allocator>
4000operator+(const _CharT* __lhs , const basic_string<_CharT,_Traits,_Allocator>& __rhs)
4001{
4002    basic_string<_CharT, _Traits, _Allocator> __r(__rhs.get_allocator());
4003    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = _Traits::length(__lhs);
4004    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = __rhs.size();
4005    __r.__init(__lhs, __lhs_sz, __lhs_sz + __rhs_sz);
4006    __r.append(__rhs.data(), __rhs_sz);
4007    return __r;
4008}
4009
4010template<class _CharT, class _Traits, class _Allocator>
4011basic_string<_CharT, _Traits, _Allocator>
4012operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Allocator>& __rhs)
4013{
4014    basic_string<_CharT, _Traits, _Allocator> __r(__rhs.get_allocator());
4015    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = __rhs.size();
4016    __r.__init(&__lhs, 1, 1 + __rhs_sz);
4017    __r.append(__rhs.data(), __rhs_sz);
4018    return __r;
4019}
4020
4021template<class _CharT, class _Traits, class _Allocator>
4022basic_string<_CharT, _Traits, _Allocator>
4023operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs)
4024{
4025    basic_string<_CharT, _Traits, _Allocator> __r(__lhs.get_allocator());
4026    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = __lhs.size();
4027    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = _Traits::length(__rhs);
4028    __r.__init(__lhs.data(), __lhs_sz, __lhs_sz + __rhs_sz);
4029    __r.append(__rhs, __rhs_sz);
4030    return __r;
4031}
4032
4033template<class _CharT, class _Traits, class _Allocator>
4034basic_string<_CharT, _Traits, _Allocator>
4035operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, _CharT __rhs)
4036{
4037    basic_string<_CharT, _Traits, _Allocator> __r(__lhs.get_allocator());
4038    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = __lhs.size();
4039    __r.__init(__lhs.data(), __lhs_sz, __lhs_sz + 1);
4040    __r.push_back(__rhs);
4041    return __r;
4042}
4043
4044#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4045
4046template<class _CharT, class _Traits, class _Allocator>
4047inline _LIBCPP_INLINE_VISIBILITY
4048basic_string<_CharT, _Traits, _Allocator>
4049operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs)
4050{
4051    return _VSTD::move(__lhs.append(__rhs));
4052}
4053
4054template<class _CharT, class _Traits, class _Allocator>
4055inline _LIBCPP_INLINE_VISIBILITY
4056basic_string<_CharT, _Traits, _Allocator>
4057operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs)
4058{
4059    return _VSTD::move(__rhs.insert(0, __lhs));
4060}
4061
4062template<class _CharT, class _Traits, class _Allocator>
4063inline _LIBCPP_INLINE_VISIBILITY
4064basic_string<_CharT, _Traits, _Allocator>
4065operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs)
4066{
4067    return _VSTD::move(__lhs.append(__rhs));
4068}
4069
4070template<class _CharT, class _Traits, class _Allocator>
4071inline _LIBCPP_INLINE_VISIBILITY
4072basic_string<_CharT, _Traits, _Allocator>
4073operator+(const _CharT* __lhs , basic_string<_CharT,_Traits,_Allocator>&& __rhs)
4074{
4075    return _VSTD::move(__rhs.insert(0, __lhs));
4076}
4077
4078template<class _CharT, class _Traits, class _Allocator>
4079inline _LIBCPP_INLINE_VISIBILITY
4080basic_string<_CharT, _Traits, _Allocator>
4081operator+(_CharT __lhs, basic_string<_CharT,_Traits,_Allocator>&& __rhs)
4082{
4083    __rhs.insert(__rhs.begin(), __lhs);
4084    return _VSTD::move(__rhs);
4085}
4086
4087template<class _CharT, class _Traits, class _Allocator>
4088inline _LIBCPP_INLINE_VISIBILITY
4089basic_string<_CharT, _Traits, _Allocator>
4090operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const _CharT* __rhs)
4091{
4092    return _VSTD::move(__lhs.append(__rhs));
4093}
4094
4095template<class _CharT, class _Traits, class _Allocator>
4096inline _LIBCPP_INLINE_VISIBILITY
4097basic_string<_CharT, _Traits, _Allocator>
4098operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, _CharT __rhs)
4099{
4100    __lhs.push_back(__rhs);
4101    return _VSTD::move(__lhs);
4102}
4103
4104#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4105
4106// swap
4107
4108template<class _CharT, class _Traits, class _Allocator>
4109inline _LIBCPP_INLINE_VISIBILITY
4110void
4111swap(basic_string<_CharT, _Traits, _Allocator>& __lhs,
4112     basic_string<_CharT, _Traits, _Allocator>& __rhs)
4113     _NOEXCEPT_(_NOEXCEPT_(__lhs.swap(__rhs)))
4114{
4115    __lhs.swap(__rhs);
4116}
4117
4118#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
4119
4120typedef basic_string<char16_t> u16string;
4121typedef basic_string<char32_t> u32string;
4122
4123#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
4124
4125_LIBCPP_FUNC_VIS int                stoi  (const string& __str, size_t* __idx = 0, int __base = 10);
4126_LIBCPP_FUNC_VIS long               stol  (const string& __str, size_t* __idx = 0, int __base = 10);
4127_LIBCPP_FUNC_VIS unsigned long      stoul (const string& __str, size_t* __idx = 0, int __base = 10);
4128_LIBCPP_FUNC_VIS long long          stoll (const string& __str, size_t* __idx = 0, int __base = 10);
4129_LIBCPP_FUNC_VIS unsigned long long stoull(const string& __str, size_t* __idx = 0, int __base = 10);
4130
4131_LIBCPP_FUNC_VIS float       stof (const string& __str, size_t* __idx = 0);
4132_LIBCPP_FUNC_VIS double      stod (const string& __str, size_t* __idx = 0);
4133_LIBCPP_FUNC_VIS long double stold(const string& __str, size_t* __idx = 0);
4134
4135_LIBCPP_FUNC_VIS string to_string(int __val);
4136_LIBCPP_FUNC_VIS string to_string(unsigned __val);
4137_LIBCPP_FUNC_VIS string to_string(long __val);
4138_LIBCPP_FUNC_VIS string to_string(unsigned long __val);
4139_LIBCPP_FUNC_VIS string to_string(long long __val);
4140_LIBCPP_FUNC_VIS string to_string(unsigned long long __val);
4141_LIBCPP_FUNC_VIS string to_string(float __val);
4142_LIBCPP_FUNC_VIS string to_string(double __val);
4143_LIBCPP_FUNC_VIS string to_string(long double __val);
4144
4145_LIBCPP_FUNC_VIS int                stoi  (const wstring& __str, size_t* __idx = 0, int __base = 10);
4146_LIBCPP_FUNC_VIS long               stol  (const wstring& __str, size_t* __idx = 0, int __base = 10);
4147_LIBCPP_FUNC_VIS unsigned long      stoul (const wstring& __str, size_t* __idx = 0, int __base = 10);
4148_LIBCPP_FUNC_VIS long long          stoll (const wstring& __str, size_t* __idx = 0, int __base = 10);
4149_LIBCPP_FUNC_VIS unsigned long long stoull(const wstring& __str, size_t* __idx = 0, int __base = 10);
4150
4151_LIBCPP_FUNC_VIS float       stof (const wstring& __str, size_t* __idx = 0);
4152_LIBCPP_FUNC_VIS double      stod (const wstring& __str, size_t* __idx = 0);
4153_LIBCPP_FUNC_VIS long double stold(const wstring& __str, size_t* __idx = 0);
4154
4155_LIBCPP_FUNC_VIS wstring to_wstring(int __val);
4156_LIBCPP_FUNC_VIS wstring to_wstring(unsigned __val);
4157_LIBCPP_FUNC_VIS wstring to_wstring(long __val);
4158_LIBCPP_FUNC_VIS wstring to_wstring(unsigned long __val);
4159_LIBCPP_FUNC_VIS wstring to_wstring(long long __val);
4160_LIBCPP_FUNC_VIS wstring to_wstring(unsigned long long __val);
4161_LIBCPP_FUNC_VIS wstring to_wstring(float __val);
4162_LIBCPP_FUNC_VIS wstring to_wstring(double __val);
4163_LIBCPP_FUNC_VIS wstring to_wstring(long double __val);
4164
4165template<class _CharT, class _Traits, class _Allocator>
4166    const typename basic_string<_CharT, _Traits, _Allocator>::size_type
4167                   basic_string<_CharT, _Traits, _Allocator>::npos;
4168
4169template<class _CharT, class _Traits, class _Allocator>
4170struct _LIBCPP_TYPE_VIS_ONLY hash<basic_string<_CharT, _Traits, _Allocator> >
4171    : public unary_function<basic_string<_CharT, _Traits, _Allocator>, size_t>
4172{
4173    size_t
4174        operator()(const basic_string<_CharT, _Traits, _Allocator>& __val) const _NOEXCEPT;
4175};
4176
4177template<class _CharT, class _Traits, class _Allocator>
4178size_t
4179hash<basic_string<_CharT, _Traits, _Allocator> >::operator()(
4180        const basic_string<_CharT, _Traits, _Allocator>& __val) const _NOEXCEPT
4181{
4182    return __do_string_hash(__val.data(), __val.data() + __val.size());
4183}
4184
4185template<class _CharT, class _Traits, class _Allocator>
4186basic_ostream<_CharT, _Traits>&
4187operator<<(basic_ostream<_CharT, _Traits>& __os,
4188           const basic_string<_CharT, _Traits, _Allocator>& __str);
4189
4190template<class _CharT, class _Traits, class _Allocator>
4191basic_istream<_CharT, _Traits>&
4192operator>>(basic_istream<_CharT, _Traits>& __is,
4193           basic_string<_CharT, _Traits, _Allocator>& __str);
4194
4195template<class _CharT, class _Traits, class _Allocator>
4196basic_istream<_CharT, _Traits>&
4197getline(basic_istream<_CharT, _Traits>& __is,
4198        basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm);
4199
4200template<class _CharT, class _Traits, class _Allocator>
4201inline _LIBCPP_INLINE_VISIBILITY
4202basic_istream<_CharT, _Traits>&
4203getline(basic_istream<_CharT, _Traits>& __is,
4204        basic_string<_CharT, _Traits, _Allocator>& __str);
4205
4206#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4207
4208template<class _CharT, class _Traits, class _Allocator>
4209inline _LIBCPP_INLINE_VISIBILITY
4210basic_istream<_CharT, _Traits>&
4211getline(basic_istream<_CharT, _Traits>&& __is,
4212        basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm);
4213
4214template<class _CharT, class _Traits, class _Allocator>
4215inline _LIBCPP_INLINE_VISIBILITY
4216basic_istream<_CharT, _Traits>&
4217getline(basic_istream<_CharT, _Traits>&& __is,
4218        basic_string<_CharT, _Traits, _Allocator>& __str);
4219
4220#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4221
4222#if _LIBCPP_DEBUG_LEVEL >= 2
4223
4224template<class _CharT, class _Traits, class _Allocator>
4225bool
4226basic_string<_CharT, _Traits, _Allocator>::__dereferenceable(const const_iterator* __i) const
4227{
4228    return this->data() <= _VSTD::__to_raw_pointer(__i->base()) &&
4229           _VSTD::__to_raw_pointer(__i->base()) < this->data() + this->size();
4230}
4231
4232template<class _CharT, class _Traits, class _Allocator>
4233bool
4234basic_string<_CharT, _Traits, _Allocator>::__decrementable(const const_iterator* __i) const
4235{
4236    return this->data() < _VSTD::__to_raw_pointer(__i->base()) &&
4237           _VSTD::__to_raw_pointer(__i->base()) <= this->data() + this->size();
4238}
4239
4240template<class _CharT, class _Traits, class _Allocator>
4241bool
4242basic_string<_CharT, _Traits, _Allocator>::__addable(const const_iterator* __i, ptrdiff_t __n) const
4243{
4244    const value_type* __p = _VSTD::__to_raw_pointer(__i->base()) + __n;
4245    return this->data() <= __p && __p <= this->data() + this->size();
4246}
4247
4248template<class _CharT, class _Traits, class _Allocator>
4249bool
4250basic_string<_CharT, _Traits, _Allocator>::__subscriptable(const const_iterator* __i, ptrdiff_t __n) const
4251{
4252    const value_type* __p = _VSTD::__to_raw_pointer(__i->base()) + __n;
4253    return this->data() <= __p && __p < this->data() + this->size();
4254}
4255
4256#endif  // _LIBCPP_DEBUG_LEVEL >= 2
4257
4258#if _LIBCPP_STD_VER > 11
4259// Literal suffixes for basic_string [basic.string.literals]
4260inline namespace literals
4261{
4262  inline namespace string_literals
4263  {
4264    inline _LIBCPP_INLINE_VISIBILITY
4265    basic_string<char> operator "" s( const char *__str, size_t __len )
4266    {
4267        return basic_string<char> (__str, __len);
4268    }
4269
4270    inline _LIBCPP_INLINE_VISIBILITY
4271    basic_string<wchar_t> operator "" s( const wchar_t *__str, size_t __len )
4272    {
4273        return basic_string<wchar_t> (__str, __len);
4274    }
4275
4276    inline _LIBCPP_INLINE_VISIBILITY
4277    basic_string<char16_t> operator "" s( const char16_t *__str, size_t __len )
4278    {
4279        return basic_string<char16_t> (__str, __len);
4280    }
4281
4282    inline _LIBCPP_INLINE_VISIBILITY
4283    basic_string<char32_t> operator "" s( const char32_t *__str, size_t __len )
4284    {
4285        return basic_string<char32_t> (__str, __len);
4286    }
4287  }
4288}
4289#endif
4290
4291_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_TYPE_VIS basic_string<char>)
4292_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_TYPE_VIS basic_string<wchar_t>)
4293_LIBCPP_EXTERN_TEMPLATE(string operator+<char, char_traits<char>, allocator<char> >(char const*, string const&))
4294
4295_LIBCPP_END_NAMESPACE_STD
4296
4297#endif  // _LIBCPP_STRING
4298