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1// -*- C++ -*-2//===----------------------------------------------------------------------===//3//4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.5// See https://llvm.org/LICENSE.txt for license information.6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP_STRING11#define _LIBCPP_STRING12 13// clang-format off14 15/*16    string synopsis17 18#include <compare>19#include <initializer_list>20 21namespace std22{23 24template <class stateT>25class fpos26{27private:28    stateT st;29public:30    fpos(streamoff = streamoff());31 32    operator streamoff() const;33 34    stateT state() const;35    void state(stateT);36 37    fpos& operator+=(streamoff);38    fpos  operator+ (streamoff) const;39    fpos& operator-=(streamoff);40    fpos  operator- (streamoff) const;41};42 43template <class stateT> streamoff operator-(const fpos<stateT>& x, const fpos<stateT>& y);44 45template <class stateT> bool operator==(const fpos<stateT>& x, const fpos<stateT>& y);46template <class stateT> bool operator!=(const fpos<stateT>& x, const fpos<stateT>& y);47 48template <class charT>49struct char_traits50{51    using char_type           = charT;52    using int_type            = ...;53    using off_type            = streamoff;54    using pos_type            = streampos;55    using state_type          = mbstate_t;56    using comparison_category = strong_ordering; // Since C++20 only for the specializations57                                                 // char, wchar_t, char8_t, char16_t, and char32_t.58 59    static void assign(char_type& c1, const char_type& c2) noexcept;60    static constexpr bool eq(char_type c1, char_type c2) noexcept;61    static constexpr bool lt(char_type c1, char_type c2) noexcept;62 63    static int              compare(const char_type* s1, const char_type* s2, size_t n);64    static size_t           length(const char_type* s);65    static const char_type* find(const char_type* s, size_t n, const char_type& a);66    static char_type*       move(char_type* s1, const char_type* s2, size_t n);67    static char_type*       copy(char_type* s1, const char_type* s2, size_t n);68    static char_type*       assign(char_type* s, size_t n, char_type a);69 70    static constexpr int_type  not_eof(int_type c) noexcept;71    static constexpr char_type to_char_type(int_type c) noexcept;72    static constexpr int_type  to_int_type(char_type c) noexcept;73    static constexpr bool      eq_int_type(int_type c1, int_type c2) noexcept;74    static constexpr int_type  eof() noexcept;75};76 77template <> struct char_traits<char>;78template <> struct char_traits<wchar_t>;79template <> struct char_traits<char8_t>;  // C++2080template <> struct char_traits<char16_t>;81template <> struct char_traits<char32_t>;82 83template<class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >84class basic_string85{86public:87// types:88    typedef traits traits_type;89    typedef typename traits_type::char_type value_type;90    typedef Allocator allocator_type;91    typedef typename allocator_type::size_type size_type;92    typedef typename allocator_type::difference_type difference_type;93    typedef typename allocator_type::reference reference;94    typedef typename allocator_type::const_reference const_reference;95    typedef typename allocator_type::pointer pointer;96    typedef typename allocator_type::const_pointer const_pointer;97    typedef implementation-defined iterator;98    typedef implementation-defined const_iterator;99    typedef std::reverse_iterator<iterator> reverse_iterator;100    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;101 102    static const size_type npos = -1;103 104    basic_string()105        noexcept(is_nothrow_default_constructible<allocator_type>::value);                      // constexpr since C++20106    explicit basic_string(const allocator_type& a);                                             // constexpr since C++20107    basic_string(const basic_string& str);                                                      // constexpr since C++20108    basic_string(basic_string&& str)109        noexcept(is_nothrow_move_constructible<allocator_type>::value);                         // constexpr since C++20110    basic_string(const basic_string& str, size_type pos,111                 const allocator_type& a = allocator_type());                                   // constexpr since C++20112    basic_string(const basic_string& str, size_type pos, size_type n,113                 const Allocator& a = Allocator());                                             // constexpr since C++20114    constexpr basic_string(115        basic_string&& str, size_type pos, const Allocator& a = Allocator());                   // since C++23116    constexpr basic_string(117        basic_string&& str, size_type pos, size_type n, const Allocator& a = Allocator());      // since C++23118    template<class T>119        basic_string(const T& t, size_type pos, size_type n, const Allocator& a = Allocator()); // C++17, constexpr since C++20120    template <class T>121        explicit basic_string(const T& t, const Allocator& a = Allocator());                    // C++17, constexpr since C++20122    basic_string(const value_type* s, const allocator_type& a = allocator_type());              // constexpr since C++20123    basic_string(const value_type* s, size_type n, const allocator_type& a = allocator_type()); // constexpr since C++20124    basic_string(nullptr_t) = delete; // C++23125    basic_string(size_type n, value_type c, const allocator_type& a = allocator_type());        // constexpr since C++20126    template<class InputIterator>127        basic_string(InputIterator begin, InputIterator end,128                     const allocator_type& a = allocator_type());                               // constexpr since C++20129    template<container-compatible-range<charT> R>130      constexpr basic_string(from_range_t, R&& rg, const Allocator& a = Allocator());           // since C++23131    basic_string(initializer_list<value_type>, const Allocator& = Allocator());                 // constexpr since C++20132    basic_string(const basic_string&, const Allocator&);                                        // constexpr since C++20133    basic_string(basic_string&&, const Allocator&);                                             // constexpr since C++20134 135    ~basic_string();                                                                            // constexpr since C++20136 137    operator basic_string_view<charT, traits>() const noexcept;                                 // constexpr since C++20138 139    basic_string& operator=(const basic_string& str);                                           // constexpr since C++20140    template <class T>141        basic_string& operator=(const T& t);                                                    // C++17, constexpr since C++20142    basic_string& operator=(basic_string&& str)143        noexcept(144             allocator_type::propagate_on_container_move_assignment::value ||145             allocator_type::is_always_equal::value );                                          // C++17, constexpr since C++20146    basic_string& operator=(const value_type* s);                                               // constexpr since C++20147    basic_string& operator=(nullptr_t) = delete; // C++23148    basic_string& operator=(value_type c);                                                      // constexpr since C++20149    basic_string& operator=(initializer_list<value_type>);                                      // constexpr since C++20150 151    iterator       begin() noexcept;                                                            // constexpr since C++20152    const_iterator begin() const noexcept;                                                      // constexpr since C++20153    iterator       end() noexcept;                                                              // constexpr since C++20154    const_iterator end() const noexcept;                                                        // constexpr since C++20155 156    reverse_iterator       rbegin() noexcept;                                                   // constexpr since C++20157    const_reverse_iterator rbegin() const noexcept;                                             // constexpr since C++20158    reverse_iterator       rend() noexcept;                                                     // constexpr since C++20159    const_reverse_iterator rend() const noexcept;                                               // constexpr since C++20160 161    const_iterator         cbegin() const noexcept;                                             // constexpr since C++20162    const_iterator         cend() const noexcept;                                               // constexpr since C++20163    const_reverse_iterator crbegin() const noexcept;                                            // constexpr since C++20164    const_reverse_iterator crend() const noexcept;                                              // constexpr since C++20165 166    size_type size() const noexcept;                                                            // constexpr since C++20167    size_type length() const noexcept;                                                          // constexpr since C++20168    size_type max_size() const noexcept;                                                        // constexpr since C++20169    size_type capacity() const noexcept;                                                        // constexpr since C++20170 171    void resize(size_type n, value_type c);                                                     // constexpr since C++20172    void resize(size_type n);                                                                   // constexpr since C++20173 174    template<class Operation>175    constexpr void resize_and_overwrite(size_type n, Operation op); // since C++23176 177    void reserve(size_type res_arg);                                                            // constexpr since C++20178    void reserve();                                                                             // deprecated in C++20, removed in C++26179    void shrink_to_fit();                                                                       // constexpr since C++20180    void clear() noexcept;                                                                      // constexpr since C++20181    bool empty() const noexcept;                                                                // constexpr since C++20182 183    const_reference operator[](size_type pos) const;                                            // constexpr since C++20184    reference       operator[](size_type pos);                                                  // constexpr since C++20185 186    const_reference at(size_type n) const;                                                      // constexpr since C++20187    reference       at(size_type n);                                                            // constexpr since C++20188 189    basic_string& operator+=(const basic_string& str);                                          // constexpr since C++20190    template <class T>191        basic_string& operator+=(const T& t);                                                   // C++17, constexpr since C++20192    basic_string& operator+=(const value_type* s);                                              // constexpr since C++20193    basic_string& operator+=(value_type c);                                                     // constexpr since C++20194    basic_string& operator+=(initializer_list<value_type>);                                     // constexpr since C++20195 196    basic_string& append(const basic_string& str);                                              // constexpr since C++20197    template <class T>198        basic_string& append(const T& t);                                                       // C++17, constexpr since C++20199    basic_string& append(const basic_string& str, size_type pos, size_type n=npos);             // C++14, constexpr since C++20200    template <class T>201        basic_string& append(const T& t, size_type pos, size_type n=npos);                      // C++17, constexpr since C++20202    basic_string& append(const value_type* s, size_type n);                                     // constexpr since C++20203    basic_string& append(const value_type* s);                                                  // constexpr since C++20204    basic_string& append(size_type n, value_type c);                                            // constexpr since C++20205    template<class InputIterator>206        basic_string& append(InputIterator first, InputIterator last);                          // constexpr since C++20207    template<container-compatible-range<charT> R>208      constexpr basic_string& append_range(R&& rg);                                             // C++23209    basic_string& append(initializer_list<value_type>);                                         // constexpr since C++20210 211    void push_back(value_type c);                                                               // constexpr since C++20212    void pop_back();                                                                            // constexpr since C++20213    reference       front();                                                                    // constexpr since C++20214    const_reference front() const;                                                              // constexpr since C++20215    reference       back();                                                                     // constexpr since C++20216    const_reference back() const;                                                               // constexpr since C++20217 218    basic_string& assign(const basic_string& str);                                              // constexpr since C++20219    template <class T>220        basic_string& assign(const T& t);                                                       // C++17, constexpr since C++20221    basic_string& assign(basic_string&& str);                                                   // constexpr since C++20222    basic_string& assign(const basic_string& str, size_type pos, size_type n=npos);             // C++14, constexpr since C++20223    template <class T>224        basic_string& assign(const T& t, size_type pos, size_type n=npos);                      // C++17, constexpr since C++20225    basic_string& assign(const value_type* s, size_type n);                                     // constexpr since C++20226    basic_string& assign(const value_type* s);                                                  // constexpr since C++20227    basic_string& assign(size_type n, value_type c);                                            // constexpr since C++20228    template<class InputIterator>229        basic_string& assign(InputIterator first, InputIterator last);                          // constexpr since C++20230    template<container-compatible-range<charT> R>231      constexpr basic_string& assign_range(R&& rg);                                             // C++23232    basic_string& assign(initializer_list<value_type>);                                         // constexpr since C++20233 234    basic_string& insert(size_type pos1, const basic_string& str);                              // constexpr since C++20235    template <class T>236        basic_string& insert(size_type pos1, const T& t);                                       // constexpr since C++20237    basic_string& insert(size_type pos1, const basic_string& str,238                         size_type pos2, size_type n2=npos);                                    // constexpr since C++20239    template <class T>240        basic_string& insert(size_type pos1, const T& t, size_type pos2, size_type n=npos);     // C++17, constexpr since C++20241    basic_string& insert(size_type pos, const value_type* s, size_type n=npos);                 // C++14, constexpr since C++20242    basic_string& insert(size_type pos, const value_type* s);                                   // constexpr since C++20243    basic_string& insert(size_type pos, size_type n, value_type c);                             // constexpr since C++20244    iterator      insert(const_iterator p, value_type c);                                       // constexpr since C++20245    iterator      insert(const_iterator p, size_type n, value_type c);                          // constexpr since C++20246    template<class InputIterator>247        iterator insert(const_iterator p, InputIterator first, InputIterator last);             // constexpr since C++20248    template<container-compatible-range<charT> R>249      constexpr iterator insert_range(const_iterator p, R&& rg);                                // C++23250    iterator      insert(const_iterator p, initializer_list<value_type>);                       // constexpr since C++20251 252    basic_string& erase(size_type pos = 0, size_type n = npos);                                 // constexpr since C++20253    iterator      erase(const_iterator position);                                               // constexpr since C++20254    iterator      erase(const_iterator first, const_iterator last);                             // constexpr since C++20255 256    basic_string& replace(size_type pos1, size_type n1, const basic_string& str);               // constexpr since C++20257    template <class T>258    basic_string& replace(size_type pos1, size_type n1, const T& t);                            // C++17, constexpr since C++20259    basic_string& replace(size_type pos1, size_type n1, const basic_string& str,260                          size_type pos2, size_type n2=npos);                                   // C++14, constexpr since C++20261    template <class T>262        basic_string& replace(size_type pos1, size_type n1, const T& t,263                              size_type pos2, size_type n2=npos);                               // C++17, constexpr since C++20264    basic_string& replace(size_type pos, size_type n1, const value_type* s, size_type n2);      // constexpr since C++20265    basic_string& replace(size_type pos, size_type n1, const value_type* s);                    // constexpr since C++20266    basic_string& replace(size_type pos, size_type n1, size_type n2, value_type c);             // constexpr since C++20267    basic_string& replace(const_iterator i1, const_iterator i2, const basic_string& str);       // constexpr since C++20268    template <class T>269        basic_string& replace(const_iterator i1, const_iterator i2, const T& t);                // C++17, constexpr since C++20270    basic_string& replace(const_iterator i1, const_iterator i2, const value_type* s, size_type n); // constexpr since C++20271    basic_string& replace(const_iterator i1, const_iterator i2, const value_type* s);           // constexpr since C++20272    basic_string& replace(const_iterator i1, const_iterator i2, size_type n, value_type c);     // constexpr since C++20273    template<class InputIterator>274        basic_string& replace(const_iterator i1, const_iterator i2, InputIterator j1, InputIterator j2); // constexpr since C++20275    template<container-compatible-range<charT> R>276      constexpr basic_string& replace_with_range(const_iterator i1, const_iterator i2, R&& rg); // C++23277    basic_string& replace(const_iterator i1, const_iterator i2, initializer_list<value_type>);  // constexpr since C++20278 279    size_type copy(value_type* s, size_type n, size_type pos = 0) const;                        // constexpr since C++20280    basic_string substr(size_type pos = 0, size_type n = npos) const;                           // constexpr in C++20, removed in C++23281    basic_string substr(size_type pos = 0, size_type n = npos) const&;                          // since C++23282    constexpr basic_string substr(size_type pos = 0, size_type n = npos) &&;                    // since C++23283    constexpr basic_string_view<charT, traits> subview(size_type pos = 0,284                                                       size_type n = npos) const;               // since C++26285    void swap(basic_string& str)286        noexcept(allocator_traits<allocator_type>::propagate_on_container_swap::value ||287                 allocator_traits<allocator_type>::is_always_equal::value);                     // C++17, constexpr since C++20288 289    const value_type* c_str() const noexcept;                                                   // constexpr since C++20290    const value_type* data() const noexcept;                                                    // constexpr since C++20291          value_type* data()       noexcept;                                                    // C++17, constexpr since C++20292 293    allocator_type get_allocator() const noexcept;                                              // constexpr since C++20294 295    size_type find(const basic_string& str, size_type pos = 0) const noexcept;                  // constexpr since C++20296    template <class T>297        size_type find(const T& t, size_type pos = 0) const noexcept;                           // C++17, noexcept as an extension, constexpr since C++20298    size_type find(const value_type* s, size_type pos, size_type n) const noexcept;             // constexpr since C++20299    size_type find(const value_type* s, size_type pos = 0) const noexcept;                      // constexpr since C++20300    size_type find(value_type c, size_type pos = 0) const noexcept;                             // constexpr since C++20301 302    size_type rfind(const basic_string& str, size_type pos = npos) const noexcept;              // constexpr since C++20303    template <class T>304        size_type rfind(const T& t, size_type pos = npos) const noexcept;                       // C++17, noexcept as an extension, constexpr since C++20305    size_type rfind(const value_type* s, size_type pos, size_type n) const noexcept;            // constexpr since C++20306    size_type rfind(const value_type* s, size_type pos = npos) const noexcept;                  // constexpr since C++20307    size_type rfind(value_type c, size_type pos = npos) const noexcept;                         // constexpr since C++20308 309    size_type find_first_of(const basic_string& str, size_type pos = 0) const noexcept;         // constexpr since C++20310    template <class T>311        size_type find_first_of(const T& t, size_type pos = 0) const noexcept;                  // C++17, noexcept as an extension, constexpr since C++20312    size_type find_first_of(const value_type* s, size_type pos, size_type n) const noexcept;    // constexpr since C++20313    size_type find_first_of(const value_type* s, size_type pos = 0) const noexcept;             // constexpr since C++20314    size_type find_first_of(value_type c, size_type pos = 0) const noexcept;                    // constexpr since C++20315 316    size_type find_last_of(const basic_string& str, size_type pos = npos) const noexcept;       // constexpr since C++20317    template <class T>318        size_type find_last_of(const T& t, size_type pos = npos) const noexcept noexcept;       // C++17, noexcept as an extension, constexpr since C++20319    size_type find_last_of(const value_type* s, size_type pos, size_type n) const noexcept;     // constexpr since C++20320    size_type find_last_of(const value_type* s, size_type pos = npos) const noexcept;           // constexpr since C++20321    size_type find_last_of(value_type c, size_type pos = npos) const noexcept;                  // constexpr since C++20322 323    size_type find_first_not_of(const basic_string& str, size_type pos = 0) const noexcept;     // constexpr since C++20324    template <class T>325        size_type find_first_not_of(const T& t, size_type pos = 0) const noexcept;              // C++17, noexcept as an extension, constexpr since C++20326    size_type find_first_not_of(const value_type* s, size_type pos, size_type n) const noexcept; // constexpr since C++20327    size_type find_first_not_of(const value_type* s, size_type pos = 0) const noexcept;         // constexpr since C++20328    size_type find_first_not_of(value_type c, size_type pos = 0) const noexcept;                // constexpr since C++20329 330    size_type find_last_not_of(const basic_string& str, size_type pos = npos) const noexcept;   // constexpr since C++20331    template <class T>332        size_type find_last_not_of(const T& t, size_type pos = npos) const noexcept;            // C++17, noexcept as an extension, constexpr since C++20333    size_type find_last_not_of(const value_type* s, size_type pos, size_type n) const noexcept; // constexpr since C++20334    size_type find_last_not_of(const value_type* s, size_type pos = npos) const noexcept;       // constexpr since C++20335    size_type find_last_not_of(value_type c, size_type pos = npos) const noexcept;              // constexpr since C++20336 337    int compare(const basic_string& str) const noexcept;                                        // constexpr since C++20338    template <class T>339        int compare(const T& t) const noexcept;                                                 // C++17, noexcept as an extension, constexpr since C++20340    int compare(size_type pos1, size_type n1, const basic_string& str) const;                   // constexpr since C++20341    template <class T>342        int compare(size_type pos1, size_type n1, const T& t) const;                            // C++17, constexpr since C++20343    int compare(size_type pos1, size_type n1, const basic_string& str,344                size_type pos2, size_type n2=npos) const;                                       // C++14, constexpr since C++20345    template <class T>346        int compare(size_type pos1, size_type n1, const T& t,347                    size_type pos2, size_type n2=npos) const;                                   // C++17, constexpr since C++20348    int compare(const value_type* s) const noexcept;                                            // constexpr since C++20349    int compare(size_type pos1, size_type n1, const value_type* s) const;                       // constexpr since C++20350    int compare(size_type pos1, size_type n1, const value_type* s, size_type n2) const;         // constexpr since C++20351 352    constexpr bool starts_with(basic_string_view<charT, traits> sv) const noexcept;             // C++20353    constexpr bool starts_with(charT c) const noexcept;                                         // C++20354    constexpr bool starts_with(const charT* s) const;                                           // C++20355    constexpr bool ends_with(basic_string_view<charT, traits> sv) const noexcept;               // C++20356    constexpr bool ends_with(charT c) const noexcept;                                           // C++20357    constexpr bool ends_with(const charT* s) const;                                             // C++20358 359    constexpr bool contains(basic_string_view<charT, traits> sv) const noexcept;                // C++23360    constexpr bool contains(charT c) const noexcept;                                            // C++23361    constexpr bool contains(const charT* s) const;                                              // C++23362};363 364template<class InputIterator,365         class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>366basic_string(InputIterator, InputIterator, Allocator = Allocator())367   -> basic_string<typename iterator_traits<InputIterator>::value_type,368                  char_traits<typename iterator_traits<InputIterator>::value_type>,369                  Allocator>;   // C++17370 371template<ranges::input_range R,372         class Allocator = allocator<ranges::range_value_t<R>>>373  basic_string(from_range_t, R&&, Allocator = Allocator())374    -> basic_string<ranges::range_value_t<R>, char_traits<ranges::range_value_t<R>>,375                    Allocator>; // C++23376 377template<class charT,378         class traits,379         class Allocator = allocator<charT>>380  explicit basic_string(basic_string_view<charT, traits>, const Allocator& = Allocator())381    -> basic_string<charT, traits, Allocator>; // C++17382 383template<class charT,384         class traits,385         class Allocator = allocator<charT>>386  basic_string(basic_string_view<charT, traits>,387                typename see below::size_type, typename see below::size_type,388                const Allocator& = Allocator())389    -> basic_string<charT, traits, Allocator>; // C++17390 391template<class charT, class traits, class Allocator>392basic_string<charT, traits, Allocator>393operator+(const basic_string<charT, traits, Allocator>& lhs,394          const basic_string<charT, traits, Allocator>& rhs);                                   // constexpr since C++20395 396template<class charT, class traits, class Allocator>397basic_string<charT, traits, Allocator>398operator+(const charT* lhs , const basic_string<charT,traits,Allocator>&rhs);                   // constexpr since C++20399 400template<class charT, class traits, class Allocator>401basic_string<charT, traits, Allocator>402operator+(charT lhs, const basic_string<charT,traits,Allocator>& rhs);                          // constexpr since C++20403 404template<class charT, class traits, class Allocator>405basic_string<charT, traits, Allocator>406operator+(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs);                 // constexpr since C++20407 408template<class charT, class traits, class Allocator>409basic_string<charT, traits, Allocator>410operator+(const basic_string<charT, traits, Allocator>& lhs, charT rhs);                        // constexpr since C++20411 412template<class charT, class traits, class Allocator>413  constexpr basic_string<charT, traits, Allocator>414    operator+(const basic_string<charT, traits, Allocator>& lhs,415              type_identity_t<basic_string_view<charT, traits>> rhs);                           // Since C++26416template<class charT, class traits, class Allocator>417  constexpr basic_string<charT, traits, Allocator>418    operator+(basic_string<charT, traits, Allocator>&& lhs,419              type_identity_t<basic_string_view<charT, traits>> rhs);                           // Since C++26420template<class charT, class traits, class Allocator>421  constexpr basic_string<charT, traits, Allocator>422    operator+(type_identity_t<basic_string_view<charT, traits>> lhs,423              const basic_string<charT, traits, Allocator>& rhs);                               // Since C++26424template<class charT, class traits, class Allocator>425  constexpr basic_string<charT, traits, Allocator>426    operator+(type_identity_t<basic_string_view<charT, traits>> lhs,427              basic_string<charT, traits, Allocator>&& rhs);                                    // Since C++26428 429 430template<class charT, class traits, class Allocator>431bool operator==(const basic_string<charT, traits, Allocator>& lhs,432                const basic_string<charT, traits, Allocator>& rhs) noexcept;                    // constexpr since C++20433 434template<class charT, class traits, class Allocator>435bool operator==(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;  // removed in C++20436 437template<class charT, class traits, class Allocator>438bool operator==(const basic_string<charT,traits,Allocator>& lhs, const charT* rhs) noexcept;    // constexpr since C++20439 440template<class charT, class traits, class Allocator>441bool operator!=(const basic_string<charT,traits,Allocator>& lhs,442                const basic_string<charT, traits, Allocator>& rhs) noexcept;                    // removed in C++20443 444template<class charT, class traits, class Allocator>445bool operator!=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;  // removed in C++20446 447template<class charT, class traits, class Allocator>448bool operator!=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;  // removed in C++20449 450template<class charT, class traits, class Allocator>451bool operator< (const basic_string<charT, traits, Allocator>& lhs,452                const basic_string<charT, traits, Allocator>& rhs) noexcept;                    // removed in C++20453 454template<class charT, class traits, class Allocator>455bool operator< (const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;  // removed in C++20456 457template<class charT, class traits, class Allocator>458bool operator< (const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;  // removed in C++20459 460template<class charT, class traits, class Allocator>461bool operator> (const basic_string<charT, traits, Allocator>& lhs,462                const basic_string<charT, traits, Allocator>& rhs) noexcept;                    // removed in C++20463 464template<class charT, class traits, class Allocator>465bool operator> (const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;  // removed in C++20466 467template<class charT, class traits, class Allocator>468bool operator> (const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;  // removed in C++20469 470template<class charT, class traits, class Allocator>471bool operator<=(const basic_string<charT, traits, Allocator>& lhs,472                const basic_string<charT, traits, Allocator>& rhs) noexcept;                    // removed in C++20473 474template<class charT, class traits, class Allocator>475bool operator<=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;  // removed in C++20476 477template<class charT, class traits, class Allocator>478bool operator<=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;  // removed in C++20479 480template<class charT, class traits, class Allocator>481bool operator>=(const basic_string<charT, traits, Allocator>& lhs,482                const basic_string<charT, traits, Allocator>& rhs) noexcept;                    // removed in C++20483 484template<class charT, class traits, class Allocator>485bool operator>=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;  // removed in C++20486 487template<class charT, class traits, class Allocator>488bool operator>=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;  // removed in C++20489 490template<class charT, class traits, class Allocator>                                            // since C++20491constexpr see below operator<=>(const basic_string<charT, traits, Allocator>& lhs,492                                const basic_string<charT, traits, Allocator>& rhs) noexcept;493 494template<class charT, class traits, class Allocator>                                            // since C++20495constexpr see below operator<=>(const basic_string<charT, traits, Allocator>& lhs,496                                const charT* rhs) noexcept;497 498template<class charT, class traits, class Allocator>499void swap(basic_string<charT, traits, Allocator>& lhs,500          basic_string<charT, traits, Allocator>& rhs)501            noexcept(noexcept(lhs.swap(rhs)));                                                  // constexpr since C++20502 503template<class charT, class traits, class Allocator>504basic_istream<charT, traits>&505operator>>(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str);506 507template<class charT, class traits, class Allocator>508basic_ostream<charT, traits>&509operator<<(basic_ostream<charT, traits>& os, const basic_string<charT, traits, Allocator>& str);510 511template<class charT, class traits, class Allocator>512basic_istream<charT, traits>&513getline(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str,514        charT delim);515 516template<class charT, class traits, class Allocator>517basic_istream<charT, traits>&518getline(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str);519 520template<class charT, class traits, class Allocator, class U>521constexpr typename basic_string<charT, traits, Allocator>::size_type522erase(basic_string<charT, traits, Allocator>& c, const U& value);    // C++20523template<class charT, class traits, class Allocator, class Predicate>524constexpr typename basic_string<charT, traits, Allocator>::size_type525erase_if(basic_string<charT, traits, Allocator>& c, Predicate pred); // C++20526 527typedef basic_string<char>    string;528typedef basic_string<wchar_t> wstring;529typedef basic_string<char8_t> u8string; // C++20530typedef basic_string<char16_t> u16string;531typedef basic_string<char32_t> u32string;532 533int                stoi  (const string& str, size_t* idx = nullptr, int base = 10);534long               stol  (const string& str, size_t* idx = nullptr, int base = 10);535unsigned long      stoul (const string& str, size_t* idx = nullptr, int base = 10);536long long          stoll (const string& str, size_t* idx = nullptr, int base = 10);537unsigned long long stoull(const string& str, size_t* idx = nullptr, int base = 10);538 539float       stof (const string& str, size_t* idx = nullptr);540double      stod (const string& str, size_t* idx = nullptr);541long double stold(const string& str, size_t* idx = nullptr);542 543string to_string(int val);544string to_string(unsigned val);545string to_string(long val);546string to_string(unsigned long val);547string to_string(long long val);548string to_string(unsigned long long val);549string to_string(float val);550string to_string(double val);551string to_string(long double val);552 553int                stoi  (const wstring& str, size_t* idx = nullptr, int base = 10);554long               stol  (const wstring& str, size_t* idx = nullptr, int base = 10);555unsigned long      stoul (const wstring& str, size_t* idx = nullptr, int base = 10);556long long          stoll (const wstring& str, size_t* idx = nullptr, int base = 10);557unsigned long long stoull(const wstring& str, size_t* idx = nullptr, int base = 10);558 559float       stof (const wstring& str, size_t* idx = nullptr);560double      stod (const wstring& str, size_t* idx = nullptr);561long double stold(const wstring& str, size_t* idx = nullptr);562 563wstring to_wstring(int val);564wstring to_wstring(unsigned val);565wstring to_wstring(long val);566wstring to_wstring(unsigned long val);567wstring to_wstring(long long val);568wstring to_wstring(unsigned long long val);569wstring to_wstring(float val);570wstring to_wstring(double val);571wstring to_wstring(long double val);572 573template <> struct hash<string>;574template <> struct hash<u8string>; // C++20575template <> struct hash<u16string>;576template <> struct hash<u32string>;577template <> struct hash<wstring>;578 579basic_string<char>     operator""s( const char *str,     size_t len );           // C++14, constexpr since C++20580basic_string<wchar_t>  operator""s( const wchar_t *str,  size_t len );           // C++14, constexpr since C++20581constexpr basic_string<char8_t>  operator""s( const char8_t *str,  size_t len ); // C++20582basic_string<char16_t> operator""s( const char16_t *str, size_t len );           // C++14, constexpr since C++20583basic_string<char32_t> operator""s( const char32_t *str, size_t len );           // C++14, constexpr since C++20584 585}  // std586 587*/588 589// clang-format on590 591#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)592#  include <__cxx03/string>593#else594#  include <__algorithm/max.h>595#  include <__algorithm/min.h>596#  include <__algorithm/remove.h>597#  include <__algorithm/remove_if.h>598#  include <__assert>599#  include <__config>600#  include <__debug_utils/sanitizers.h>601#  include <__format/enable_insertable.h>602#  include <__functional/hash.h>603#  include <__functional/is_transparent.h>604#  include <__functional/unary_function.h>605#  include <__fwd/string.h>606#  include <__iterator/bounded_iter.h>607#  include <__iterator/distance.h>608#  include <__iterator/iterator_traits.h>609#  include <__iterator/reverse_iterator.h>610#  include <__iterator/wrap_iter.h>611#  include <__memory/addressof.h>612#  include <__memory/allocate_at_least.h>613#  include <__memory/allocator.h>614#  include <__memory/allocator_traits.h>615#  include <__memory/compressed_pair.h>616#  include <__memory/construct_at.h>617#  include <__memory/noexcept_move_assign_container.h>618#  include <__memory/pointer_traits.h>619#  include <__memory/swap_allocator.h>620#  include <__memory_resource/polymorphic_allocator.h>621#  include <__ranges/access.h>622#  include <__ranges/concepts.h>623#  include <__ranges/container_compatible_range.h>624#  include <__ranges/from_range.h>625#  include <__string/char_traits.h>626#  include <__string/extern_template_lists.h>627#  include <__type_traits/conditional.h>628#  include <__type_traits/enable_if.h>629#  include <__type_traits/is_allocator.h>630#  include <__type_traits/is_array.h>631#  include <__type_traits/is_convertible.h>632#  include <__type_traits/is_generic_transparent_comparator.h>633#  include <__type_traits/is_nothrow_assignable.h>634#  include <__type_traits/is_nothrow_constructible.h>635#  include <__type_traits/is_same.h>636#  include <__type_traits/is_standard_layout.h>637#  include <__type_traits/is_trivially_constructible.h>638#  include <__type_traits/is_trivially_copyable.h>639#  include <__type_traits/is_trivially_relocatable.h>640#  include <__type_traits/remove_cvref.h>641#  include <__utility/default_three_way_comparator.h>642#  include <__utility/exception_guard.h>643#  include <__utility/forward.h>644#  include <__utility/is_pointer_in_range.h>645#  include <__utility/move.h>646#  include <__utility/no_destroy.h>647#  include <__utility/scope_guard.h>648#  include <__utility/swap.h>649#  include <climits>650#  include <cstdio> // EOF651#  include <cstring>652#  include <limits>653#  include <stdexcept>654#  include <string_view>655#  include <version>656 657#  if _LIBCPP_HAS_WIDE_CHARACTERS658#    include <cwchar>659#  endif660 661// standard-mandated includes662 663// [iterator.range]664#  include <__iterator/access.h>665#  include <__iterator/data.h>666#  include <__iterator/empty.h>667#  include <__iterator/reverse_access.h>668#  include <__iterator/size.h>669 670// [string.syn]671#  include <compare>672#  include <initializer_list>673 674#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)675#    pragma GCC system_header676#  endif677 678_LIBCPP_PUSH_MACROS679#  include <__undef_macros>680 681#  if __has_feature(address_sanitizer) && _LIBCPP_INSTRUMENTED_WITH_ASAN682#    define _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS __attribute__((__no_sanitize__("address")))683// This macro disables AddressSanitizer (ASan) instrumentation for a specific function,684// allowing memory accesses that would normally trigger ASan errors to proceed without crashing.685// This is useful for accessing parts of objects memory, which should not be accessed,686// such as unused bytes in short strings, that should never be accessed687// by other parts of the program.688#  else689#    define _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS690#  endif691 692_LIBCPP_BEGIN_NAMESPACE_STD693 694// basic_string695 696template <class _CharT, class _Traits, class _Allocator>697_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>698__concatenate_strings(const _Allocator& __alloc,699                      __type_identity_t<basic_string_view<_CharT, _Traits> > __str1,700                      __type_identity_t<basic_string_view<_CharT, _Traits> > __str2);701 702template <class _Iter>703inline const bool __string_is_trivial_iterator_v = false;704 705template <class _Tp>706inline const bool __string_is_trivial_iterator_v<_Tp*> = is_arithmetic<_Tp>::value;707 708template <class _Iter>709inline const bool __string_is_trivial_iterator_v<__wrap_iter<_Iter> > = __string_is_trivial_iterator_v<_Iter>;710 711template <class _CharT, class _Traits, class _Tp>712inline const bool __can_be_converted_to_string_view_v =713    is_convertible<const _Tp&, basic_string_view<_CharT, _Traits> >::value &&714    !is_convertible<const _Tp&, const _CharT*>::value;715 716struct __uninitialized_size_tag {};717struct __init_with_sentinel_tag {};718 719template <size_t _PaddingSize>720struct __padding {721  char __padding_[_PaddingSize];722};723 724template <>725struct __padding<0> {};726 727template <class _CharT, class _Traits, class _Allocator>728class basic_string {729public:730  using __self _LIBCPP_NODEBUG         = basic_string;731  using __self_view _LIBCPP_NODEBUG    = basic_string_view<_CharT, _Traits>;732  using traits_type                    = _Traits;733  using value_type                     = _CharT;734  using allocator_type                 = _Allocator;735  using __alloc_traits _LIBCPP_NODEBUG = allocator_traits<allocator_type>;736  using size_type                      = typename __alloc_traits::size_type;737  using difference_type                = typename __alloc_traits::difference_type;738  using reference                      = value_type&;739  using const_reference                = const value_type&;740  using pointer                        = typename __alloc_traits::pointer;741  using const_pointer                  = typename __alloc_traits::const_pointer;742 743  // A basic_string contains the following members which may be trivially relocatable:744  // - pointer: is currently assumed to be trivially relocatable, but is still checked in case that changes745  // - size_type: is always trivially relocatable, since it has to be an integral type746  // - value_type: is always trivially relocatable, since it has to be trivial747  // - unsigned char: is a fundamental type, so it's trivially relocatable748  // - allocator_type: may or may not be trivially relocatable, so it's checked749  //750  // This string implementation doesn't contain any references into itself. It only contains a bit that says whether751  // it is in small or large string mode, so the entire structure is trivially relocatable if its members are.752#  if __has_feature(address_sanitizer) && _LIBCPP_INSTRUMENTED_WITH_ASAN753  // When compiling with AddressSanitizer (ASan), basic_string cannot be trivially754  // relocatable. Because the object's memory might be poisoned when its content755  // is kept inside objects memory (short string optimization), instead of in allocated756  // external memory. In such cases, the destructor is responsible for unpoisoning757  // the memory to avoid triggering false positives.758  // Therefore it's crucial to ensure the destructor is called.759  using __trivially_relocatable = void;760#  else761  using __trivially_relocatable _LIBCPP_NODEBUG = __conditional_t<762      __libcpp_is_trivially_relocatable<allocator_type>::value && __libcpp_is_trivially_relocatable<pointer>::value,763      basic_string,764      void>;765#  endif766 767#  if __has_feature(address_sanitizer) && _LIBCPP_INSTRUMENTED_WITH_ASAN768  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pointer __asan_volatile_wrapper(pointer const& __ptr) const {769    if (__libcpp_is_constant_evaluated())770      return __ptr;771 772    pointer volatile __copy_ptr = __ptr;773 774    return const_cast<pointer&>(__copy_ptr);775  }776 777  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_pointer778  __asan_volatile_wrapper(const_pointer const& __ptr) const {779    if (__libcpp_is_constant_evaluated())780      return __ptr;781 782    const_pointer volatile __copy_ptr = __ptr;783 784    return const_cast<const_pointer&>(__copy_ptr);785  }786#    define _LIBCPP_ASAN_VOLATILE_WRAPPER(PTR) __asan_volatile_wrapper(PTR)787#  else788#    define _LIBCPP_ASAN_VOLATILE_WRAPPER(PTR) PTR789#  endif790 791  static_assert(!is_array<value_type>::value, "Character type of basic_string must not be an array");792  static_assert(is_standard_layout<value_type>::value, "Character type of basic_string must be standard-layout");793  static_assert(is_trivially_default_constructible<value_type>::value,794                "Character type of basic_string must be trivially default constructible");795  static_assert(is_trivially_copyable<value_type>::value, "Character type of basic_string must be trivially copyable");796  static_assert(is_same<_CharT, typename traits_type::char_type>::value,797                "traits_type::char_type must be the same type as CharT");798  static_assert(is_same<typename allocator_type::value_type, value_type>::value,799                "Allocator::value_type must be same type as value_type");800  static_assert(__check_valid_allocator<allocator_type>::value, "");801 802#  ifdef _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING803  // Users might provide custom allocators, and prior to C++20 we have no existing way to detect whether the allocator's804  // pointer type is contiguous (though it has to be by the Standard). Using the wrapper type ensures the iterator is805  // considered contiguous.806  using iterator       = __bounded_iter<__wrap_iter<pointer> >;807  using const_iterator = __bounded_iter<__wrap_iter<const_pointer> >;808#  else809  using iterator       = __wrap_iter<pointer>;810  using const_iterator = __wrap_iter<const_pointer>;811#  endif812  using reverse_iterator       = std::reverse_iterator<iterator>;813  using const_reverse_iterator = std::reverse_iterator<const_iterator>;814 815  using __alloc_result _LIBCPP_NODEBUG = __allocation_result<pointer, size_type>;816 817private:818  static_assert(CHAR_BIT == 8, "This implementation assumes that one byte contains 8 bits");819 820#  ifdef _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT821 822  struct __long {823    __long() = default;824 825    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __long(__alloc_result __alloc, size_type __size)826        : __data_(__alloc.ptr), __size_(__size), __cap_(__alloc.count / __endian_factor), __is_long_(true) {827      _LIBCPP_ASSERT_INTERNAL(!__fits_in_sso(__alloc.count), "Long capacity should always be larger than the SSO");828    }829 830    pointer __data_;831    size_type __size_;832    size_type __cap_ : sizeof(size_type) * CHAR_BIT - 1;833    size_type __is_long_ : 1;834  };835 836  enum { __min_cap = (sizeof(__long) - 1) / sizeof(value_type) > 2 ? (sizeof(__long) - 1) / sizeof(value_type) : 2 };837 838  struct __short {839    value_type __data_[__min_cap];840    _LIBCPP_NO_UNIQUE_ADDRESS __padding<sizeof(value_type) - 1> __padding_;841    unsigned char __size_    : 7;842    unsigned char __is_long_ : 1;843  };844 845  // The __endian_factor is required because the field we use to store the size846  // has one fewer bit than it would if it were not a bitfield.847  //848  // If the LSB is used to store the short-flag in the short string representation,849  // we have to multiply the size by two when it is stored and divide it by two when850  // it is loaded to make sure that we always store an even number. In the long string851  // representation, we can ignore this because we can assume that we always allocate852  // an even amount of value_types.853  //854  // If the MSB is used for the short-flag, the max_size() is numeric_limits<size_type>::max() / 2.855  // This does not impact the short string representation, since we never need the MSB856  // for representing the size of a short string anyway.857 858#    ifdef _LIBCPP_BIG_ENDIAN859  static const size_type __endian_factor = 2;860#    else861  static const size_type __endian_factor = 1;862#    endif863 864#  else // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT865 866#    ifdef _LIBCPP_BIG_ENDIAN867  static const size_type __endian_factor = 1;868#    else869  static const size_type __endian_factor = 2;870#    endif871 872  // Attribute 'packed' is used to keep the layout compatible with the873  // previous definition that did not use bit fields. This is because on874  // some platforms bit fields have a default size rather than the actual875  // size used, e.g., it is 4 bytes on AIX. See D128285 for details.876  struct __long {877    __long() = default;878 879    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __long(__alloc_result __alloc, size_type __size)880        : __is_long_(true), __cap_(__alloc.count / __endian_factor), __size_(__size), __data_(__alloc.ptr) {881      _LIBCPP_ASSERT_INTERNAL(!__fits_in_sso(__alloc.count), "Long capacity should always be larger than the SSO");882    }883 884    struct _LIBCPP_PACKED {885      size_type __is_long_ : 1;886      size_type __cap_ : sizeof(size_type) * CHAR_BIT - 1;887    };888    size_type __size_;889    pointer __data_;890  };891 892  enum { __min_cap = (sizeof(__long) - 1) / sizeof(value_type) > 2 ? (sizeof(__long) - 1) / sizeof(value_type) : 2 };893 894  struct __short {895    struct _LIBCPP_PACKED {896      unsigned char __is_long_ : 1;897      unsigned char __size_    : 7;898    };899    _LIBCPP_NO_UNIQUE_ADDRESS __padding<sizeof(value_type) - 1> __padding_;900    value_type __data_[__min_cap];901  };902 903#  endif // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT904 905  static_assert(sizeof(__short) == (sizeof(value_type) * (__min_cap + 1)), "__short has an unexpected size.");906 907  union __rep {908    __short __s;909    __long __l;910 911    __rep() = default;912    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __rep(__short __r) : __s(__r) {}913    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __rep(__long __r) : __l(__r) {}914    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __rep(__uninitialized_tag) {}915  };916 917  _LIBCPP_COMPRESSED_PAIR(__rep, __rep_, allocator_type, __alloc_);918 919  // annotate the string with its size() at scope exit. The string has to be in a valid state at that point.920  struct __annotate_new_size {921    basic_string& __str_;922 923    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __annotate_new_size(basic_string& __str) : __str_(__str) {}924 925    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void operator()() { __str_.__annotate_new(__str_.size()); }926  };927 928  // Construct a string with the given allocator and enough storage to hold `__size` characters, but929  // don't initialize the characters. The contents of the string, including the null terminator, must be930  // initialized separately.931  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit basic_string(932      __uninitialized_size_tag, size_type __size, const allocator_type& __a)933      : __alloc_(__a) {934    __init_internal_buffer(__size);935  }936 937  template <class _Iter, class _Sent>938  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20939  basic_string(__init_with_sentinel_tag, _Iter __first, _Sent __last, const allocator_type& __a)940      : __alloc_(__a) {941    __init_with_sentinel(std::move(__first), std::move(__last));942  }943 944  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator __make_iterator(pointer __p) {945#  ifdef _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING946    // Bound the iterator according to the size (and not the capacity, unlike vector).947    //948    // By the Standard, string iterators are generally not guaranteed to stay valid when the container is modified,949    // regardless of whether reallocation occurs. This allows us to check for out-of-bounds accesses using logical size,950    // a stricter check, since correct code can never rely on being able to access newly-added elements via an existing951    // iterator.952    return std::__make_bounded_iter(953        std::__wrap_iter<pointer>(__p),954        std::__wrap_iter<pointer>(__get_pointer()),955        std::__wrap_iter<pointer>(__get_pointer() + size()));956#  else957    return iterator(__p);958#  endif // _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING959  }960 961  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator __make_const_iterator(const_pointer __p) const {962#  ifdef _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING963    // Bound the iterator according to the size (and not the capacity, unlike vector).964    return std::__make_bounded_iter(965        std::__wrap_iter<const_pointer>(__p),966        std::__wrap_iter<const_pointer>(__get_pointer()),967        std::__wrap_iter<const_pointer>(__get_pointer() + size()));968#  else969    return const_iterator(__p);970#  endif                    // _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING971  }972 973public:974  _LIBCPP_TEMPLATE_DATA_VIS static const size_type npos = -1;975 976  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string()977      _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)978#  if _LIBCPP_STD_VER >= 20 // TODO(LLVM 23): Remove this condition; this is a workaround for https://llvm.org/PR154567979      : __rep_(__short())980#  else981      : __rep_()982#  endif983  {984    __annotate_new(0);985  }986 987  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit basic_string(const allocator_type& __a)988#  if _LIBCPP_STD_VER <= 14989      _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)990#  else991      _NOEXCEPT992#  endif993#  if _LIBCPP_STD_VER >= 20 // TODO(LLVM 23): Remove this condition; this is a workaround for https://llvm.org/PR154567994      : __rep_(__short()),995#  else996      : __rep_(),997#  endif998        __alloc_(__a) {999    __annotate_new(0);1000  }1001 1002  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS basic_string(const basic_string& __str)1003      : __alloc_(__alloc_traits::select_on_container_copy_construction(__str.__alloc_)) {1004    if (!__str.__is_long()) {1005      __rep_ = __str.__rep_;1006      __annotate_new(__get_short_size());1007    } else1008      __init_copy_ctor_external(std::__to_address(__str.__get_long_pointer()), __str.__get_long_size());1009  }1010 1011  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS1012  basic_string(const basic_string& __str, const allocator_type& __a)1013      : __alloc_(__a) {1014    if (!__str.__is_long()) {1015      __rep_ = __str.__rep_;1016      __annotate_new(__get_short_size());1017    } else1018      __init_copy_ctor_external(std::__to_address(__str.__get_long_pointer()), __str.__get_long_size());1019  }1020 1021#  ifndef _LIBCPP_CXX03_LANG1022  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(basic_string&& __str)1023#    if _LIBCPP_STD_VER <= 141024      _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)1025#    else1026      _NOEXCEPT1027#    endif1028      // Turning off ASan instrumentation for variable initialization with _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS1029      // does not work consistently during initialization of __r_, so we instead unpoison __str's memory manually first.1030      // __str's memory needs to be unpoisoned only in the case where it's a short string.1031      : __rep_([](basic_string& __s) -> decltype(__s.__rep_)&& {1032          if (!__s.__is_long())1033            __s.__annotate_delete();1034          return std::move(__s.__rep_);1035        }(__str)),1036        __alloc_(std::move(__str.__alloc_)) {1037    __str.__rep_ = __rep();1038    __str.__annotate_new(0);1039    if (!__is_long())1040      __annotate_new(size());1041  }1042 1043  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(basic_string&& __str, const allocator_type& __a)1044      : __alloc_(__a) {1045    if (__str.__is_long() && __a != __str.__alloc_) // copy, not move1046      __init(std::__to_address(__str.__get_long_pointer()), __str.__get_long_size());1047    else {1048      if (__libcpp_is_constant_evaluated())1049        __rep_ = __rep();1050      if (!__str.__is_long())1051        __str.__annotate_delete();1052      __rep_       = __str.__rep_;1053      __str.__rep_ = __rep();1054      __str.__annotate_new(0);1055      if (!__is_long() && this != std::addressof(__str))1056        __annotate_new(size());1057    }1058  }1059#  endif // _LIBCPP_CXX03_LANG1060 1061  template <__enable_if_t<__is_allocator_v<_Allocator>, int> = 0>1062  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s) {1063    _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "basic_string(const char*) detected nullptr");1064    __init(__s, traits_type::length(__s));1065  }1066 1067  template <__enable_if_t<__is_allocator_v<_Allocator>, int> = 0>1068  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX201069  basic_string(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s, const _Allocator& __a)1070      : __alloc_(__a) {1071    _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "basic_string(const char*, allocator) detected nullptr");1072    __init(__s, traits_type::length(__s));1073  }1074 1075#  if _LIBCPP_STD_VER >= 231076  basic_string(nullptr_t) = delete;1077#  endif1078 1079  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(const _CharT* __s, size_type __n)1080      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {1081    _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "basic_string(const char*, n) detected nullptr");1082    __init(__s, __n);1083  }1084 1085  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX201086  basic_string(const _CharT* __s, size_type __n, const _Allocator& __a)1087      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero")1088      : __alloc_(__a) {1089    _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "basic_string(const char*, n, allocator) detected nullptr");1090    __init(__s, __n);1091  }1092 1093  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(size_type __n, _CharT __c) { __init(__n, __c); }1094 1095#  if _LIBCPP_STD_VER >= 231096  _LIBCPP_HIDE_FROM_ABI constexpr basic_string(1097      basic_string&& __str, size_type __pos, const _Allocator& __alloc = _Allocator())1098      : basic_string(std::move(__str), __pos, npos, __alloc) {}1099 1100  _LIBCPP_HIDE_FROM_ABI constexpr basic_string(1101      basic_string&& __str, size_type __pos, size_type __n, const _Allocator& __alloc = _Allocator())1102      : __alloc_(__alloc) {1103    if (__pos > __str.size())1104      this->__throw_out_of_range();1105 1106    auto __len = std::min<size_type>(__n, __str.size() - __pos);1107    if (__alloc_traits::is_always_equal::value || __alloc == __str.__alloc_) {1108      __move_assign(std::move(__str), __pos, __len);1109    } else {1110      // Perform a copy because the allocators are not compatible.1111      __init(__str.data() + __pos, __len);1112    }1113  }1114#  endif1115 1116  template <__enable_if_t<__is_allocator_v<_Allocator>, int> = 0>1117  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(size_type __n, _CharT __c, const _Allocator& __a)1118      : __alloc_(__a) {1119    __init(__n, __c);1120  }1121 1122  _LIBCPP_CONSTEXPR_SINCE_CXX201123  basic_string(const basic_string& __str, size_type __pos, size_type __n, const _Allocator& __a = _Allocator())1124      : __alloc_(__a) {1125    size_type __str_sz = __str.size();1126    if (__pos > __str_sz)1127      this->__throw_out_of_range();1128    __init(__str.data() + __pos, std::min(__n, __str_sz - __pos));1129  }1130 1131  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX201132  basic_string(const basic_string& __str, size_type __pos, const _Allocator& __a = _Allocator())1133      : __alloc_(__a) {1134    size_type __str_sz = __str.size();1135    if (__pos > __str_sz)1136      this->__throw_out_of_range();1137    __init(__str.data() + __pos, __str_sz - __pos);1138  }1139 1140  template <class _Tp,1141            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&1142                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,1143                          int> = 0>1144  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX201145  basic_string(const _Tp& __t, size_type __pos, size_type __n, const allocator_type& __a = allocator_type())1146      : __alloc_(__a) {1147    __self_view __sv0 = __t;1148    __self_view __sv  = __sv0.substr(__pos, __n);1149    __init(__sv.data(), __sv.size());1150  }1151 1152  template <class _Tp,1153            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&1154                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,1155                          int> = 0>1156  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit basic_string(const _Tp& __t) {1157    __self_view __sv = __t;1158    __init(__sv.data(), __sv.size());1159  }1160 1161  template <class _Tp,1162            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&1163                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,1164                          int> = 0>1165  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit basic_string(const _Tp& __t, const allocator_type& __a)1166      : __alloc_(__a) {1167    __self_view __sv = __t;1168    __init(__sv.data(), __sv.size());1169  }1170 1171  template <class _InputIterator, __enable_if_t<__has_input_iterator_category<_InputIterator>::value, int> = 0>1172  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(_InputIterator __first, _InputIterator __last) {1173    __init(__first, __last);1174  }1175 1176  template <class _InputIterator, __enable_if_t<__has_input_iterator_category<_InputIterator>::value, int> = 0>1177  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX201178  basic_string(_InputIterator __first, _InputIterator __last, const allocator_type& __a)1179      : __alloc_(__a) {1180    __init(__first, __last);1181  }1182 1183#  if _LIBCPP_STD_VER >= 231184  template <_ContainerCompatibleRange<_CharT> _Range>1185  _LIBCPP_HIDE_FROM_ABI constexpr basic_string(1186      from_range_t, _Range&& __range, const allocator_type& __a = allocator_type())1187      : __alloc_(__a) {1188    if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {1189      __init_with_size(ranges::begin(__range), ranges::end(__range), ranges::distance(__range));1190    } else {1191      __init_with_sentinel(ranges::begin(__range), ranges::end(__range));1192    }1193  }1194#  endif1195 1196#  ifndef _LIBCPP_CXX03_LANG1197  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(initializer_list<_CharT> __il) {1198    __init(__il.begin(), __il.end());1199  }1200 1201  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(initializer_list<_CharT> __il, const _Allocator& __a)1202      : __alloc_(__a) {1203    __init(__il.begin(), __il.end());1204  }1205#  endif // _LIBCPP_CXX03_LANG1206 1207  // TODO(boomanaiden154): Once we mark this in destructors as dead on return,1208  // we can use a normal call to __reset_internal_buffer and remove the extra1209  // __rep constructor.1210  inline _LIBCPP_CONSTEXPR_SINCE_CXX20 ~basic_string() { __reset_internal_buffer(__rep(__uninitialized_tag())); }1211 1212  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 operator __self_view() const _NOEXCEPT {1213    return __self_view(typename __self_view::__assume_valid(), data(), size());1214  }1215 1216  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS basic_string&1217  operator=(const basic_string& __str);1218 1219  template <class _Tp,1220            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&1221                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,1222                          int> = 0>1223  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator=(const _Tp& __t) {1224    __self_view __sv = __t;1225    return assign(__sv);1226  }1227 1228#  ifndef _LIBCPP_CXX03_LANG1229  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1230  operator=(basic_string&& __str) noexcept(__noexcept_move_assign_container<_Allocator, __alloc_traits>::value) {1231    __move_assign(__str, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());1232    return *this;1233  }1234 1235  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator=(initializer_list<value_type> __il) {1236    return assign(__il.begin(), __il.size());1237  }1238#  endif1239  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1240  operator=(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) {1241    return assign(__s);1242  }1243#  if _LIBCPP_STD_VER >= 231244  basic_string& operator=(nullptr_t) = delete;1245#  endif1246  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator=(value_type __c);1247 1248  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator begin() _NOEXCEPT {1249    return __make_iterator(__get_pointer());1250  }1251  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator begin() const _NOEXCEPT {1252    return __make_const_iterator(__get_pointer());1253  }1254  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator end() _NOEXCEPT {1255    return __make_iterator(__get_pointer() + size());1256  }1257  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator end() const _NOEXCEPT {1258    return __make_const_iterator(__get_pointer() + size());1259  }1260 1261  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reverse_iterator rbegin() _NOEXCEPT {1262    return reverse_iterator(end());1263  }1264  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator1265  rbegin() const _NOEXCEPT {1266    return const_reverse_iterator(end());1267  }1268  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reverse_iterator rend() _NOEXCEPT {1269    return reverse_iterator(begin());1270  }1271  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator rend() const _NOEXCEPT {1272    return const_reverse_iterator(begin());1273  }1274 1275  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator cbegin() const _NOEXCEPT {1276    return begin();1277  }1278  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator cend() const _NOEXCEPT {1279    return end();1280  }1281  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator1282  crbegin() const _NOEXCEPT {1283    return rbegin();1284  }1285  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator crend() const _NOEXCEPT {1286    return rend();1287  }1288 1289  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type size() const _NOEXCEPT {1290    return __is_long() ? __get_long_size() : __get_short_size();1291  }1292  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type length() const _NOEXCEPT {1293    return size();1294  }1295 1296  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type max_size() const _NOEXCEPT {1297    if (size_type __m = __alloc_traits::max_size(__alloc_); __m <= std::numeric_limits<size_type>::max() / 2) {1298      size_type __res = __m - __alignment;1299 1300      // When the __endian_factor == 2, our string representation assumes that the capacity1301      // (including the null terminator) is always even, so we have to make sure the lowest bit isn't set when the1302      // string grows to max_size()1303      if (__endian_factor == 2)1304        __res &= ~size_type(1);1305 1306      // We have to allocate space for the null terminator, but max_size() doesn't include it.1307      return __res - 1;1308    } else {1309      bool __uses_lsb = __endian_factor == 2;1310      return __uses_lsb ? __m - __alignment - 1 : (__m / 2) - __alignment - 1;1311    }1312  }1313 1314  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type capacity() const _NOEXCEPT {1315    return (__is_long() ? __get_long_cap() : static_cast<size_type>(__min_cap)) - 1;1316  }1317 1318  _LIBCPP_CONSTEXPR_SINCE_CXX20 void resize(size_type __n, value_type __c);1319  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void resize(size_type __n) { resize(__n, value_type()); }1320 1321  _LIBCPP_CONSTEXPR_SINCE_CXX20 void reserve(size_type __requested_capacity);1322 1323#  if _LIBCPP_STD_VER >= 231324  template <class _Op>1325  _LIBCPP_HIDE_FROM_ABI constexpr void resize_and_overwrite(size_type __n, _Op __op) {1326    using __result_type = decltype(std::move(__op)(data(), auto(__n)));1327    static_assert(__integer_like<__result_type>, "Operation return type must be integer-like");1328    size_type __sz  = size();1329    size_type __cap = capacity();1330    if (__n > __cap)1331      __grow_by_without_replace(__cap, __n - __cap, __sz, __sz, 0);1332    __annotate_delete();1333    __set_size(__n);1334    __annotate_new(__n);1335    __erase_to_end(std::move(__op)(data(), auto(__n)));1336  }1337#  endif1338 1339#  if _LIBCPP_STD_VER < 26 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_STRING_RESERVE)1340  _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_HIDE_FROM_ABI void reserve() _NOEXCEPT { shrink_to_fit(); }1341#  endif1342  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void shrink_to_fit() _NOEXCEPT;1343  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void clear() _NOEXCEPT;1344 1345  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool empty() const _NOEXCEPT {1346    return size() == 0;1347  }1348 1349  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference1350  operator[](size_type __pos) const _NOEXCEPT {1351    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__pos <= size(), "string index out of bounds");1352    if (__builtin_constant_p(__pos) && !__fits_in_sso(__pos)) {1353      return *(__get_long_pointer() + __pos);1354    }1355    return *(data() + __pos);1356  }1357 1358  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference1359  operator[](size_type __pos) _NOEXCEPT {1360    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__pos <= size(), "string index out of bounds");1361    if (__builtin_constant_p(__pos) && !__fits_in_sso(__pos)) {1362      return *(__get_long_pointer() + __pos);1363    }1364    return *(__get_pointer() + __pos);1365  }1366 1367  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference at(size_type __n) const;1368  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 reference at(size_type __n);1369 1370  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(const basic_string& __str) {1371    return append(__str);1372  }1373 1374  template <class _Tp,1375            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&1376                              !is_same<__remove_cvref_t<_Tp>, basic_string >::value,1377                          int> = 0>1378  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(const _Tp& __t) {1379    __self_view __sv = __t;1380    return append(__sv);1381  }1382 1383  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1384  operator+=(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) {1385    return append(__s);1386  }1387 1388  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(value_type __c) {1389    push_back(__c);1390    return *this;1391  }1392 1393#  ifndef _LIBCPP_CXX03_LANG1394  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(initializer_list<value_type> __il) {1395    return append(__il);1396  }1397#  endif // _LIBCPP_CXX03_LANG1398 1399  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const basic_string& __str) {1400    return append(__str.data(), __str.size());1401  }1402 1403  template <class _Tp,1404            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&1405                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,1406                          int> = 0>1407  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const _Tp& __t) {1408    __self_view __sv = __t;1409    return append(__sv.data(), __sv.size());1410  }1411 1412  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const basic_string& __str, size_type __pos, size_type __n = npos);1413 1414  template <class _Tp,1415            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&1416                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,1417                          int> = 0>1418  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1419  append(const _Tp& __t, size_type __pos, size_type __n = npos) {1420    __self_view __sv = __t;1421    size_type __sz   = __sv.size();1422    if (__pos > __sz)1423      __throw_out_of_range();1424    return append(__sv.data() + __pos, std::min(__n, __sz - __pos));1425  }1426 1427  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const value_type* __s, size_type __n)1428      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero");1429  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);1430  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(size_type __n, value_type __c);1431 1432  template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>1433  _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1434  append(_InputIterator __first, _InputIterator __last) {1435    const basic_string __temp(__first, __last, __alloc_);1436    append(__temp.data(), __temp.size());1437    return *this;1438  }1439 1440  template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>1441  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1442  append(_ForwardIterator __first, _ForwardIterator __last) {1443    size_type __sz  = size();1444    size_type __cap = capacity();1445    size_type __n   = static_cast<size_type>(std::distance(__first, __last));1446    if (__n == 0)1447      return *this;1448 1449    if (__string_is_trivial_iterator_v<_ForwardIterator> && !__addr_in_range(*__first)) {1450      if (__cap - __sz < __n)1451        __grow_by_without_replace(__cap, __sz + __n - __cap, __sz, __sz, 0);1452      __annotate_increase(__n);1453      auto __end = __copy_non_overlapping_range(__first, __last, std::__to_address(__get_pointer() + __sz));1454      traits_type::assign(*__end, value_type());1455      __set_size(__sz + __n);1456      return *this;1457    } else {1458      const basic_string __temp(__first, __last, __alloc_);1459      return append(__temp.data(), __temp.size());1460    }1461  }1462 1463#  if _LIBCPP_STD_VER >= 231464  template <_ContainerCompatibleRange<_CharT> _Range>1465  _LIBCPP_HIDE_FROM_ABI constexpr basic_string& append_range(_Range&& __range) {1466    insert_range(end(), std::forward<_Range>(__range));1467    return *this;1468  }1469#  endif1470 1471#  ifndef _LIBCPP_CXX03_LANG1472  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(initializer_list<value_type> __il) {1473    return append(__il.begin(), __il.size());1474  }1475#  endif // _LIBCPP_CXX03_LANG1476 1477  _LIBCPP_CONSTEXPR_SINCE_CXX20 void push_back(value_type __c);1478  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void pop_back();1479 1480  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference front() _NOEXCEPT {1481    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string::front(): string is empty");1482    return *__get_pointer();1483  }1484 1485  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference front() const _NOEXCEPT {1486    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string::front(): string is empty");1487    return *data();1488  }1489 1490  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference back() _NOEXCEPT {1491    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string::back(): string is empty");1492    return *(__get_pointer() + size() - 1);1493  }1494 1495  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference back() const _NOEXCEPT {1496    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string::back(): string is empty");1497    return *(data() + size() - 1);1498  }1499 1500  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>1501  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const _Tp& __t) {1502    __self_view __sv = __t;1503    return assign(__sv.data(), __sv.size());1504  }1505 1506#  if _LIBCPP_STD_VER >= 201507  _LIBCPP_HIDE_FROM_ABI constexpr void __move_assign(basic_string&& __str, size_type __pos, size_type __len) {1508    // Pilfer the allocation from __str.1509    _LIBCPP_ASSERT_INTERNAL(__alloc_ == __str.__alloc_, "__move_assign called with wrong allocator");1510    size_type __old_sz = __str.size();1511    if (!__str.__is_long())1512      __str.__annotate_delete();1513    __rep_       = __str.__rep_;1514    __str.__rep_ = __rep();1515    __str.__annotate_new(0);1516 1517    _Traits::move(data(), data() + __pos, __len);1518    __set_size(__len);1519    _Traits::assign(data()[__len], value_type());1520 1521    if (!__is_long()) {1522      __annotate_new(__len);1523    } else if (__old_sz > __len) {1524      __annotate_shrink(__old_sz);1525    }1526  }1527#  endif1528 1529  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const basic_string& __str) {1530    return *this = __str;1531  }1532#  ifndef _LIBCPP_CXX03_LANG1533  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1534  assign(basic_string&& __str) noexcept(__noexcept_move_assign_container<_Allocator, __alloc_traits>::value) {1535    *this = std::move(__str);1536    return *this;1537  }1538#  endif1539  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const basic_string& __str, size_type __pos, size_type __n = npos);1540 1541  template <class _Tp,1542            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&1543                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,1544                          int> = 0>1545  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1546  assign(const _Tp& __t, size_type __pos, size_type __n = npos) {1547    __self_view __sv = __t;1548    size_type __sz   = __sv.size();1549    if (__pos > __sz)1550      __throw_out_of_range();1551    return assign(__sv.data() + __pos, std::min(__n, __sz - __pos));1552  }1553 1554  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const value_type* __s, size_type __n)1555      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero");1556  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);1557  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(size_type __n, value_type __c);1558 1559  template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>1560  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1561  assign(_InputIterator __first, _InputIterator __last) {1562    __assign_with_sentinel(__first, __last);1563    return *this;1564  }1565 1566  template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>1567  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1568  assign(_ForwardIterator __first, _ForwardIterator __last) {1569    if (__string_is_trivial_iterator_v<_ForwardIterator>) {1570      size_type __n = static_cast<size_type>(std::distance(__first, __last));1571      __assign_trivial(__first, __last, __n);1572    } else {1573      __assign_with_sentinel(__first, __last);1574    }1575 1576    return *this;1577  }1578 1579#  if _LIBCPP_STD_VER >= 231580  template <_ContainerCompatibleRange<_CharT> _Range>1581  _LIBCPP_HIDE_FROM_ABI constexpr basic_string& assign_range(_Range&& __range) {1582    if constexpr (__string_is_trivial_iterator_v<ranges::iterator_t<_Range>> &&1583                  (ranges::forward_range<_Range> || ranges::sized_range<_Range>)) {1584      size_type __n = static_cast<size_type>(ranges::distance(__range));1585      __assign_trivial(ranges::begin(__range), ranges::end(__range), __n);1586 1587    } else {1588      __assign_with_sentinel(ranges::begin(__range), ranges::end(__range));1589    }1590 1591    return *this;1592  }1593#  endif1594 1595#  ifndef _LIBCPP_CXX03_LANG1596  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(initializer_list<value_type> __il) {1597    return assign(__il.begin(), __il.size());1598  }1599#  endif // _LIBCPP_CXX03_LANG1600 1601  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1602  insert(size_type __pos1, const basic_string& __str) {1603    return insert(__pos1, __str.data(), __str.size());1604  }1605 1606  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>1607  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos1, const _Tp& __t) {1608    __self_view __sv = __t;1609    return insert(__pos1, __sv.data(), __sv.size());1610  }1611 1612  template <class _Tp,1613            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&1614                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,1615                          int> = 0>1616  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1617  insert(size_type __pos1, const _Tp& __t, size_type __pos2, size_type __n = npos) {1618    __self_view __sv   = __t;1619    size_type __str_sz = __sv.size();1620    if (__pos2 > __str_sz)1621      __throw_out_of_range();1622    return insert(__pos1, __sv.data() + __pos2, std::min(__n, __str_sz - __pos2));1623  }1624 1625  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1626  insert(size_type __pos1, const basic_string& __str, size_type __pos2, size_type __n = npos);1627  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, const value_type* __s, size_type __n)1628      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero");1629  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);1630  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, size_type __n, value_type __c);1631  _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator insert(const_iterator __pos, value_type __c);1632 1633#  if _LIBCPP_STD_VER >= 231634  template <_ContainerCompatibleRange<_CharT> _Range>1635  _LIBCPP_HIDE_FROM_ABI constexpr iterator insert_range(const_iterator __position, _Range&& __range) {1636    if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {1637      auto __n = static_cast<size_type>(ranges::distance(__range));1638      return __insert_with_size(__position, ranges::begin(__range), ranges::end(__range), __n);1639 1640    } else {1641      basic_string __temp(from_range, std::forward<_Range>(__range), __alloc_);1642      return insert(__position, __temp.data(), __temp.data() + __temp.size());1643    }1644  }1645#  endif1646 1647  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator1648  insert(const_iterator __pos, size_type __n, value_type __c) {1649    difference_type __p = __pos - begin();1650    insert(static_cast<size_type>(__p), __n, __c);1651    return begin() + __p;1652  }1653 1654  template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>1655  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator1656  insert(const_iterator __pos, _InputIterator __first, _InputIterator __last) {1657    const basic_string __temp(__first, __last, __alloc_);1658    return insert(__pos, __temp.data(), __temp.data() + __temp.size());1659  }1660 1661  template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>1662  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator1663  insert(const_iterator __pos, _ForwardIterator __first, _ForwardIterator __last) {1664    auto __n = static_cast<size_type>(std::distance(__first, __last));1665    return __insert_with_size(__pos, __first, __last, __n);1666  }1667 1668#  ifndef _LIBCPP_CXX03_LANG1669  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator1670  insert(const_iterator __pos, initializer_list<value_type> __il) {1671    return insert(__pos, __il.begin(), __il.end());1672  }1673#  endif // _LIBCPP_CXX03_LANG1674 1675  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& erase(size_type __pos = 0, size_type __n = npos);1676  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator erase(const_iterator __pos);1677  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator erase(const_iterator __first, const_iterator __last);1678 1679  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1680  replace(size_type __pos1, size_type __n1, const basic_string& __str) {1681    return replace(__pos1, __n1, __str.data(), __str.size());1682  }1683 1684  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>1685  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1686  replace(size_type __pos1, size_type __n1, const _Tp& __t) {1687    __self_view __sv = __t;1688    return replace(__pos1, __n1, __sv.data(), __sv.size());1689  }1690 1691  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1692  replace(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2 = npos);1693 1694  template <class _Tp,1695            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&1696                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,1697                          int> = 0>1698  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1699  replace(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2 = npos) {1700    __self_view __sv   = __t;1701    size_type __str_sz = __sv.size();1702    if (__pos2 > __str_sz)1703      __throw_out_of_range();1704    return replace(__pos1, __n1, __sv.data() + __pos2, std::min(__n2, __str_sz - __pos2));1705  }1706 1707  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1708  replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2)1709      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n2 != 0 && __s == nullptr, " if n2 is not zero");1710  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1711  replace(size_type __pos, size_type __n1, const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);1712  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& replace(size_type __pos, size_type __n1, size_type __n2, value_type __c);1713 1714  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1715  replace(const_iterator __i1, const_iterator __i2, const basic_string& __str) {1716    return replace(1717        static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __str.data(), __str.size());1718  }1719 1720  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>1721  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1722  replace(const_iterator __i1, const_iterator __i2, const _Tp& __t) {1723    __self_view __sv = __t;1724    return replace(__i1 - begin(), __i2 - __i1, __sv);1725  }1726 1727  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1728  replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n) {1729    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s, __n);1730  }1731 1732  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1733  replace(const_iterator __i1, const_iterator __i2, const value_type* __s) {1734    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s);1735  }1736 1737  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1738  replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c) {1739    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __n, __c);1740  }1741 1742  template <class _InputIterator, __enable_if_t<__has_input_iterator_category<_InputIterator>::value, int> = 0>1743  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1744  replace(const_iterator __i1, const_iterator __i2, _InputIterator __j1, _InputIterator __j2) {1745    const basic_string __temp(__j1, __j2, __alloc_);1746    return replace(__i1, __i2, __temp);1747  }1748 1749#  if _LIBCPP_STD_VER >= 231750  template <_ContainerCompatibleRange<_CharT> _Range>1751  _LIBCPP_HIDE_FROM_ABI constexpr basic_string&1752  replace_with_range(const_iterator __i1, const_iterator __i2, _Range&& __range) {1753    basic_string __temp(from_range, std::forward<_Range>(__range), __alloc_);1754    return replace(__i1, __i2, __temp);1755  }1756#  endif1757 1758#  ifndef _LIBCPP_CXX03_LANG1759  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&1760  replace(const_iterator __i1, const_iterator __i2, initializer_list<value_type> __il) {1761    return replace(__i1, __i2, __il.begin(), __il.end());1762  }1763#  endif // _LIBCPP_CXX03_LANG1764 1765  _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type copy(value_type* __s, size_type __n, size_type __pos = 0) const;1766 1767#  if _LIBCPP_STD_VER <= 201768  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI1769  _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string substr(size_type __pos = 0, size_type __n = npos) const {1770    return basic_string(*this, __pos, __n);1771  }1772#  else1773  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr basic_string substr(size_type __pos = 0, size_type __n = npos) const& {1774    return basic_string(*this, __pos, __n);1775  }1776 1777  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr basic_string substr(size_type __pos = 0, size_type __n = npos) && {1778    return basic_string(std::move(*this), __pos, __n);1779  }1780#  endif1781#  if _LIBCPP_STD_VER >= 261782  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr __self_view subview(size_type __pos = 0, size_type __n = npos) const {1783    return __self_view(*this).subview(__pos, __n);1784  }1785#  endif1786 1787  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(basic_string& __str)1788#  if _LIBCPP_STD_VER >= 141789      _NOEXCEPT;1790#  else1791      _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable_v<allocator_type>);1792#  endif1793 1794  // [string.ops]1795  // ------------1796 1797  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const value_type* c_str() const _NOEXCEPT {1798    return data();1799  }1800 1801  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const value_type* data() const _NOEXCEPT {1802    return std::__to_address(__get_pointer());1803  }1804#  if _LIBCPP_STD_VER >= 171805  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 value_type* data() _NOEXCEPT {1806    return std::__to_address(__get_pointer());1807  }1808#  endif1809 1810  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 allocator_type get_allocator() const _NOEXCEPT {1811    return __alloc_;1812  }1813 1814  // find1815 1816  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1817  find(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT {1818    return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __str.data(), __pos, __str.size());1819  }1820 1821  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>1822  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1823  find(const _Tp& __t, size_type __pos = 0) const _NOEXCEPT {1824    __self_view __sv = __t;1825    return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __sv.data(), __pos, __sv.size());1826  }1827 1828  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1829  find(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT1830      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {1831    _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find(): received nullptr");1832    return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);1833  }1834 1835  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1836  find(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = 0) const _NOEXCEPT {1837    _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::find(): received nullptr");1838    return std::__str_find<value_type, size_type, traits_type, npos>(1839        data(), size(), __s, __pos, traits_type::length(__s));1840  }1841 1842  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type find(value_type __c, size_type __pos = 0) const _NOEXCEPT {1843    return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);1844  }1845 1846  // rfind1847 1848  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1849  rfind(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT {1850    return std::__str_rfind<value_type, size_type, traits_type, npos>(1851        data(), size(), __str.data(), __pos, __str.size());1852  }1853 1854  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>1855  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1856  rfind(const _Tp& __t, size_type __pos = npos) const _NOEXCEPT {1857    __self_view __sv = __t;1858    return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __sv.data(), __pos, __sv.size());1859  }1860 1861  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1862  rfind(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT1863      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {1864    _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::rfind(): received nullptr");1865    return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);1866  }1867 1868  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1869  rfind(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = npos) const _NOEXCEPT {1870    _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::rfind(): received nullptr");1871    return std::__str_rfind<value_type, size_type, traits_type, npos>(1872        data(), size(), __s, __pos, traits_type::length(__s));1873  }1874 1875  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1876  rfind(value_type __c, size_type __pos = npos) const _NOEXCEPT {1877    return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);1878  }1879 1880  // find_first_of1881 1882  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1883  find_first_of(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT {1884    return std::__str_find_first_of<value_type, size_type, traits_type, npos>(1885        data(), size(), __str.data(), __pos, __str.size());1886  }1887 1888  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>1889  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1890  find_first_of(const _Tp& __t, size_type __pos = 0) const _NOEXCEPT {1891    __self_view __sv = __t;1892    return std::__str_find_first_of<value_type, size_type, traits_type, npos>(1893        data(), size(), __sv.data(), __pos, __sv.size());1894  }1895 1896  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1897  find_first_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT1898      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {1899    _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_first_of(): received nullptr");1900    return std::__str_find_first_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);1901  }1902 1903  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1904  find_first_of(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = 0) const _NOEXCEPT {1905    _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::find_first_of(): received nullptr");1906    return std::__str_find_first_of<value_type, size_type, traits_type, npos>(1907        data(), size(), __s, __pos, traits_type::length(__s));1908  }1909 1910  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1911  find_first_of(value_type __c, size_type __pos = 0) const _NOEXCEPT {1912    return find(__c, __pos);1913  }1914 1915  // find_last_of1916 1917  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1918  find_last_of(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT {1919    return std::__str_find_last_of<value_type, size_type, traits_type, npos>(1920        data(), size(), __str.data(), __pos, __str.size());1921  }1922 1923  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>1924  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1925  find_last_of(const _Tp& __t, size_type __pos = npos) const _NOEXCEPT {1926    __self_view __sv = __t;1927    return std::__str_find_last_of<value_type, size_type, traits_type, npos>(1928        data(), size(), __sv.data(), __pos, __sv.size());1929  }1930 1931  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1932  find_last_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT1933      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {1934    _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_last_of(): received nullptr");1935    return std::__str_find_last_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);1936  }1937 1938  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1939  find_last_of(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = npos) const _NOEXCEPT {1940    _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::find_last_of(): received nullptr");1941    return std::__str_find_last_of<value_type, size_type, traits_type, npos>(1942        data(), size(), __s, __pos, traits_type::length(__s));1943  }1944 1945  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1946  find_last_of(value_type __c, size_type __pos = npos) const _NOEXCEPT {1947    return rfind(__c, __pos);1948  }1949 1950  // find_first_not_of1951 1952  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1953  find_first_not_of(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT {1954    return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(1955        data(), size(), __str.data(), __pos, __str.size());1956  }1957 1958  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>1959  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1960  find_first_not_of(const _Tp& __t, size_type __pos = 0) const _NOEXCEPT {1961    __self_view __sv = __t;1962    return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(1963        data(), size(), __sv.data(), __pos, __sv.size());1964  }1965 1966  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1967  find_first_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT1968      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {1969    _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_first_not_of(): received nullptr");1970    return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);1971  }1972 1973  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1974  find_first_not_of(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = 0) const _NOEXCEPT {1975    _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::find_first_not_of(): received nullptr");1976    return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(1977        data(), size(), __s, __pos, traits_type::length(__s));1978  }1979 1980  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1981  find_first_not_of(value_type __c, size_type __pos = 0) const _NOEXCEPT {1982    return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);1983  }1984 1985  // find_last_not_of1986 1987  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1988  find_last_not_of(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT {1989    return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(1990        data(), size(), __str.data(), __pos, __str.size());1991  }1992 1993  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>1994  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type1995  find_last_not_of(const _Tp& __t, size_type __pos = npos) const _NOEXCEPT {1996    __self_view __sv = __t;1997    return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(1998        data(), size(), __sv.data(), __pos, __sv.size());1999  }2000 2001  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type2002  find_last_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT2003      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {2004    _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_last_not_of(): received nullptr");2005    return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);2006  }2007 2008  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type2009  find_last_not_of(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = npos) const _NOEXCEPT {2010    _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::find_last_not_of(): received nullptr");2011    return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(2012        data(), size(), __s, __pos, traits_type::length(__s));2013  }2014 2015  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type2016  find_last_not_of(value_type __c, size_type __pos = npos) const _NOEXCEPT {2017    return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);2018  }2019 2020  // compare2021 2022  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int2023  compare(const basic_string& __str) const _NOEXCEPT {2024    return compare(__self_view(__str));2025  }2026 2027  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>2028  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int compare(const _Tp& __t) const _NOEXCEPT {2029    __self_view __sv = __t;2030    size_t __lhs_sz  = size();2031    size_t __rhs_sz  = __sv.size();2032    int __result     = traits_type::compare(data(), __sv.data(), std::min(__lhs_sz, __rhs_sz));2033    if (__result != 0)2034      return __result;2035    if (__lhs_sz < __rhs_sz)2036      return -1;2037    if (__lhs_sz > __rhs_sz)2038      return 1;2039    return 0;2040  }2041 2042  template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>2043  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int2044  compare(size_type __pos1, size_type __n1, const _Tp& __t) const {2045    __self_view __sv = __t;2046    return compare(__pos1, __n1, __sv.data(), __sv.size());2047  }2048 2049  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int2050  compare(size_type __pos1, size_type __n1, const basic_string& __str) const {2051    return compare(__pos1, __n1, __str.data(), __str.size());2052  }2053 2054  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 int2055  compare(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2 = npos) const {2056    return compare(__pos1, __n1, __self_view(__str), __pos2, __n2);2057  }2058 2059  template <class _Tp,2060            __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&2061                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,2062                          int> = 0>2063  [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int2064  compare(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2 = npos) const {2065    __self_view __sv = __t;2066    return __self_view(*this).substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));2067  }2068 2069  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 int2070  compare(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const _NOEXCEPT {2071    _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::compare(): received nullptr");2072    return compare(0, npos, __s, traits_type::length(__s));2073  }2074 2075  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 int2076  compare(size_type __pos1, size_type __n1, const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const {2077    _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::compare(): received nullptr");2078    return compare(__pos1, __n1, __s, traits_type::length(__s));2079  }2080 2081  [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 int2082  compare(size_type __pos1, size_type __n1, const value_type* __s, size_type __n2) const2083      _LIBCPP_DIAGNOSE_NULLPTR_IF(__n2 != 0 && __s == nullptr, " if n2 is not zero");2084 2085  // starts_with2086 2087#  if _LIBCPP_STD_VER >= 202088  [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool starts_with(__self_view __sv) const noexcept {2089    return __self_view(typename __self_view::__assume_valid(), data(), size()).starts_with(__sv);2090  }2091 2092  [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool starts_with(value_type __c) const noexcept {2093    return !empty() && _Traits::eq(front(), __c);2094  }2095 2096  [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool2097  starts_with(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const noexcept {2098    return starts_with(__self_view(__s));2099  }2100 2101  // ends_with2102 2103  [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool ends_with(__self_view __sv) const noexcept {2104    return __self_view(typename __self_view::__assume_valid(), data(), size()).ends_with(__sv);2105  }2106 2107  [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool ends_with(value_type __c) const noexcept {2108    return !empty() && _Traits::eq(back(), __c);2109  }2110 2111  [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool2112  ends_with(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const noexcept {2113    return ends_with(__self_view(__s));2114  }2115#  endif2116 2117  // contains2118 2119#  if _LIBCPP_STD_VER >= 232120  [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool contains(__self_view __sv) const noexcept {2121    return __self_view(typename __self_view::__assume_valid(), data(), size()).contains(__sv);2122  }2123 2124  [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool contains(value_type __c) const noexcept {2125    return __self_view(typename __self_view::__assume_valid(), data(), size()).contains(__c);2126  }2127 2128  [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool2129  contains(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const {2130    return __self_view(typename __self_view::__assume_valid(), data(), size()).contains(__s);2131  }2132#  endif2133 2134  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __invariants() const;2135 2136private:2137  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS bool2138  __is_long() const _NOEXCEPT {2139    if (__libcpp_is_constant_evaluated() && __builtin_constant_p(__rep_.__l.__is_long_)) {2140      return __rep_.__l.__is_long_;2141    }2142    return __rep_.__s.__is_long_;2143  }2144 2145  _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI static bool __fits_in_sso(size_type __sz) { return __sz < __min_cap; }2146 2147  template <class _Iterator, class _Sentinel>2148  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void2149  __assign_trivial(_Iterator __first, _Sentinel __last, size_type __n);2150 2151  template <class _Iterator, class _Sentinel>2152  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __assign_with_sentinel(_Iterator __first, _Sentinel __last);2153 2154  // Copy [__first, __last) into [__dest, __dest + (__last - __first)). Assumes that the ranges don't overlap.2155  template <class _ForwardIter, class _Sent>2156  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static value_type*2157  __copy_non_overlapping_range(_ForwardIter __first, _Sent __last, value_type* __dest) {2158#  ifndef _LIBCPP_CXX03_LANG2159    if constexpr (__libcpp_is_contiguous_iterator<_ForwardIter>::value &&2160                  is_same<value_type, __remove_cvref_t<decltype(*__first)>>::value &&2161                  is_same<_ForwardIter, _Sent>::value) {2162      _LIBCPP_ASSERT_INTERNAL(2163          !std::__is_overlapping_range(std::__to_address(__first), std::__to_address(__last), __dest),2164          "__copy_non_overlapping_range called with an overlapping range!");2165      traits_type::copy(__dest, std::__to_address(__first), __last - __first);2166      return __dest + (__last - __first);2167    }2168#  endif2169 2170    for (; __first != __last; ++__first)2171      traits_type::assign(*__dest++, *__first);2172    return __dest;2173  }2174 2175  template <class _ForwardIterator, class _Sentinel>2176  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 iterator2177  __insert_from_safe_copy(size_type __n, size_type __ip, _ForwardIterator __first, _Sentinel __last) {2178    size_type __sz  = size();2179    size_type __cap = capacity();2180    value_type* __p;2181    if (__cap - __sz >= __n) {2182      __annotate_increase(__n);2183      __p                = std::__to_address(__get_pointer());2184      size_type __n_move = __sz - __ip;2185      if (__n_move != 0)2186        traits_type::move(__p + __ip + __n, __p + __ip, __n_move);2187    } else {2188      __grow_by_without_replace(__cap, __sz + __n - __cap, __sz, __ip, 0, __n);2189      __p = std::__to_address(__get_long_pointer());2190    }2191    __sz += __n;2192    __set_size(__sz);2193    traits_type::assign(__p[__sz], value_type());2194    __copy_non_overlapping_range(std::move(__first), std::move(__last), __p + __ip);2195 2196    return begin() + __ip;2197  }2198 2199  template <class _Iterator, class _Sentinel>2200  _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator2201  __insert_with_size(const_iterator __pos, _Iterator __first, _Sentinel __last, size_type __n);2202 2203  // internal buffer accessors2204  // -------------------------2205 2206  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS void2207  __set_short_size(size_type __s) _NOEXCEPT {2208    _LIBCPP_ASSERT_INTERNAL(__s < __min_cap, "__s should never be greater than or equal to the short string capacity");2209    __rep_.__s.__size_    = __s;2210    __rep_.__s.__is_long_ = false;2211  }2212 2213  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS size_type2214  __get_short_size() const _NOEXCEPT {2215    _LIBCPP_ASSERT_INTERNAL(!__rep_.__s.__is_long_, "String has to be short when trying to get the short size");2216    return __rep_.__s.__size_;2217  }2218 2219  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __set_long_size(size_type __s) _NOEXCEPT {2220    __rep_.__l.__size_ = __s;2221  }2222 2223  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type __get_long_size() const _NOEXCEPT {2224    _LIBCPP_ASSERT_INTERNAL(__rep_.__l.__is_long_, "String has to be long when trying to get the long size");2225    return __rep_.__l.__size_;2226  }2227 2228  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __set_size(size_type __s) _NOEXCEPT {2229    if (__is_long())2230      __set_long_size(__s);2231    else2232      __set_short_size(__s);2233  }2234 2235  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type __get_long_cap() const _NOEXCEPT {2236    _LIBCPP_ASSERT_INTERNAL(__rep_.__l.__is_long_, "String has to be long when trying to get the long capacity");2237    return __rep_.__l.__cap_ * __endian_factor;2238  }2239 2240  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pointer __get_long_pointer() _NOEXCEPT {2241    _LIBCPP_ASSERT_INTERNAL(__rep_.__l.__is_long_, "String has to be long when trying to get the long pointer");2242    return _LIBCPP_ASAN_VOLATILE_WRAPPER(__rep_.__l.__data_);2243  }2244 2245  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_pointer __get_long_pointer() const _NOEXCEPT {2246    _LIBCPP_ASSERT_INTERNAL(__rep_.__l.__is_long_, "String has to be long when trying to get the long pointer");2247    return _LIBCPP_ASAN_VOLATILE_WRAPPER(__rep_.__l.__data_);2248  }2249 2250  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS pointer2251  __get_short_pointer() _NOEXCEPT {2252    return _LIBCPP_ASAN_VOLATILE_WRAPPER(pointer_traits<pointer>::pointer_to(__rep_.__s.__data_[0]));2253  }2254 2255  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS const_pointer2256  __get_short_pointer() const _NOEXCEPT {2257    return _LIBCPP_ASAN_VOLATILE_WRAPPER(pointer_traits<const_pointer>::pointer_to(__rep_.__s.__data_[0]));2258  }2259 2260  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pointer __get_pointer() _NOEXCEPT {2261    return __is_long() ? __get_long_pointer() : __get_short_pointer();2262  }2263  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_pointer __get_pointer() const _NOEXCEPT {2264    return __is_long() ? __get_long_pointer() : __get_short_pointer();2265  }2266 2267  // Internal buffer management2268  // --------------------------2269  //2270  // These functions are only responsible for managing the buffer itself, not the value inside the buffer. As such,2271  // none of these facilities ensure that there is a null terminator at `data()[size()]`.2272 2273  // Allocate a buffer of __capacity size with __alloc and return it2274  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX20 __long2275  __allocate_long_buffer(_Allocator& __alloc, size_type __capacity) {2276    _LIBCPP_ASSERT_INTERNAL(!__fits_in_sso(__capacity),2277                            "Trying to allocate long buffer for a capacity what would fit into the small buffer");2278    auto __buffer = std::__allocate_at_least(__alloc, __align_allocation_size(__capacity));2279 2280    if (__libcpp_is_constant_evaluated()) {2281      for (size_type __i = 0; __i != __buffer.count; ++__i)2282        std::__construct_at(std::addressof(__buffer.ptr[__i]));2283    }2284 2285    return __long(__buffer, __capacity);2286  }2287 2288  // Replace the current buffer with __new_rep. Deallocate the old long buffer if it exists.2289  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __reset_internal_buffer(__rep __new_rep = __short()) {2290    __annotate_delete();2291    if (__is_long())2292      __alloc_traits::deallocate(__alloc_, __get_long_pointer(), __get_long_cap());2293    __rep_ = __new_rep;2294  }2295 2296  // Initialize the internal buffer to hold __size elements2297  // The elements and null terminator have to be set by the caller2298  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pointer __init_internal_buffer(size_type __size) {2299    if (__libcpp_is_constant_evaluated())2300      __rep_ = __rep();2301 2302    if (__size > max_size())2303      __throw_length_error();2304 2305    if (__fits_in_sso(__size)) {2306      __set_short_size(__size);2307      __annotate_new(__size);2308      return __get_short_pointer();2309    } else {2310      __rep_.__l = __allocate_long_buffer(__alloc_, __size);2311      __annotate_new(__size);2312      return __get_long_pointer();2313    }2314  }2315 2316  // ASan annotation helpers2317  // -----------------------2318 2319  // The following functions are no-ops outside of AddressSanitizer mode.2320  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void2321  __annotate_contiguous_container(const void* __old_mid, const void* __new_mid) const {2322    (void)__old_mid;2323    (void)__new_mid;2324#  if _LIBCPP_INSTRUMENTED_WITH_ASAN2325#    if defined(__APPLE__)2326    // TODO: remove after addressing issue #96099 (https://llvm.org/PR96099)2327    if (!__is_long())2328      return;2329#    endif2330    std::__annotate_contiguous_container<_Allocator>(data(), data() + capacity() + 1, __old_mid, __new_mid);2331#  endif2332  }2333 2334  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __annotate_new(size_type __current_size) const _NOEXCEPT {2335    __annotate_contiguous_container(data() + capacity() + 1, data() + __current_size + 1);2336  }2337 2338  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __annotate_delete() const _NOEXCEPT {2339    __annotate_contiguous_container(data() + size() + 1, data() + capacity() + 1);2340  }2341 2342  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __annotate_increase(size_type __n) const _NOEXCEPT {2343    __annotate_contiguous_container(data() + size() + 1, data() + size() + 1 + __n);2344  }2345 2346  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __annotate_shrink(size_type __old_size) const _NOEXCEPT {2347    __annotate_contiguous_container(data() + __old_size + 1, data() + size() + 1);2348  }2349 2350  // Disable ASan annotations and enable them again when going out of scope. It is assumed that the string is in a valid2351  // state at that point, so `size()` can be called safely.2352  struct [[__nodiscard__]] __annotation_guard {2353    __annotation_guard(const __annotation_guard&)            = delete;2354    __annotation_guard& operator=(const __annotation_guard&) = delete;2355 2356    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __annotation_guard(basic_string& __str) : __str_(__str) {2357      __str_.__annotate_delete();2358    }2359 2360    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 ~__annotation_guard() { __str_.__annotate_new(__str_.size()); }2361 2362    basic_string& __str_;2363  };2364 2365  template <size_type __a>2366  static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type __align_it(size_type __s) _NOEXCEPT {2367    return (__s + (__a - 1)) & ~(__a - 1);2368  }2369  enum { __alignment = 8 };2370 2371  // This makes sure that we're using a capacity with some extra alignment, since allocators almost always over-align2372  // the allocations anyways, improving memory usage. More importantly, this ensures that the lowest bit is never set2373  // if __endian_factor == 2, allowing us to store whether we're in the long string inside the lowest bit.2374  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type2375  __align_allocation_size(size_type __size) _NOEXCEPT {2376    _LIBCPP_ASSERT_INTERNAL(2377        !__fits_in_sso(__size), "Trying to align allocation of a size which would fit into the SSO");2378    const size_type __boundary = sizeof(value_type) < __alignment ? __alignment / sizeof(value_type) : __endian_factor;2379    size_type __guess          = __align_it<__boundary>(__size + 1);2380    if (__guess == __min_cap + 1)2381      __guess += __endian_factor;2382 2383    _LIBCPP_ASSERT_INTERNAL(__guess >= __size, "aligned allocation size is below the requested size");2384    return __guess;2385  }2386 2387  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type2388  __get_amortized_growth_capacity(size_type __required_capacity) {2389    size_type __max_size = max_size();2390    if (__required_capacity > __max_size)2391      __throw_length_error();2392    size_type __current_cap = capacity();2393    _LIBCPP_ASSERT_INTERNAL(2394        __current_cap < __required_capacity, "Trying to grow string even though there is enough capacity already?");2395    if (__current_cap > __max_size / 2 - __alignment)2396      return __max_size;2397    return std::max(__required_capacity, 2 * __current_cap);2398  }2399 2400  inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void __init(const value_type* __s, size_type __sz);2401  inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void __init(size_type __n, value_type __c);2402 2403  // Slow path for the (inlined) copy constructor for 'long' strings.2404  // Always externally instantiated and not inlined.2405  // Requires that __s is zero terminated.2406  // The main reason for this function to exist is because for unstable, we2407  // want to allow inlining of the copy constructor. However, we don't want2408  // to call the __init() functions as those are marked as inline which may2409  // result in over-aggressive inlining by the compiler, where our aim is2410  // to only inline the fast path code directly in the ctor.2411  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE void __init_copy_ctor_external(const value_type* __s, size_type __sz);2412 2413  template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>2414  inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void __init(_InputIterator __first, _InputIterator __last);2415 2416  template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>2417  inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void __init(_ForwardIterator __first, _ForwardIterator __last);2418 2419  template <class _InputIterator, class _Sentinel>2420  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void2421  __init_with_sentinel(_InputIterator __first, _Sentinel __last);2422  template <class _InputIterator, class _Sentinel>2423  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void2424  __init_with_size(_InputIterator __first, _Sentinel __last, size_type __sz);2425 2426  _LIBCPP_CONSTEXPR_SINCE_CXX202427#  if _LIBCPP_ABI_VERSION >= 2 //  We want to use the function in the dylib in ABIv12428  _LIBCPP_HIDE_FROM_ABI2429#  endif2430  _LIBCPP_DEPRECATED_("use __grow_by_without_replace") void __grow_by(2431      size_type __old_cap,2432      size_type __delta_cap,2433      size_type __old_sz,2434      size_type __n_copy,2435      size_type __n_del,2436      size_type __n_add = 0);2437  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __grow_by_without_replace(2438      size_type __old_cap,2439      size_type __delta_cap,2440      size_type __old_sz,2441      size_type __n_copy,2442      size_type __n_del,2443      size_type __n_add = 0);2444  _LIBCPP_CONSTEXPR_SINCE_CXX20 void __grow_by_and_replace(2445      size_type __old_cap,2446      size_type __delta_cap,2447      size_type __old_sz,2448      size_type __n_copy,2449      size_type __n_del,2450      size_type __n_add,2451      const value_type* __p_new_stuff);2452 2453  // __assign_no_alias is invoked for assignment operations where we2454  // have proof that the input does not alias the current instance.2455  // For example, operator=(basic_string) performs a 'self' check.2456  template <bool __is_short>2457  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string& __assign_no_alias(const value_type* __s, size_type __n);2458 2459  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __erase_to_end(size_type __pos) {2460    _LIBCPP_ASSERT_INTERNAL(__pos <= capacity(), "Trying to erase at position outside the strings capacity!");2461    __null_terminate_at(std::__to_address(__get_pointer()), __pos);2462  }2463 2464  // __erase_external_with_move is invoked for erase() invocations where2465  // `n ~= npos`, likely requiring memory moves on the string data.2466  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE void __erase_external_with_move(size_type __pos, size_type __n);2467 2468  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __copy_assign_alloc(const basic_string& __str) {2469    __copy_assign_alloc(2470        __str, integral_constant<bool, __alloc_traits::propagate_on_container_copy_assignment::value>());2471  }2472 2473  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __copy_assign_alloc(const basic_string& __str, true_type) {2474    if (__alloc_ == __str.__alloc_)2475      __alloc_ = __str.__alloc_;2476    else {2477      if (!__str.__is_long()) {2478        __reset_internal_buffer();2479        __alloc_ = __str.__alloc_;2480      } else {2481        __annotate_delete();2482        auto __guard = std::__make_scope_guard(__annotate_new_size(*this));2483        auto __alloc = __str.__alloc_;2484        __reset_internal_buffer(__allocate_long_buffer(__alloc, __str.size()));2485        __alloc_ = std::move(__alloc);2486      }2487    }2488  }2489 2490  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void2491  __copy_assign_alloc(const basic_string&, false_type) _NOEXCEPT {}2492 2493#  ifndef _LIBCPP_CXX03_LANG2494  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void2495  __move_assign(basic_string& __str, false_type) noexcept(__alloc_traits::is_always_equal::value);2496  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS void2497  __move_assign(basic_string& __str, true_type)2498#    if _LIBCPP_STD_VER >= 172499      noexcept;2500#    else2501      noexcept(is_nothrow_move_assignable<allocator_type>::value);2502#    endif2503#  endif2504 2505  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign_alloc(basic_string& __str)2506      _NOEXCEPT_(!__alloc_traits::propagate_on_container_move_assignment::value ||2507                 is_nothrow_move_assignable<allocator_type>::value) {2508    __move_assign_alloc(2509        __str, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());2510  }2511 2512  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign_alloc(basic_string& __c, true_type)2513      _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) {2514    __alloc_ = std::move(__c.__alloc_);2515  }2516 2517  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign_alloc(basic_string&, false_type) _NOEXCEPT {}2518 2519  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string& __assign_external(const value_type* __s);2520  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string& __assign_external(const value_type* __s, size_type __n);2521 2522  // Assigns the value in __s, guaranteed to be __n < __min_cap in length.2523  inline _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& __assign_short(const value_type* __s, size_type __n) {2524    size_type __old_size = size();2525    if (__n > __old_size)2526      __annotate_increase(__n - __old_size);2527    pointer __p;2528    if (__is_long()) {2529      __set_long_size(__n);2530      __p = __get_long_pointer();2531    } else {2532      __set_short_size(__n);2533      __p = __get_short_pointer();2534    }2535    traits_type::move(std::__to_address(__p), __s, __n);2536    traits_type::assign(__p[__n], value_type());2537    if (__old_size > __n)2538      __annotate_shrink(__old_size);2539    return *this;2540  }2541 2542  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&2543  __null_terminate_at(value_type* __p, size_type __newsz) {2544    size_type __old_size = size();2545    if (__newsz > __old_size)2546      __annotate_increase(__newsz - __old_size);2547    __set_size(__newsz);2548    traits_type::assign(__p[__newsz], value_type());2549    if (__old_size > __newsz)2550      __annotate_shrink(__old_size);2551    return *this;2552  }2553 2554  template <class _Tp>2555  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __addr_in_range(const _Tp& __v) const {2556    return std::__is_pointer_in_range(data(), data() + size() + 1, std::addressof(__v));2557  }2558 2559  [[__noreturn__]] _LIBCPP_HIDE_FROM_ABI static void __throw_length_error() {2560    std::__throw_length_error("basic_string");2561  }2562 2563  [[__noreturn__]] _LIBCPP_HIDE_FROM_ABI static void __throw_out_of_range() {2564    std::__throw_out_of_range("basic_string");2565  }2566 2567  friend _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string2568  __concatenate_strings<>(const _Allocator&, __type_identity_t<__self_view>, __type_identity_t<__self_view>);2569 2570  template <class _CharT2, class _Traits2, class _Allocator2>2571  friend inline _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool2572  operator==(const basic_string<_CharT2, _Traits2, _Allocator2>&, const _CharT2*) _NOEXCEPT;2573 2574  // These functions aren't used anymore but are part of out ABI, so we need to provide them in the dylib for backwards2575  // compatibility2576#  ifdef _LIBCPP_BUILDING_LIBRARY2577  void __init(const value_type* __s, size_type __sz, size_type __reserve);2578#  endif2579};2580 2581// These declarations must appear before any functions are implicitly used2582// so that they have the correct visibility specifier.2583#  define _LIBCPP_DECLARE(...) extern template _LIBCPP_EXPORTED_FROM_ABI __VA_ARGS__;2584#  ifdef _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION2585_LIBCPP_STRING_UNSTABLE_EXTERN_TEMPLATE_LIST(_LIBCPP_DECLARE, char)2586#    if _LIBCPP_HAS_WIDE_CHARACTERS2587_LIBCPP_STRING_UNSTABLE_EXTERN_TEMPLATE_LIST(_LIBCPP_DECLARE, wchar_t)2588#    endif2589#  else2590_LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST(_LIBCPP_DECLARE, char)2591#    if _LIBCPP_HAS_WIDE_CHARACTERS2592_LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST(_LIBCPP_DECLARE, wchar_t)2593#    endif2594#  endif2595#  undef _LIBCPP_DECLARE2596 2597#  if _LIBCPP_STD_VER <= 17 || !__has_builtin(__builtin_lt_synthesizes_from_spaceship)2598template <class _CharT, class _Traits, class _Alloc>2599struct __default_three_way_comparator<basic_string<_CharT, _Traits, _Alloc>, basic_string<_CharT, _Traits, _Alloc> > {2600  using __string_t _LIBCPP_NODEBUG = basic_string<_CharT, _Traits, _Alloc>;2601 2602  _LIBCPP_HIDE_FROM_ABI static int operator()(const __string_t& __lhs, const __string_t& __rhs) {2603    auto __min_len = std::min(__lhs.size(), __rhs.size());2604    auto __ret     = _Traits::compare(__lhs.data(), __rhs.data(), __min_len);2605    if (__ret == 0)2606      return __lhs.size() == __rhs.size() ? 0 : __lhs.size() < __rhs.size() ? -1 : 1;2607    return __ret;2608  }2609};2610#  endif2611 2612template <class _Comparator, class _CharT, class _Traits, class _Alloc>2613inline const bool __is_transparently_comparable_v<_Comparator,2614                                                  basic_string<_CharT, _Traits, _Alloc>,2615                                                  const _CharT*,2616                                                  __enable_if_t<__is_generic_transparent_comparator_v<_Comparator> > > =2617    true;2618 2619template <class _Comparator, class _CharT, class _Traits, class _Alloc, size_t _Np>2620inline const bool __is_transparently_comparable_v<_Comparator,2621                                                  basic_string<_CharT, _Traits, _Alloc>,2622                                                  _CharT[_Np],2623                                                  __enable_if_t<__is_generic_transparent_comparator_v<_Comparator> > > =2624    true;2625 2626#  if _LIBCPP_STD_VER >= 172627template <class _InputIterator,2628          class _CharT     = __iterator_value_type<_InputIterator>,2629          class _Allocator = allocator<_CharT>,2630          class            = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,2631          class            = enable_if_t<__is_allocator_v<_Allocator>>>2632basic_string(_InputIterator, _InputIterator, _Allocator = _Allocator())2633    -> basic_string<_CharT, char_traits<_CharT>, _Allocator>;2634 2635template <class _CharT,2636          class _Traits,2637          class _Allocator = allocator<_CharT>,2638          class            = enable_if_t<__is_allocator_v<_Allocator>>>2639explicit basic_string(basic_string_view<_CharT, _Traits>, const _Allocator& = _Allocator())2640    -> basic_string<_CharT, _Traits, _Allocator>;2641 2642template <class _CharT,2643          class _Traits,2644          class _Allocator = allocator<_CharT>,2645          class            = enable_if_t<__is_allocator_v<_Allocator>>,2646          class _Sz        = typename allocator_traits<_Allocator>::size_type >2647basic_string(basic_string_view<_CharT, _Traits>, _Sz, _Sz, const _Allocator& = _Allocator())2648    -> basic_string<_CharT, _Traits, _Allocator>;2649#  endif2650 2651#  if _LIBCPP_STD_VER >= 232652template <ranges::input_range _Range,2653          class _Allocator = allocator<ranges::range_value_t<_Range>>,2654          class            = enable_if_t<__is_allocator_v<_Allocator>>>2655basic_string(from_range_t, _Range&&, _Allocator = _Allocator())2656    -> basic_string<ranges::range_value_t<_Range>, char_traits<ranges::range_value_t<_Range>>, _Allocator>;2657#  endif2658 2659template <class _CharT, class _Traits, class _Allocator>2660_LIBCPP_CONSTEXPR_SINCE_CXX20 void2661basic_string<_CharT, _Traits, _Allocator>::__init(const value_type* __s, size_type __sz) {2662  pointer __p = __init_internal_buffer(__sz);2663  traits_type::copy(std::__to_address(__p), __s, __sz);2664  traits_type::assign(__p[__sz], value_type());2665}2666 2667template <class _CharT, class _Traits, class _Allocator>2668_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE void2669basic_string<_CharT, _Traits, _Allocator>::__init_copy_ctor_external(const value_type* __s, size_type __sz) {2670  pointer __p = __init_internal_buffer(__sz);2671  traits_type::copy(std::__to_address(__p), __s, __sz + 1);2672}2673 2674template <class _CharT, class _Traits, class _Allocator>2675_LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::__init(size_type __n, value_type __c) {2676  pointer __p = __init_internal_buffer(__n);2677  traits_type::assign(std::__to_address(__p), __n, __c);2678  traits_type::assign(__p[__n], value_type());2679}2680 2681template <class _CharT, class _Traits, class _Allocator>2682template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> >2683_LIBCPP_CONSTEXPR_SINCE_CXX20 void2684basic_string<_CharT, _Traits, _Allocator>::__init(_InputIterator __first, _InputIterator __last) {2685  __init_with_sentinel(std::move(__first), std::move(__last));2686}2687 2688template <class _CharT, class _Traits, class _Allocator>2689template <class _InputIterator, class _Sentinel>2690_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void2691basic_string<_CharT, _Traits, _Allocator>::__init_with_sentinel(_InputIterator __first, _Sentinel __last) {2692  __rep_ = __rep();2693  __annotate_new(0);2694 2695  auto __guard = std::__make_exception_guard([this] { __reset_internal_buffer(); });2696  for (; __first != __last; ++__first)2697    push_back(*__first);2698  __guard.__complete();2699}2700 2701template <class _CharT, class _Traits, class _Allocator>2702template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> >2703_LIBCPP_CONSTEXPR_SINCE_CXX20 void2704basic_string<_CharT, _Traits, _Allocator>::__init(_ForwardIterator __first, _ForwardIterator __last) {2705  size_type __sz = static_cast<size_type>(std::distance(__first, __last));2706  __init_with_size(__first, __last, __sz);2707}2708 2709template <class _CharT, class _Traits, class _Allocator>2710template <class _InputIterator, class _Sentinel>2711_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void2712basic_string<_CharT, _Traits, _Allocator>::__init_with_size(_InputIterator __first, _Sentinel __last, size_type __sz) {2713  pointer __p = __init_internal_buffer(__sz);2714 2715  auto __guard = std::__make_exception_guard([this] { __reset_internal_buffer(); });2716  auto __end   = __copy_non_overlapping_range(std::move(__first), std::move(__last), std::__to_address(__p));2717  traits_type::assign(*__end, value_type());2718  __guard.__complete();2719}2720 2721template <class _CharT, class _Traits, class _Allocator>2722_LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::__grow_by_and_replace(2723    size_type __old_cap,2724    size_type __delta_cap,2725    size_type __old_sz,2726    size_type __n_copy,2727    size_type __n_del,2728    size_type __n_add,2729    const value_type* __p_new_stuff) {2730  __long __buffer = __allocate_long_buffer(__alloc_, __get_amortized_growth_capacity(__old_cap + __delta_cap));2731  pointer __old_p = __get_pointer();2732  __annotate_delete();2733  auto __guard = std::__make_scope_guard(__annotate_new_size(*this));2734  if (__n_copy != 0)2735    traits_type::copy(std::__to_address(__buffer.__data_), std::__to_address(__old_p), __n_copy);2736  if (__n_add != 0)2737    traits_type::copy(std::__to_address(__buffer.__data_) + __n_copy, __p_new_stuff, __n_add);2738  size_type __sec_cp_sz = __old_sz - __n_del - __n_copy;2739  if (__sec_cp_sz != 0)2740    traits_type::copy(std::__to_address(__buffer.__data_) + __n_copy + __n_add,2741                      std::__to_address(__old_p) + __n_copy + __n_del,2742                      __sec_cp_sz);2743  __buffer.__size_ = __n_copy + __n_add + __sec_cp_sz;2744  traits_type::assign(__buffer.__data_[__buffer.__size_], value_type());2745  __reset_internal_buffer(__buffer);2746}2747 2748// __grow_by is deprecated because it does not set the size. It may not update the size when the size is changed, and it2749// may also not set the size at all when the string was short initially. This leads to unpredictable size value. It is2750// not removed or changed to avoid breaking the ABI.2751template <class _CharT, class _Traits, class _Allocator>2752void _LIBCPP_CONSTEXPR_SINCE_CXX202753#  if _LIBCPP_ABI_VERSION >= 2 // We want to use the function in the dylib in ABIv12754_LIBCPP_HIDE_FROM_ABI2755#  endif2756_LIBCPP_DEPRECATED_("use __grow_by_without_replace") basic_string<_CharT, _Traits, _Allocator>::__grow_by(2757    size_type __old_cap,2758    size_type __delta_cap,2759    size_type __old_sz,2760    size_type __n_copy,2761    size_type __n_del,2762    size_type __n_add) {2763  __long __buffer = __allocate_long_buffer(__alloc_, __get_amortized_growth_capacity(__old_cap + __delta_cap));2764  pointer __old_p = __get_pointer();2765  if (__n_copy != 0)2766    traits_type::copy(std::__to_address(__buffer.__data_), std::__to_address(__old_p), __n_copy);2767  size_type __sec_cp_sz = __old_sz - __n_del - __n_copy;2768  if (__sec_cp_sz != 0)2769    traits_type::copy(std::__to_address(__buffer.__data_) + __n_copy + __n_add,2770                      std::__to_address(__old_p) + __n_copy + __n_del,2771                      __sec_cp_sz);2772 2773  // This is -1 to make sure the caller sets the size properly, since old versions of this function didn't set the size2774  // at all.2775  __buffer.__size_ = -1;2776  __reset_internal_buffer(__buffer);2777}2778 2779template <class _CharT, class _Traits, class _Allocator>2780void _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI2781basic_string<_CharT, _Traits, _Allocator>::__grow_by_without_replace(2782    size_type __old_cap,2783    size_type __delta_cap,2784    size_type __old_sz,2785    size_type __n_copy,2786    size_type __n_del,2787    size_type __n_add) {2788  __annotate_delete();2789  auto __guard = std::__make_scope_guard(__annotate_new_size(*this));2790  _LIBCPP_SUPPRESS_DEPRECATED_PUSH2791  __grow_by(__old_cap, __delta_cap, __old_sz, __n_copy, __n_del, __n_add);2792  _LIBCPP_SUPPRESS_DEPRECATED_POP2793  // Due to the ABI of __grow_by we have to set the size after calling it.2794  __set_long_size(__old_sz - __n_del + __n_add);2795}2796 2797// assign2798 2799template <class _CharT, class _Traits, class _Allocator>2800template <bool __is_short>2801_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string<_CharT, _Traits, _Allocator>&2802basic_string<_CharT, _Traits, _Allocator>::__assign_no_alias(const value_type* __s, size_type __n) {2803  const auto __cap  = __is_short ? static_cast<size_type>(__min_cap) : __get_long_cap();2804  const auto __size = __is_short ? __get_short_size() : __get_long_size();2805  if (__n >= __cap) {2806    __grow_by_and_replace(__cap - 1, __n - __cap + 1, __size, 0, __size, __n, __s);2807    return *this;2808  }2809 2810  __annotate_delete();2811  auto __guard = std::__make_scope_guard(__annotate_new_size(*this));2812  pointer __p;2813  if (__is_short) {2814    __p = __get_short_pointer();2815    __set_short_size(__n);2816  } else {2817    __p = __get_long_pointer();2818    __set_long_size(__n);2819  }2820  traits_type::copy(std::__to_address(__p), __s, __n);2821  traits_type::assign(__p[__n], value_type());2822  return *this;2823}2824 2825template <class _CharT, class _Traits, class _Allocator>2826_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string<_CharT, _Traits, _Allocator>&2827basic_string<_CharT, _Traits, _Allocator>::__assign_external(const value_type* __s, size_type __n) {2828  const auto __cap  = capacity();2829  const auto __size = size();2830  if (__cap >= __n) {2831    if (__n > __size)2832      __annotate_increase(__n - __size);2833    value_type* __p = std::__to_address(__get_pointer());2834    traits_type::move(__p, __s, __n);2835    return __null_terminate_at(__p, __n);2836  } else {2837    __grow_by_and_replace(__cap, __n - __cap, __size, 0, __size, __n, __s);2838    return *this;2839  }2840}2841 2842template <class _CharT, class _Traits, class _Allocator>2843_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&2844basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s, size_type __n) {2845  _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::assign received nullptr");2846  return (__builtin_constant_p(__n) && __fits_in_sso(__n)) ? __assign_short(__s, __n) : __assign_external(__s, __n);2847}2848 2849template <class _CharT, class _Traits, class _Allocator>2850_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&2851basic_string<_CharT, _Traits, _Allocator>::assign(size_type __n, value_type __c) {2852  size_type __cap      = capacity();2853  size_type __old_size = size();2854  if (__cap < __n) {2855    __grow_by_without_replace(__cap, __n - __cap, __old_size, 0, __old_size);2856    __annotate_increase(__n);2857  } else if (__n > __old_size)2858    __annotate_increase(__n - __old_size);2859  value_type* __p = std::__to_address(__get_pointer());2860  traits_type::assign(__p, __n, __c);2861  return __null_terminate_at(__p, __n);2862}2863 2864template <class _CharT, class _Traits, class _Allocator>2865_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&2866basic_string<_CharT, _Traits, _Allocator>::operator=(value_type __c) {2867  size_type __old_size = size();2868  if (__old_size == 0)2869    __annotate_increase(1);2870  pointer __p;2871  if (__is_long()) {2872    __p = __get_long_pointer();2873    __set_long_size(1);2874  } else {2875    __p = __get_short_pointer();2876    __set_short_size(1);2877  }2878  traits_type::assign(*__p, __c);2879  traits_type::assign(*++__p, value_type());2880  if (__old_size > 1)2881    __annotate_shrink(__old_size);2882  return *this;2883}2884 2885template <class _CharT, class _Traits, class _Allocator>2886_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS basic_string<_CharT, _Traits, _Allocator>&2887basic_string<_CharT, _Traits, _Allocator>::operator=(const basic_string& __str) {2888  if (this == std::addressof(__str))2889    return *this;2890 2891  __copy_assign_alloc(__str);2892 2893  if (__is_long())2894    return __assign_no_alias<false>(__str.data(), __str.size());2895 2896  if (__str.__is_long())2897    return __assign_no_alias<true>(__str.data(), __str.size());2898 2899  __annotate_delete();2900  auto __guard = std::__make_scope_guard(__annotate_new_size(*this));2901  __rep_       = __str.__rep_;2902 2903  return *this;2904}2905 2906#  ifndef _LIBCPP_CXX03_LANG2907 2908template <class _CharT, class _Traits, class _Allocator>2909inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::__move_assign(2910    basic_string& __str, false_type) noexcept(__alloc_traits::is_always_equal::value) {2911  if (__alloc_ != __str.__alloc_)2912    assign(__str);2913  else2914    __move_assign(__str, true_type());2915}2916 2917template <class _CharT, class _Traits, class _Allocator>2918inline _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS void2919basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, true_type)2920#    if _LIBCPP_STD_VER >= 172921    noexcept2922#    else2923    noexcept(is_nothrow_move_assignable<allocator_type>::value)2924#    endif2925{2926  __annotate_delete();2927  if (__is_long()) {2928    __reset_internal_buffer();2929#    if _LIBCPP_STD_VER <= 142930    if (!is_nothrow_move_assignable<allocator_type>::value) {2931      __set_short_size(0);2932      traits_type::assign(__get_short_pointer()[0], value_type());2933      __annotate_new(0);2934    }2935#    endif2936  }2937  size_type __str_old_size = __str.size();2938  bool __str_was_short     = !__str.__is_long();2939 2940  __move_assign_alloc(__str);2941  __rep_ = __str.__rep_;2942  __str.__set_short_size(0);2943  traits_type::assign(__str.__get_short_pointer()[0], value_type());2944 2945  if (__str_was_short && this != std::addressof(__str))2946    __str.__annotate_shrink(__str_old_size);2947  else2948    // ASan annotations: was long, so object memory is unpoisoned as new.2949    // Or is same as *this, and __annotate_delete() was called.2950    __str.__annotate_new(0);2951 2952  // ASan annotations: Guard against `std::string s; s = std::move(s);`2953  // You can find more here: https://en.cppreference.com/w/cpp/utility/move2954  // Quote: "Unless otherwise specified, all standard library objects that have been moved2955  // from are placed in a "valid but unspecified state", meaning the object's class2956  // invariants hold (so functions without preconditions, such as the assignment operator,2957  // can be safely used on the object after it was moved from):"2958  // Quote: "v = std::move(v); // the value of v is unspecified"2959  if (!__is_long() && std::addressof(__str) != this)2960    // If it is long string, delete was never called on original __str's buffer.2961    __annotate_new(__get_short_size());2962}2963 2964#  endif2965 2966template <class _CharT, class _Traits, class _Allocator>2967template <class _InputIterator, class _Sentinel>2968_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void2969basic_string<_CharT, _Traits, _Allocator>::__assign_with_sentinel(_InputIterator __first, _Sentinel __last) {2970  const basic_string __temp(__init_with_sentinel_tag(), std::move(__first), std::move(__last), __alloc_);2971  assign(__temp.data(), __temp.size());2972}2973 2974template <class _CharT, class _Traits, class _Allocator>2975template <class _Iterator, class _Sentinel>2976_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void2977basic_string<_CharT, _Traits, _Allocator>::__assign_trivial(_Iterator __first, _Sentinel __last, size_type __n) {2978  _LIBCPP_ASSERT_INTERNAL(2979      __string_is_trivial_iterator_v<_Iterator>, "The iterator type given to `__assign_trivial` must be trivial");2980 2981  size_type __old_size = size();2982  size_type __cap      = capacity();2983  if (__cap < __n) {2984    // Unlike `append` functions, if the input range points into the string itself, there is no case that the input2985    // range could get invalidated by reallocation:2986    // 1. If the input range is a subset of the string itself, its size cannot exceed the capacity of the string,2987    //    thus no reallocation would happen.2988    // 2. In the exotic case where the input range is the byte representation of the string itself, the string2989    //    object itself stays valid even if reallocation happens.2990    size_type __sz = size();2991    __grow_by_without_replace(__cap, __n - __cap, __sz, 0, __sz);2992    __annotate_increase(__n);2993  } else if (__n > __old_size)2994    __annotate_increase(__n - __old_size);2995  pointer __p = __get_pointer();2996  for (; __first != __last; ++__p, (void)++__first)2997    traits_type::assign(*__p, *__first);2998  traits_type::assign(*__p, value_type());2999  __set_size(__n);3000  if (__n < __old_size)3001    __annotate_shrink(__old_size);3002}3003 3004template <class _CharT, class _Traits, class _Allocator>3005_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3006basic_string<_CharT, _Traits, _Allocator>::assign(const basic_string& __str, size_type __pos, size_type __n) {3007  size_type __sz = __str.size();3008  if (__pos > __sz)3009    this->__throw_out_of_range();3010  return assign(__str.data() + __pos, std::min(__n, __sz - __pos));3011}3012 3013template <class _CharT, class _Traits, class _Allocator>3014_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string<_CharT, _Traits, _Allocator>&3015basic_string<_CharT, _Traits, _Allocator>::__assign_external(const value_type* __s) {3016  return __assign_external(__s, traits_type::length(__s));3017}3018 3019template <class _CharT, class _Traits, class _Allocator>3020_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3021basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s) {3022  _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::assign received nullptr");3023  if (auto __len = traits_type::length(__s); __builtin_constant_p(__len) && __fits_in_sso(__len))3024    return __assign_short(__s, __len);3025  return __assign_external(__s);3026}3027// append3028 3029template <class _CharT, class _Traits, class _Allocator>3030_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3031basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s, size_type __n) {3032  _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::append received nullptr");3033  size_type __cap = capacity();3034  size_type __sz  = size();3035  if (__cap - __sz < __n) {3036    __grow_by_and_replace(__cap, __sz + __n - __cap, __sz, __sz, 0, __n, __s);3037    return *this;3038  }3039 3040  if (__n == 0)3041    return *this;3042 3043  __annotate_increase(__n);3044  value_type* __p = std::__to_address(__get_pointer());3045  traits_type::copy(__p + __sz, __s, __n);3046  __sz += __n;3047  __set_size(__sz);3048  traits_type::assign(__p[__sz], value_type());3049  return *this;3050}3051 3052template <class _CharT, class _Traits, class _Allocator>3053_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3054basic_string<_CharT, _Traits, _Allocator>::append(size_type __n, value_type __c) {3055  if (__n == 0)3056    return *this;3057 3058  size_type __cap = capacity();3059  size_type __sz  = size();3060  if (__cap - __sz < __n)3061    __grow_by_without_replace(__cap, __sz + __n - __cap, __sz, __sz, 0);3062  __annotate_increase(__n);3063  pointer __p = __get_pointer();3064  traits_type::assign(std::__to_address(__p) + __sz, __n, __c);3065  __sz += __n;3066  __set_size(__sz);3067  traits_type::assign(__p[__sz], value_type());3068  return *this;3069}3070 3071template <class _CharT, class _Traits, class _Allocator>3072_LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::push_back(value_type __c) {3073  bool __is_short = !__is_long();3074  size_type __cap;3075  size_type __sz;3076  if (__is_short) {3077    __cap = __min_cap - 1;3078    __sz  = __get_short_size();3079  } else {3080    __cap = __get_long_cap() - 1;3081    __sz  = __get_long_size();3082  }3083  if (__sz == __cap) {3084    __grow_by_without_replace(__cap, 1, __sz, __sz, 0);3085    __is_short = false; // the string is always long after __grow_by3086  }3087  __annotate_increase(1);3088  pointer __p;3089  if (__is_short) {3090    __p = __get_short_pointer() + __sz;3091    __set_short_size(__sz + 1);3092  } else {3093    __p = __get_long_pointer() + __sz;3094    __set_long_size(__sz + 1);3095  }3096  traits_type::assign(*__p, __c);3097  traits_type::assign(*++__p, value_type());3098}3099 3100template <class _CharT, class _Traits, class _Allocator>3101_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3102basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str, size_type __pos, size_type __n) {3103  size_type __sz = __str.size();3104  if (__pos > __sz)3105    this->__throw_out_of_range();3106  return append(__str.data() + __pos, std::min(__n, __sz - __pos));3107}3108 3109template <class _CharT, class _Traits, class _Allocator>3110_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3111basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s) {3112  _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::append received nullptr");3113  return append(__s, traits_type::length(__s));3114}3115 3116// insert3117 3118template <class _CharT, class _Traits, class _Allocator>3119_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3120basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s, size_type __n) {3121  _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::insert received nullptr");3122  size_type __sz = size();3123  if (__pos > __sz)3124    this->__throw_out_of_range();3125  size_type __cap = capacity();3126 3127  if (__cap - __sz < __n) {3128    __grow_by_and_replace(__cap, __sz + __n - __cap, __sz, __pos, 0, __n, __s);3129    return *this;3130  }3131 3132  if (__n == 0)3133    return *this;3134 3135  __annotate_increase(__n);3136  value_type* __p    = std::__to_address(__get_pointer());3137  size_type __n_move = __sz - __pos;3138  if (__n_move != 0) {3139    if (std::__is_pointer_in_range(__p + __pos, __p + __sz, __s))3140      __s += __n;3141    traits_type::move(__p + __pos + __n, __p + __pos, __n_move);3142  }3143  traits_type::move(__p + __pos, __s, __n);3144  __sz += __n;3145  __set_size(__sz);3146  traits_type::assign(__p[__sz], value_type());3147  return *this;3148}3149 3150template <class _CharT, class _Traits, class _Allocator>3151_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3152basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, size_type __n, value_type __c) {3153  size_type __sz = size();3154  if (__pos > __sz)3155    this->__throw_out_of_range();3156 3157  if (__n == 0)3158    return *this;3159 3160  size_type __cap = capacity();3161  value_type* __p;3162  if (__cap - __sz >= __n) {3163    __annotate_increase(__n);3164    __p                = std::__to_address(__get_pointer());3165    size_type __n_move = __sz - __pos;3166    if (__n_move != 0)3167      traits_type::move(__p + __pos + __n, __p + __pos, __n_move);3168  } else {3169    __grow_by_without_replace(__cap, __sz + __n - __cap, __sz, __pos, 0, __n);3170    __p = std::__to_address(__get_long_pointer());3171  }3172  traits_type::assign(__p + __pos, __n, __c);3173  __sz += __n;3174  __set_size(__sz);3175  traits_type::assign(__p[__sz], value_type());3176  return *this;3177}3178 3179template <class _CharT, class _Traits, class _Allocator>3180template <class _Iterator, class _Sentinel>3181_LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::iterator3182basic_string<_CharT, _Traits, _Allocator>::__insert_with_size(3183    const_iterator __pos, _Iterator __first, _Sentinel __last, size_type __n) {3184  size_type __ip = static_cast<size_type>(__pos - begin());3185  if (__n == 0)3186    return begin() + __ip;3187 3188  if (__string_is_trivial_iterator_v<_Iterator> && !__addr_in_range(*__first)) {3189    return __insert_from_safe_copy(__n, __ip, std::move(__first), std::move(__last));3190  } else {3191    const basic_string __temp(__init_with_sentinel_tag(), std::move(__first), std::move(__last), __alloc_);3192    return __insert_from_safe_copy(__n, __ip, __temp.begin(), __temp.end());3193  }3194}3195 3196template <class _CharT, class _Traits, class _Allocator>3197_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3198basic_string<_CharT, _Traits, _Allocator>::insert(3199    size_type __pos1, const basic_string& __str, size_type __pos2, size_type __n) {3200  size_type __str_sz = __str.size();3201  if (__pos2 > __str_sz)3202    this->__throw_out_of_range();3203  return insert(__pos1, __str.data() + __pos2, std::min(__n, __str_sz - __pos2));3204}3205 3206template <class _CharT, class _Traits, class _Allocator>3207_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3208basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s) {3209  _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::insert received nullptr");3210  return insert(__pos, __s, traits_type::length(__s));3211}3212 3213template <class _CharT, class _Traits, class _Allocator>3214_LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::iterator3215basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, value_type __c) {3216  size_type __ip  = static_cast<size_type>(__pos - begin());3217  size_type __sz  = size();3218  size_type __cap = capacity();3219  value_type* __p;3220  if (__cap == __sz) {3221    __grow_by_without_replace(__cap, 1, __sz, __ip, 0, 1);3222    __p = std::__to_address(__get_long_pointer());3223  } else {3224    __annotate_increase(1);3225    __p                = std::__to_address(__get_pointer());3226    size_type __n_move = __sz - __ip;3227    if (__n_move != 0)3228      traits_type::move(__p + __ip + 1, __p + __ip, __n_move);3229  }3230  traits_type::assign(__p[__ip], __c);3231  traits_type::assign(__p[++__sz], value_type());3232  __set_size(__sz);3233  return begin() + static_cast<difference_type>(__ip);3234}3235 3236// replace3237 3238template <class _CharT, class _Traits, class _Allocator>3239_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3240basic_string<_CharT, _Traits, _Allocator>::replace(3241    size_type __pos, size_type __n1, const value_type* __s, size_type __n2)3242    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK {3243  _LIBCPP_ASSERT_NON_NULL(__n2 == 0 || __s != nullptr, "string::replace received nullptr");3244  size_type __sz = size();3245  if (__pos > __sz)3246    this->__throw_out_of_range();3247  __n1            = std::min(__n1, __sz - __pos);3248  size_type __cap = capacity();3249  if (__cap - __sz + __n1 < __n2) {3250    __grow_by_and_replace(__cap, __sz - __n1 + __n2 - __cap, __sz, __pos, __n1, __n2, __s);3251    return *this;3252  }3253 3254  value_type* __p = std::__to_address(__get_pointer());3255  if (__n1 != __n2) {3256    if (__n2 > __n1)3257      __annotate_increase(__n2 - __n1);3258    size_type __n_move = __sz - __pos - __n1;3259    if (__n_move != 0) {3260      if (__n1 > __n2) {3261        traits_type::move(__p + __pos, __s, __n2);3262        traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);3263        return __null_terminate_at(__p, __sz + (__n2 - __n1));3264      }3265      if (std::__is_pointer_in_range(__p + __pos + 1, __p + __sz, __s)) {3266        if (__p + __pos + __n1 <= __s) {3267          __s += __n2 - __n1;3268        } else { // __p + __pos < __s < __p + __pos + __n13269          traits_type::move(__p + __pos, __s, __n1);3270          __pos += __n1;3271          __s += __n2;3272          __n2 -= __n1;3273          __n1 = 0;3274        }3275      }3276      traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);3277    }3278  }3279  traits_type::move(__p + __pos, __s, __n2);3280  return __null_terminate_at(__p, __sz + (__n2 - __n1));3281}3282 3283template <class _CharT, class _Traits, class _Allocator>3284_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3285basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, size_type __n2, value_type __c) {3286  size_type __sz = size();3287  if (__pos > __sz)3288    this->__throw_out_of_range();3289  __n1            = std::min(__n1, __sz - __pos);3290  size_type __cap = capacity();3291  value_type* __p;3292  if (__cap - __sz + __n1 >= __n2) {3293    __p = std::__to_address(__get_pointer());3294    if (__n1 != __n2) {3295      if (__n2 > __n1)3296        __annotate_increase(__n2 - __n1);3297      size_type __n_move = __sz - __pos - __n1;3298      if (__n_move != 0)3299        traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);3300    }3301  } else {3302    __grow_by_without_replace(__cap, __sz - __n1 + __n2 - __cap, __sz, __pos, __n1, __n2);3303    __p = std::__to_address(__get_long_pointer());3304  }3305  traits_type::assign(__p + __pos, __n2, __c);3306  return __null_terminate_at(__p, __sz - (__n1 - __n2));3307}3308 3309template <class _CharT, class _Traits, class _Allocator>3310_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3311basic_string<_CharT, _Traits, _Allocator>::replace(3312    size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2) {3313  size_type __str_sz = __str.size();3314  if (__pos2 > __str_sz)3315    this->__throw_out_of_range();3316  return replace(__pos1, __n1, __str.data() + __pos2, std::min(__n2, __str_sz - __pos2));3317}3318 3319template <class _CharT, class _Traits, class _Allocator>3320_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3321basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s) {3322  _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::replace received nullptr");3323  return replace(__pos, __n1, __s, traits_type::length(__s));3324}3325 3326// erase3327 3328// 'externally instantiated' erase() implementation, called when __n != npos.3329// Does not check __pos against size()3330template <class _CharT, class _Traits, class _Allocator>3331_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE void3332basic_string<_CharT, _Traits, _Allocator>::__erase_external_with_move(size_type __pos, size_type __n) {3333  if (__n == 0)3334    return;3335 3336  size_type __sz     = size();3337  value_type* __p    = std::__to_address(__get_pointer());3338  __n                = std::min(__n, __sz - __pos);3339  size_type __n_move = __sz - __pos - __n;3340  if (__n_move != 0)3341    traits_type::move(__p + __pos, __p + __pos + __n, __n_move);3342  __null_terminate_at(__p, __sz - __n);3343}3344 3345template <class _CharT, class _Traits, class _Allocator>3346_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&3347basic_string<_CharT, _Traits, _Allocator>::erase(size_type __pos, size_type __n) {3348  if (__pos > size())3349    this->__throw_out_of_range();3350  if (__n == npos) {3351    __erase_to_end(__pos);3352  } else {3353    __erase_external_with_move(__pos, __n);3354  }3355  return *this;3356}3357 3358template <class _CharT, class _Traits, class _Allocator>3359inline _LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::iterator3360basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __pos) {3361  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(3362      __pos != end(), "string::erase(iterator) called with a non-dereferenceable iterator");3363  iterator __b  = begin();3364  size_type __r = static_cast<size_type>(__pos - __b);3365  erase(__r, 1);3366  return __b + static_cast<difference_type>(__r);3367}3368 3369template <class _CharT, class _Traits, class _Allocator>3370inline _LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::iterator3371basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __first, const_iterator __last) {3372  _LIBCPP_ASSERT_VALID_INPUT_RANGE(__first <= __last, "string::erase(first, last) called with invalid range");3373  iterator __b  = begin();3374  size_type __r = static_cast<size_type>(__first - __b);3375  erase(__r, static_cast<size_type>(__last - __first));3376  return __b + static_cast<difference_type>(__r);3377}3378 3379template <class _CharT, class _Traits, class _Allocator>3380inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::pop_back() {3381  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string::pop_back(): string is already empty");3382  __erase_to_end(size() - 1);3383}3384 3385template <class _CharT, class _Traits, class _Allocator>3386inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::clear() _NOEXCEPT {3387  size_type __old_size;3388  if (__is_long()) {3389    __old_size = __get_long_size();3390    traits_type::assign(*__get_long_pointer(), value_type());3391    __set_long_size(0);3392  } else {3393    __old_size = __get_short_size();3394    traits_type::assign(*__get_short_pointer(), value_type());3395    __set_short_size(0);3396  }3397  __annotate_shrink(__old_size);3398}3399 3400template <class _CharT, class _Traits, class _Allocator>3401_LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::resize(size_type __n, value_type __c) {3402  size_type __sz = size();3403  if (__n > __sz)3404    append(__n - __sz, __c);3405  else3406    __erase_to_end(__n);3407}3408 3409template <class _CharT, class _Traits, class _Allocator>3410_LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::reserve(size_type __requested_capacity) {3411  if (__requested_capacity > max_size())3412    this->__throw_length_error();3413 3414  // Make sure reserve(n) never shrinks. This is technically only required in C++203415  // and later (since P0966R1), however we provide consistent behavior in all Standard3416  // modes because this function is instantiated in the shared library.3417  if (__requested_capacity <= capacity())3418    return;3419 3420  __annotation_guard __g(*this);3421  __long __buffer  = __allocate_long_buffer(__alloc_, __requested_capacity);3422  __buffer.__size_ = size();3423  traits_type::copy(std::__to_address(__buffer.__data_), data(), __buffer.__size_ + 1);3424  __reset_internal_buffer(__buffer);3425}3426 3427template <class _CharT, class _Traits, class _Allocator>3428inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::shrink_to_fit() _NOEXCEPT {3429  if (!__is_long())3430    return;3431 3432  const auto __ptr  = __get_long_pointer();3433  const auto __size = __get_long_size();3434  const auto __cap  = __get_long_cap();3435 3436  // We're a long string and we're shrinking into the small buffer.3437  if (__fits_in_sso(__size)) {3438    __annotation_guard __g(*this);3439    __set_short_size(__size);3440    traits_type::copy(std::__to_address(__get_short_pointer()), std::__to_address(__ptr), __size + 1);3441    __alloc_traits::deallocate(__alloc_, __ptr, __cap);3442    return;3443  }3444 3445  if (__align_allocation_size(__size) == __cap)3446    return;3447 3448#  if _LIBCPP_HAS_EXCEPTIONS3449  try {3450#  endif // _LIBCPP_HAS_EXCEPTIONS3451    __annotation_guard __g(*this);3452    __long __buffer = __allocate_long_buffer(__alloc_, __size);3453 3454    // The Standard mandates shrink_to_fit() does not increase the capacity.3455    // With equal capacity keep the existing buffer. This avoids extra work3456    // due to swapping the elements.3457    if (__buffer.__cap_ * __endian_factor - 1 >= capacity()) {3458      __alloc_traits::deallocate(__alloc_, __buffer.__data_, __buffer.__cap_ * __endian_factor);3459      return;3460    }3461 3462    traits_type::copy(std::__to_address(__buffer.__data_), std::__to_address(__get_long_pointer()), __size + 1);3463    __reset_internal_buffer(__buffer);3464#  if _LIBCPP_HAS_EXCEPTIONS3465  } catch (...) {3466    return;3467  }3468#  endif // _LIBCPP_HAS_EXCEPTIONS3469}3470 3471template <class _CharT, class _Traits, class _Allocator>3472_LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::const_reference3473basic_string<_CharT, _Traits, _Allocator>::at(size_type __n) const {3474  if (__n >= size())3475    this->__throw_out_of_range();3476  return (*this)[__n];3477}3478 3479template <class _CharT, class _Traits, class _Allocator>3480_LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::reference3481basic_string<_CharT, _Traits, _Allocator>::at(size_type __n) {3482  if (__n >= size())3483    this->__throw_out_of_range();3484  return (*this)[__n];3485}3486 3487template <class _CharT, class _Traits, class _Allocator>3488_LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::size_type3489basic_string<_CharT, _Traits, _Allocator>::copy(value_type* __s, size_type __n, size_type __pos) const {3490  size_type __sz = size();3491  if (__pos > __sz)3492    this->__throw_out_of_range();3493  size_type __rlen = std::min(__n, __sz - __pos);3494  traits_type::copy(__s, data() + __pos, __rlen);3495  return __rlen;3496}3497 3498template <class _CharT, class _Traits, class _Allocator>3499inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::swap(basic_string& __str)3500#  if _LIBCPP_STD_VER >= 143501    _NOEXCEPT3502#  else3503    _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable_v<allocator_type>)3504#  endif3505{3506  _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(3507      __alloc_traits::propagate_on_container_swap::value || __alloc_traits::is_always_equal::value ||3508          __alloc_ == __str.__alloc_,3509      "swapping non-equal allocators");3510  if (!__is_long())3511    __annotate_delete();3512  if (this != std::addressof(__str) && !__str.__is_long())3513    __str.__annotate_delete();3514  std::swap(__rep_, __str.__rep_);3515  std::__swap_allocator(__alloc_, __str.__alloc_);3516  if (!__is_long())3517    __annotate_new(__get_short_size());3518  if (this != std::addressof(__str) && !__str.__is_long())3519    __str.__annotate_new(__str.__get_short_size());3520}3521 3522// compare3523 3524template <class _CharT, class _Traits, class _Allocator>3525inline _LIBCPP_CONSTEXPR_SINCE_CXX20 int basic_string<_CharT, _Traits, _Allocator>::compare(3526    size_type __pos1, size_type __n1, const value_type* __s, size_type __n2) const {3527  _LIBCPP_ASSERT_NON_NULL(__n2 == 0 || __s != nullptr, "string::compare(): received nullptr");3528  size_type __sz = size();3529  if (__pos1 > __sz || __n2 == npos)3530    this->__throw_out_of_range();3531  size_type __rlen = std::min(__n1, __sz - __pos1);3532  int __r          = traits_type::compare(data() + __pos1, __s, std::min(__rlen, __n2));3533  if (__r == 0) {3534    if (__rlen < __n2)3535      __r = -1;3536    else if (__rlen > __n2)3537      __r = 1;3538  }3539  return __r;3540}3541 3542// __invariants3543 3544template <class _CharT, class _Traits, class _Allocator>3545inline _LIBCPP_CONSTEXPR_SINCE_CXX20 bool basic_string<_CharT, _Traits, _Allocator>::__invariants() const {3546  if (size() > capacity())3547    return false;3548  if (capacity() < __min_cap - 1)3549    return false;3550  if (data() == nullptr)3551    return false;3552  if (!_Traits::eq(data()[size()], value_type()))3553    return false;3554  return true;3555}3556 3557// operator==3558 3559template <class _CharT, class _Traits, class _Allocator>3560inline _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool3561operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs,3562           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3563  size_t __lhs_sz = __lhs.size();3564  return __lhs_sz == __rhs.size() && _Traits::compare(__lhs.data(), __rhs.data(), __lhs_sz) == 0;3565}3566 3567template <class _CharT, class _Traits, class _Allocator>3568inline _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool3569operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs,3570           const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __rhs) _NOEXCEPT {3571  _LIBCPP_ASSERT_NON_NULL(__rhs != nullptr, "operator==(basic_string, char*): received nullptr");3572 3573  using _String = basic_string<_CharT, _Traits, _Allocator>;3574 3575  size_t __rhs_len = _Traits::length(__rhs);3576  if (__builtin_constant_p(__rhs_len) && !_String::__fits_in_sso(__rhs_len)) {3577    if (!__lhs.__is_long())3578      return false;3579  }3580  if (__rhs_len != __lhs.size())3581    return false;3582  return __lhs.compare(0, _String::npos, __rhs, __rhs_len) == 0;3583}3584 3585#  if _LIBCPP_STD_VER <= 173586template <class _CharT, class _Traits, class _Allocator>3587inline _LIBCPP_HIDE_FROM_ABI bool3588operator==(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3589  return __rhs == __lhs;3590}3591#  endif // _LIBCPP_STD_VER <= 173592 3593#  if _LIBCPP_STD_VER >= 203594 3595template <class _CharT, class _Traits, class _Allocator>3596_LIBCPP_HIDE_FROM_ABI constexpr auto operator<=>(const basic_string<_CharT, _Traits, _Allocator>& __lhs,3597                                                 const basic_string<_CharT, _Traits, _Allocator>& __rhs) noexcept {3598  return basic_string_view<_CharT, _Traits>(__lhs) <=> basic_string_view<_CharT, _Traits>(__rhs);3599}3600 3601template <class _CharT, class _Traits, class _Allocator>3602_LIBCPP_HIDE_FROM_ABI constexpr auto3603operator<=>(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) {3604  return basic_string_view<_CharT, _Traits>(__lhs) <=> basic_string_view<_CharT, _Traits>(__rhs);3605}3606 3607#  else  // _LIBCPP_STD_VER >= 203608 3609template <class _CharT, class _Traits, class _Allocator>3610inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,3611                                             const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3612  return !(__lhs == __rhs);3613}3614 3615template <class _CharT, class _Traits, class _Allocator>3616inline _LIBCPP_HIDE_FROM_ABI bool3617operator!=(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3618  return !(__lhs == __rhs);3619}3620 3621template <class _CharT, class _Traits, class _Allocator>3622inline _LIBCPP_HIDE_FROM_ABI bool3623operator!=(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {3624  return !(__lhs == __rhs);3625}3626 3627// operator<3628 3629template <class _CharT, class _Traits, class _Allocator>3630inline _LIBCPP_HIDE_FROM_ABI bool operator<(const basic_string<_CharT, _Traits, _Allocator>& __lhs,3631                                            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3632  return __lhs.compare(__rhs) < 0;3633}3634 3635template <class _CharT, class _Traits, class _Allocator>3636inline _LIBCPP_HIDE_FROM_ABI bool3637operator<(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {3638  return __lhs.compare(__rhs) < 0;3639}3640 3641template <class _CharT, class _Traits, class _Allocator>3642inline _LIBCPP_HIDE_FROM_ABI bool3643operator<(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3644  return __rhs.compare(__lhs) > 0;3645}3646 3647// operator>3648 3649template <class _CharT, class _Traits, class _Allocator>3650inline _LIBCPP_HIDE_FROM_ABI bool operator>(const basic_string<_CharT, _Traits, _Allocator>& __lhs,3651                                            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3652  return __rhs < __lhs;3653}3654 3655template <class _CharT, class _Traits, class _Allocator>3656inline _LIBCPP_HIDE_FROM_ABI bool3657operator>(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {3658  return __rhs < __lhs;3659}3660 3661template <class _CharT, class _Traits, class _Allocator>3662inline _LIBCPP_HIDE_FROM_ABI bool3663operator>(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3664  return __rhs < __lhs;3665}3666 3667// operator<=3668 3669template <class _CharT, class _Traits, class _Allocator>3670inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,3671                                             const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3672  return !(__rhs < __lhs);3673}3674 3675template <class _CharT, class _Traits, class _Allocator>3676inline _LIBCPP_HIDE_FROM_ABI bool3677operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {3678  return !(__rhs < __lhs);3679}3680 3681template <class _CharT, class _Traits, class _Allocator>3682inline _LIBCPP_HIDE_FROM_ABI bool3683operator<=(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3684  return !(__rhs < __lhs);3685}3686 3687// operator>=3688 3689template <class _CharT, class _Traits, class _Allocator>3690inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,3691                                             const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3692  return !(__lhs < __rhs);3693}3694 3695template <class _CharT, class _Traits, class _Allocator>3696inline _LIBCPP_HIDE_FROM_ABI bool3697operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {3698  return !(__lhs < __rhs);3699}3700 3701template <class _CharT, class _Traits, class _Allocator>3702inline _LIBCPP_HIDE_FROM_ABI bool3703operator>=(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {3704  return !(__lhs < __rhs);3705}3706#  endif // _LIBCPP_STD_VER >= 203707 3708// operator +3709 3710template <class _CharT, class _Traits, class _Allocator>3711_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3712__concatenate_strings(const _Allocator& __alloc,3713                      __type_identity_t<basic_string_view<_CharT, _Traits> > __str1,3714                      __type_identity_t<basic_string_view<_CharT, _Traits> > __str2) {3715  using _String = basic_string<_CharT, _Traits, _Allocator>;3716  _String __r(__uninitialized_size_tag(),3717              __str1.size() + __str2.size(),3718              _String::__alloc_traits::select_on_container_copy_construction(__alloc));3719  auto __ptr = std::__to_address(__r.__get_pointer());3720  _Traits::copy(__ptr, __str1.data(), __str1.size());3721  _Traits::copy(__ptr + __str1.size(), __str2.data(), __str2.size());3722  _Traits::assign(__ptr[__str1.size() + __str2.size()], _CharT());3723  return __r;3724}3725 3726template <class _CharT, class _Traits, class _Allocator>3727_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3728operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs,3729          const basic_string<_CharT, _Traits, _Allocator>& __rhs) {3730  return std::__concatenate_strings<_CharT, _Traits>(__lhs.get_allocator(), __lhs, __rhs);3731}3732 3733template <class _CharT, class _Traits, class _Allocator>3734_LIBCPP_HIDDEN _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3735operator+(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) {3736  return std::__concatenate_strings<_CharT, _Traits>(__rhs.get_allocator(), __lhs, __rhs);3737}3738 3739extern template _LIBCPP_EXPORTED_FROM_ABI string operator+3740    <char, char_traits<char>, allocator<char> >(char const*, string const&);3741 3742template <class _CharT, class _Traits, class _Allocator>3743_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3744operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) {3745  return std::__concatenate_strings<_CharT, _Traits>(3746      __rhs.get_allocator(), basic_string_view<_CharT, _Traits>(std::addressof(__lhs), 1), __rhs);3747}3748 3749template <class _CharT, class _Traits, class _Allocator>3750_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3751operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) {3752  return std::__concatenate_strings<_CharT, _Traits>(__lhs.get_allocator(), __lhs, __rhs);3753}3754 3755template <class _CharT, class _Traits, class _Allocator>3756_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3757operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, _CharT __rhs) {3758  return std::__concatenate_strings<_CharT, _Traits>(3759      __lhs.get_allocator(), __lhs, basic_string_view<_CharT, _Traits>(std::addressof(__rhs), 1));3760}3761#  if _LIBCPP_STD_VER >= 263762 3763template <class _CharT, class _Traits, class _Allocator>3764_LIBCPP_HIDE_FROM_ABI constexpr basic_string<_CharT, _Traits, _Allocator>3765operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs,3766          type_identity_t<basic_string_view<_CharT, _Traits>> __rhs) {3767  return std::__concatenate_strings<_CharT, _Traits>(__lhs.get_allocator(), __lhs, __rhs);3768}3769 3770template <class _CharT, class _Traits, class _Allocator>3771_LIBCPP_HIDE_FROM_ABI constexpr basic_string<_CharT, _Traits, _Allocator>3772operator+(type_identity_t<basic_string_view<_CharT, _Traits>> __lhs,3773          const basic_string<_CharT, _Traits, _Allocator>& __rhs) {3774  return std::__concatenate_strings<_CharT, _Traits>(__rhs.get_allocator(), __lhs, __rhs);3775}3776 3777#  endif // _LIBCPP_STD_VER >= 263778 3779#  ifndef _LIBCPP_CXX03_LANG3780 3781template <class _CharT, class _Traits, class _Allocator>3782inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3783operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) {3784  return std::move(__lhs.append(__rhs));3785}3786 3787template <class _CharT, class _Traits, class _Allocator>3788inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3789operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs) {3790  return std::move(__rhs.insert(0, __lhs));3791}3792 3793template <class _CharT, class _Traits, class _Allocator>3794inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3795operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs) {3796  return std::move(__lhs.append(__rhs));3797}3798 3799template <class _CharT, class _Traits, class _Allocator>3800inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3801operator+(const _CharT* __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs) {3802  return std::move(__rhs.insert(0, __lhs));3803}3804 3805template <class _CharT, class _Traits, class _Allocator>3806inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3807operator+(_CharT __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs) {3808  __rhs.insert(__rhs.begin(), __lhs);3809  return std::move(__rhs);3810}3811 3812template <class _CharT, class _Traits, class _Allocator>3813inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3814operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const _CharT* __rhs) {3815  return std::move(__lhs.append(__rhs));3816}3817 3818template <class _CharT, class _Traits, class _Allocator>3819inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>3820operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, _CharT __rhs) {3821  __lhs.push_back(__rhs);3822  return std::move(__lhs);3823}3824 3825#  endif // _LIBCPP_CXX03_LANG3826 3827#  if _LIBCPP_STD_VER >= 263828 3829template <class _CharT, class _Traits, class _Allocator>3830_LIBCPP_HIDE_FROM_ABI constexpr basic_string<_CharT, _Traits, _Allocator>3831operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs,3832          type_identity_t<basic_string_view<_CharT, _Traits>> __rhs) {3833  return std::move(__lhs.append(__rhs));3834}3835 3836template <class _CharT, class _Traits, class _Allocator>3837_LIBCPP_HIDE_FROM_ABI constexpr basic_string<_CharT, _Traits, _Allocator>3838operator+(type_identity_t<basic_string_view<_CharT, _Traits>> __lhs,3839          basic_string<_CharT, _Traits, _Allocator>&& __rhs) {3840  return std::move(__rhs.insert(0, __lhs));3841}3842 3843#  endif // _LIBCPP_STD_VER >= 263844 3845// swap3846 3847template <class _CharT, class _Traits, class _Allocator>3848inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void3849swap(basic_string<_CharT, _Traits, _Allocator>& __lhs, basic_string<_CharT, _Traits, _Allocator>& __rhs)3850    _NOEXCEPT_(_NOEXCEPT_(__lhs.swap(__rhs))) {3851  __lhs.swap(__rhs);3852}3853 3854[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI int stoi(const string& __str, size_t* __idx = nullptr, int __base = 10);3855[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI unsigned long3856stoul(const string& __str, size_t* __idx = nullptr, int __base = 10);3857[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long stol(const string& __str, size_t* __idx = nullptr, int __base = 10);3858[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long long3859stoll(const string& __str, size_t* __idx = nullptr, int __base = 10);3860[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI unsigned long long3861stoull(const string& __str, size_t* __idx = nullptr, int __base = 10);3862 3863[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI float stof(const string& __str, size_t* __idx = nullptr);3864[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI double stod(const string& __str, size_t* __idx = nullptr);3865[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long double stold(const string& __str, size_t* __idx = nullptr);3866 3867[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(int __val);3868[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(unsigned __val);3869[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(long __val);3870[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(unsigned long __val);3871[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(long long __val);3872[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(unsigned long long __val);3873[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(float __val);3874[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(double __val);3875[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(long double __val);3876 3877#  if _LIBCPP_HAS_WIDE_CHARACTERS3878[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI int stoi(const wstring& __str, size_t* __idx = nullptr, int __base = 10);3879[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long stol(const wstring& __str, size_t* __idx = nullptr, int __base = 10);3880[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI unsigned long3881stoul(const wstring& __str, size_t* __idx = nullptr, int __base = 10);3882[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long long3883stoll(const wstring& __str, size_t* __idx = nullptr, int __base = 10);3884[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI unsigned long long3885stoull(const wstring& __str, size_t* __idx = nullptr, int __base = 10);3886 3887[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI float stof(const wstring& __str, size_t* __idx = nullptr);3888[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI double stod(const wstring& __str, size_t* __idx = nullptr);3889[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long double stold(const wstring& __str, size_t* __idx = nullptr);3890 3891[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(int __val);3892[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(unsigned __val);3893[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(long __val);3894[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(unsigned long __val);3895[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(long long __val);3896[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(unsigned long long __val);3897[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(float __val);3898[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(double __val);3899[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(long double __val);3900#  endif // _LIBCPP_HAS_WIDE_CHARACTERS3901 3902template <class _CharT, class _Traits, class _Allocator>3903_LIBCPP_TEMPLATE_DATA_VIS const typename basic_string<_CharT, _Traits, _Allocator>::size_type3904    basic_string<_CharT, _Traits, _Allocator>::npos;3905 3906template <class _CharT, class _Allocator>3907struct __string_hash : public __unary_function<basic_string<_CharT, char_traits<_CharT>, _Allocator>, size_t> {3908  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI size_t3909  operator()(const basic_string<_CharT, char_traits<_CharT>, _Allocator>& __val) const _NOEXCEPT {3910    return std::__do_string_hash(__val.data(), __val.data() + __val.size());3911  }3912};3913 3914template <class _Allocator>3915struct hash<basic_string<char, char_traits<char>, _Allocator> > : __string_hash<char, _Allocator> {};3916 3917#  if _LIBCPP_HAS_CHAR8_T3918template <class _Allocator>3919struct hash<basic_string<char8_t, char_traits<char8_t>, _Allocator> > : __string_hash<char8_t, _Allocator> {};3920#  endif3921 3922template <class _Allocator>3923struct hash<basic_string<char16_t, char_traits<char16_t>, _Allocator> > : __string_hash<char16_t, _Allocator> {};3924 3925template <class _Allocator>3926struct hash<basic_string<char32_t, char_traits<char32_t>, _Allocator> > : __string_hash<char32_t, _Allocator> {};3927 3928#  if _LIBCPP_HAS_WIDE_CHARACTERS3929template <class _Allocator>3930struct hash<basic_string<wchar_t, char_traits<wchar_t>, _Allocator> > : __string_hash<wchar_t, _Allocator> {};3931#  endif3932 3933template <class _CharT, class _Traits, class _Allocator>3934_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&3935operator<<(basic_ostream<_CharT, _Traits>& __os, const basic_string<_CharT, _Traits, _Allocator>& __str);3936 3937template <class _CharT, class _Traits, class _Allocator>3938_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&3939operator>>(basic_istream<_CharT, _Traits>& __is, basic_string<_CharT, _Traits, _Allocator>& __str);3940 3941template <class _CharT, class _Traits, class _Allocator>3942_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&3943getline(basic_istream<_CharT, _Traits>& __is, basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm);3944 3945template <class _CharT, class _Traits, class _Allocator>3946inline _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&3947getline(basic_istream<_CharT, _Traits>& __is, basic_string<_CharT, _Traits, _Allocator>& __str);3948 3949template <class _CharT, class _Traits, class _Allocator>3950inline _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&3951getline(basic_istream<_CharT, _Traits>&& __is, basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm);3952 3953template <class _CharT, class _Traits, class _Allocator>3954inline _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&3955getline(basic_istream<_CharT, _Traits>&& __is, basic_string<_CharT, _Traits, _Allocator>& __str);3956 3957#  if _LIBCPP_STD_VER >= 203958template <class _CharT, class _Traits, class _Allocator, class _Up>3959inline _LIBCPP_HIDE_FROM_ABI constexpr typename basic_string<_CharT, _Traits, _Allocator>::size_type3960erase(basic_string<_CharT, _Traits, _Allocator>& __str, const _Up& __v) {3961  auto __old_size = __str.size();3962  __str.erase(std::remove(__str.begin(), __str.end(), __v), __str.end());3963  return __old_size - __str.size();3964}3965 3966template <class _CharT, class _Traits, class _Allocator, class _Predicate>3967inline _LIBCPP_HIDE_FROM_ABI constexpr typename basic_string<_CharT, _Traits, _Allocator>::size_type3968erase_if(basic_string<_CharT, _Traits, _Allocator>& __str, _Predicate __pred) {3969  auto __old_size = __str.size();3970  __str.erase(std::remove_if(__str.begin(), __str.end(), __pred), __str.end());3971  return __old_size - __str.size();3972}3973#  endif3974 3975#  if _LIBCPP_STD_VER >= 143976// Literal suffixes for basic_string [basic.string.literals]3977inline namespace literals {3978inline namespace string_literals {3979[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<char>3980operator""s(const char* __str, size_t __len) {3981  return basic_string<char>(__str, __len);3982}3983 3984#    if _LIBCPP_HAS_WIDE_CHARACTERS3985[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI3986_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<wchar_t> operator""s(const wchar_t* __str, size_t __len) {3987  return basic_string<wchar_t>(__str, __len);3988}3989#    endif3990 3991#    if _LIBCPP_HAS_CHAR8_T3992[[__nodiscard__]] inline3993    _LIBCPP_HIDE_FROM_ABI constexpr basic_string<char8_t> operator""s(const char8_t* __str, size_t __len) {3994  return basic_string<char8_t>(__str, __len);3995}3996#    endif3997 3998[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI3999_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<char16_t> operator""s(const char16_t* __str, size_t __len) {4000  return basic_string<char16_t>(__str, __len);4001}4002 4003[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<char32_t>4004operator""s(const char32_t* __str, size_t __len) {4005  return basic_string<char32_t>(__str, __len);4006}4007} // namespace string_literals4008} // namespace literals4009 4010#    if _LIBCPP_STD_VER >= 204011template <>4012inline constexpr bool __format::__enable_insertable<std::basic_string<char>> = true;4013#      if _LIBCPP_HAS_WIDE_CHARACTERS4014template <>4015inline constexpr bool __format::__enable_insertable<std::basic_string<wchar_t>> = true;4016#      endif4017#    endif4018 4019#  endif4020 4021_LIBCPP_END_NAMESPACE_STD4022 4023_LIBCPP_POP_MACROS4024 4025#  if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 204026#    include <algorithm>4027#    include <concepts>4028#    include <cstdlib>4029#    include <iterator>4030#    include <new>4031#    include <optional>4032#    include <type_traits>4033#    include <typeinfo>4034#    include <utility>4035#  endif4036#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)4037 4038#endif // _LIBCPP_STRING4039