|  | // -*- C++ -*- | 
|  | //===-------------------------- __string ----------------------------------===// | 
|  | // | 
|  | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | 
|  | // See https://llvm.org/LICENSE.txt for license information. | 
|  | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #ifndef _LIBCPP___STRING | 
|  | #define _LIBCPP___STRING | 
|  |  | 
|  | #include <__config> | 
|  | #include <__algorithm/copy.h> | 
|  | #include <__algorithm/copy_backward.h> | 
|  | #include <__algorithm/copy_n.h> | 
|  | #include <__algorithm/fill_n.h> | 
|  | #include <__algorithm/find_first_of.h> | 
|  | #include <__algorithm/find_end.h> | 
|  | #include <__algorithm/min.h> | 
|  | #include <__functional/hash.h>     // for __murmur2_or_cityhash | 
|  | #include <__iterator/iterator_traits.h> | 
|  | #include <cstdio>      // for EOF | 
|  | #include <cstdint>     // for uint_least16_t | 
|  | #include <cstring>     // for memcpy | 
|  | #include <cwchar>      // for wmemcpy | 
|  | #include <type_traits> // for __libcpp_is_constant_evaluated | 
|  |  | 
|  | #include <__debug> | 
|  |  | 
|  | #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) | 
|  | #pragma GCC system_header | 
|  | #endif | 
|  |  | 
|  | _LIBCPP_PUSH_MACROS | 
|  | #include <__undef_macros> | 
|  |  | 
|  |  | 
|  | _LIBCPP_BEGIN_NAMESPACE_STD | 
|  |  | 
|  | // The the extern template ABI lists are kept outside of <string> to improve the | 
|  | // readability of that header. | 
|  |  | 
|  | // The extern template ABI lists are kept outside of <string> to improve the | 
|  | // readability of that header. We maintain 2 ABI lists: | 
|  | // - _LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST | 
|  | // - _LIBCPP_STRING_UNSTABLE_EXTERN_TEMPLATE_LIST | 
|  | // As the name implies, the ABI lists define the V1 (Stable) and unstable ABI. | 
|  | // | 
|  | // For unstable, we may explicitly remove function that are external in V1, | 
|  | // and add (new) external functions to better control inlining and compiler | 
|  | // optimization opportunities. | 
|  | // | 
|  | // For stable, the ABI list should rarely change, except for adding new | 
|  | // functions supporting new c++ version / API changes. Typically entries | 
|  | // must never be removed from the stable list. | 
|  | #define _LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST(_Func, _CharType) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::replace(size_type, size_type, value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::rfind(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__init(value_type const*, size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::basic_string(basic_string const&)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::replace(size_type, size_type, value_type const*)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::basic_string(basic_string const&, allocator<_CharType> const&)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find_last_not_of(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::~basic_string()) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find_first_not_of(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::insert(size_type, size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::operator=(value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__init(value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS const _CharType& basic_string<_CharType>::at(size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::insert(size_type, value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find_first_of(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::replace(size_type, size_type, size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::assign(value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::reserve(size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::append(value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::assign(basic_string const&, size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::copy(value_type*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::basic_string(basic_string const&, size_type, size_type, allocator<_CharType> const&)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find(value_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__init(size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::insert(size_type, value_type const*)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find_last_of(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__grow_by(size_type, size_type, size_type, size_type, size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__grow_by_and_replace(size_type, size_type, size_type, size_type, size_type, size_type, value_type const*)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::push_back(value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::append(size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::rfind(value_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS const basic_string<_CharType>::size_type basic_string<_CharType>::npos) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::assign(size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::erase(size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::append(basic_string const&, size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS int basic_string<_CharType>::compare(value_type const*) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS int basic_string<_CharType>::compare(size_type, size_type, value_type const*) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS _CharType& basic_string<_CharType>::at(size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::assign(value_type const*)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS int basic_string<_CharType>::compare(size_type, size_type, basic_string const&, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS int basic_string<_CharType>::compare(size_type, size_type, value_type const*, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::operator=(basic_string const&)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::append(value_type const*)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::replace(size_type, size_type, basic_string const&, size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::iterator basic_string<_CharType>::insert(basic_string::const_iterator, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::resize(size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::insert(size_type, basic_string const&, size_type, size_type)) | 
|  |  | 
|  | #define _LIBCPP_STRING_UNSTABLE_EXTERN_TEMPLATE_LIST(_Func, _CharType) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::replace(size_type, size_type, value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::rfind(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__init(value_type const*, size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::replace(size_type, size_type, value_type const*)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find_last_not_of(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::~basic_string()) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find_first_not_of(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::insert(size_type, size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::operator=(value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__init(value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__init_copy_ctor_external(value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS const _CharType& basic_string<_CharType>::at(size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::insert(size_type, value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find_first_of(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::replace(size_type, size_type, size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::__assign_external(value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::__assign_external(value_type const*)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::reserve(size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::append(value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::assign(basic_string const&, size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::copy(value_type*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::basic_string(basic_string const&, size_type, size_type, allocator<_CharType> const&)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find(value_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__init(size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::insert(size_type, value_type const*)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find_last_of(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__grow_by(size_type, size_type, size_type, size_type, size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__grow_by_and_replace(size_type, size_type, size_type, size_type, size_type, size_type, value_type const*)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::__assign_no_alias<false>(value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::__assign_no_alias<true>(value_type const*, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::push_back(value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::append(size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::rfind(value_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS const basic_string<_CharType>::size_type basic_string<_CharType>::npos) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::assign(size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::__erase_external_with_move(size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::append(basic_string const&, size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS int basic_string<_CharType>::compare(value_type const*) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS int basic_string<_CharType>::compare(size_type, size_type, value_type const*) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS _CharType& basic_string<_CharType>::at(size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::size_type basic_string<_CharType>::find(value_type const*, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS int basic_string<_CharType>::compare(size_type, size_type, basic_string const&, size_type, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS int basic_string<_CharType>::compare(size_type, size_type, value_type const*, size_type) const) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::append(value_type const*)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::replace(size_type, size_type, basic_string const&, size_type, size_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>::iterator basic_string<_CharType>::insert(basic_string::const_iterator, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS void basic_string<_CharType>::resize(size_type, value_type)) \ | 
|  | _Func(_LIBCPP_FUNC_VIS basic_string<_CharType>& basic_string<_CharType>::insert(size_type, basic_string const&, size_type, size_type)) | 
|  |  | 
|  |  | 
|  | // char_traits | 
|  |  | 
|  | template <class _CharT> | 
|  | struct _LIBCPP_TEMPLATE_VIS char_traits | 
|  | { | 
|  | typedef _CharT    char_type; | 
|  | typedef int       int_type; | 
|  | typedef streamoff off_type; | 
|  | typedef streampos pos_type; | 
|  | typedef mbstate_t state_type; | 
|  |  | 
|  | static inline void _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT | 
|  | {return __c1 == __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT | 
|  | {return __c1 < __c2;} | 
|  |  | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | int compare(const char_type* __s1, const char_type* __s2, size_t __n); | 
|  | _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | size_t length(const char_type* __s); | 
|  | _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | const char_type* find(const char_type* __s, size_t __n, const char_type& __a); | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type*       move(char_type* __s1, const char_type* __s2, size_t __n); | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n); | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type*       assign(char_type* __s, size_t __n, char_type __a); | 
|  |  | 
|  | static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT | 
|  | {return eq_int_type(__c, eof()) ? ~eof() : __c;} | 
|  | static inline _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT | 
|  | {return char_type(__c);} | 
|  | static inline _LIBCPP_CONSTEXPR int_type  to_int_type(char_type __c) _NOEXCEPT | 
|  | {return int_type(__c);} | 
|  | static inline _LIBCPP_CONSTEXPR bool      eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT | 
|  | {return __c1 == __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR int_type  eof() _NOEXCEPT | 
|  | {return int_type(EOF);} | 
|  | }; | 
|  |  | 
|  | template <class _CharT> | 
|  | _LIBCPP_CONSTEXPR_AFTER_CXX14 int | 
|  | char_traits<_CharT>::compare(const char_type* __s1, const char_type* __s2, size_t __n) | 
|  | { | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | { | 
|  | if (lt(*__s1, *__s2)) | 
|  | return -1; | 
|  | if (lt(*__s2, *__s1)) | 
|  | return 1; | 
|  | } | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | template <class _CharT> | 
|  | inline | 
|  | _LIBCPP_CONSTEXPR_AFTER_CXX14 size_t | 
|  | char_traits<_CharT>::length(const char_type* __s) | 
|  | { | 
|  | size_t __len = 0; | 
|  | for (; !eq(*__s, char_type(0)); ++__s) | 
|  | ++__len; | 
|  | return __len; | 
|  | } | 
|  |  | 
|  | template <class _CharT> | 
|  | inline | 
|  | _LIBCPP_CONSTEXPR_AFTER_CXX14 const _CharT* | 
|  | char_traits<_CharT>::find(const char_type* __s, size_t __n, const char_type& __a) | 
|  | { | 
|  | for (; __n; --__n) | 
|  | { | 
|  | if (eq(*__s, __a)) | 
|  | return __s; | 
|  | ++__s; | 
|  | } | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | template <class _CharT> | 
|  | _LIBCPP_CONSTEXPR_AFTER_CXX17 _CharT* | 
|  | char_traits<_CharT>::move(char_type* __s1, const char_type* __s2, size_t __n) | 
|  | { | 
|  | if (__n == 0) return __s1; | 
|  | char_type* __r = __s1; | 
|  | if (__s1 < __s2) | 
|  | { | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | assign(*__s1, *__s2); | 
|  | } | 
|  | else if (__s2 < __s1) | 
|  | { | 
|  | __s1 += __n; | 
|  | __s2 += __n; | 
|  | for (; __n; --__n) | 
|  | assign(*--__s1, *--__s2); | 
|  | } | 
|  | return __r; | 
|  | } | 
|  |  | 
|  | template <class _CharT> | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | _CharT* | 
|  | char_traits<_CharT>::copy(char_type* __s1, const char_type* __s2, size_t __n) | 
|  | { | 
|  | _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range"); | 
|  | char_type* __r = __s1; | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | assign(*__s1, *__s2); | 
|  | return __r; | 
|  | } | 
|  |  | 
|  | template <class _CharT> | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | _CharT* | 
|  | char_traits<_CharT>::assign(char_type* __s, size_t __n, char_type __a) | 
|  | { | 
|  | char_type* __r = __s; | 
|  | for (; __n; --__n, ++__s) | 
|  | assign(*__s, __a); | 
|  | return __r; | 
|  | } | 
|  |  | 
|  | // constexpr versions of move/copy/assign. | 
|  |  | 
|  | template <class _CharT> | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | _CharT* __move_constexpr(_CharT* __s1, const _CharT* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | if (__n == 0) return __s1; | 
|  | if (__s1 < __s2) { | 
|  | _VSTD::copy(__s2, __s2 + __n, __s1); | 
|  | } else if (__s2 < __s1) { | 
|  | _VSTD::copy_backward(__s2, __s2 + __n, __s1 + __n); | 
|  | } | 
|  | return __s1; | 
|  | } | 
|  |  | 
|  | template <class _CharT> | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | _CharT* __copy_constexpr(_CharT* __s1, const _CharT* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | _VSTD::copy_n(__s2, __n, __s1); | 
|  | return __s1; | 
|  | } | 
|  |  | 
|  | template <class _CharT> | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | _CharT* __assign_constexpr(_CharT* __s, size_t __n, _CharT __a) _NOEXCEPT | 
|  | { | 
|  | _VSTD::fill_n(__s, __n, __a); | 
|  | return __s; | 
|  | } | 
|  |  | 
|  | // char_traits<char> | 
|  |  | 
|  | template <> | 
|  | struct _LIBCPP_TEMPLATE_VIS char_traits<char> | 
|  | { | 
|  | typedef char      char_type; | 
|  | typedef int       int_type; | 
|  | typedef streamoff off_type; | 
|  | typedef streampos pos_type; | 
|  | typedef mbstate_t state_type; | 
|  |  | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT | 
|  | {return __c1 == __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT | 
|  | {return (unsigned char)__c1 < (unsigned char)__c2;} | 
|  |  | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT; | 
|  | static inline size_t _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | length(const char_type* __s)  _NOEXCEPT {return __builtin_strlen(__s);} | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT; | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type* move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | return __libcpp_is_constant_evaluated() | 
|  | ? _VSTD::__move_constexpr(__s1, __s2, __n) | 
|  | : __n == 0 ? __s1 : (char_type*)_VSTD::memmove(__s1, __s2, __n); | 
|  | } | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type* copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range"); | 
|  | return __libcpp_is_constant_evaluated() | 
|  | ? _VSTD::__copy_constexpr(__s1, __s2, __n) | 
|  | : __n == 0 ? __s1 : (char_type*)_VSTD::memcpy(__s1, __s2, __n); | 
|  | } | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type* assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT | 
|  | { | 
|  | return __libcpp_is_constant_evaluated() | 
|  | ? _VSTD::__assign_constexpr(__s, __n, __a) | 
|  | : __n == 0 ? __s : (char_type*)_VSTD::memset(__s, to_int_type(__a), __n); | 
|  | } | 
|  |  | 
|  | static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT | 
|  | {return eq_int_type(__c, eof()) ? ~eof() : __c;} | 
|  | static inline _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT | 
|  | {return char_type(__c);} | 
|  | static inline _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT | 
|  | {return int_type((unsigned char)__c);} | 
|  | static inline _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT | 
|  | {return __c1 == __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR int_type  eof() _NOEXCEPT | 
|  | {return int_type(EOF);} | 
|  | }; | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | int | 
|  | char_traits<char>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | if (__n == 0) | 
|  | return 0; | 
|  | #if __has_feature(cxx_constexpr_string_builtins) | 
|  | return __builtin_memcmp(__s1, __s2, __n); | 
|  | #elif _LIBCPP_STD_VER <= 14 | 
|  | return _VSTD::memcmp(__s1, __s2, __n); | 
|  | #else | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | { | 
|  | if (lt(*__s1, *__s2)) | 
|  | return -1; | 
|  | if (lt(*__s2, *__s1)) | 
|  | return 1; | 
|  | } | 
|  | return 0; | 
|  | #endif | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | const char* | 
|  | char_traits<char>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT | 
|  | { | 
|  | if (__n == 0) | 
|  | return nullptr; | 
|  | #if __has_feature(cxx_constexpr_string_builtins) | 
|  | return __builtin_char_memchr(__s, to_int_type(__a), __n); | 
|  | #elif _LIBCPP_STD_VER <= 14 | 
|  | return (const char_type*) _VSTD::memchr(__s, to_int_type(__a), __n); | 
|  | #else | 
|  | for (; __n; --__n) | 
|  | { | 
|  | if (eq(*__s, __a)) | 
|  | return __s; | 
|  | ++__s; | 
|  | } | 
|  | return nullptr; | 
|  | #endif | 
|  | } | 
|  |  | 
|  |  | 
|  | // char_traits<wchar_t> | 
|  |  | 
|  | template <> | 
|  | struct _LIBCPP_TEMPLATE_VIS char_traits<wchar_t> | 
|  | { | 
|  | typedef wchar_t   char_type; | 
|  | typedef wint_t    int_type; | 
|  | typedef streamoff off_type; | 
|  | typedef streampos pos_type; | 
|  | typedef mbstate_t state_type; | 
|  |  | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT | 
|  | {return __c1 == __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT | 
|  | {return __c1 < __c2;} | 
|  |  | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT; | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | size_t length(const char_type* __s) _NOEXCEPT; | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT; | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type* move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | return __libcpp_is_constant_evaluated() | 
|  | ? _VSTD::__move_constexpr(__s1, __s2, __n) | 
|  | : __n == 0 ? __s1 : _VSTD::wmemmove(__s1, __s2, __n); | 
|  | } | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type* copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range"); | 
|  | return __libcpp_is_constant_evaluated() | 
|  | ? _VSTD::__copy_constexpr(__s1, __s2, __n) | 
|  | : __n == 0 ? __s1 : _VSTD::wmemcpy(__s1, __s2, __n); | 
|  | } | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type* assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT | 
|  | { | 
|  | return __libcpp_is_constant_evaluated() | 
|  | ? _VSTD::__assign_constexpr(__s, __n, __a) | 
|  | : __n == 0 ? __s : _VSTD::wmemset(__s, __a, __n); | 
|  | } | 
|  | static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT | 
|  | {return eq_int_type(__c, eof()) ? ~eof() : __c;} | 
|  | static inline _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT | 
|  | {return char_type(__c);} | 
|  | static inline _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT | 
|  | {return int_type(__c);} | 
|  | static inline _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT | 
|  | {return __c1 == __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT | 
|  | {return int_type(WEOF);} | 
|  | }; | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | int | 
|  | char_traits<wchar_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | if (__n == 0) | 
|  | return 0; | 
|  | #if __has_feature(cxx_constexpr_string_builtins) | 
|  | return __builtin_wmemcmp(__s1, __s2, __n); | 
|  | #elif _LIBCPP_STD_VER <= 14 | 
|  | return _VSTD::wmemcmp(__s1, __s2, __n); | 
|  | #else | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | { | 
|  | if (lt(*__s1, *__s2)) | 
|  | return -1; | 
|  | if (lt(*__s2, *__s1)) | 
|  | return 1; | 
|  | } | 
|  | return 0; | 
|  | #endif | 
|  | } | 
|  |  | 
|  |  | 
|  | template <class _Traits> | 
|  | _LIBCPP_INLINE_VISIBILITY | 
|  | _LIBCPP_CONSTEXPR | 
|  | inline size_t __char_traits_length_checked(const typename _Traits::char_type* __s) _NOEXCEPT { | 
|  | #if _LIBCPP_DEBUG_LEVEL >= 1 | 
|  | return __s ? _Traits::length(__s) : (_VSTD::__libcpp_debug_function(_VSTD::__libcpp_debug_info(__FILE__, __LINE__, "p == nullptr", "null pointer pass to non-null argument of char_traits<...>::length")), 0); | 
|  | #else | 
|  | return _Traits::length(__s); | 
|  | #endif | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | size_t | 
|  | char_traits<wchar_t>::length(const char_type* __s) _NOEXCEPT | 
|  | { | 
|  | #if __has_feature(cxx_constexpr_string_builtins) | 
|  | return __builtin_wcslen(__s); | 
|  | #elif _LIBCPP_STD_VER <= 14 | 
|  | return _VSTD::wcslen(__s); | 
|  | #else | 
|  | size_t __len = 0; | 
|  | for (; !eq(*__s, char_type(0)); ++__s) | 
|  | ++__len; | 
|  | return __len; | 
|  | #endif | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | const wchar_t* | 
|  | char_traits<wchar_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT | 
|  | { | 
|  | if (__n == 0) | 
|  | return nullptr; | 
|  | #if __has_feature(cxx_constexpr_string_builtins) | 
|  | return __builtin_wmemchr(__s, __a, __n); | 
|  | #elif _LIBCPP_STD_VER <= 14 | 
|  | return _VSTD::wmemchr(__s, __a, __n); | 
|  | #else | 
|  | for (; __n; --__n) | 
|  | { | 
|  | if (eq(*__s, __a)) | 
|  | return __s; | 
|  | ++__s; | 
|  | } | 
|  | return nullptr; | 
|  | #endif | 
|  | } | 
|  |  | 
|  |  | 
|  | #ifndef _LIBCPP_HAS_NO_CHAR8_T | 
|  |  | 
|  | template <> | 
|  | struct _LIBCPP_TEMPLATE_VIS char_traits<char8_t> | 
|  | { | 
|  | typedef char8_t        char_type; | 
|  | typedef unsigned int   int_type; | 
|  | typedef streamoff      off_type; | 
|  | typedef u8streampos    pos_type; | 
|  | typedef mbstate_t      state_type; | 
|  |  | 
|  | static inline constexpr void assign(char_type& __c1, const char_type& __c2) noexcept | 
|  | {__c1 = __c2;} | 
|  | static inline constexpr bool eq(char_type __c1, char_type __c2) noexcept | 
|  | {return __c1 == __c2;} | 
|  | static inline constexpr bool lt(char_type __c1, char_type __c2) noexcept | 
|  | {return __c1 < __c2;} | 
|  |  | 
|  | static constexpr | 
|  | int              compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT; | 
|  |  | 
|  | static constexpr | 
|  | size_t           length(const char_type* __s) _NOEXCEPT; | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY static constexpr | 
|  | const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT; | 
|  |  | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type*       move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | return __libcpp_is_constant_evaluated() | 
|  | ? _VSTD::__move_constexpr(__s1, __s2, __n) | 
|  | : __n == 0 ? __s1 : (char_type*)_VSTD::memmove(__s1, __s2, __n); | 
|  | } | 
|  |  | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range"); | 
|  | return __libcpp_is_constant_evaluated() | 
|  | ? _VSTD::__copy_constexpr(__s1, __s2, __n) | 
|  | : __n == 0 ? __s1 : (char_type*)_VSTD::memcpy(__s1, __s2, __n); | 
|  | } | 
|  |  | 
|  | static _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char_type*       assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT | 
|  | { | 
|  | return __libcpp_is_constant_evaluated() | 
|  | ? _VSTD::__assign_constexpr(__s, __n, __a) | 
|  | : __n == 0 ? __s : (char_type*)_VSTD::memset(__s, to_int_type(__a), __n); | 
|  | } | 
|  |  | 
|  | static inline constexpr int_type  not_eof(int_type __c) noexcept | 
|  | {return eq_int_type(__c, eof()) ? ~eof() : __c;} | 
|  | static inline constexpr char_type to_char_type(int_type __c) noexcept | 
|  | {return char_type(__c);} | 
|  | static inline constexpr int_type to_int_type(char_type __c) noexcept | 
|  | {return int_type(__c);} | 
|  | static inline constexpr bool eq_int_type(int_type __c1, int_type __c2) noexcept | 
|  | {return __c1 == __c2;} | 
|  | static inline constexpr int_type eof() noexcept | 
|  | {return int_type(EOF);} | 
|  | }; | 
|  |  | 
|  | // TODO use '__builtin_strlen' if it ever supports char8_t ?? | 
|  | inline constexpr | 
|  | size_t | 
|  | char_traits<char8_t>::length(const char_type* __s) _NOEXCEPT | 
|  | { | 
|  | size_t __len = 0; | 
|  | for (; !eq(*__s, char_type(0)); ++__s) | 
|  | ++__len; | 
|  | return __len; | 
|  | } | 
|  |  | 
|  | inline constexpr | 
|  | int | 
|  | char_traits<char8_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | #if __has_feature(cxx_constexpr_string_builtins) | 
|  | return __builtin_memcmp(__s1, __s2, __n); | 
|  | #else | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | { | 
|  | if (lt(*__s1, *__s2)) | 
|  | return -1; | 
|  | if (lt(*__s2, *__s1)) | 
|  | return 1; | 
|  | } | 
|  | return 0; | 
|  | #endif | 
|  | } | 
|  |  | 
|  | // TODO use '__builtin_char_memchr' if it ever supports char8_t ?? | 
|  | inline constexpr | 
|  | const char8_t* | 
|  | char_traits<char8_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT | 
|  | { | 
|  | for (; __n; --__n) | 
|  | { | 
|  | if (eq(*__s, __a)) | 
|  | return __s; | 
|  | ++__s; | 
|  | } | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | #endif // #_LIBCPP_HAS_NO_CHAR8_T | 
|  |  | 
|  | #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS | 
|  |  | 
|  | template <> | 
|  | struct _LIBCPP_TEMPLATE_VIS char_traits<char16_t> | 
|  | { | 
|  | typedef char16_t       char_type; | 
|  | typedef uint_least16_t int_type; | 
|  | typedef streamoff      off_type; | 
|  | typedef u16streampos   pos_type; | 
|  | typedef mbstate_t      state_type; | 
|  |  | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT | 
|  | {return __c1 == __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT | 
|  | {return __c1 < __c2;} | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | int              compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT; | 
|  | _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | size_t           length(const char_type* __s) _NOEXCEPT; | 
|  | _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT; | 
|  | _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT; | 
|  | _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT; | 
|  | _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | static char_type*       assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT; | 
|  |  | 
|  | static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT | 
|  | {return eq_int_type(__c, eof()) ? ~eof() : __c;} | 
|  | static inline _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT | 
|  | {return char_type(__c);} | 
|  | static inline _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT | 
|  | {return int_type(__c);} | 
|  | static inline _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT | 
|  | {return __c1 == __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT | 
|  | {return int_type(0xFFFF);} | 
|  | }; | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | int | 
|  | char_traits<char16_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | { | 
|  | if (lt(*__s1, *__s2)) | 
|  | return -1; | 
|  | if (lt(*__s2, *__s1)) | 
|  | return 1; | 
|  | } | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | size_t | 
|  | char_traits<char16_t>::length(const char_type* __s) _NOEXCEPT | 
|  | { | 
|  | size_t __len = 0; | 
|  | for (; !eq(*__s, char_type(0)); ++__s) | 
|  | ++__len; | 
|  | return __len; | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | const char16_t* | 
|  | char_traits<char16_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT | 
|  | { | 
|  | for (; __n; --__n) | 
|  | { | 
|  | if (eq(*__s, __a)) | 
|  | return __s; | 
|  | ++__s; | 
|  | } | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char16_t* | 
|  | char_traits<char16_t>::move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | if (__n == 0) return __s1; | 
|  | char_type* __r = __s1; | 
|  | if (__s1 < __s2) | 
|  | { | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | assign(*__s1, *__s2); | 
|  | } | 
|  | else if (__s2 < __s1) | 
|  | { | 
|  | __s1 += __n; | 
|  | __s2 += __n; | 
|  | for (; __n; --__n) | 
|  | assign(*--__s1, *--__s2); | 
|  | } | 
|  | return __r; | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char16_t* | 
|  | char_traits<char16_t>::copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range"); | 
|  | char_type* __r = __s1; | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | assign(*__s1, *__s2); | 
|  | return __r; | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char16_t* | 
|  | char_traits<char16_t>::assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT | 
|  | { | 
|  | char_type* __r = __s; | 
|  | for (; __n; --__n, ++__s) | 
|  | assign(*__s, __a); | 
|  | return __r; | 
|  | } | 
|  |  | 
|  | template <> | 
|  | struct _LIBCPP_TEMPLATE_VIS char_traits<char32_t> | 
|  | { | 
|  | typedef char32_t       char_type; | 
|  | typedef uint_least32_t int_type; | 
|  | typedef streamoff      off_type; | 
|  | typedef u32streampos   pos_type; | 
|  | typedef mbstate_t      state_type; | 
|  |  | 
|  | static inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT | 
|  | {return __c1 == __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT | 
|  | {return __c1 < __c2;} | 
|  |  | 
|  | _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | int              compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT; | 
|  | _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | size_t           length(const char_type* __s) _NOEXCEPT; | 
|  | _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT; | 
|  | _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT; | 
|  | _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT; | 
|  | _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | static char_type*       assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT; | 
|  |  | 
|  | static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT | 
|  | {return eq_int_type(__c, eof()) ? ~eof() : __c;} | 
|  | static inline _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT | 
|  | {return char_type(__c);} | 
|  | static inline _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT | 
|  | {return int_type(__c);} | 
|  | static inline _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT | 
|  | {return __c1 == __c2;} | 
|  | static inline _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT | 
|  | {return int_type(0xFFFFFFFF);} | 
|  | }; | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | int | 
|  | char_traits<char32_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | { | 
|  | if (lt(*__s1, *__s2)) | 
|  | return -1; | 
|  | if (lt(*__s2, *__s1)) | 
|  | return 1; | 
|  | } | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | size_t | 
|  | char_traits<char32_t>::length(const char_type* __s) _NOEXCEPT | 
|  | { | 
|  | size_t __len = 0; | 
|  | for (; !eq(*__s, char_type(0)); ++__s) | 
|  | ++__len; | 
|  | return __len; | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX14 | 
|  | const char32_t* | 
|  | char_traits<char32_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT | 
|  | { | 
|  | for (; __n; --__n) | 
|  | { | 
|  | if (eq(*__s, __a)) | 
|  | return __s; | 
|  | ++__s; | 
|  | } | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char32_t* | 
|  | char_traits<char32_t>::move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | if (__n == 0) return __s1; | 
|  | char_type* __r = __s1; | 
|  | if (__s1 < __s2) | 
|  | { | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | assign(*__s1, *__s2); | 
|  | } | 
|  | else if (__s2 < __s1) | 
|  | { | 
|  | __s1 += __n; | 
|  | __s2 += __n; | 
|  | for (; __n; --__n) | 
|  | assign(*--__s1, *--__s2); | 
|  | } | 
|  | return __r; | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char32_t* | 
|  | char_traits<char32_t>::copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT | 
|  | { | 
|  | _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range"); | 
|  | char_type* __r = __s1; | 
|  | for (; __n; --__n, ++__s1, ++__s2) | 
|  | assign(*__s1, *__s2); | 
|  | return __r; | 
|  | } | 
|  |  | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX17 | 
|  | char32_t* | 
|  | char_traits<char32_t>::assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT | 
|  | { | 
|  | char_type* __r = __s; | 
|  | for (; __n; --__n, ++__s) | 
|  | assign(*__s, __a); | 
|  | return __r; | 
|  | } | 
|  |  | 
|  | #endif // _LIBCPP_HAS_NO_UNICODE_CHARS | 
|  |  | 
|  | // helper fns for basic_string and string_view | 
|  |  | 
|  | // __str_find | 
|  | template<class _CharT, class _SizeT, class _Traits, _SizeT __npos> | 
|  | inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
|  | __str_find(const _CharT *__p, _SizeT __sz, | 
|  | _CharT __c, _SizeT __pos) _NOEXCEPT | 
|  | { | 
|  | if (__pos >= __sz) | 
|  | return __npos; | 
|  | const _CharT* __r = _Traits::find(__p + __pos, __sz - __pos, __c); | 
|  | if (__r == nullptr) | 
|  | return __npos; | 
|  | return static_cast<_SizeT>(__r - __p); | 
|  | } | 
|  |  | 
|  | template <class _CharT, class _Traits> | 
|  | inline _LIBCPP_CONSTEXPR_AFTER_CXX11 const _CharT * | 
|  | __search_substring(const _CharT *__first1, const _CharT *__last1, | 
|  | const _CharT *__first2, const _CharT *__last2) _NOEXCEPT { | 
|  | // Take advantage of knowing source and pattern lengths. | 
|  | // Stop short when source is smaller than pattern. | 
|  | const ptrdiff_t __len2 = __last2 - __first2; | 
|  | if (__len2 == 0) | 
|  | return __first1; | 
|  |  | 
|  | ptrdiff_t __len1 = __last1 - __first1; | 
|  | if (__len1 < __len2) | 
|  | return __last1; | 
|  |  | 
|  | // First element of __first2 is loop invariant. | 
|  | _CharT __f2 = *__first2; | 
|  | while (true) { | 
|  | __len1 = __last1 - __first1; | 
|  | // Check whether __first1 still has at least __len2 bytes. | 
|  | if (__len1 < __len2) | 
|  | return __last1; | 
|  |  | 
|  | // Find __f2 the first byte matching in __first1. | 
|  | __first1 = _Traits::find(__first1, __len1 - __len2 + 1, __f2); | 
|  | if (__first1 == nullptr) | 
|  | return __last1; | 
|  |  | 
|  | // It is faster to compare from the first byte of __first1 even if we | 
|  | // already know that it matches the first byte of __first2: this is because | 
|  | // __first2 is most likely aligned, as it is user's "pattern" string, and | 
|  | // __first1 + 1 is most likely not aligned, as the match is in the middle of | 
|  | // the string. | 
|  | if (_Traits::compare(__first1, __first2, __len2) == 0) | 
|  | return __first1; | 
|  |  | 
|  | ++__first1; | 
|  | } | 
|  | } | 
|  |  | 
|  | template<class _CharT, class _SizeT, class _Traits, _SizeT __npos> | 
|  | inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
|  | __str_find(const _CharT *__p, _SizeT __sz, | 
|  | const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT | 
|  | { | 
|  | if (__pos > __sz) | 
|  | return __npos; | 
|  |  | 
|  | if (__n == 0) // There is nothing to search, just return __pos. | 
|  | return __pos; | 
|  |  | 
|  | const _CharT *__r = __search_substring<_CharT, _Traits>( | 
|  | __p + __pos, __p + __sz, __s, __s + __n); | 
|  |  | 
|  | if (__r == __p + __sz) | 
|  | return __npos; | 
|  | return static_cast<_SizeT>(__r - __p); | 
|  | } | 
|  |  | 
|  |  | 
|  | // __str_rfind | 
|  |  | 
|  | template<class _CharT, class _SizeT, class _Traits, _SizeT __npos> | 
|  | inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
|  | __str_rfind(const _CharT *__p, _SizeT __sz, | 
|  | _CharT __c, _SizeT __pos) _NOEXCEPT | 
|  | { | 
|  | if (__sz < 1) | 
|  | return __npos; | 
|  | if (__pos < __sz) | 
|  | ++__pos; | 
|  | else | 
|  | __pos = __sz; | 
|  | for (const _CharT* __ps = __p + __pos; __ps != __p;) | 
|  | { | 
|  | if (_Traits::eq(*--__ps, __c)) | 
|  | return static_cast<_SizeT>(__ps - __p); | 
|  | } | 
|  | return __npos; | 
|  | } | 
|  |  | 
|  | template<class _CharT, class _SizeT, class _Traits, _SizeT __npos> | 
|  | inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
|  | __str_rfind(const _CharT *__p, _SizeT __sz, | 
|  | const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT | 
|  | { | 
|  | __pos = _VSTD::min(__pos, __sz); | 
|  | if (__n < __sz - __pos) | 
|  | __pos += __n; | 
|  | else | 
|  | __pos = __sz; | 
|  | const _CharT* __r = _VSTD::__find_end( | 
|  | __p, __p + __pos, __s, __s + __n, _Traits::eq, | 
|  | random_access_iterator_tag(), random_access_iterator_tag()); | 
|  | if (__n > 0 && __r == __p + __pos) | 
|  | return __npos; | 
|  | return static_cast<_SizeT>(__r - __p); | 
|  | } | 
|  |  | 
|  | // __str_find_first_of | 
|  | template<class _CharT, class _SizeT, class _Traits, _SizeT __npos> | 
|  | inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
|  | __str_find_first_of(const _CharT *__p, _SizeT __sz, | 
|  | const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT | 
|  | { | 
|  | if (__pos >= __sz || __n == 0) | 
|  | return __npos; | 
|  | const _CharT* __r = _VSTD::__find_first_of_ce | 
|  | (__p + __pos, __p + __sz, __s, __s + __n, _Traits::eq ); | 
|  | if (__r == __p + __sz) | 
|  | return __npos; | 
|  | return static_cast<_SizeT>(__r - __p); | 
|  | } | 
|  |  | 
|  |  | 
|  | // __str_find_last_of | 
|  | template<class _CharT, class _SizeT, class _Traits, _SizeT __npos> | 
|  | inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
|  | __str_find_last_of(const _CharT *__p, _SizeT __sz, | 
|  | const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT | 
|  | { | 
|  | if (__n != 0) | 
|  | { | 
|  | if (__pos < __sz) | 
|  | ++__pos; | 
|  | else | 
|  | __pos = __sz; | 
|  | for (const _CharT* __ps = __p + __pos; __ps != __p;) | 
|  | { | 
|  | const _CharT* __r = _Traits::find(__s, __n, *--__ps); | 
|  | if (__r) | 
|  | return static_cast<_SizeT>(__ps - __p); | 
|  | } | 
|  | } | 
|  | return __npos; | 
|  | } | 
|  |  | 
|  |  | 
|  | // __str_find_first_not_of | 
|  | template<class _CharT, class _SizeT, class _Traits, _SizeT __npos> | 
|  | inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
|  | __str_find_first_not_of(const _CharT *__p, _SizeT __sz, | 
|  | const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT | 
|  | { | 
|  | if (__pos < __sz) | 
|  | { | 
|  | const _CharT* __pe = __p + __sz; | 
|  | for (const _CharT* __ps = __p + __pos; __ps != __pe; ++__ps) | 
|  | if (_Traits::find(__s, __n, *__ps) == nullptr) | 
|  | return static_cast<_SizeT>(__ps - __p); | 
|  | } | 
|  | return __npos; | 
|  | } | 
|  |  | 
|  |  | 
|  | template<class _CharT, class _SizeT, class _Traits, _SizeT __npos> | 
|  | inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
|  | __str_find_first_not_of(const _CharT *__p, _SizeT __sz, | 
|  | _CharT __c, _SizeT __pos) _NOEXCEPT | 
|  | { | 
|  | if (__pos < __sz) | 
|  | { | 
|  | const _CharT* __pe = __p + __sz; | 
|  | for (const _CharT* __ps = __p + __pos; __ps != __pe; ++__ps) | 
|  | if (!_Traits::eq(*__ps, __c)) | 
|  | return static_cast<_SizeT>(__ps - __p); | 
|  | } | 
|  | return __npos; | 
|  | } | 
|  |  | 
|  |  | 
|  | // __str_find_last_not_of | 
|  | template<class _CharT, class _SizeT, class _Traits, _SizeT __npos> | 
|  | inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
|  | __str_find_last_not_of(const _CharT *__p, _SizeT __sz, | 
|  | const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT | 
|  | { | 
|  | if (__pos < __sz) | 
|  | ++__pos; | 
|  | else | 
|  | __pos = __sz; | 
|  | for (const _CharT* __ps = __p + __pos; __ps != __p;) | 
|  | if (_Traits::find(__s, __n, *--__ps) == nullptr) | 
|  | return static_cast<_SizeT>(__ps - __p); | 
|  | return __npos; | 
|  | } | 
|  |  | 
|  |  | 
|  | template<class _CharT, class _SizeT, class _Traits, _SizeT __npos> | 
|  | inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
|  | __str_find_last_not_of(const _CharT *__p, _SizeT __sz, | 
|  | _CharT __c, _SizeT __pos) _NOEXCEPT | 
|  | { | 
|  | if (__pos < __sz) | 
|  | ++__pos; | 
|  | else | 
|  | __pos = __sz; | 
|  | for (const _CharT* __ps = __p + __pos; __ps != __p;) | 
|  | if (!_Traits::eq(*--__ps, __c)) | 
|  | return static_cast<_SizeT>(__ps - __p); | 
|  | return __npos; | 
|  | } | 
|  |  | 
|  | template<class _Ptr> | 
|  | inline _LIBCPP_INLINE_VISIBILITY | 
|  | size_t __do_string_hash(_Ptr __p, _Ptr __e) | 
|  | { | 
|  | typedef typename iterator_traits<_Ptr>::value_type value_type; | 
|  | return __murmur2_or_cityhash<size_t>()(__p, (__e-__p)*sizeof(value_type)); | 
|  | } | 
|  |  | 
|  | template <class _CharT, class _Iter, class _Traits=char_traits<_CharT> > | 
|  | struct __quoted_output_proxy | 
|  | { | 
|  | _Iter  __first; | 
|  | _Iter  __last; | 
|  | _CharT  __delim; | 
|  | _CharT  __escape; | 
|  |  | 
|  | __quoted_output_proxy(_Iter __f, _Iter __l, _CharT __d, _CharT __e) | 
|  | : __first(__f), __last(__l), __delim(__d), __escape(__e) {} | 
|  | //  This would be a nice place for a string_ref | 
|  | }; | 
|  |  | 
|  | _LIBCPP_END_NAMESPACE_STD | 
|  |  | 
|  | _LIBCPP_POP_MACROS | 
|  |  | 
|  | #endif // _LIBCPP___STRING |