| // -*- C++ -*- | 
 | //===------------------------ string_view ---------------------------------===// | 
 | // | 
 | // 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_VIEW | 
 | #define _LIBCPP_STRING_VIEW | 
 |  | 
 | /* | 
 | string_view synopsis | 
 |  | 
 | namespace std { | 
 |  | 
 |     // 7.2, Class template basic_string_view | 
 |     template<class charT, class traits = char_traits<charT>> | 
 |         class basic_string_view; | 
 |  | 
 |     // 7.9, basic_string_view non-member comparison functions | 
 |     template<class charT, class traits> | 
 |     constexpr bool operator==(basic_string_view<charT, traits> x, | 
 |                               basic_string_view<charT, traits> y) noexcept; | 
 |     template<class charT, class traits> | 
 |     constexpr bool operator!=(basic_string_view<charT, traits> x, | 
 |                               basic_string_view<charT, traits> y) noexcept; | 
 |     template<class charT, class traits> | 
 |     constexpr bool operator< (basic_string_view<charT, traits> x, | 
 |                                  basic_string_view<charT, traits> y) noexcept; | 
 |     template<class charT, class traits> | 
 |     constexpr bool operator> (basic_string_view<charT, traits> x, | 
 |                               basic_string_view<charT, traits> y) noexcept; | 
 |     template<class charT, class traits> | 
 |     constexpr bool operator<=(basic_string_view<charT, traits> x, | 
 |                                  basic_string_view<charT, traits> y) noexcept; | 
 |     template<class charT, class traits> | 
 |     constexpr bool operator>=(basic_string_view<charT, traits> x, | 
 |                               basic_string_view<charT, traits> y) noexcept; | 
 |     // see below, sufficient additional overloads of comparison functions | 
 |  | 
 |     // 7.10, Inserters and extractors | 
 |     template<class charT, class traits> | 
 |       basic_ostream<charT, traits>& | 
 |         operator<<(basic_ostream<charT, traits>& os, | 
 |                    basic_string_view<charT, traits> str); | 
 |  | 
 |     // basic_string_view typedef names | 
 |     typedef basic_string_view<char> string_view; | 
 |     typedef basic_string_view<char16_t> u16string_view; | 
 |     typedef basic_string_view<char32_t> u32string_view; | 
 |     typedef basic_string_view<wchar_t> wstring_view; | 
 |  | 
 |     template<class charT, class traits = char_traits<charT>> | 
 |     class basic_string_view { | 
 |       public: | 
 |       // types | 
 |       typedef traits traits_type; | 
 |       typedef charT value_type; | 
 |       typedef charT* pointer; | 
 |       typedef const charT* const_pointer; | 
 |       typedef charT& reference; | 
 |       typedef const charT& const_reference; | 
 |       typedef implementation-defined const_iterator; | 
 |       typedef const_iterator iterator; | 
 |       typedef reverse_iterator<const_iterator> const_reverse_iterator; | 
 |       typedef const_reverse_iterator reverse_iterator; | 
 |       typedef size_t size_type; | 
 |       typedef ptrdiff_t difference_type; | 
 |       static constexpr size_type npos = size_type(-1); | 
 |  | 
 |       // 7.3, basic_string_view constructors and assignment operators | 
 |       constexpr basic_string_view() noexcept; | 
 |       constexpr basic_string_view(const basic_string_view&) noexcept = default; | 
 |       basic_string_view& operator=(const basic_string_view&) noexcept = default; | 
 |       template<class Allocator> | 
 |       constexpr basic_string_view(const charT* str); | 
 |       constexpr basic_string_view(const charT* str, size_type len); | 
 |  | 
 |       // 7.4, basic_string_view iterator support | 
 |       constexpr const_iterator begin() const noexcept; | 
 |       constexpr const_iterator end() const noexcept; | 
 |       constexpr const_iterator cbegin() const noexcept; | 
 |       constexpr const_iterator cend() const noexcept; | 
 |       const_reverse_iterator rbegin() const noexcept; | 
 |       const_reverse_iterator rend() const noexcept; | 
 |       const_reverse_iterator crbegin() const noexcept; | 
 |       const_reverse_iterator crend() const noexcept; | 
 |  | 
 |       // 7.5, basic_string_view capacity | 
 |       constexpr size_type size() const noexcept; | 
 |       constexpr size_type length() const noexcept; | 
 |       constexpr size_type max_size() const noexcept; | 
 |       constexpr bool empty() const noexcept; | 
 |  | 
 |       // 7.6, basic_string_view element access | 
 |       constexpr const_reference operator[](size_type pos) const; | 
 |       constexpr const_reference at(size_type pos) const; | 
 |       constexpr const_reference front() const; | 
 |       constexpr const_reference back() const; | 
 |       constexpr const_pointer data() const noexcept; | 
 |  | 
 |       // 7.7, basic_string_view modifiers | 
 |       constexpr void remove_prefix(size_type n); | 
 |       constexpr void remove_suffix(size_type n); | 
 |       constexpr void swap(basic_string_view& s) noexcept; | 
 |  | 
 |       size_type copy(charT* s, size_type n, size_type pos = 0) const; | 
 |  | 
 |       constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const; | 
 |       constexpr int compare(basic_string_view s) const noexcept; | 
 |       constexpr int compare(size_type pos1, size_type n1, basic_string_view s) const; | 
 |       constexpr int compare(size_type pos1, size_type n1, | 
 |                             basic_string_view s, size_type pos2, size_type n2) const; | 
 |       constexpr int compare(const charT* s) const; | 
 |       constexpr int compare(size_type pos1, size_type n1, const charT* s) const; | 
 |       constexpr int compare(size_type pos1, size_type n1, | 
 |                             const charT* s, size_type n2) const; | 
 |       constexpr size_type find(basic_string_view s, size_type pos = 0) const noexcept; | 
 |       constexpr size_type find(charT c, size_type pos = 0) const noexcept; | 
 |       constexpr size_type find(const charT* s, size_type pos, size_type n) const; | 
 |       constexpr size_type find(const charT* s, size_type pos = 0) const; | 
 |       constexpr size_type rfind(basic_string_view s, size_type pos = npos) const noexcept; | 
 |       constexpr size_type rfind(charT c, size_type pos = npos) const noexcept; | 
 |       constexpr size_type rfind(const charT* s, size_type pos, size_type n) const; | 
 |       constexpr size_type rfind(const charT* s, size_type pos = npos) const; | 
 |       constexpr size_type find_first_of(basic_string_view s, size_type pos = 0) const noexcept; | 
 |       constexpr size_type find_first_of(charT c, size_type pos = 0) const noexcept; | 
 |       constexpr size_type find_first_of(const charT* s, size_type pos, size_type n) const; | 
 |       constexpr size_type find_first_of(const charT* s, size_type pos = 0) const; | 
 |       constexpr size_type find_last_of(basic_string_view s, size_type pos = npos) const noexcept; | 
 |       constexpr size_type find_last_of(charT c, size_type pos = npos) const noexcept; | 
 |       constexpr size_type find_last_of(const charT* s, size_type pos, size_type n) const; | 
 |       constexpr size_type find_last_of(const charT* s, size_type pos = npos) const; | 
 |       constexpr size_type find_first_not_of(basic_string_view s, size_type pos = 0) const noexcept; | 
 |       constexpr size_type find_first_not_of(charT c, size_type pos = 0) const noexcept; | 
 |       constexpr size_type find_first_not_of(const charT* s, size_type pos, size_type n) const; | 
 |       constexpr size_type find_first_not_of(const charT* s, size_type pos = 0) const; | 
 |       constexpr size_type find_last_not_of(basic_string_view s, size_type pos = npos) const noexcept; | 
 |       constexpr size_type find_last_not_of(charT c, size_type pos = npos) const noexcept; | 
 |       constexpr size_type find_last_not_of(const charT* s, size_type pos, size_type n) const; | 
 |       constexpr size_type find_last_not_of(const charT* s, size_type pos = npos) const; | 
 |  | 
 |       constexpr bool starts_with(basic_string_view s) const noexcept; // C++2a | 
 |       constexpr bool starts_with(charT c) const noexcept;             // C++2a | 
 |       constexpr bool starts_with(const charT* s) const;               // C++2a | 
 |       constexpr bool ends_with(basic_string_view s) const noexcept;   // C++2a | 
 |       constexpr bool ends_with(charT c) const noexcept;               // C++2a | 
 |       constexpr bool ends_with(const charT* s) const;                 // C++2a | 
 |  | 
 |      private: | 
 |       const_pointer data_;  // exposition only | 
 |       size_type     size_;  // exposition only | 
 |     }; | 
 |  | 
 |   // 7.11, Hash support | 
 |   template <class T> struct hash; | 
 |   template <> struct hash<string_view>; | 
 |   template <> struct hash<u16string_view>; | 
 |   template <> struct hash<u32string_view>; | 
 |   template <> struct hash<wstring_view>; | 
 |  | 
 |   constexpr basic_string_view<char>     operator "" sv( const char *str,     size_t len ) noexcept; | 
 |   constexpr basic_string_view<wchar_t>  operator "" sv( const wchar_t *str,  size_t len ) noexcept; | 
 |   constexpr basic_string_view<char16_t> operator "" sv( const char16_t *str, size_t len ) noexcept; | 
 |   constexpr basic_string_view<char32_t> operator "" sv( const char32_t *str, size_t len ) noexcept; | 
 |  | 
 | }  // namespace std | 
 |  | 
 |  | 
 | */ | 
 |  | 
 | #include <__config> | 
 | #include <__string> | 
 | #include <iosfwd> | 
 | #include <algorithm> | 
 | #include <iterator> | 
 | #include <limits> | 
 | #include <stdexcept> | 
 | #include <version> | 
 | #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 | 
 |  | 
 | template<class _CharT, class _Traits = char_traits<_CharT> > | 
 | class _LIBCPP_TEMPLATE_VIS basic_string_view { | 
 | public: | 
 |     // types | 
 |     typedef _Traits                                    traits_type; | 
 |     typedef _CharT                                     value_type; | 
 |     typedef _CharT*                                    pointer; | 
 |     typedef const _CharT*                              const_pointer; | 
 |     typedef _CharT&                                    reference; | 
 |     typedef const _CharT&                              const_reference; | 
 |     typedef const_pointer                              const_iterator; // See [string.view.iterators] | 
 |     typedef const_iterator                             iterator; | 
 |     typedef _VSTD::reverse_iterator<const_iterator>    const_reverse_iterator; | 
 |     typedef const_reverse_iterator                     reverse_iterator; | 
 |     typedef size_t                                     size_type; | 
 |     typedef ptrdiff_t                                  difference_type; | 
 |     static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1); | 
 |  | 
 |     static_assert((!is_array<value_type>::value), "Character type of basic_string_view must not be an array"); | 
 |     static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string_view must be standard-layout"); | 
 |     static_assert(( is_trivial<value_type>::value), "Character type of basic_string_view must be trivial"); | 
 |     static_assert((is_same<_CharT, typename traits_type::char_type>::value), | 
 |                   "traits_type::char_type must be the same type as CharT"); | 
 |  | 
 |     // [string.view.cons], construct/copy | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {} | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     basic_string_view(const basic_string_view&) _NOEXCEPT = default; | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default; | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT | 
 |         : __data(__s), __size(__len) | 
 |     { | 
 | #if _LIBCPP_STD_VER > 11 | 
 |     _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr"); | 
 | #endif | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     basic_string_view(const _CharT* __s) | 
 |         : __data(__s), __size(std::__char_traits_length_checked<_Traits>(__s)) {} | 
 |  | 
 |     // [string.view.iterators], iterators | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     const_iterator begin()  const _NOEXCEPT { return cbegin(); } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     const_iterator end()    const _NOEXCEPT { return cend(); } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     const_iterator cbegin() const _NOEXCEPT { return __data; } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     const_iterator cend()   const _NOEXCEPT { return __data + __size; } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY | 
 |     const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY | 
 |     const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY | 
 |     const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY | 
 |     const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); } | 
 |  | 
 |     // [string.view.capacity], capacity | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     size_type size()     const _NOEXCEPT { return __size; } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     size_type length()   const _NOEXCEPT { return __size; } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max(); } | 
 |  | 
 |     _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR | 
 |     bool empty()         const _NOEXCEPT { return __size == 0; } | 
 |  | 
 |     // [string.view.access], element access | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     const_reference operator[](size_type __pos) const _NOEXCEPT { return __data[__pos]; } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     const_reference at(size_type __pos) const | 
 |     { | 
 |         return __pos >= size() | 
 |             ? (__throw_out_of_range("string_view::at"), __data[0]) | 
 |             : __data[__pos]; | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     const_reference front() const _NOEXCEPT | 
 |     { | 
 |         return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0]; | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     const_reference back() const _NOEXCEPT | 
 |     { | 
 |         return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1]; | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     const_pointer data() const _NOEXCEPT { return __data; } | 
 |  | 
 |     // [string.view.modifiers], modifiers: | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     void remove_prefix(size_type __n) _NOEXCEPT | 
 |     { | 
 |         _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()"); | 
 |         __data += __n; | 
 |         __size -= __n; | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     void remove_suffix(size_type __n) _NOEXCEPT | 
 |     { | 
 |         _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()"); | 
 |         __size -= __n; | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     void swap(basic_string_view& __other) _NOEXCEPT | 
 |     { | 
 |         const value_type *__p = __data; | 
 |         __data = __other.__data; | 
 |         __other.__data = __p; | 
 |  | 
 |         size_type __sz = __size; | 
 |         __size = __other.__size; | 
 |         __other.__size = __sz; | 
 |     } | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY | 
 |     size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const | 
 |     { | 
 |         if (__pos > size()) | 
 |             __throw_out_of_range("string_view::copy"); | 
 |         size_type __rlen = _VSTD::min(__n, size() - __pos); | 
 |         _Traits::copy(__s, data() + __pos, __rlen); | 
 |         return __rlen; | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY | 
 |     basic_string_view substr(size_type __pos = 0, size_type __n = npos) const | 
 |     { | 
 |         return __pos > size() | 
 |             ? (__throw_out_of_range("string_view::substr"), basic_string_view()) | 
 |             : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos)); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT | 
 |     { | 
 |         size_type __rlen = _VSTD::min( size(), __sv.size()); | 
 |         int __retval = _Traits::compare(data(), __sv.data(), __rlen); | 
 |         if ( __retval == 0 ) // first __rlen chars matched | 
 |             __retval = size() == __sv.size() ? 0 : ( size() < __sv.size() ? -1 : 1 ); | 
 |         return __retval; | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const | 
 |     { | 
 |         return substr(__pos1, __n1).compare(__sv); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     int compare(                       size_type __pos1, size_type __n1, | 
 |                 basic_string_view __sv, size_type __pos2, size_type __n2) const | 
 |     { | 
 |         return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2)); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     int compare(const _CharT* __s) const _NOEXCEPT | 
 |     { | 
 |         return compare(basic_string_view(__s)); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     int compare(size_type __pos1, size_type __n1, const _CharT* __s) const | 
 |     { | 
 |         return substr(__pos1, __n1).compare(basic_string_view(__s)); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const | 
 |     { | 
 |         return substr(__pos1, __n1).compare(basic_string_view(__s, __n2)); | 
 |     } | 
 |  | 
 |     // find | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT | 
 |     { | 
 |         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr"); | 
 |         return __str_find<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s.data(), __pos, __s.size()); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT | 
 |     { | 
 |         return __str_find<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __c, __pos); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find(const _CharT* __s, size_type __pos, size_type __n) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr"); | 
 |         return __str_find<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, __n); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find(const _CharT* __s, size_type __pos = 0) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr"); | 
 |         return __str_find<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, traits_type::length(__s)); | 
 |     } | 
 |  | 
 |     // rfind | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT | 
 |     { | 
 |         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr"); | 
 |         return __str_rfind<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s.data(), __pos, __s.size()); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT | 
 |     { | 
 |         return __str_rfind<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __c, __pos); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr"); | 
 |         return __str_rfind<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, __n); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type rfind(const _CharT* __s, size_type __pos=npos) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr"); | 
 |         return __str_rfind<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, traits_type::length(__s)); | 
 |     } | 
 |  | 
 |     // find_first_of | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT | 
 |     { | 
 |         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr"); | 
 |         return __str_find_first_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s.data(), __pos, __s.size()); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT | 
 |     { return find(__c, __pos); } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr"); | 
 |         return __str_find_first_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, __n); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_first_of(const _CharT* __s, size_type __pos=0) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr"); | 
 |         return __str_find_first_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, traits_type::length(__s)); | 
 |     } | 
 |  | 
 |     // find_last_of | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT | 
 |     { | 
 |         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr"); | 
 |         return __str_find_last_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s.data(), __pos, __s.size()); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT | 
 |     { return rfind(__c, __pos); } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr"); | 
 |         return __str_find_last_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, __n); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_last_of(const _CharT* __s, size_type __pos=npos) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr"); | 
 |         return __str_find_last_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, traits_type::length(__s)); | 
 |     } | 
 |  | 
 |     // find_first_not_of | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT | 
 |     { | 
 |         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr"); | 
 |         return __str_find_first_not_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s.data(), __pos, __s.size()); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT | 
 |     { | 
 |         return __str_find_first_not_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __c, __pos); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr"); | 
 |         return __str_find_first_not_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, __n); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_first_not_of(const _CharT* __s, size_type __pos=0) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr"); | 
 |         return __str_find_first_not_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, traits_type::length(__s)); | 
 |     } | 
 |  | 
 |     // find_last_not_of | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_last_not_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT | 
 |     { | 
 |         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): received nullptr"); | 
 |         return __str_find_last_not_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s.data(), __pos, __s.size()); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_last_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT | 
 |     { | 
 |         return __str_find_last_not_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __c, __pos); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr"); | 
 |         return __str_find_last_not_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, __n); | 
 |     } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const | 
 |     { | 
 |         _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr"); | 
 |         return __str_find_last_not_of<value_type, size_type, traits_type, npos> | 
 |             (data(), size(), __s, __pos, traits_type::length(__s)); | 
 |     } | 
 |  | 
 | #if _LIBCPP_STD_VER > 17 | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     bool starts_with(basic_string_view __s) const _NOEXCEPT | 
 |     { return size() >= __s.size() && compare(0, __s.size(), __s) == 0; } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     bool starts_with(value_type __c) const _NOEXCEPT | 
 |     { return !empty() && _Traits::eq(front(), __c); } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     bool starts_with(const value_type* __s) const _NOEXCEPT | 
 |     { return starts_with(basic_string_view(__s)); } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     bool ends_with(basic_string_view __s) const _NOEXCEPT | 
 |     { return size() >= __s.size() && compare(size() - __s.size(), npos, __s) == 0; } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     bool ends_with(value_type __c) const _NOEXCEPT | 
 |     { return !empty() && _Traits::eq(back(), __c); } | 
 |  | 
 |     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 |     bool ends_with(const value_type* __s) const _NOEXCEPT | 
 |     { return ends_with(basic_string_view(__s)); } | 
 | #endif | 
 |  | 
 | private: | 
 |     const   value_type* __data; | 
 |     size_type           __size; | 
 | }; | 
 |  | 
 |  | 
 | // [string.view.comparison] | 
 | // operator == | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator==(basic_string_view<_CharT, _Traits> __lhs, | 
 |                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     if ( __lhs.size() != __rhs.size()) return false; | 
 |     return __lhs.compare(__rhs) == 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator==(basic_string_view<_CharT, _Traits> __lhs, | 
 |                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT | 
 | { | 
 |     if ( __lhs.size() != __rhs.size()) return false; | 
 |     return __lhs.compare(__rhs) == 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, | 
 |                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     if ( __lhs.size() != __rhs.size()) return false; | 
 |     return __lhs.compare(__rhs) == 0; | 
 | } | 
 |  | 
 |  | 
 | // operator != | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     if ( __lhs.size() != __rhs.size()) | 
 |         return true; | 
 |     return __lhs.compare(__rhs) != 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator!=(basic_string_view<_CharT, _Traits> __lhs, | 
 |                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT | 
 | { | 
 |     if ( __lhs.size() != __rhs.size()) | 
 |         return true; | 
 |     return __lhs.compare(__rhs) != 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, | 
 |                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     if ( __lhs.size() != __rhs.size()) | 
 |         return true; | 
 |     return __lhs.compare(__rhs) != 0; | 
 | } | 
 |  | 
 |  | 
 | // operator < | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) < 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator<(basic_string_view<_CharT, _Traits> __lhs, | 
 |                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) < 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, | 
 |                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) < 0; | 
 | } | 
 |  | 
 |  | 
 | // operator > | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) > 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator>(basic_string_view<_CharT, _Traits> __lhs, | 
 |                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) > 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, | 
 |                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) > 0; | 
 | } | 
 |  | 
 |  | 
 | // operator <= | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) <= 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator<=(basic_string_view<_CharT, _Traits> __lhs, | 
 |                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) <= 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, | 
 |                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) <= 0; | 
 | } | 
 |  | 
 |  | 
 | // operator >= | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) >= 0; | 
 | } | 
 |  | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator>=(basic_string_view<_CharT, _Traits> __lhs, | 
 |                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) >= 0; | 
 | } | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY | 
 | bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, | 
 |                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT | 
 | { | 
 |     return __lhs.compare(__rhs) >= 0; | 
 | } | 
 |  | 
 |  | 
 | template<class _CharT, class _Traits> | 
 | basic_ostream<_CharT, _Traits>& | 
 | operator<<(basic_ostream<_CharT, _Traits>& __os, | 
 |            basic_string_view<_CharT, _Traits> __str); | 
 |  | 
 | typedef basic_string_view<char>     string_view; | 
 | #ifndef _LIBCPP_NO_HAS_CHAR8_T | 
 | typedef basic_string_view<char8_t>  u8string_view; | 
 | #endif | 
 | typedef basic_string_view<char16_t> u16string_view; | 
 | typedef basic_string_view<char32_t> u32string_view; | 
 | typedef basic_string_view<wchar_t>  wstring_view; | 
 |  | 
 | // [string.view.hash] | 
 | template<class _CharT> | 
 | struct _LIBCPP_TEMPLATE_VIS hash<basic_string_view<_CharT, char_traits<_CharT> > > | 
 |     : public unary_function<basic_string_view<_CharT, char_traits<_CharT> >, size_t> | 
 | { | 
 |     _LIBCPP_INLINE_VISIBILITY | 
 |     size_t operator()(const basic_string_view<_CharT, char_traits<_CharT> > __val) const _NOEXCEPT { | 
 |         return __do_string_hash(__val.data(), __val.data() + __val.size()); | 
 |     } | 
 | }; | 
 |  | 
 |  | 
 | #if _LIBCPP_STD_VER > 11 | 
 | inline namespace literals | 
 | { | 
 |   inline namespace string_view_literals | 
 |   { | 
 |     inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR | 
 |     basic_string_view<char> operator "" sv(const char *__str, size_t __len) _NOEXCEPT | 
 |     { | 
 |         return basic_string_view<char> (__str, __len); | 
 |     } | 
 |  | 
 |     inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR | 
 |     basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len) _NOEXCEPT | 
 |     { | 
 |         return basic_string_view<wchar_t> (__str, __len); | 
 |     } | 
 |  | 
 | #ifndef _LIBCPP_NO_HAS_CHAR8_T | 
 |     inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR | 
 |     basic_string_view<char8_t> operator "" sv(const char8_t *__str, size_t __len) _NOEXCEPT | 
 |     { | 
 |         return basic_string_view<char8_t> (__str, __len); | 
 |     } | 
 | #endif | 
 |  | 
 |     inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR | 
 |     basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len) _NOEXCEPT | 
 |     { | 
 |         return basic_string_view<char16_t> (__str, __len); | 
 |     } | 
 |  | 
 |     inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR | 
 |     basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len) _NOEXCEPT | 
 |     { | 
 |         return basic_string_view<char32_t> (__str, __len); | 
 |     } | 
 |   } | 
 | } | 
 | #endif | 
 | _LIBCPP_END_NAMESPACE_STD | 
 |  | 
 | _LIBCPP_POP_MACROS | 
 |  | 
 | #endif // _LIBCPP_STRING_VIEW |