xref: /freebsd/contrib/llvm-project/libcxx/include/string_view (revision 19fae0f66023a97a9b464b3beeeabb2081f575b3)
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-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_STRING_VIEW
11#define _LIBCPP_STRING_VIEW
12
13/*
14
15    string_view synopsis
16
17#include <compare>
18
19namespace std {
20
21    // 7.2, Class template basic_string_view
22    template<class charT, class traits = char_traits<charT>>
23        class basic_string_view;
24
25    template<class charT, class traits>
26    inline constexpr bool ranges::enable_view<basic_string_view<charT, traits>> = true;
27
28    template<class charT, class traits>
29    inline constexpr bool ranges::enable_borrowed_range<basic_string_view<charT, traits>> = true;  // C++20
30
31    // 7.9, basic_string_view non-member comparison functions
32    template<class charT, class traits>
33    constexpr bool operator==(basic_string_view<charT, traits> x,
34                              basic_string_view<charT, traits> y) noexcept;
35    template<class charT, class traits>                                                            // Removed in C++20
36    constexpr bool operator!=(basic_string_view<charT, traits> x,
37                              basic_string_view<charT, traits> y) noexcept;
38    template<class charT, class traits>                                                            // Removed in C++20
39    constexpr bool operator< (basic_string_view<charT, traits> x,
40                                 basic_string_view<charT, traits> y) noexcept;
41    template<class charT, class traits>                                                            // Removed in C++20
42    constexpr bool operator> (basic_string_view<charT, traits> x,
43                              basic_string_view<charT, traits> y) noexcept;
44    template<class charT, class traits>                                                            // Removed in C++20
45    constexpr bool operator<=(basic_string_view<charT, traits> x,
46                                 basic_string_view<charT, traits> y) noexcept;
47    template<class charT, class traits>                                                            // Removed in C++20
48    constexpr bool operator>=(basic_string_view<charT, traits> x,
49                              basic_string_view<charT, traits> y) noexcept;
50    template<class charT, class traits>                                                            // Since C++20
51    constexpr see below operator<=>(basic_string_view<charT, traits> x,
52                                    basic_string_view<charT, traits> y) noexcept;
53
54    // see below, sufficient additional overloads of comparison functions
55
56    // 7.10, Inserters and extractors
57    template<class charT, class traits>
58      basic_ostream<charT, traits>&
59        operator<<(basic_ostream<charT, traits>& os,
60                   basic_string_view<charT, traits> str);
61
62    // basic_string_view typedef names
63    typedef basic_string_view<char> string_view;
64    typedef basic_string_view<char8_t> u8string_view; // C++20
65    typedef basic_string_view<char16_t> u16string_view;
66    typedef basic_string_view<char32_t> u32string_view;
67    typedef basic_string_view<wchar_t> wstring_view;
68
69    template<class charT, class traits = char_traits<charT>>
70    class basic_string_view {
71      public:
72      // types
73      typedef traits traits_type;
74      typedef charT value_type;
75      typedef charT* pointer;
76      typedef const charT* const_pointer;
77      typedef charT& reference;
78      typedef const charT& const_reference;
79      typedef implementation-defined const_iterator;
80      typedef const_iterator iterator;
81      typedef reverse_iterator<const_iterator> const_reverse_iterator;
82      typedef const_reverse_iterator reverse_iterator;
83      typedef size_t size_type;
84      typedef ptrdiff_t difference_type;
85      static constexpr size_type npos = size_type(-1);
86
87      // 7.3, basic_string_view constructors and assignment operators
88      constexpr basic_string_view() noexcept;
89      constexpr basic_string_view(const basic_string_view&) noexcept = default;
90      basic_string_view& operator=(const basic_string_view&) noexcept = default;
91      template<class Allocator>
92      constexpr basic_string_view(const charT* str);
93      basic_string_view(nullptr_t) = delete; // C++2b
94      constexpr basic_string_view(const charT* str, size_type len);
95      template <class It, class End>
96      constexpr basic_string_view(It begin, End end); // C++20
97      template <class Range>
98      constexpr basic_string_view(Range&& r); // C++23
99
100      // 7.4, basic_string_view iterator support
101      constexpr const_iterator begin() const noexcept;
102      constexpr const_iterator end() const noexcept;
103      constexpr const_iterator cbegin() const noexcept;
104      constexpr const_iterator cend() const noexcept;
105      const_reverse_iterator rbegin() const noexcept;
106      const_reverse_iterator rend() const noexcept;
107      const_reverse_iterator crbegin() const noexcept;
108      const_reverse_iterator crend() const noexcept;
109
110      // 7.5, basic_string_view capacity
111      constexpr size_type size() const noexcept;
112      constexpr size_type length() const noexcept;
113      constexpr size_type max_size() const noexcept;
114      constexpr bool empty() const noexcept;
115
116      // 7.6, basic_string_view element access
117      constexpr const_reference operator[](size_type pos) const;
118      constexpr const_reference at(size_type pos) const;
119      constexpr const_reference front() const;
120      constexpr const_reference back() const;
121      constexpr const_pointer data() const noexcept;
122
123      // 7.7, basic_string_view modifiers
124      constexpr void remove_prefix(size_type n);
125      constexpr void remove_suffix(size_type n);
126      constexpr void swap(basic_string_view& s) noexcept;
127
128      size_type copy(charT* s, size_type n, size_type pos = 0) const;  // constexpr in C++20
129
130      constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
131      constexpr int compare(basic_string_view s) const noexcept;
132      constexpr int compare(size_type pos1, size_type n1, basic_string_view s) const;
133      constexpr int compare(size_type pos1, size_type n1,
134                            basic_string_view s, size_type pos2, size_type n2) const;
135      constexpr int compare(const charT* s) const;
136      constexpr int compare(size_type pos1, size_type n1, const charT* s) const;
137      constexpr int compare(size_type pos1, size_type n1,
138                            const charT* s, size_type n2) const;
139      constexpr size_type find(basic_string_view s, size_type pos = 0) const noexcept;
140      constexpr size_type find(charT c, size_type pos = 0) const noexcept;
141      constexpr size_type find(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
142      constexpr size_type find(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
143      constexpr size_type rfind(basic_string_view s, size_type pos = npos) const noexcept;
144      constexpr size_type rfind(charT c, size_type pos = npos) const noexcept;
145      constexpr size_type rfind(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
146      constexpr size_type rfind(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
147      constexpr size_type find_first_of(basic_string_view s, size_type pos = 0) const noexcept;
148      constexpr size_type find_first_of(charT c, size_type pos = 0) const noexcept;
149      constexpr size_type find_first_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
150      constexpr size_type find_first_of(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
151      constexpr size_type find_last_of(basic_string_view s, size_type pos = npos) const noexcept;
152      constexpr size_type find_last_of(charT c, size_type pos = npos) const noexcept;
153      constexpr size_type find_last_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
154      constexpr size_type find_last_of(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
155      constexpr size_type find_first_not_of(basic_string_view s, size_type pos = 0) const noexcept;
156      constexpr size_type find_first_not_of(charT c, size_type pos = 0) const noexcept;
157      constexpr size_type find_first_not_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
158      constexpr size_type find_first_not_of(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
159      constexpr size_type find_last_not_of(basic_string_view s, size_type pos = npos) const noexcept;
160      constexpr size_type find_last_not_of(charT c, size_type pos = npos) const noexcept;
161      constexpr size_type find_last_not_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
162      constexpr size_type find_last_not_of(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
163
164      constexpr bool starts_with(basic_string_view s) const noexcept; // C++20
165      constexpr bool starts_with(charT c) const noexcept;             // C++20
166      constexpr bool starts_with(const charT* s) const;               // C++20
167      constexpr bool ends_with(basic_string_view s) const noexcept;   // C++20
168      constexpr bool ends_with(charT c) const noexcept;               // C++20
169      constexpr bool ends_with(const charT* s) const;                 // C++20
170
171      constexpr bool contains(basic_string_view s) const noexcept; // C++2b
172      constexpr bool contains(charT c) const noexcept;             // C++2b
173      constexpr bool contains(const charT* s) const;               // C++2b
174
175     private:
176      const_pointer data_;  // exposition only
177      size_type     size_;  // exposition only
178    };
179
180  // basic_string_view deduction guides
181  template<class It, class End>
182    basic_string_view(It, End) -> basic_string_view<iter_value_t<It>>; // C++20
183  template<class Range>
184    basic_string_view(Range&&) -> basic_string_view<ranges::range_value_t<Range>>; // C++23
185
186  // 7.11, Hash support
187  template <class T> struct hash;
188  template <> struct hash<string_view>;
189  template <> struct hash<u8string_view>; // C++20
190  template <> struct hash<u16string_view>;
191  template <> struct hash<u32string_view>;
192  template <> struct hash<wstring_view>;
193
194  constexpr basic_string_view<char>     operator "" sv(const char *str,     size_t len) noexcept;
195  constexpr basic_string_view<wchar_t>  operator "" sv(const wchar_t *str,  size_t len) noexcept;
196  constexpr basic_string_view<char8_t>  operator "" sv(const char8_t *str,  size_t len) noexcept; // C++20
197  constexpr basic_string_view<char16_t> operator "" sv(const char16_t *str, size_t len) noexcept;
198  constexpr basic_string_view<char32_t> operator "" sv(const char32_t *str, size_t len) noexcept;
199
200}  // namespace std
201
202
203*/
204
205#include <__algorithm/min.h>
206#include <__assert> // all public C++ headers provide the assertion handler
207#include <__config>
208#include <__functional/hash.h>
209#include <__functional/unary_function.h>
210#include <__fwd/string_view.h>
211#include <__iterator/concepts.h>
212#include <__iterator/readable_traits.h>
213#include <__iterator/reverse_iterator.h>
214#include <__memory/pointer_traits.h>
215#include <__ranges/concepts.h>
216#include <__ranges/data.h>
217#include <__ranges/enable_borrowed_range.h>
218#include <__ranges/enable_view.h>
219#include <__ranges/size.h>
220#include <__string/char_traits.h>
221#include <iosfwd>
222#include <limits>
223#include <stdexcept>
224#include <type_traits>
225#include <version>
226
227// standard-mandated includes
228
229// [iterator.range]
230#include <__iterator/access.h>
231#include <__iterator/data.h>
232#include <__iterator/empty.h>
233#include <__iterator/reverse_access.h>
234#include <__iterator/size.h>
235
236// [string.view.synop]
237#include <compare>
238
239#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
240#  pragma GCC system_header
241#endif
242
243_LIBCPP_PUSH_MACROS
244#include <__undef_macros>
245
246
247_LIBCPP_BEGIN_NAMESPACE_STD
248
249// TODO: This is a workaround for some vendors to carry a downstream diff to accept `nullptr` in
250//       string_view constructors. This can be refactored when this exact form isn't needed anymore.
251template <class _Traits>
252_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
253inline size_t __char_traits_length_checked(const typename _Traits::char_type* __s) _NOEXCEPT {
254  // This needs to be a single statement for C++11 constexpr
255  return _LIBCPP_ASSERT(__s != nullptr, "null pointer passed to non-null argument of char_traits<...>::length"), _Traits::length(__s);
256}
257
258template<class _CharT, class _Traits>
259class basic_string_view {
260public:
261    // types
262    using traits_type            = _Traits;
263    using value_type             = _CharT;
264    using pointer                = _CharT*;
265    using const_pointer          = const _CharT*;
266    using reference              = _CharT&;
267    using const_reference        = const _CharT&;
268    using const_iterator         = const_pointer; // See [string.view.iterators]
269    using iterator               = const_iterator;
270    using const_reverse_iterator = _VSTD::reverse_iterator<const_iterator>;
271    using reverse_iterator       = const_reverse_iterator;
272    using size_type              = size_t;
273    using difference_type        = ptrdiff_t;
274    static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);
275
276    static_assert((!is_array<value_type>::value), "Character type of basic_string_view must not be an array");
277    static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string_view must be standard-layout");
278    static_assert(( is_trivial<value_type>::value), "Character type of basic_string_view must be trivial");
279    static_assert((is_same<_CharT, typename traits_type::char_type>::value),
280                  "traits_type::char_type must be the same type as CharT");
281
282    // [string.view.cons], construct/copy
283    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
284    basic_string_view() _NOEXCEPT : __data_(nullptr), __size_(0) {}
285
286    _LIBCPP_INLINE_VISIBILITY
287    basic_string_view(const basic_string_view&) _NOEXCEPT = default;
288
289    _LIBCPP_INLINE_VISIBILITY
290    basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;
291
292    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
293    basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT
294        : __data_(__s), __size_(__len)
295    {
296#if _LIBCPP_STD_VER > 11
297    _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr");
298#endif
299    }
300
301#if _LIBCPP_STD_VER > 17
302    template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
303      requires (is_same_v<iter_value_t<_It>, _CharT> && !is_convertible_v<_End, size_type>)
304    constexpr _LIBCPP_HIDE_FROM_ABI basic_string_view(_It __begin, _End __end)
305       : __data_(_VSTD::to_address(__begin)), __size_(__end - __begin)
306    {
307      _LIBCPP_ASSERT((__end - __begin) >= 0, "std::string_view::string_view(iterator, sentinel) received invalid range");
308    }
309#endif // _LIBCPP_STD_VER > 17
310
311#if _LIBCPP_STD_VER > 20
312    template <class _Range>
313      requires (
314        !is_same_v<remove_cvref_t<_Range>, basic_string_view> &&
315        ranges::contiguous_range<_Range> &&
316        ranges::sized_range<_Range> &&
317        is_same_v<ranges::range_value_t<_Range>, _CharT> &&
318        !is_convertible_v<_Range, const _CharT*> &&
319        (!requires(remove_cvref_t<_Range>& __d) {
320          __d.operator _VSTD::basic_string_view<_CharT, _Traits>();
321        }) &&
322        (!requires {
323         typename remove_reference_t<_Range>::traits_type;
324        } || is_same_v<typename remove_reference_t<_Range>::traits_type, _Traits>)
325      )
326    constexpr explicit _LIBCPP_HIDE_FROM_ABI
327    basic_string_view(_Range&& __r) : __data_(ranges::data(__r)), __size_(ranges::size(__r)) {}
328#endif // _LIBCPP_STD_VER > 20
329
330    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
331    basic_string_view(const _CharT* __s)
332        : __data_(__s), __size_(_VSTD::__char_traits_length_checked<_Traits>(__s)) {}
333
334#if _LIBCPP_STD_VER > 20
335    basic_string_view(nullptr_t) = delete;
336#endif
337
338    // [string.view.iterators], iterators
339    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
340    const_iterator begin()  const _NOEXCEPT { return cbegin(); }
341
342    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
343    const_iterator end()    const _NOEXCEPT { return cend(); }
344
345    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
346    const_iterator cbegin() const _NOEXCEPT { return __data_; }
347
348    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
349    const_iterator cend()   const _NOEXCEPT { return __data_ + __size_; }
350
351    _LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_INLINE_VISIBILITY
352    const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
353
354    _LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_INLINE_VISIBILITY
355    const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
356
357    _LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_INLINE_VISIBILITY
358    const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
359
360    _LIBCPP_CONSTEXPR_SINCE_CXX17 _LIBCPP_INLINE_VISIBILITY
361    const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
362
363    // [string.view.capacity], capacity
364    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
365    size_type size()     const _NOEXCEPT { return __size_; }
366
367    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
368    size_type length()   const _NOEXCEPT { return __size_; }
369
370    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
371    size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max() / sizeof(value_type); }
372
373    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
374    bool empty()         const _NOEXCEPT { return __size_ == 0; }
375
376    // [string.view.access], element access
377    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
378    const_reference operator[](size_type __pos) const _NOEXCEPT {
379      return _LIBCPP_ASSERT(__pos < size(), "string_view[] index out of bounds"), __data_[__pos];
380    }
381
382    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
383    const_reference at(size_type __pos) const
384    {
385        return __pos >= size()
386            ? (__throw_out_of_range("string_view::at"), __data_[0])
387            : __data_[__pos];
388    }
389
390    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
391    const_reference front() const _NOEXCEPT
392    {
393        return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data_[0];
394    }
395
396    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
397    const_reference back() const _NOEXCEPT
398    {
399        return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data_[__size_-1];
400    }
401
402    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
403    const_pointer data() const _NOEXCEPT { return __data_; }
404
405    // [string.view.modifiers], modifiers:
406    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
407    void remove_prefix(size_type __n) _NOEXCEPT
408    {
409        _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
410        __data_ += __n;
411        __size_ -= __n;
412    }
413
414    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
415    void remove_suffix(size_type __n) _NOEXCEPT
416    {
417        _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
418        __size_ -= __n;
419    }
420
421    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
422    void swap(basic_string_view& __other) _NOEXCEPT
423    {
424        const value_type *__p = __data_;
425        __data_ = __other.__data_;
426        __other.__data_ = __p;
427
428        size_type __sz = __size_;
429        __size_ = __other.__size_;
430        __other.__size_ = __sz;
431    }
432
433    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
434    size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
435    {
436        if (__pos > size())
437            __throw_out_of_range("string_view::copy");
438        size_type __rlen = _VSTD::min(__n, size() - __pos);
439        _Traits::copy(__s, data() + __pos, __rlen);
440        return __rlen;
441    }
442
443    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
444    basic_string_view substr(size_type __pos = 0, size_type __n = npos) const
445    {
446        return __pos > size()
447            ? (__throw_out_of_range("string_view::substr"), basic_string_view())
448            : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
449    }
450
451    _LIBCPP_CONSTEXPR_SINCE_CXX14 int compare(basic_string_view __sv) const _NOEXCEPT
452    {
453        size_type __rlen = _VSTD::min(size(), __sv.size());
454        int __retval = _Traits::compare(data(), __sv.data(), __rlen);
455        if (__retval == 0) // first __rlen chars matched
456            __retval = size() == __sv.size() ? 0 : (size() < __sv.size() ? -1 : 1);
457        return __retval;
458    }
459
460    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
461    int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
462    {
463        return substr(__pos1, __n1).compare(__sv);
464    }
465
466    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
467    int compare(                       size_type __pos1, size_type __n1,
468                basic_string_view __sv, size_type __pos2, size_type __n2) const
469    {
470        return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
471    }
472
473    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
474    int compare(const _CharT* __s) const _NOEXCEPT
475    {
476        return compare(basic_string_view(__s));
477    }
478
479    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
480    int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
481    {
482        return substr(__pos1, __n1).compare(basic_string_view(__s));
483    }
484
485    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
486    int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
487    {
488        return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
489    }
490
491    // find
492    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
493    size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
494    {
495        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
496        return std::__str_find<value_type, size_type, traits_type, npos>
497            (data(), size(), __s.data(), __pos, __s.size());
498    }
499
500    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
501    size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
502    {
503        return std::__str_find<value_type, size_type, traits_type, npos>
504            (data(), size(), __c, __pos);
505    }
506
507    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
508    size_type find(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
509    {
510        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
511        return std::__str_find<value_type, size_type, traits_type, npos>
512            (data(), size(), __s, __pos, __n);
513    }
514
515    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
516    size_type find(const _CharT* __s, size_type __pos = 0) const _NOEXCEPT
517    {
518        _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr");
519        return std::__str_find<value_type, size_type, traits_type, npos>
520            (data(), size(), __s, __pos, traits_type::length(__s));
521    }
522
523    // rfind
524    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
525    size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
526    {
527        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
528        return std::__str_rfind<value_type, size_type, traits_type, npos>
529            (data(), size(), __s.data(), __pos, __s.size());
530    }
531
532    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
533    size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
534    {
535        return std::__str_rfind<value_type, size_type, traits_type, npos>
536            (data(), size(), __c, __pos);
537    }
538
539    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
540    size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
541    {
542        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
543        return std::__str_rfind<value_type, size_type, traits_type, npos>
544            (data(), size(), __s, __pos, __n);
545    }
546
547    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
548    size_type rfind(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
549    {
550        _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr");
551        return std::__str_rfind<value_type, size_type, traits_type, npos>
552            (data(), size(), __s, __pos, traits_type::length(__s));
553    }
554
555    // find_first_of
556    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
557    size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
558    {
559        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
560        return std::__str_find_first_of<value_type, size_type, traits_type, npos>
561            (data(), size(), __s.data(), __pos, __s.size());
562    }
563
564    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
565    size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
566    { return find(__c, __pos); }
567
568    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
569    size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
570    {
571        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
572        return std::__str_find_first_of<value_type, size_type, traits_type, npos>
573            (data(), size(), __s, __pos, __n);
574    }
575
576    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
577    size_type find_first_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
578    {
579        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr");
580        return std::__str_find_first_of<value_type, size_type, traits_type, npos>
581            (data(), size(), __s, __pos, traits_type::length(__s));
582    }
583
584    // find_last_of
585    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
586    size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
587    {
588        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
589        return std::__str_find_last_of<value_type, size_type, traits_type, npos>
590            (data(), size(), __s.data(), __pos, __s.size());
591    }
592
593    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
594    size_type find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
595    { return rfind(__c, __pos); }
596
597    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
598    size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
599    {
600        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
601        return std::__str_find_last_of<value_type, size_type, traits_type, npos>
602            (data(), size(), __s, __pos, __n);
603    }
604
605    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
606    size_type find_last_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
607    {
608        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr");
609        return std::__str_find_last_of<value_type, size_type, traits_type, npos>
610            (data(), size(), __s, __pos, traits_type::length(__s));
611    }
612
613    // find_first_not_of
614    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
615    size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
616    {
617        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
618        return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>
619            (data(), size(), __s.data(), __pos, __s.size());
620    }
621
622    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
623    size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
624    {
625        return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>
626            (data(), size(), __c, __pos);
627    }
628
629    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
630    size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
631    {
632        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
633        return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>
634            (data(), size(), __s, __pos, __n);
635    }
636
637    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
638    size_type find_first_not_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
639    {
640        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
641        return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>
642            (data(), size(), __s, __pos, traits_type::length(__s));
643    }
644
645    // find_last_not_of
646    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
647    size_type find_last_not_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
648    {
649        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): received nullptr");
650        return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>
651            (data(), size(), __s.data(), __pos, __s.size());
652    }
653
654    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
655    size_type find_last_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
656    {
657        return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>
658            (data(), size(), __c, __pos);
659    }
660
661    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
662    size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
663    {
664        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
665        return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>
666            (data(), size(), __s, __pos, __n);
667    }
668
669    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
670    size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
671    {
672        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
673        return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>
674            (data(), size(), __s, __pos, traits_type::length(__s));
675    }
676
677#if _LIBCPP_STD_VER > 17
678    constexpr _LIBCPP_INLINE_VISIBILITY
679    bool starts_with(basic_string_view __s) const noexcept
680    { return size() >= __s.size() && compare(0, __s.size(), __s) == 0; }
681
682    constexpr _LIBCPP_INLINE_VISIBILITY
683    bool starts_with(value_type __c) const noexcept
684    { return !empty() && _Traits::eq(front(), __c); }
685
686    constexpr _LIBCPP_INLINE_VISIBILITY
687    bool starts_with(const value_type* __s) const noexcept
688    { return starts_with(basic_string_view(__s)); }
689
690    constexpr _LIBCPP_INLINE_VISIBILITY
691    bool ends_with(basic_string_view __s) const noexcept
692    { return size() >= __s.size() && compare(size() - __s.size(), npos, __s) == 0; }
693
694    constexpr _LIBCPP_INLINE_VISIBILITY
695    bool ends_with(value_type __c) const noexcept
696    { return !empty() && _Traits::eq(back(), __c); }
697
698    constexpr _LIBCPP_INLINE_VISIBILITY
699    bool ends_with(const value_type* __s) const noexcept
700    { return ends_with(basic_string_view(__s)); }
701#endif
702
703#if _LIBCPP_STD_VER > 20
704    constexpr _LIBCPP_INLINE_VISIBILITY
705    bool contains(basic_string_view __sv) const noexcept
706    { return find(__sv) != npos; }
707
708    constexpr _LIBCPP_INLINE_VISIBILITY
709    bool contains(value_type __c) const noexcept
710    { return find(__c) != npos; }
711
712    constexpr _LIBCPP_INLINE_VISIBILITY
713    bool contains(const value_type* __s) const
714    { return find(__s) != npos; }
715#endif
716
717private:
718    const   value_type* __data_;
719    size_type           __size_;
720};
721_LIBCPP_CTAD_SUPPORTED_FOR_TYPE(basic_string_view);
722
723#if _LIBCPP_STD_VER > 17
724template <class _CharT, class _Traits>
725inline constexpr bool ranges::enable_view<basic_string_view<_CharT, _Traits>> = true;
726
727template <class _CharT, class _Traits>
728inline constexpr bool ranges::enable_borrowed_range<basic_string_view<_CharT, _Traits> > = true;
729#endif // _LIBCPP_STD_VER > 17
730
731// [string.view.deduct]
732
733#if _LIBCPP_STD_VER > 17
734template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
735  basic_string_view(_It, _End) -> basic_string_view<iter_value_t<_It>>;
736#endif // _LIBCPP_STD_VER > 17
737
738
739#if _LIBCPP_STD_VER > 20
740template <ranges::contiguous_range _Range>
741  basic_string_view(_Range) -> basic_string_view<ranges::range_value_t<_Range>>;
742#endif
743
744// [string.view.comparison]
745// operator ==
746template<class _CharT, class _Traits>
747_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
748bool operator==(basic_string_view<_CharT, _Traits> __lhs,
749                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
750{
751    if (__lhs.size() != __rhs.size()) return false;
752    return __lhs.compare(__rhs) == 0;
753}
754
755// The dummy default template parameters are used to work around a MSVC issue with mangling, see VSO-409326 for details.
756// This applies to the other sufficient overloads below for the other comparison operators.
757template<class _CharT, class _Traits, int = 1>
758_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
759bool operator==(basic_string_view<_CharT, _Traits> __lhs,
760                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
761{
762    if (__lhs.size() != __rhs.size()) return false;
763    return __lhs.compare(__rhs) == 0;
764}
765
766#if _LIBCPP_STD_VER < 20
767// This overload is automatically generated in C++20.
768template<class _CharT, class _Traits, int = 2>
769_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
770bool operator==(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
771                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
772{
773    if (__lhs.size() != __rhs.size()) return false;
774    return __lhs.compare(__rhs) == 0;
775}
776#endif // _LIBCPP_STD_VER > 17
777
778// operator <=>
779
780#if _LIBCPP_STD_VER > 17
781
782template <class _CharT, class _Traits>
783_LIBCPP_HIDE_FROM_ABI constexpr auto
784operator<=>(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) noexcept {
785    if constexpr (requires { typename _Traits::comparison_category; }) {
786        // [string.view]/4
787        static_assert(
788            __comparison_category<typename _Traits::comparison_category>,
789            "return type is not a comparison category type");
790        return static_cast<typename _Traits::comparison_category>(__lhs.compare(__rhs) <=> 0);
791    } else {
792        return static_cast<weak_ordering>(__lhs.compare(__rhs) <=> 0);
793    }
794}
795
796template <class _CharT, class _Traits, int = 1>
797_LIBCPP_HIDE_FROM_ABI constexpr auto operator<=>(
798    basic_string_view<_CharT, _Traits> __lhs, type_identity_t<basic_string_view<_CharT, _Traits>> __rhs) noexcept {
799    if constexpr (requires { typename _Traits::comparison_category; }) {
800        // [string.view]/4
801        static_assert(
802            __comparison_category<typename _Traits::comparison_category>,
803            "return type is not a comparison category type");
804        return static_cast<typename _Traits::comparison_category>(__lhs.compare(__rhs) <=> 0);
805    } else {
806        return static_cast<weak_ordering>(__lhs.compare(__rhs) <=> 0);
807    }
808}
809
810#else //  _LIBCPP_STD_VER > 17
811
812// operator !=
813template<class _CharT, class _Traits>
814_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
815bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
816{
817    if (__lhs.size() != __rhs.size())
818        return true;
819    return __lhs.compare(__rhs) != 0;
820}
821
822template<class _CharT, class _Traits, int = 1>
823_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
824bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
825                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
826{
827    if (__lhs.size() != __rhs.size())
828        return true;
829    return __lhs.compare(__rhs) != 0;
830}
831
832template<class _CharT, class _Traits, int = 2>
833_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
834bool operator!=(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
835                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
836{
837    if (__lhs.size() != __rhs.size())
838        return true;
839    return __lhs.compare(__rhs) != 0;
840}
841
842
843// operator <
844template<class _CharT, class _Traits>
845_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
846bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
847{
848    return __lhs.compare(__rhs) < 0;
849}
850
851template<class _CharT, class _Traits, int = 1>
852_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
853bool operator<(basic_string_view<_CharT, _Traits> __lhs,
854                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
855{
856    return __lhs.compare(__rhs) < 0;
857}
858
859template<class _CharT, class _Traits, int = 2>
860_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
861bool operator<(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
862                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
863{
864    return __lhs.compare(__rhs) < 0;
865}
866
867
868// operator >
869template<class _CharT, class _Traits>
870_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
871bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
872{
873    return __lhs.compare(__rhs) > 0;
874}
875
876template<class _CharT, class _Traits, int = 1>
877_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
878bool operator>(basic_string_view<_CharT, _Traits> __lhs,
879                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
880{
881    return __lhs.compare(__rhs) > 0;
882}
883
884template<class _CharT, class _Traits, int = 2>
885_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
886bool operator>(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
887                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
888{
889    return __lhs.compare(__rhs) > 0;
890}
891
892
893// operator <=
894template<class _CharT, class _Traits>
895_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
896bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
897{
898    return __lhs.compare(__rhs) <= 0;
899}
900
901template<class _CharT, class _Traits, int = 1>
902_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
903bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
904                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
905{
906    return __lhs.compare(__rhs) <= 0;
907}
908
909template<class _CharT, class _Traits, int = 2>
910_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
911bool operator<=(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
912                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
913{
914    return __lhs.compare(__rhs) <= 0;
915}
916
917
918// operator >=
919template<class _CharT, class _Traits>
920_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
921bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
922{
923    return __lhs.compare(__rhs) >= 0;
924}
925
926
927template<class _CharT, class _Traits, int = 1>
928_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
929bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
930                __type_identity_t<basic_string_view<_CharT, _Traits> > __rhs) _NOEXCEPT
931{
932    return __lhs.compare(__rhs) >= 0;
933}
934
935template<class _CharT, class _Traits, int = 2>
936_LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_INLINE_VISIBILITY
937bool operator>=(__type_identity_t<basic_string_view<_CharT, _Traits> > __lhs,
938                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
939{
940    return __lhs.compare(__rhs) >= 0;
941}
942
943#endif //  _LIBCPP_STD_VER > 17
944
945template<class _CharT, class _Traits>
946_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
947operator<<(basic_ostream<_CharT, _Traits>& __os,
948           basic_string_view<_CharT, _Traits> __str);
949
950// [string.view.hash]
951template<class _CharT>
952struct __string_view_hash : public __unary_function<basic_string_view<_CharT, char_traits<_CharT> >, size_t>
953{
954    _LIBCPP_INLINE_VISIBILITY
955    size_t operator()(const basic_string_view<_CharT, char_traits<_CharT> > __val) const _NOEXCEPT {
956        return std::__do_string_hash(__val.data(), __val.data() + __val.size());
957    }
958};
959
960template <>
961struct hash<basic_string_view<char, char_traits<char> > > : __string_view_hash<char> {};
962
963#ifndef _LIBCPP_HAS_NO_CHAR8_T
964template <>
965struct hash<basic_string_view<char8_t, char_traits<char8_t> > > : __string_view_hash<char8_t> {};
966#endif
967
968template <>
969struct hash<basic_string_view<char16_t, char_traits<char16_t> > > : __string_view_hash<char16_t> {};
970
971template <>
972struct hash<basic_string_view<char32_t, char_traits<char32_t> > > : __string_view_hash<char32_t> {};
973
974#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
975template <>
976struct hash<basic_string_view<wchar_t, char_traits<wchar_t> > > : __string_view_hash<wchar_t> {};
977#endif
978
979#if _LIBCPP_STD_VER > 11
980inline namespace literals
981{
982  inline namespace string_view_literals
983  {
984    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
985    basic_string_view<char> operator "" sv(const char *__str, size_t __len) _NOEXCEPT
986    {
987        return basic_string_view<char> (__str, __len);
988    }
989
990#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
991    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
992    basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len) _NOEXCEPT
993    {
994        return basic_string_view<wchar_t> (__str, __len);
995    }
996#endif
997
998#ifndef _LIBCPP_HAS_NO_CHAR8_T
999    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1000    basic_string_view<char8_t> operator "" sv(const char8_t *__str, size_t __len) _NOEXCEPT
1001    {
1002        return basic_string_view<char8_t> (__str, __len);
1003    }
1004#endif
1005
1006    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1007    basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len) _NOEXCEPT
1008    {
1009        return basic_string_view<char16_t> (__str, __len);
1010    }
1011
1012    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1013    basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len) _NOEXCEPT
1014    {
1015        return basic_string_view<char32_t> (__str, __len);
1016    }
1017  } // namespace string_view_literals
1018} // namespace literals
1019#endif
1020_LIBCPP_END_NAMESPACE_STD
1021
1022_LIBCPP_POP_MACROS
1023
1024#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
1025#  include <algorithm>
1026#  include <concepts>
1027#  include <functional>
1028#  include <iterator>
1029#endif
1030
1031#endif // _LIBCPP_STRING_VIEW
1032