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
17namespace std {
18
19    // 7.2, Class template basic_string_view
20    template<class charT, class traits = char_traits<charT>>
21        class basic_string_view;
22
23    template<class charT, class traits>
24    inline constexpr bool ranges::enable_view<basic_string_view<charT, traits>> = true;
25
26    template<class charT, class traits>
27    inline constexpr bool ranges::enable_borrowed_range<basic_string_view<charT, traits>> = true;  // C++20
28
29    // 7.9, basic_string_view non-member comparison functions
30    template<class charT, class traits>
31    constexpr bool operator==(basic_string_view<charT, traits> x,
32                              basic_string_view<charT, traits> y) noexcept;
33    template<class charT, class traits>
34    constexpr bool operator!=(basic_string_view<charT, traits> x,
35                              basic_string_view<charT, traits> y) noexcept;
36    template<class charT, class traits>
37    constexpr bool operator< (basic_string_view<charT, traits> x,
38                                 basic_string_view<charT, traits> y) noexcept;
39    template<class charT, class traits>
40    constexpr bool operator> (basic_string_view<charT, traits> x,
41                              basic_string_view<charT, traits> y) noexcept;
42    template<class charT, class traits>
43    constexpr bool operator<=(basic_string_view<charT, traits> x,
44                                 basic_string_view<charT, traits> y) noexcept;
45    template<class charT, class traits>
46    constexpr bool operator>=(basic_string_view<charT, traits> x,
47                              basic_string_view<charT, traits> y) noexcept;
48    // see below, sufficient additional overloads of comparison functions
49
50    // 7.10, Inserters and extractors
51    template<class charT, class traits>
52      basic_ostream<charT, traits>&
53        operator<<(basic_ostream<charT, traits>& os,
54                   basic_string_view<charT, traits> str);
55
56    // basic_string_view typedef names
57    typedef basic_string_view<char> string_view;
58    typedef basic_string_view<char8_t> u8string_view; // C++20
59    typedef basic_string_view<char16_t> u16string_view;
60    typedef basic_string_view<char32_t> u32string_view;
61    typedef basic_string_view<wchar_t> wstring_view;
62
63    template<class charT, class traits = char_traits<charT>>
64    class basic_string_view {
65      public:
66      // types
67      typedef traits traits_type;
68      typedef charT value_type;
69      typedef charT* pointer;
70      typedef const charT* const_pointer;
71      typedef charT& reference;
72      typedef const charT& const_reference;
73      typedef implementation-defined const_iterator;
74      typedef const_iterator iterator;
75      typedef reverse_iterator<const_iterator> const_reverse_iterator;
76      typedef const_reverse_iterator reverse_iterator;
77      typedef size_t size_type;
78      typedef ptrdiff_t difference_type;
79      static constexpr size_type npos = size_type(-1);
80
81      // 7.3, basic_string_view constructors and assignment operators
82      constexpr basic_string_view() noexcept;
83      constexpr basic_string_view(const basic_string_view&) noexcept = default;
84      basic_string_view& operator=(const basic_string_view&) noexcept = default;
85      template<class Allocator>
86      constexpr basic_string_view(const charT* str);
87      basic_string_view(nullptr_t) = delete; // C++2b
88      constexpr basic_string_view(const charT* str, size_type len);
89      template <class It, class End>
90      constexpr basic_string_view(It begin, End end); // C++20
91      template <class Range>
92      constexpr basic_string_view(Range&& r); // C++23
93
94      // 7.4, basic_string_view iterator support
95      constexpr const_iterator begin() const noexcept;
96      constexpr const_iterator end() const noexcept;
97      constexpr const_iterator cbegin() const noexcept;
98      constexpr const_iterator cend() const noexcept;
99      const_reverse_iterator rbegin() const noexcept;
100      const_reverse_iterator rend() const noexcept;
101      const_reverse_iterator crbegin() const noexcept;
102      const_reverse_iterator crend() const noexcept;
103
104      // 7.5, basic_string_view capacity
105      constexpr size_type size() const noexcept;
106      constexpr size_type length() const noexcept;
107      constexpr size_type max_size() const noexcept;
108      constexpr bool empty() const noexcept;
109
110      // 7.6, basic_string_view element access
111      constexpr const_reference operator[](size_type pos) const;
112      constexpr const_reference at(size_type pos) const;
113      constexpr const_reference front() const;
114      constexpr const_reference back() const;
115      constexpr const_pointer data() const noexcept;
116
117      // 7.7, basic_string_view modifiers
118      constexpr void remove_prefix(size_type n);
119      constexpr void remove_suffix(size_type n);
120      constexpr void swap(basic_string_view& s) noexcept;
121
122      size_type copy(charT* s, size_type n, size_type pos = 0) const;  // constexpr in C++20
123
124      constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
125      constexpr int compare(basic_string_view s) const noexcept;
126      constexpr int compare(size_type pos1, size_type n1, basic_string_view s) const;
127      constexpr int compare(size_type pos1, size_type n1,
128                            basic_string_view s, size_type pos2, size_type n2) const;
129      constexpr int compare(const charT* s) const;
130      constexpr int compare(size_type pos1, size_type n1, const charT* s) const;
131      constexpr int compare(size_type pos1, size_type n1,
132                            const charT* s, size_type n2) const;
133      constexpr size_type find(basic_string_view s, size_type pos = 0) const noexcept;
134      constexpr size_type find(charT c, size_type pos = 0) const noexcept;
135      constexpr size_type find(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
136      constexpr size_type find(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
137      constexpr size_type rfind(basic_string_view s, size_type pos = npos) const noexcept;
138      constexpr size_type rfind(charT c, size_type pos = npos) const noexcept;
139      constexpr size_type rfind(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
140      constexpr size_type rfind(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
141      constexpr size_type find_first_of(basic_string_view s, size_type pos = 0) const noexcept;
142      constexpr size_type find_first_of(charT c, size_type pos = 0) const noexcept;
143      constexpr size_type find_first_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
144      constexpr size_type find_first_of(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
145      constexpr size_type find_last_of(basic_string_view s, size_type pos = npos) const noexcept;
146      constexpr size_type find_last_of(charT c, size_type pos = npos) const noexcept;
147      constexpr size_type find_last_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
148      constexpr size_type find_last_of(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
149      constexpr size_type find_first_not_of(basic_string_view s, size_type pos = 0) const noexcept;
150      constexpr size_type find_first_not_of(charT c, size_type pos = 0) const noexcept;
151      constexpr size_type find_first_not_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
152      constexpr size_type find_first_not_of(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
153      constexpr size_type find_last_not_of(basic_string_view s, size_type pos = npos) const noexcept;
154      constexpr size_type find_last_not_of(charT c, size_type pos = npos) const noexcept;
155      constexpr size_type find_last_not_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
156      constexpr size_type find_last_not_of(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
157
158      constexpr bool starts_with(basic_string_view s) const noexcept; // C++20
159      constexpr bool starts_with(charT c) const noexcept;             // C++20
160      constexpr bool starts_with(const charT* s) const;               // C++20
161      constexpr bool ends_with(basic_string_view s) const noexcept;   // C++20
162      constexpr bool ends_with(charT c) const noexcept;               // C++20
163      constexpr bool ends_with(const charT* s) const;                 // C++20
164
165      constexpr bool contains(basic_string_view s) const noexcept; // C++2b
166      constexpr bool contains(charT c) const noexcept;             // C++2b
167      constexpr bool contains(const charT* s) const;               // C++2b
168
169     private:
170      const_pointer data_;  // exposition only
171      size_type     size_;  // exposition only
172    };
173
174  // basic_string_view deduction guides
175  template<class It, class End>
176    basic_string_view(It, End) -> basic_string_view<iter_value_t<It>>; // C++20
177  template<class Range>
178    basic_string_view(Range&&) -> basic_string_view<ranges::range_value_t<Range>>; // C++23
179
180  // 7.11, Hash support
181  template <class T> struct hash;
182  template <> struct hash<string_view>;
183  template <> struct hash<u8string_view>; // C++20
184  template <> struct hash<u16string_view>;
185  template <> struct hash<u32string_view>;
186  template <> struct hash<wstring_view>;
187
188  constexpr basic_string_view<char>     operator "" sv( const char *str,     size_t len ) noexcept;
189  constexpr basic_string_view<wchar_t>  operator "" sv( const wchar_t *str,  size_t len ) noexcept;
190  constexpr basic_string_view<char8_t>  operator "" sv( const char8_t *str,  size_t len ) noexcept; // C++20
191  constexpr basic_string_view<char16_t> operator "" sv( const char16_t *str, size_t len ) noexcept;
192  constexpr basic_string_view<char32_t> operator "" sv( const char32_t *str, size_t len ) noexcept;
193
194}  // namespace std
195
196
197*/
198
199#include <__algorithm/min.h>
200#include <__assert> // all public C++ headers provide the assertion handler
201#include <__config>
202#include <__functional/hash.h>
203#include <__functional/unary_function.h>
204#include <__fwd/string_view.h>
205#include <__iterator/concepts.h>
206#include <__iterator/readable_traits.h>
207#include <__iterator/reverse_iterator.h>
208#include <__memory/pointer_traits.h>
209#include <__ranges/concepts.h>
210#include <__ranges/data.h>
211#include <__ranges/enable_borrowed_range.h>
212#include <__ranges/enable_view.h>
213#include <__ranges/size.h>
214#include <__string/char_traits.h>
215#include <compare>
216#include <iosfwd>
217#include <limits>
218#include <stdexcept>
219#include <type_traits>
220#include <version>
221
222#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
223#  pragma GCC system_header
224#endif
225
226_LIBCPP_PUSH_MACROS
227#include <__undef_macros>
228
229
230_LIBCPP_BEGIN_NAMESPACE_STD
231
232// TODO: This is a workaround for some vendors to carry a downstream diff to accept `nullptr` in
233//       string_view constructors. This can be refactored when this exact form isn't needed anymore.
234template <class _Traits>
235_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
236inline size_t __char_traits_length_checked(const typename _Traits::char_type* __s) _NOEXCEPT {
237  // This needs to be a single statement for C++11 constexpr
238  return _LIBCPP_ASSERT(__s != nullptr, "null pointer passed to non-null argument of char_traits<...>::length"), _Traits::length(__s);
239}
240
241template<class _CharT, class _Traits>
242class
243    _LIBCPP_PREFERRED_NAME(string_view)
244#ifndef _LIBCPP_HAS_NO_CHAR8_T
245    _LIBCPP_PREFERRED_NAME(u8string_view)
246#endif
247    _LIBCPP_PREFERRED_NAME(u16string_view)
248    _LIBCPP_PREFERRED_NAME(u32string_view)
249    _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wstring_view))
250    basic_string_view {
251public:
252    // types
253    typedef _Traits                                    traits_type;
254    typedef _CharT                                     value_type;
255    typedef _CharT*                                    pointer;
256    typedef const _CharT*                              const_pointer;
257    typedef _CharT&                                    reference;
258    typedef const _CharT&                              const_reference;
259    typedef const_pointer                              const_iterator; // See [string.view.iterators]
260    typedef const_iterator                             iterator;
261    typedef _VSTD::reverse_iterator<const_iterator>    const_reverse_iterator;
262    typedef const_reverse_iterator                     reverse_iterator;
263    typedef size_t                                     size_type;
264    typedef ptrdiff_t                                  difference_type;
265    static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);
266
267    static_assert((!is_array<value_type>::value), "Character type of basic_string_view must not be an array");
268    static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string_view must be standard-layout");
269    static_assert(( is_trivial<value_type>::value), "Character type of basic_string_view must be trivial");
270    static_assert((is_same<_CharT, typename traits_type::char_type>::value),
271                  "traits_type::char_type must be the same type as CharT");
272
273    // [string.view.cons], construct/copy
274    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
275    basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {}
276
277    _LIBCPP_INLINE_VISIBILITY
278    basic_string_view(const basic_string_view&) _NOEXCEPT = default;
279
280    _LIBCPP_INLINE_VISIBILITY
281    basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;
282
283    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
284    basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT
285        : __data(__s), __size(__len)
286    {
287#if _LIBCPP_STD_VER > 11
288    _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr");
289#endif
290    }
291
292#if _LIBCPP_STD_VER > 17
293    template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
294      requires (is_same_v<iter_value_t<_It>, _CharT> && !is_convertible_v<_End, size_type>)
295    constexpr _LIBCPP_HIDE_FROM_ABI basic_string_view(_It __begin, _End __end)
296       : __data(_VSTD::to_address(__begin)), __size(__end - __begin)
297    {
298      _LIBCPP_ASSERT((__end - __begin) >= 0, "std::string_view::string_view(iterator, sentinel) received invalid range");
299    }
300#endif // _LIBCPP_STD_VER > 17
301
302#if _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
303    template <class _Range>
304      requires (
305        !is_same_v<remove_cvref_t<_Range>, basic_string_view> &&
306        ranges::contiguous_range<_Range> &&
307        ranges::sized_range<_Range> &&
308        is_same_v<ranges::range_value_t<_Range>, _CharT> &&
309        !is_convertible_v<_Range, const _CharT*> &&
310        (!requires(remove_cvref_t<_Range>& d) {
311          d.operator _VSTD::basic_string_view<_CharT, _Traits>();
312        }) &&
313        (!requires {
314         typename remove_reference_t<_Range>::traits_type;
315        } || is_same_v<typename remove_reference_t<_Range>::traits_type, _Traits>)
316      )
317    constexpr _LIBCPP_HIDE_FROM_ABI
318    basic_string_view(_Range&& __r) : __data(ranges::data(__r)), __size(ranges::size(__r)) {}
319#endif // _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
320
321    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
322    basic_string_view(const _CharT* __s)
323        : __data(__s), __size(_VSTD::__char_traits_length_checked<_Traits>(__s)) {}
324
325#if _LIBCPP_STD_VER > 20
326    basic_string_view(nullptr_t) = delete;
327#endif
328
329    // [string.view.iterators], iterators
330    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
331    const_iterator begin()  const _NOEXCEPT { return cbegin(); }
332
333    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
334    const_iterator end()    const _NOEXCEPT { return cend(); }
335
336    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
337    const_iterator cbegin() const _NOEXCEPT { return __data; }
338
339    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
340    const_iterator cend()   const _NOEXCEPT { return __data + __size; }
341
342    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
343    const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
344
345    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
346    const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
347
348    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
349    const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
350
351    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
352    const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
353
354    // [string.view.capacity], capacity
355    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
356    size_type size()     const _NOEXCEPT { return __size; }
357
358    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
359    size_type length()   const _NOEXCEPT { return __size; }
360
361    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
362    size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max() / sizeof(value_type); }
363
364    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
365    bool empty()         const _NOEXCEPT { return __size == 0; }
366
367    // [string.view.access], element access
368    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
369    const_reference operator[](size_type __pos) const _NOEXCEPT {
370      return _LIBCPP_ASSERT(__pos < size(), "string_view[] index out of bounds"), __data[__pos];
371    }
372
373    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
374    const_reference at(size_type __pos) const
375    {
376        return __pos >= size()
377            ? (__throw_out_of_range("string_view::at"), __data[0])
378            : __data[__pos];
379    }
380
381    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
382    const_reference front() const _NOEXCEPT
383    {
384        return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0];
385    }
386
387    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
388    const_reference back() const _NOEXCEPT
389    {
390        return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1];
391    }
392
393    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
394    const_pointer data() const _NOEXCEPT { return __data; }
395
396    // [string.view.modifiers], modifiers:
397    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
398    void remove_prefix(size_type __n) _NOEXCEPT
399    {
400        _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
401        __data += __n;
402        __size -= __n;
403    }
404
405    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
406    void remove_suffix(size_type __n) _NOEXCEPT
407    {
408        _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
409        __size -= __n;
410    }
411
412    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
413    void swap(basic_string_view& __other) _NOEXCEPT
414    {
415        const value_type *__p = __data;
416        __data = __other.__data;
417        __other.__data = __p;
418
419        size_type __sz = __size;
420        __size = __other.__size;
421        __other.__size = __sz;
422    }
423
424    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
425    size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
426    {
427        if (__pos > size())
428            __throw_out_of_range("string_view::copy");
429        size_type __rlen = _VSTD::min(__n, size() - __pos);
430        _Traits::copy(__s, data() + __pos, __rlen);
431        return __rlen;
432    }
433
434    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
435    basic_string_view substr(size_type __pos = 0, size_type __n = npos) const
436    {
437        return __pos > size()
438            ? (__throw_out_of_range("string_view::substr"), basic_string_view())
439            : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
440    }
441
442    _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT
443    {
444        size_type __rlen = _VSTD::min( size(), __sv.size());
445        int __retval = _Traits::compare(data(), __sv.data(), __rlen);
446        if ( __retval == 0 ) // first __rlen chars matched
447            __retval = size() == __sv.size() ? 0 : ( size() < __sv.size() ? -1 : 1 );
448        return __retval;
449    }
450
451    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
452    int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
453    {
454        return substr(__pos1, __n1).compare(__sv);
455    }
456
457    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
458    int compare(                       size_type __pos1, size_type __n1,
459                basic_string_view __sv, size_type __pos2, size_type __n2) const
460    {
461        return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
462    }
463
464    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
465    int compare(const _CharT* __s) const _NOEXCEPT
466    {
467        return compare(basic_string_view(__s));
468    }
469
470    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
471    int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
472    {
473        return substr(__pos1, __n1).compare(basic_string_view(__s));
474    }
475
476    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
477    int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
478    {
479        return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
480    }
481
482    // find
483    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
484    size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
485    {
486        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
487        return __str_find<value_type, size_type, traits_type, npos>
488            (data(), size(), __s.data(), __pos, __s.size());
489    }
490
491    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
492    size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
493    {
494        return __str_find<value_type, size_type, traits_type, npos>
495            (data(), size(), __c, __pos);
496    }
497
498    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
499    size_type find(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
500    {
501        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
502        return __str_find<value_type, size_type, traits_type, npos>
503            (data(), size(), __s, __pos, __n);
504    }
505
506    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
507    size_type find(const _CharT* __s, size_type __pos = 0) const _NOEXCEPT
508    {
509        _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr");
510        return __str_find<value_type, size_type, traits_type, npos>
511            (data(), size(), __s, __pos, traits_type::length(__s));
512    }
513
514    // rfind
515    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
516    size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
517    {
518        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
519        return __str_rfind<value_type, size_type, traits_type, npos>
520            (data(), size(), __s.data(), __pos, __s.size());
521    }
522
523    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
524    size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
525    {
526        return __str_rfind<value_type, size_type, traits_type, npos>
527            (data(), size(), __c, __pos);
528    }
529
530    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
531    size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
532    {
533        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
534        return __str_rfind<value_type, size_type, traits_type, npos>
535            (data(), size(), __s, __pos, __n);
536    }
537
538    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
539    size_type rfind(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
540    {
541        _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr");
542        return __str_rfind<value_type, size_type, traits_type, npos>
543            (data(), size(), __s, __pos, traits_type::length(__s));
544    }
545
546    // find_first_of
547    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
548    size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
549    {
550        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
551        return __str_find_first_of<value_type, size_type, traits_type, npos>
552            (data(), size(), __s.data(), __pos, __s.size());
553    }
554
555    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
556    size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
557    { return find(__c, __pos); }
558
559    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
560    size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
561    {
562        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
563        return __str_find_first_of<value_type, size_type, traits_type, npos>
564            (data(), size(), __s, __pos, __n);
565    }
566
567    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
568    size_type find_first_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
569    {
570        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr");
571        return __str_find_first_of<value_type, size_type, traits_type, npos>
572            (data(), size(), __s, __pos, traits_type::length(__s));
573    }
574
575    // find_last_of
576    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
577    size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
578    {
579        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
580        return __str_find_last_of<value_type, size_type, traits_type, npos>
581            (data(), size(), __s.data(), __pos, __s.size());
582    }
583
584    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
585    size_type find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
586    { return rfind(__c, __pos); }
587
588    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
589    size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
590    {
591        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
592        return __str_find_last_of<value_type, size_type, traits_type, npos>
593            (data(), size(), __s, __pos, __n);
594    }
595
596    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
597    size_type find_last_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
598    {
599        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr");
600        return __str_find_last_of<value_type, size_type, traits_type, npos>
601            (data(), size(), __s, __pos, traits_type::length(__s));
602    }
603
604    // find_first_not_of
605    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
606    size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
607    {
608        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
609        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
610            (data(), size(), __s.data(), __pos, __s.size());
611    }
612
613    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
614    size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
615    {
616        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
617            (data(), size(), __c, __pos);
618    }
619
620    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
621    size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
622    {
623        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
624        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
625            (data(), size(), __s, __pos, __n);
626    }
627
628    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
629    size_type find_first_not_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
630    {
631        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
632        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
633            (data(), size(), __s, __pos, traits_type::length(__s));
634    }
635
636    // find_last_not_of
637    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
638    size_type find_last_not_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
639    {
640        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): received nullptr");
641        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
642            (data(), size(), __s.data(), __pos, __s.size());
643    }
644
645    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
646    size_type find_last_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
647    {
648        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
649            (data(), size(), __c, __pos);
650    }
651
652    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
653    size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
654    {
655        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
656        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
657            (data(), size(), __s, __pos, __n);
658    }
659
660    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
661    size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
662    {
663        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
664        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
665            (data(), size(), __s, __pos, traits_type::length(__s));
666    }
667
668#if _LIBCPP_STD_VER > 17
669    constexpr _LIBCPP_INLINE_VISIBILITY
670    bool starts_with(basic_string_view __s) const noexcept
671    { return size() >= __s.size() && compare(0, __s.size(), __s) == 0; }
672
673    constexpr _LIBCPP_INLINE_VISIBILITY
674    bool starts_with(value_type __c) const noexcept
675    { return !empty() && _Traits::eq(front(), __c); }
676
677    constexpr _LIBCPP_INLINE_VISIBILITY
678    bool starts_with(const value_type* __s) const noexcept
679    { return starts_with(basic_string_view(__s)); }
680
681    constexpr _LIBCPP_INLINE_VISIBILITY
682    bool ends_with(basic_string_view __s) const noexcept
683    { return size() >= __s.size() && compare(size() - __s.size(), npos, __s) == 0; }
684
685    constexpr _LIBCPP_INLINE_VISIBILITY
686    bool ends_with(value_type __c) const noexcept
687    { return !empty() && _Traits::eq(back(), __c); }
688
689    constexpr _LIBCPP_INLINE_VISIBILITY
690    bool ends_with(const value_type* __s) const noexcept
691    { return ends_with(basic_string_view(__s)); }
692#endif
693
694#if _LIBCPP_STD_VER > 20
695    constexpr _LIBCPP_INLINE_VISIBILITY
696    bool contains(basic_string_view __sv) const noexcept
697    { return find(__sv) != npos; }
698
699    constexpr _LIBCPP_INLINE_VISIBILITY
700    bool contains(value_type __c) const noexcept
701    { return find(__c) != npos; }
702
703    constexpr _LIBCPP_INLINE_VISIBILITY
704    bool contains(const value_type* __s) const
705    { return find(__s) != npos; }
706#endif
707
708private:
709    const   value_type* __data;
710    size_type           __size;
711};
712
713#if _LIBCPP_STD_VER > 17
714template <class _CharT, class _Traits>
715inline constexpr bool ranges::enable_view<basic_string_view<_CharT, _Traits>> = true;
716
717template <class _CharT, class _Traits>
718inline constexpr bool ranges::enable_borrowed_range<basic_string_view<_CharT, _Traits> > = true;
719#endif // _LIBCPP_STD_VER > 17
720
721// [string.view.deduct]
722
723#if _LIBCPP_STD_VER > 17
724template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
725  basic_string_view(_It, _End) -> basic_string_view<iter_value_t<_It>>;
726#endif // _LIBCPP_STD_VER > 17
727
728
729#if _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
730template <ranges::contiguous_range _Range>
731  basic_string_view(_Range) -> basic_string_view<ranges::range_value_t<_Range>>;
732#endif // _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
733
734// [string.view.comparison]
735// operator ==
736template<class _CharT, class _Traits>
737_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
738bool operator==(basic_string_view<_CharT, _Traits> __lhs,
739                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
740{
741    if ( __lhs.size() != __rhs.size()) return false;
742    return __lhs.compare(__rhs) == 0;
743}
744
745// The dummy default template parameters are used to work around a MSVC issue with mangling, see VSO-409326 for details.
746// This applies to the other sufficient overloads below for the other comparison operators.
747template<class _CharT, class _Traits, int = 1>
748_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
749bool operator==(basic_string_view<_CharT, _Traits> __lhs,
750                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
751{
752    if ( __lhs.size() != __rhs.size()) return false;
753    return __lhs.compare(__rhs) == 0;
754}
755
756template<class _CharT, class _Traits, int = 2>
757_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
758bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
759                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
760{
761    if ( __lhs.size() != __rhs.size()) return false;
762    return __lhs.compare(__rhs) == 0;
763}
764
765
766// operator !=
767template<class _CharT, class _Traits>
768_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
769bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
770{
771    if ( __lhs.size() != __rhs.size())
772        return true;
773    return __lhs.compare(__rhs) != 0;
774}
775
776template<class _CharT, class _Traits, int = 1>
777_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
778bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
779                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
780{
781    if ( __lhs.size() != __rhs.size())
782        return true;
783    return __lhs.compare(__rhs) != 0;
784}
785
786template<class _CharT, class _Traits, int = 2>
787_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
788bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
789                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
790{
791    if ( __lhs.size() != __rhs.size())
792        return true;
793    return __lhs.compare(__rhs) != 0;
794}
795
796
797// operator <
798template<class _CharT, class _Traits>
799_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
800bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
801{
802    return __lhs.compare(__rhs) < 0;
803}
804
805template<class _CharT, class _Traits, int = 1>
806_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
807bool operator<(basic_string_view<_CharT, _Traits> __lhs,
808                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
809{
810    return __lhs.compare(__rhs) < 0;
811}
812
813template<class _CharT, class _Traits, int = 2>
814_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
815bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
816                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
817{
818    return __lhs.compare(__rhs) < 0;
819}
820
821
822// operator >
823template<class _CharT, class _Traits>
824_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
825bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
826{
827    return __lhs.compare(__rhs) > 0;
828}
829
830template<class _CharT, class _Traits, int = 1>
831_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
832bool operator>(basic_string_view<_CharT, _Traits> __lhs,
833                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
834{
835    return __lhs.compare(__rhs) > 0;
836}
837
838template<class _CharT, class _Traits, int = 2>
839_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
840bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
841                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
842{
843    return __lhs.compare(__rhs) > 0;
844}
845
846
847// operator <=
848template<class _CharT, class _Traits>
849_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
850bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
851{
852    return __lhs.compare(__rhs) <= 0;
853}
854
855template<class _CharT, class _Traits, int = 1>
856_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
857bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
858                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
859{
860    return __lhs.compare(__rhs) <= 0;
861}
862
863template<class _CharT, class _Traits, int = 2>
864_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
865bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
866                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
867{
868    return __lhs.compare(__rhs) <= 0;
869}
870
871
872// operator >=
873template<class _CharT, class _Traits>
874_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
875bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
876{
877    return __lhs.compare(__rhs) >= 0;
878}
879
880
881template<class _CharT, class _Traits, int = 1>
882_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
883bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
884                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
885{
886    return __lhs.compare(__rhs) >= 0;
887}
888
889template<class _CharT, class _Traits, int = 2>
890_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
891bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
892                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
893{
894    return __lhs.compare(__rhs) >= 0;
895}
896
897
898template<class _CharT, class _Traits>
899basic_ostream<_CharT, _Traits>&
900operator<<(basic_ostream<_CharT, _Traits>& __os,
901           basic_string_view<_CharT, _Traits> __str);
902
903// [string.view.hash]
904template<class _CharT>
905struct _LIBCPP_TEMPLATE_VIS hash<basic_string_view<_CharT, char_traits<_CharT> > >
906    : public unary_function<basic_string_view<_CharT, char_traits<_CharT> >, size_t>
907{
908    _LIBCPP_INLINE_VISIBILITY
909    size_t operator()(const basic_string_view<_CharT, char_traits<_CharT> > __val) const _NOEXCEPT {
910        return __do_string_hash(__val.data(), __val.data() + __val.size());
911    }
912};
913
914
915#if _LIBCPP_STD_VER > 11
916inline namespace literals
917{
918  inline namespace string_view_literals
919  {
920    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
921    basic_string_view<char> operator "" sv(const char *__str, size_t __len) _NOEXCEPT
922    {
923        return basic_string_view<char> (__str, __len);
924    }
925
926#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
927    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
928    basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len) _NOEXCEPT
929    {
930        return basic_string_view<wchar_t> (__str, __len);
931    }
932#endif
933
934#ifndef _LIBCPP_HAS_NO_CHAR8_T
935    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
936    basic_string_view<char8_t> operator "" sv(const char8_t *__str, size_t __len) _NOEXCEPT
937    {
938        return basic_string_view<char8_t> (__str, __len);
939    }
940#endif
941
942    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
943    basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len) _NOEXCEPT
944    {
945        return basic_string_view<char16_t> (__str, __len);
946    }
947
948    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
949    basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len) _NOEXCEPT
950    {
951        return basic_string_view<char32_t> (__str, __len);
952    }
953  } // namespace string_view_literals
954} // namespace literals
955#endif
956_LIBCPP_END_NAMESPACE_STD
957
958_LIBCPP_POP_MACROS
959
960#endif // _LIBCPP_STRING_VIEW
961