xref: /freebsd/contrib/llvm-project/libcxx/include/string_view (revision 5e801ac66d24704442eba426ed13c3effb8a34e7)
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/*
14string_view synopsis
15
16namespace std {
17
18    // 7.2, Class template basic_string_view
19    template<class charT, class traits = char_traits<charT>>
20        class basic_string_view;
21
22    template<class charT, class traits>
23    inline constexpr bool ranges::enable_view<basic_string_view<charT, traits>> = true;
24
25    template<class charT, class traits>
26    inline constexpr bool ranges::enable_borrowed_range<basic_string_view<charT, traits>> = true;  // C++20
27
28    // 7.9, basic_string_view non-member comparison functions
29    template<class charT, class traits>
30    constexpr bool operator==(basic_string_view<charT, traits> x,
31                              basic_string_view<charT, traits> y) noexcept;
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>
36    constexpr bool operator< (basic_string_view<charT, traits> x,
37                                 basic_string_view<charT, traits> y) noexcept;
38    template<class charT, class traits>
39    constexpr bool operator> (basic_string_view<charT, traits> x,
40                              basic_string_view<charT, traits> y) noexcept;
41    template<class charT, class traits>
42    constexpr bool operator<=(basic_string_view<charT, traits> x,
43                                 basic_string_view<charT, traits> y) noexcept;
44    template<class charT, class traits>
45    constexpr bool operator>=(basic_string_view<charT, traits> x,
46                              basic_string_view<charT, traits> y) noexcept;
47    // see below, sufficient additional overloads of comparison functions
48
49    // 7.10, Inserters and extractors
50    template<class charT, class traits>
51      basic_ostream<charT, traits>&
52        operator<<(basic_ostream<charT, traits>& os,
53                   basic_string_view<charT, traits> str);
54
55    // basic_string_view typedef names
56    typedef basic_string_view<char> string_view;
57    typedef basic_string_view<char8_t> u8string_view; // C++20
58    typedef basic_string_view<char16_t> u16string_view;
59    typedef basic_string_view<char32_t> u32string_view;
60    typedef basic_string_view<wchar_t> wstring_view;
61
62    template<class charT, class traits = char_traits<charT>>
63    class basic_string_view {
64      public:
65      // types
66      typedef traits traits_type;
67      typedef charT value_type;
68      typedef charT* pointer;
69      typedef const charT* const_pointer;
70      typedef charT& reference;
71      typedef const charT& const_reference;
72      typedef implementation-defined const_iterator;
73      typedef const_iterator iterator;
74      typedef reverse_iterator<const_iterator> const_reverse_iterator;
75      typedef const_reverse_iterator reverse_iterator;
76      typedef size_t size_type;
77      typedef ptrdiff_t difference_type;
78      static constexpr size_type npos = size_type(-1);
79
80      // 7.3, basic_string_view constructors and assignment operators
81      constexpr basic_string_view() noexcept;
82      constexpr basic_string_view(const basic_string_view&) noexcept = default;
83      basic_string_view& operator=(const basic_string_view&) noexcept = default;
84      template<class Allocator>
85      constexpr basic_string_view(const charT* str);
86      basic_string_view(nullptr_t) = delete; // C++2b
87      constexpr basic_string_view(const charT* str, size_type len);
88      template <class It, class End>
89      constexpr basic_string_view(It begin, End end); // C++20
90
91      // 7.4, basic_string_view iterator support
92      constexpr const_iterator begin() const noexcept;
93      constexpr const_iterator end() const noexcept;
94      constexpr const_iterator cbegin() const noexcept;
95      constexpr const_iterator cend() const noexcept;
96      const_reverse_iterator rbegin() const noexcept;
97      const_reverse_iterator rend() const noexcept;
98      const_reverse_iterator crbegin() const noexcept;
99      const_reverse_iterator crend() const noexcept;
100
101      // 7.5, basic_string_view capacity
102      constexpr size_type size() const noexcept;
103      constexpr size_type length() const noexcept;
104      constexpr size_type max_size() const noexcept;
105      constexpr bool empty() const noexcept;
106
107      // 7.6, basic_string_view element access
108      constexpr const_reference operator[](size_type pos) const;
109      constexpr const_reference at(size_type pos) const;
110      constexpr const_reference front() const;
111      constexpr const_reference back() const;
112      constexpr const_pointer data() const noexcept;
113
114      // 7.7, basic_string_view modifiers
115      constexpr void remove_prefix(size_type n);
116      constexpr void remove_suffix(size_type n);
117      constexpr void swap(basic_string_view& s) noexcept;
118
119      size_type copy(charT* s, size_type n, size_type pos = 0) const;  // constexpr in C++20
120
121      constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
122      constexpr int compare(basic_string_view s) const noexcept;
123      constexpr int compare(size_type pos1, size_type n1, basic_string_view s) const;
124      constexpr int compare(size_type pos1, size_type n1,
125                            basic_string_view s, size_type pos2, size_type n2) const;
126      constexpr int compare(const charT* s) const;
127      constexpr int compare(size_type pos1, size_type n1, const charT* s) const;
128      constexpr int compare(size_type pos1, size_type n1,
129                            const charT* s, size_type n2) const;
130      constexpr size_type find(basic_string_view s, size_type pos = 0) const noexcept;
131      constexpr size_type find(charT c, size_type pos = 0) const noexcept;
132      constexpr size_type find(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
133      constexpr size_type find(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
134      constexpr size_type rfind(basic_string_view s, size_type pos = npos) const noexcept;
135      constexpr size_type rfind(charT c, size_type pos = npos) const noexcept;
136      constexpr size_type rfind(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
137      constexpr size_type rfind(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
138      constexpr size_type find_first_of(basic_string_view s, size_type pos = 0) const noexcept;
139      constexpr size_type find_first_of(charT c, size_type pos = 0) const noexcept;
140      constexpr size_type find_first_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
141      constexpr size_type find_first_of(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
142      constexpr size_type find_last_of(basic_string_view s, size_type pos = npos) const noexcept;
143      constexpr size_type find_last_of(charT c, size_type pos = npos) const noexcept;
144      constexpr size_type find_last_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
145      constexpr size_type find_last_of(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
146      constexpr size_type find_first_not_of(basic_string_view s, size_type pos = 0) const noexcept;
147      constexpr size_type find_first_not_of(charT c, size_type pos = 0) const noexcept;
148      constexpr size_type find_first_not_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
149      constexpr size_type find_first_not_of(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
150      constexpr size_type find_last_not_of(basic_string_view s, size_type pos = npos) const noexcept;
151      constexpr size_type find_last_not_of(charT c, size_type pos = npos) const noexcept;
152      constexpr size_type find_last_not_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
153      constexpr size_type find_last_not_of(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
154
155      constexpr bool starts_with(basic_string_view s) const noexcept; // C++20
156      constexpr bool starts_with(charT c) const noexcept;             // C++20
157      constexpr bool starts_with(const charT* s) const;               // C++20
158      constexpr bool ends_with(basic_string_view s) const noexcept;   // C++20
159      constexpr bool ends_with(charT c) const noexcept;               // C++20
160      constexpr bool ends_with(const charT* s) const;                 // C++20
161
162      constexpr bool contains(basic_string_view s) const noexcept; // C++2b
163      constexpr bool contains(charT c) const noexcept;             // C++2b
164      constexpr bool contains(const charT* s) const;               // C++2b
165
166     private:
167      const_pointer data_;  // exposition only
168      size_type     size_;  // exposition only
169    };
170
171  // basic_string_view deduction guides
172  template<class It, class End>
173    basic_string_view(It, End) -> basic_string_view<iter_value_t<It>>; // C++20
174
175  // 7.11, Hash support
176  template <class T> struct hash;
177  template <> struct hash<string_view>;
178  template <> struct hash<u8string_view>; // C++20
179  template <> struct hash<u16string_view>;
180  template <> struct hash<u32string_view>;
181  template <> struct hash<wstring_view>;
182
183  constexpr basic_string_view<char>     operator "" sv( const char *str,     size_t len ) noexcept;
184  constexpr basic_string_view<wchar_t>  operator "" sv( const wchar_t *str,  size_t len ) noexcept;
185  constexpr basic_string_view<char8_t>  operator "" sv( const char8_t *str,  size_t len ) noexcept; // C++20
186  constexpr basic_string_view<char16_t> operator "" sv( const char16_t *str, size_t len ) noexcept;
187  constexpr basic_string_view<char32_t> operator "" sv( const char32_t *str, size_t len ) noexcept;
188
189}  // namespace std
190
191
192*/
193
194#include <__concepts/convertible_to.h>
195#include <__concepts/same_as.h>
196#include <__config>
197#include <__debug>
198#include <__ranges/enable_borrowed_range.h>
199#include <__ranges/enable_view.h>
200#include <__string>
201#include <algorithm>
202#include <compare>
203#include <iosfwd>
204#include <iterator>
205#include <limits>
206#include <stdexcept>
207#include <version>
208
209#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
210#pragma GCC system_header
211#endif
212
213_LIBCPP_PUSH_MACROS
214#include <__undef_macros>
215
216
217_LIBCPP_BEGIN_NAMESPACE_STD
218
219template<class _CharT, class _Traits = char_traits<_CharT> >
220    class _LIBCPP_TEMPLATE_VIS basic_string_view;
221
222typedef basic_string_view<char>     string_view;
223#ifndef _LIBCPP_HAS_NO_CHAR8_T
224typedef basic_string_view<char8_t>  u8string_view;
225#endif
226typedef basic_string_view<char16_t> u16string_view;
227typedef basic_string_view<char32_t> u32string_view;
228#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
229typedef basic_string_view<wchar_t>  wstring_view;
230#endif
231
232template<class _CharT, class _Traits>
233class
234    _LIBCPP_PREFERRED_NAME(string_view)
235#ifndef _LIBCPP_HAS_NO_CHAR8_T
236    _LIBCPP_PREFERRED_NAME(u8string_view)
237#endif
238    _LIBCPP_PREFERRED_NAME(u16string_view)
239    _LIBCPP_PREFERRED_NAME(u32string_view)
240    _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wstring_view))
241    basic_string_view {
242public:
243    // types
244    typedef _Traits                                    traits_type;
245    typedef _CharT                                     value_type;
246    typedef _CharT*                                    pointer;
247    typedef const _CharT*                              const_pointer;
248    typedef _CharT&                                    reference;
249    typedef const _CharT&                              const_reference;
250    typedef const_pointer                              const_iterator; // See [string.view.iterators]
251    typedef const_iterator                             iterator;
252    typedef _VSTD::reverse_iterator<const_iterator>    const_reverse_iterator;
253    typedef const_reverse_iterator                     reverse_iterator;
254    typedef size_t                                     size_type;
255    typedef ptrdiff_t                                  difference_type;
256    static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);
257
258    static_assert((!is_array<value_type>::value), "Character type of basic_string_view must not be an array");
259    static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string_view must be standard-layout");
260    static_assert(( is_trivial<value_type>::value), "Character type of basic_string_view must be trivial");
261    static_assert((is_same<_CharT, typename traits_type::char_type>::value),
262                  "traits_type::char_type must be the same type as CharT");
263
264    // [string.view.cons], construct/copy
265    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
266    basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {}
267
268    _LIBCPP_INLINE_VISIBILITY
269    basic_string_view(const basic_string_view&) _NOEXCEPT = default;
270
271    _LIBCPP_INLINE_VISIBILITY
272    basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;
273
274    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
275    basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT
276        : __data(__s), __size(__len)
277    {
278#if _LIBCPP_STD_VER > 11
279    _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr");
280#endif
281    }
282
283#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
284    template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
285      requires (same_as<iter_value_t<_It>, _CharT> && !convertible_to<_End, size_type>)
286    constexpr _LIBCPP_HIDE_FROM_ABI basic_string_view(_It __begin, _End __end)
287       : __data(_VSTD::to_address(__begin)), __size(__end - __begin)
288    {
289      _LIBCPP_ASSERT((__end - __begin) >= 0, "std::string_view::string_view(iterator, sentinel) received invalid range");
290    }
291#endif
292
293    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
294    basic_string_view(const _CharT* __s)
295        : __data(__s), __size(_VSTD::__char_traits_length_checked<_Traits>(__s)) {}
296
297#if _LIBCPP_STD_VER > 20
298    basic_string_view(nullptr_t) = delete;
299#endif
300
301    // [string.view.iterators], iterators
302    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
303    const_iterator begin()  const _NOEXCEPT { return cbegin(); }
304
305    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
306    const_iterator end()    const _NOEXCEPT { return cend(); }
307
308    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
309    const_iterator cbegin() const _NOEXCEPT { return __data; }
310
311    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
312    const_iterator cend()   const _NOEXCEPT { return __data + __size; }
313
314    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
315    const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
316
317    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
318    const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
319
320    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
321    const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
322
323    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
324    const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
325
326    // [string.view.capacity], capacity
327    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
328    size_type size()     const _NOEXCEPT { return __size; }
329
330    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
331    size_type length()   const _NOEXCEPT { return __size; }
332
333    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
334    size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max(); }
335
336    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
337    bool empty()         const _NOEXCEPT { return __size == 0; }
338
339    // [string.view.access], element access
340    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
341    const_reference operator[](size_type __pos) const _NOEXCEPT {
342      return _LIBCPP_ASSERT(__pos < size(), "string_view[] index out of bounds"), __data[__pos];
343    }
344
345    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
346    const_reference at(size_type __pos) const
347    {
348        return __pos >= size()
349            ? (__throw_out_of_range("string_view::at"), __data[0])
350            : __data[__pos];
351    }
352
353    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
354    const_reference front() const _NOEXCEPT
355    {
356        return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0];
357    }
358
359    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
360    const_reference back() const _NOEXCEPT
361    {
362        return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1];
363    }
364
365    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
366    const_pointer data() const _NOEXCEPT { return __data; }
367
368    // [string.view.modifiers], modifiers:
369    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
370    void remove_prefix(size_type __n) _NOEXCEPT
371    {
372        _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
373        __data += __n;
374        __size -= __n;
375    }
376
377    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
378    void remove_suffix(size_type __n) _NOEXCEPT
379    {
380        _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
381        __size -= __n;
382    }
383
384    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
385    void swap(basic_string_view& __other) _NOEXCEPT
386    {
387        const value_type *__p = __data;
388        __data = __other.__data;
389        __other.__data = __p;
390
391        size_type __sz = __size;
392        __size = __other.__size;
393        __other.__size = __sz;
394    }
395
396    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
397    size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
398    {
399        if (__pos > size())
400            __throw_out_of_range("string_view::copy");
401        size_type __rlen = _VSTD::min(__n, size() - __pos);
402        _Traits::copy(__s, data() + __pos, __rlen);
403        return __rlen;
404    }
405
406    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
407    basic_string_view substr(size_type __pos = 0, size_type __n = npos) const
408    {
409        return __pos > size()
410            ? (__throw_out_of_range("string_view::substr"), basic_string_view())
411            : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
412    }
413
414    _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT
415    {
416        size_type __rlen = _VSTD::min( size(), __sv.size());
417        int __retval = _Traits::compare(data(), __sv.data(), __rlen);
418        if ( __retval == 0 ) // first __rlen chars matched
419            __retval = size() == __sv.size() ? 0 : ( size() < __sv.size() ? -1 : 1 );
420        return __retval;
421    }
422
423    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
424    int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
425    {
426        return substr(__pos1, __n1).compare(__sv);
427    }
428
429    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
430    int compare(                       size_type __pos1, size_type __n1,
431                basic_string_view __sv, size_type __pos2, size_type __n2) const
432    {
433        return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
434    }
435
436    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
437    int compare(const _CharT* __s) const _NOEXCEPT
438    {
439        return compare(basic_string_view(__s));
440    }
441
442    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
443    int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
444    {
445        return substr(__pos1, __n1).compare(basic_string_view(__s));
446    }
447
448    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
449    int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
450    {
451        return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
452    }
453
454    // find
455    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
456    size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
457    {
458        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
459        return __str_find<value_type, size_type, traits_type, npos>
460            (data(), size(), __s.data(), __pos, __s.size());
461    }
462
463    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
464    size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
465    {
466        return __str_find<value_type, size_type, traits_type, npos>
467            (data(), size(), __c, __pos);
468    }
469
470    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
471    size_type find(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
472    {
473        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
474        return __str_find<value_type, size_type, traits_type, npos>
475            (data(), size(), __s, __pos, __n);
476    }
477
478    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
479    size_type find(const _CharT* __s, size_type __pos = 0) const _NOEXCEPT
480    {
481        _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr");
482        return __str_find<value_type, size_type, traits_type, npos>
483            (data(), size(), __s, __pos, traits_type::length(__s));
484    }
485
486    // rfind
487    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
488    size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
489    {
490        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
491        return __str_rfind<value_type, size_type, traits_type, npos>
492            (data(), size(), __s.data(), __pos, __s.size());
493    }
494
495    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
496    size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
497    {
498        return __str_rfind<value_type, size_type, traits_type, npos>
499            (data(), size(), __c, __pos);
500    }
501
502    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
503    size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
504    {
505        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
506        return __str_rfind<value_type, size_type, traits_type, npos>
507            (data(), size(), __s, __pos, __n);
508    }
509
510    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
511    size_type rfind(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
512    {
513        _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr");
514        return __str_rfind<value_type, size_type, traits_type, npos>
515            (data(), size(), __s, __pos, traits_type::length(__s));
516    }
517
518    // find_first_of
519    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
520    size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
521    {
522        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
523        return __str_find_first_of<value_type, size_type, traits_type, npos>
524            (data(), size(), __s.data(), __pos, __s.size());
525    }
526
527    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
528    size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
529    { return find(__c, __pos); }
530
531    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
532    size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
533    {
534        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
535        return __str_find_first_of<value_type, size_type, traits_type, npos>
536            (data(), size(), __s, __pos, __n);
537    }
538
539    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
540    size_type find_first_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
541    {
542        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr");
543        return __str_find_first_of<value_type, size_type, traits_type, npos>
544            (data(), size(), __s, __pos, traits_type::length(__s));
545    }
546
547    // find_last_of
548    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
549    size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
550    {
551        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
552        return __str_find_last_of<value_type, size_type, traits_type, npos>
553            (data(), size(), __s.data(), __pos, __s.size());
554    }
555
556    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
557    size_type find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
558    { return rfind(__c, __pos); }
559
560    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
561    size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
562    {
563        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
564        return __str_find_last_of<value_type, size_type, traits_type, npos>
565            (data(), size(), __s, __pos, __n);
566    }
567
568    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
569    size_type find_last_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
570    {
571        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr");
572        return __str_find_last_of<value_type, size_type, traits_type, npos>
573            (data(), size(), __s, __pos, traits_type::length(__s));
574    }
575
576    // find_first_not_of
577    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
578    size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
579    {
580        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
581        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
582            (data(), size(), __s.data(), __pos, __s.size());
583    }
584
585    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
586    size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
587    {
588        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
589            (data(), size(), __c, __pos);
590    }
591
592    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
593    size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
594    {
595        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
596        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
597            (data(), size(), __s, __pos, __n);
598    }
599
600    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
601    size_type find_first_not_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
602    {
603        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
604        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
605            (data(), size(), __s, __pos, traits_type::length(__s));
606    }
607
608    // find_last_not_of
609    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
610    size_type find_last_not_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
611    {
612        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): received nullptr");
613        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
614            (data(), size(), __s.data(), __pos, __s.size());
615    }
616
617    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
618    size_type find_last_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
619    {
620        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
621            (data(), size(), __c, __pos);
622    }
623
624    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
625    size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
626    {
627        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
628        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
629            (data(), size(), __s, __pos, __n);
630    }
631
632    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
633    size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
634    {
635        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
636        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
637            (data(), size(), __s, __pos, traits_type::length(__s));
638    }
639
640#if _LIBCPP_STD_VER > 17
641    constexpr _LIBCPP_INLINE_VISIBILITY
642    bool starts_with(basic_string_view __s) const noexcept
643    { return size() >= __s.size() && compare(0, __s.size(), __s) == 0; }
644
645    constexpr _LIBCPP_INLINE_VISIBILITY
646    bool starts_with(value_type __c) const noexcept
647    { return !empty() && _Traits::eq(front(), __c); }
648
649    constexpr _LIBCPP_INLINE_VISIBILITY
650    bool starts_with(const value_type* __s) const noexcept
651    { return starts_with(basic_string_view(__s)); }
652
653    constexpr _LIBCPP_INLINE_VISIBILITY
654    bool ends_with(basic_string_view __s) const noexcept
655    { return size() >= __s.size() && compare(size() - __s.size(), npos, __s) == 0; }
656
657    constexpr _LIBCPP_INLINE_VISIBILITY
658    bool ends_with(value_type __c) const noexcept
659    { return !empty() && _Traits::eq(back(), __c); }
660
661    constexpr _LIBCPP_INLINE_VISIBILITY
662    bool ends_with(const value_type* __s) const noexcept
663    { return ends_with(basic_string_view(__s)); }
664#endif
665
666#if _LIBCPP_STD_VER > 20
667    constexpr _LIBCPP_INLINE_VISIBILITY
668    bool contains(basic_string_view __sv) const noexcept
669    { return find(__sv) != npos; }
670
671    constexpr _LIBCPP_INLINE_VISIBILITY
672    bool contains(value_type __c) const noexcept
673    { return find(__c) != npos; }
674
675    constexpr _LIBCPP_INLINE_VISIBILITY
676    bool contains(const value_type* __s) const
677    { return find(__s) != npos; }
678#endif
679
680private:
681    const   value_type* __data;
682    size_type           __size;
683};
684
685#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
686template <class _CharT, class _Traits>
687inline constexpr bool ranges::enable_view<basic_string_view<_CharT, _Traits>> = true;
688
689template <class _CharT, class _Traits>
690inline constexpr bool ranges::enable_borrowed_range<basic_string_view<_CharT, _Traits> > = true;
691#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
692
693// [string.view.deduct]
694
695#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
696template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
697  basic_string_view(_It, _End) -> basic_string_view<iter_value_t<_It>>;
698#endif
699
700// [string.view.comparison]
701// operator ==
702template<class _CharT, class _Traits>
703_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
704bool operator==(basic_string_view<_CharT, _Traits> __lhs,
705                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
706{
707    if ( __lhs.size() != __rhs.size()) return false;
708    return __lhs.compare(__rhs) == 0;
709}
710
711template<class _CharT, class _Traits>
712_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
713bool operator==(basic_string_view<_CharT, _Traits> __lhs,
714                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
715{
716    if ( __lhs.size() != __rhs.size()) return false;
717    return __lhs.compare(__rhs) == 0;
718}
719
720template<class _CharT, class _Traits>
721_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
722bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
723                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
724{
725    if ( __lhs.size() != __rhs.size()) return false;
726    return __lhs.compare(__rhs) == 0;
727}
728
729
730// operator !=
731template<class _CharT, class _Traits>
732_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
733bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
734{
735    if ( __lhs.size() != __rhs.size())
736        return true;
737    return __lhs.compare(__rhs) != 0;
738}
739
740template<class _CharT, class _Traits>
741_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
742bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
743                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
744{
745    if ( __lhs.size() != __rhs.size())
746        return true;
747    return __lhs.compare(__rhs) != 0;
748}
749
750template<class _CharT, class _Traits>
751_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
752bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
753                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
754{
755    if ( __lhs.size() != __rhs.size())
756        return true;
757    return __lhs.compare(__rhs) != 0;
758}
759
760
761// operator <
762template<class _CharT, class _Traits>
763_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
764bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
765{
766    return __lhs.compare(__rhs) < 0;
767}
768
769template<class _CharT, class _Traits>
770_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
771bool operator<(basic_string_view<_CharT, _Traits> __lhs,
772                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
773{
774    return __lhs.compare(__rhs) < 0;
775}
776
777template<class _CharT, class _Traits>
778_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
779bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
780                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
781{
782    return __lhs.compare(__rhs) < 0;
783}
784
785
786// operator >
787template<class _CharT, class _Traits>
788_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
789bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
790{
791    return __lhs.compare(__rhs) > 0;
792}
793
794template<class _CharT, class _Traits>
795_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
796bool operator>(basic_string_view<_CharT, _Traits> __lhs,
797                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
798{
799    return __lhs.compare(__rhs) > 0;
800}
801
802template<class _CharT, class _Traits>
803_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
804bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
805                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
806{
807    return __lhs.compare(__rhs) > 0;
808}
809
810
811// operator <=
812template<class _CharT, class _Traits>
813_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
814bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
815{
816    return __lhs.compare(__rhs) <= 0;
817}
818
819template<class _CharT, class _Traits>
820_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
821bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
822                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
823{
824    return __lhs.compare(__rhs) <= 0;
825}
826
827template<class _CharT, class _Traits>
828_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
829bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
830                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
831{
832    return __lhs.compare(__rhs) <= 0;
833}
834
835
836// operator >=
837template<class _CharT, class _Traits>
838_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
839bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
840{
841    return __lhs.compare(__rhs) >= 0;
842}
843
844
845template<class _CharT, class _Traits>
846_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
847bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
848                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
849{
850    return __lhs.compare(__rhs) >= 0;
851}
852
853template<class _CharT, class _Traits>
854_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
855bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
856                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
857{
858    return __lhs.compare(__rhs) >= 0;
859}
860
861
862template<class _CharT, class _Traits>
863basic_ostream<_CharT, _Traits>&
864operator<<(basic_ostream<_CharT, _Traits>& __os,
865           basic_string_view<_CharT, _Traits> __str);
866
867// [string.view.hash]
868template<class _CharT>
869struct _LIBCPP_TEMPLATE_VIS hash<basic_string_view<_CharT, char_traits<_CharT> > >
870    : public unary_function<basic_string_view<_CharT, char_traits<_CharT> >, size_t>
871{
872    _LIBCPP_INLINE_VISIBILITY
873    size_t operator()(const basic_string_view<_CharT, char_traits<_CharT> > __val) const _NOEXCEPT {
874        return __do_string_hash(__val.data(), __val.data() + __val.size());
875    }
876};
877
878
879#if _LIBCPP_STD_VER > 11
880inline namespace literals
881{
882  inline namespace string_view_literals
883  {
884    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
885    basic_string_view<char> operator "" sv(const char *__str, size_t __len) _NOEXCEPT
886    {
887        return basic_string_view<char> (__str, __len);
888    }
889
890#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
891    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
892    basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len) _NOEXCEPT
893    {
894        return basic_string_view<wchar_t> (__str, __len);
895    }
896#endif
897
898#ifndef _LIBCPP_HAS_NO_CHAR8_T
899    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
900    basic_string_view<char8_t> operator "" sv(const char8_t *__str, size_t __len) _NOEXCEPT
901    {
902        return basic_string_view<char8_t> (__str, __len);
903    }
904#endif
905
906    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
907    basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len) _NOEXCEPT
908    {
909        return basic_string_view<char16_t> (__str, __len);
910    }
911
912    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
913    basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len) _NOEXCEPT
914    {
915        return basic_string_view<char32_t> (__str, __len);
916    }
917  }
918}
919#endif
920_LIBCPP_END_NAMESPACE_STD
921
922_LIBCPP_POP_MACROS
923
924#endif // _LIBCPP_STRING_VIEW
925