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 <__config>
195#include <__debug>
196#include <__ranges/enable_borrowed_range.h>
197#include <__ranges/enable_view.h>
198#include <__string>
199#include <algorithm>
200#include <compare>
201#include <iosfwd>
202#include <iterator>
203#include <limits>
204#include <stdexcept>
205#include <version>
206
207#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
208#pragma GCC system_header
209#endif
210
211_LIBCPP_PUSH_MACROS
212#include <__undef_macros>
213
214
215_LIBCPP_BEGIN_NAMESPACE_STD
216
217template<class _CharT, class _Traits = char_traits<_CharT> >
218    class _LIBCPP_TEMPLATE_VIS basic_string_view;
219
220typedef basic_string_view<char>     string_view;
221#ifndef _LIBCPP_HAS_NO_CHAR8_T
222typedef basic_string_view<char8_t>  u8string_view;
223#endif
224typedef basic_string_view<char16_t> u16string_view;
225typedef basic_string_view<char32_t> u32string_view;
226#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
227typedef basic_string_view<wchar_t>  wstring_view;
228#endif
229
230template<class _CharT, class _Traits>
231class
232    _LIBCPP_PREFERRED_NAME(string_view)
233#ifndef _LIBCPP_HAS_NO_CHAR8_T
234    _LIBCPP_PREFERRED_NAME(u8string_view)
235#endif
236    _LIBCPP_PREFERRED_NAME(u16string_view)
237    _LIBCPP_PREFERRED_NAME(u32string_view)
238    _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wstring_view))
239    basic_string_view {
240public:
241    // types
242    typedef _Traits                                    traits_type;
243    typedef _CharT                                     value_type;
244    typedef _CharT*                                    pointer;
245    typedef const _CharT*                              const_pointer;
246    typedef _CharT&                                    reference;
247    typedef const _CharT&                              const_reference;
248    typedef const_pointer                              const_iterator; // See [string.view.iterators]
249    typedef const_iterator                             iterator;
250    typedef _VSTD::reverse_iterator<const_iterator>    const_reverse_iterator;
251    typedef const_reverse_iterator                     reverse_iterator;
252    typedef size_t                                     size_type;
253    typedef ptrdiff_t                                  difference_type;
254    static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);
255
256    static_assert((!is_array<value_type>::value), "Character type of basic_string_view must not be an array");
257    static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string_view must be standard-layout");
258    static_assert(( is_trivial<value_type>::value), "Character type of basic_string_view must be trivial");
259    static_assert((is_same<_CharT, typename traits_type::char_type>::value),
260                  "traits_type::char_type must be the same type as CharT");
261
262    // [string.view.cons], construct/copy
263    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
264    basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {}
265
266    _LIBCPP_INLINE_VISIBILITY
267    basic_string_view(const basic_string_view&) _NOEXCEPT = default;
268
269    _LIBCPP_INLINE_VISIBILITY
270    basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;
271
272    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
273    basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT
274        : __data(__s), __size(__len)
275    {
276#if _LIBCPP_STD_VER > 11
277    _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr");
278#endif
279    }
280
281#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
282    template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
283      requires (is_same_v<iter_value_t<_It>, _CharT> && !is_convertible_v<_End, size_type>)
284    constexpr _LIBCPP_HIDE_FROM_ABI basic_string_view(_It __begin, _End __end)
285       : __data(_VSTD::to_address(__begin)), __size(__end - __begin)
286    {
287      _LIBCPP_ASSERT((__end - __begin) >= 0, "std::string_view::string_view(iterator, sentinel) received invalid range");
288    }
289#endif
290
291    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
292    basic_string_view(const _CharT* __s)
293        : __data(__s), __size(_VSTD::__char_traits_length_checked<_Traits>(__s)) {}
294
295#if _LIBCPP_STD_VER > 20
296    basic_string_view(nullptr_t) = delete;
297#endif
298
299    // [string.view.iterators], iterators
300    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
301    const_iterator begin()  const _NOEXCEPT { return cbegin(); }
302
303    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
304    const_iterator end()    const _NOEXCEPT { return cend(); }
305
306    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
307    const_iterator cbegin() const _NOEXCEPT { return __data; }
308
309    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
310    const_iterator cend()   const _NOEXCEPT { return __data + __size; }
311
312    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
313    const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
314
315    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
316    const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
317
318    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
319    const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
320
321    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
322    const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
323
324    // [string.view.capacity], capacity
325    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
326    size_type size()     const _NOEXCEPT { return __size; }
327
328    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
329    size_type length()   const _NOEXCEPT { return __size; }
330
331    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
332    size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max(); }
333
334    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
335    bool empty()         const _NOEXCEPT { return __size == 0; }
336
337    // [string.view.access], element access
338    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
339    const_reference operator[](size_type __pos) const _NOEXCEPT {
340      return _LIBCPP_ASSERT(__pos < size(), "string_view[] index out of bounds"), __data[__pos];
341    }
342
343    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
344    const_reference at(size_type __pos) const
345    {
346        return __pos >= size()
347            ? (__throw_out_of_range("string_view::at"), __data[0])
348            : __data[__pos];
349    }
350
351    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
352    const_reference front() const _NOEXCEPT
353    {
354        return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0];
355    }
356
357    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
358    const_reference back() const _NOEXCEPT
359    {
360        return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1];
361    }
362
363    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
364    const_pointer data() const _NOEXCEPT { return __data; }
365
366    // [string.view.modifiers], modifiers:
367    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
368    void remove_prefix(size_type __n) _NOEXCEPT
369    {
370        _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
371        __data += __n;
372        __size -= __n;
373    }
374
375    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
376    void remove_suffix(size_type __n) _NOEXCEPT
377    {
378        _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
379        __size -= __n;
380    }
381
382    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
383    void swap(basic_string_view& __other) _NOEXCEPT
384    {
385        const value_type *__p = __data;
386        __data = __other.__data;
387        __other.__data = __p;
388
389        size_type __sz = __size;
390        __size = __other.__size;
391        __other.__size = __sz;
392    }
393
394    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
395    size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
396    {
397        if (__pos > size())
398            __throw_out_of_range("string_view::copy");
399        size_type __rlen = _VSTD::min(__n, size() - __pos);
400        _Traits::copy(__s, data() + __pos, __rlen);
401        return __rlen;
402    }
403
404    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
405    basic_string_view substr(size_type __pos = 0, size_type __n = npos) const
406    {
407        return __pos > size()
408            ? (__throw_out_of_range("string_view::substr"), basic_string_view())
409            : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
410    }
411
412    _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT
413    {
414        size_type __rlen = _VSTD::min( size(), __sv.size());
415        int __retval = _Traits::compare(data(), __sv.data(), __rlen);
416        if ( __retval == 0 ) // first __rlen chars matched
417            __retval = size() == __sv.size() ? 0 : ( size() < __sv.size() ? -1 : 1 );
418        return __retval;
419    }
420
421    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
422    int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
423    {
424        return substr(__pos1, __n1).compare(__sv);
425    }
426
427    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
428    int compare(                       size_type __pos1, size_type __n1,
429                basic_string_view __sv, size_type __pos2, size_type __n2) const
430    {
431        return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
432    }
433
434    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
435    int compare(const _CharT* __s) const _NOEXCEPT
436    {
437        return compare(basic_string_view(__s));
438    }
439
440    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
441    int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
442    {
443        return substr(__pos1, __n1).compare(basic_string_view(__s));
444    }
445
446    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
447    int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
448    {
449        return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
450    }
451
452    // find
453    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
454    size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
455    {
456        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
457        return __str_find<value_type, size_type, traits_type, npos>
458            (data(), size(), __s.data(), __pos, __s.size());
459    }
460
461    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
462    size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
463    {
464        return __str_find<value_type, size_type, traits_type, npos>
465            (data(), size(), __c, __pos);
466    }
467
468    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
469    size_type find(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
470    {
471        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
472        return __str_find<value_type, size_type, traits_type, npos>
473            (data(), size(), __s, __pos, __n);
474    }
475
476    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
477    size_type find(const _CharT* __s, size_type __pos = 0) const _NOEXCEPT
478    {
479        _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr");
480        return __str_find<value_type, size_type, traits_type, npos>
481            (data(), size(), __s, __pos, traits_type::length(__s));
482    }
483
484    // rfind
485    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
486    size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
487    {
488        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
489        return __str_rfind<value_type, size_type, traits_type, npos>
490            (data(), size(), __s.data(), __pos, __s.size());
491    }
492
493    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
494    size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
495    {
496        return __str_rfind<value_type, size_type, traits_type, npos>
497            (data(), size(), __c, __pos);
498    }
499
500    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
501    size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
502    {
503        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
504        return __str_rfind<value_type, size_type, traits_type, npos>
505            (data(), size(), __s, __pos, __n);
506    }
507
508    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
509    size_type rfind(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
510    {
511        _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr");
512        return __str_rfind<value_type, size_type, traits_type, npos>
513            (data(), size(), __s, __pos, traits_type::length(__s));
514    }
515
516    // find_first_of
517    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
518    size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
519    {
520        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
521        return __str_find_first_of<value_type, size_type, traits_type, npos>
522            (data(), size(), __s.data(), __pos, __s.size());
523    }
524
525    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
526    size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
527    { return find(__c, __pos); }
528
529    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
530    size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
531    {
532        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
533        return __str_find_first_of<value_type, size_type, traits_type, npos>
534            (data(), size(), __s, __pos, __n);
535    }
536
537    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
538    size_type find_first_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
539    {
540        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr");
541        return __str_find_first_of<value_type, size_type, traits_type, npos>
542            (data(), size(), __s, __pos, traits_type::length(__s));
543    }
544
545    // find_last_of
546    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
547    size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
548    {
549        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
550        return __str_find_last_of<value_type, size_type, traits_type, npos>
551            (data(), size(), __s.data(), __pos, __s.size());
552    }
553
554    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
555    size_type find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
556    { return rfind(__c, __pos); }
557
558    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
559    size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
560    {
561        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
562        return __str_find_last_of<value_type, size_type, traits_type, npos>
563            (data(), size(), __s, __pos, __n);
564    }
565
566    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
567    size_type find_last_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
568    {
569        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr");
570        return __str_find_last_of<value_type, size_type, traits_type, npos>
571            (data(), size(), __s, __pos, traits_type::length(__s));
572    }
573
574    // find_first_not_of
575    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
576    size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
577    {
578        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
579        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
580            (data(), size(), __s.data(), __pos, __s.size());
581    }
582
583    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
584    size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
585    {
586        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
587            (data(), size(), __c, __pos);
588    }
589
590    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
591    size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
592    {
593        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
594        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
595            (data(), size(), __s, __pos, __n);
596    }
597
598    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
599    size_type find_first_not_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
600    {
601        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
602        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
603            (data(), size(), __s, __pos, traits_type::length(__s));
604    }
605
606    // find_last_not_of
607    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
608    size_type find_last_not_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
609    {
610        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): received nullptr");
611        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
612            (data(), size(), __s.data(), __pos, __s.size());
613    }
614
615    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
616    size_type find_last_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
617    {
618        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
619            (data(), size(), __c, __pos);
620    }
621
622    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
623    size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
624    {
625        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
626        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
627            (data(), size(), __s, __pos, __n);
628    }
629
630    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
631    size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
632    {
633        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
634        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
635            (data(), size(), __s, __pos, traits_type::length(__s));
636    }
637
638#if _LIBCPP_STD_VER > 17
639    constexpr _LIBCPP_INLINE_VISIBILITY
640    bool starts_with(basic_string_view __s) const noexcept
641    { return size() >= __s.size() && compare(0, __s.size(), __s) == 0; }
642
643    constexpr _LIBCPP_INLINE_VISIBILITY
644    bool starts_with(value_type __c) const noexcept
645    { return !empty() && _Traits::eq(front(), __c); }
646
647    constexpr _LIBCPP_INLINE_VISIBILITY
648    bool starts_with(const value_type* __s) const noexcept
649    { return starts_with(basic_string_view(__s)); }
650
651    constexpr _LIBCPP_INLINE_VISIBILITY
652    bool ends_with(basic_string_view __s) const noexcept
653    { return size() >= __s.size() && compare(size() - __s.size(), npos, __s) == 0; }
654
655    constexpr _LIBCPP_INLINE_VISIBILITY
656    bool ends_with(value_type __c) const noexcept
657    { return !empty() && _Traits::eq(back(), __c); }
658
659    constexpr _LIBCPP_INLINE_VISIBILITY
660    bool ends_with(const value_type* __s) const noexcept
661    { return ends_with(basic_string_view(__s)); }
662#endif
663
664#if _LIBCPP_STD_VER > 20
665    constexpr _LIBCPP_INLINE_VISIBILITY
666    bool contains(basic_string_view __sv) const noexcept
667    { return find(__sv) != npos; }
668
669    constexpr _LIBCPP_INLINE_VISIBILITY
670    bool contains(value_type __c) const noexcept
671    { return find(__c) != npos; }
672
673    constexpr _LIBCPP_INLINE_VISIBILITY
674    bool contains(const value_type* __s) const
675    { return find(__s) != npos; }
676#endif
677
678private:
679    const   value_type* __data;
680    size_type           __size;
681};
682
683#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
684template <class _CharT, class _Traits>
685inline constexpr bool ranges::enable_view<basic_string_view<_CharT, _Traits>> = true;
686
687template <class _CharT, class _Traits>
688inline constexpr bool ranges::enable_borrowed_range<basic_string_view<_CharT, _Traits> > = true;
689#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
690
691// [string.view.deduct]
692
693#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
694template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
695  basic_string_view(_It, _End) -> basic_string_view<iter_value_t<_It>>;
696#endif
697
698// [string.view.comparison]
699// operator ==
700template<class _CharT, class _Traits>
701_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
702bool operator==(basic_string_view<_CharT, _Traits> __lhs,
703                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
704{
705    if ( __lhs.size() != __rhs.size()) return false;
706    return __lhs.compare(__rhs) == 0;
707}
708
709template<class _CharT, class _Traits>
710_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
711bool operator==(basic_string_view<_CharT, _Traits> __lhs,
712                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
713{
714    if ( __lhs.size() != __rhs.size()) return false;
715    return __lhs.compare(__rhs) == 0;
716}
717
718template<class _CharT, class _Traits>
719_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
720bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
721                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
722{
723    if ( __lhs.size() != __rhs.size()) return false;
724    return __lhs.compare(__rhs) == 0;
725}
726
727
728// operator !=
729template<class _CharT, class _Traits>
730_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
731bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
732{
733    if ( __lhs.size() != __rhs.size())
734        return true;
735    return __lhs.compare(__rhs) != 0;
736}
737
738template<class _CharT, class _Traits>
739_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
740bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
741                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
742{
743    if ( __lhs.size() != __rhs.size())
744        return true;
745    return __lhs.compare(__rhs) != 0;
746}
747
748template<class _CharT, class _Traits>
749_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
750bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
751                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
752{
753    if ( __lhs.size() != __rhs.size())
754        return true;
755    return __lhs.compare(__rhs) != 0;
756}
757
758
759// operator <
760template<class _CharT, class _Traits>
761_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
762bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
763{
764    return __lhs.compare(__rhs) < 0;
765}
766
767template<class _CharT, class _Traits>
768_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
769bool operator<(basic_string_view<_CharT, _Traits> __lhs,
770                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
771{
772    return __lhs.compare(__rhs) < 0;
773}
774
775template<class _CharT, class _Traits>
776_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
777bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
778                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
779{
780    return __lhs.compare(__rhs) < 0;
781}
782
783
784// operator >
785template<class _CharT, class _Traits>
786_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
787bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
788{
789    return __lhs.compare(__rhs) > 0;
790}
791
792template<class _CharT, class _Traits>
793_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
794bool operator>(basic_string_view<_CharT, _Traits> __lhs,
795                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
796{
797    return __lhs.compare(__rhs) > 0;
798}
799
800template<class _CharT, class _Traits>
801_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
802bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
803                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
804{
805    return __lhs.compare(__rhs) > 0;
806}
807
808
809// operator <=
810template<class _CharT, class _Traits>
811_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
812bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
813{
814    return __lhs.compare(__rhs) <= 0;
815}
816
817template<class _CharT, class _Traits>
818_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
819bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
820                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
821{
822    return __lhs.compare(__rhs) <= 0;
823}
824
825template<class _CharT, class _Traits>
826_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
827bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
828                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
829{
830    return __lhs.compare(__rhs) <= 0;
831}
832
833
834// operator >=
835template<class _CharT, class _Traits>
836_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
837bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
838{
839    return __lhs.compare(__rhs) >= 0;
840}
841
842
843template<class _CharT, class _Traits>
844_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
845bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
846                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
847{
848    return __lhs.compare(__rhs) >= 0;
849}
850
851template<class _CharT, class _Traits>
852_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
853bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
854                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
855{
856    return __lhs.compare(__rhs) >= 0;
857}
858
859
860template<class _CharT, class _Traits>
861basic_ostream<_CharT, _Traits>&
862operator<<(basic_ostream<_CharT, _Traits>& __os,
863           basic_string_view<_CharT, _Traits> __str);
864
865// [string.view.hash]
866template<class _CharT>
867struct _LIBCPP_TEMPLATE_VIS hash<basic_string_view<_CharT, char_traits<_CharT> > >
868    : public unary_function<basic_string_view<_CharT, char_traits<_CharT> >, size_t>
869{
870    _LIBCPP_INLINE_VISIBILITY
871    size_t operator()(const basic_string_view<_CharT, char_traits<_CharT> > __val) const _NOEXCEPT {
872        return __do_string_hash(__val.data(), __val.data() + __val.size());
873    }
874};
875
876
877#if _LIBCPP_STD_VER > 11
878inline namespace literals
879{
880  inline namespace string_view_literals
881  {
882    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
883    basic_string_view<char> operator "" sv(const char *__str, size_t __len) _NOEXCEPT
884    {
885        return basic_string_view<char> (__str, __len);
886    }
887
888#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
889    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
890    basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len) _NOEXCEPT
891    {
892        return basic_string_view<wchar_t> (__str, __len);
893    }
894#endif
895
896#ifndef _LIBCPP_HAS_NO_CHAR8_T
897    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
898    basic_string_view<char8_t> operator "" sv(const char8_t *__str, size_t __len) _NOEXCEPT
899    {
900        return basic_string_view<char8_t> (__str, __len);
901    }
902#endif
903
904    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
905    basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len) _NOEXCEPT
906    {
907        return basic_string_view<char16_t> (__str, __len);
908    }
909
910    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
911    basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len) _NOEXCEPT
912    {
913        return basic_string_view<char32_t> (__str, __len);
914    }
915  }
916}
917#endif
918_LIBCPP_END_NAMESPACE_STD
919
920_LIBCPP_POP_MACROS
921
922#endif // _LIBCPP_STRING_VIEW
923