1// -*- C++ -*-
2//===------------------------ string_view ---------------------------------===//
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    // 7.9, basic_string_view non-member comparison functions
23    template<class charT, class traits>
24    constexpr bool operator==(basic_string_view<charT, traits> x,
25                              basic_string_view<charT, traits> y) noexcept;
26    template<class charT, class traits>
27    constexpr bool operator!=(basic_string_view<charT, traits> x,
28                              basic_string_view<charT, traits> y) noexcept;
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    // see below, sufficient additional overloads of comparison functions
42
43    // 7.10, Inserters and extractors
44    template<class charT, class traits>
45      basic_ostream<charT, traits>&
46        operator<<(basic_ostream<charT, traits>& os,
47                   basic_string_view<charT, traits> str);
48
49    // basic_string_view typedef names
50    typedef basic_string_view<char> string_view;
51    typedef basic_string_view<char8_t> u8string_view; // C++20
52    typedef basic_string_view<char16_t> u16string_view;
53    typedef basic_string_view<char32_t> u32string_view;
54    typedef basic_string_view<wchar_t> wstring_view;
55
56    template<class charT, class traits = char_traits<charT>>
57    class basic_string_view {
58      public:
59      // types
60      typedef traits traits_type;
61      typedef charT value_type;
62      typedef charT* pointer;
63      typedef const charT* const_pointer;
64      typedef charT& reference;
65      typedef const charT& const_reference;
66      typedef implementation-defined const_iterator;
67      typedef const_iterator iterator;
68      typedef reverse_iterator<const_iterator> const_reverse_iterator;
69      typedef const_reverse_iterator reverse_iterator;
70      typedef size_t size_type;
71      typedef ptrdiff_t difference_type;
72      static constexpr size_type npos = size_type(-1);
73
74      // 7.3, basic_string_view constructors and assignment operators
75      constexpr basic_string_view() noexcept;
76      constexpr basic_string_view(const basic_string_view&) noexcept = default;
77      basic_string_view& operator=(const basic_string_view&) noexcept = default;
78      template<class Allocator>
79      constexpr basic_string_view(const charT* str);
80      constexpr basic_string_view(const charT* str, size_type len);
81
82      // 7.4, basic_string_view iterator support
83      constexpr const_iterator begin() const noexcept;
84      constexpr const_iterator end() const noexcept;
85      constexpr const_iterator cbegin() const noexcept;
86      constexpr const_iterator cend() const noexcept;
87      const_reverse_iterator rbegin() const noexcept;
88      const_reverse_iterator rend() const noexcept;
89      const_reverse_iterator crbegin() const noexcept;
90      const_reverse_iterator crend() const noexcept;
91
92      // 7.5, basic_string_view capacity
93      constexpr size_type size() const noexcept;
94      constexpr size_type length() const noexcept;
95      constexpr size_type max_size() const noexcept;
96      constexpr bool empty() const noexcept;
97
98      // 7.6, basic_string_view element access
99      constexpr const_reference operator[](size_type pos) const;
100      constexpr const_reference at(size_type pos) const;
101      constexpr const_reference front() const;
102      constexpr const_reference back() const;
103      constexpr const_pointer data() const noexcept;
104
105      // 7.7, basic_string_view modifiers
106      constexpr void remove_prefix(size_type n);
107      constexpr void remove_suffix(size_type n);
108      constexpr void swap(basic_string_view& s) noexcept;
109
110      size_type copy(charT* s, size_type n, size_type pos = 0) const;  // constexpr in C++20
111
112      constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
113      constexpr int compare(basic_string_view s) const noexcept;
114      constexpr int compare(size_type pos1, size_type n1, basic_string_view s) const;
115      constexpr int compare(size_type pos1, size_type n1,
116                            basic_string_view s, size_type pos2, size_type n2) const;
117      constexpr int compare(const charT* s) const;
118      constexpr int compare(size_type pos1, size_type n1, const charT* s) const;
119      constexpr int compare(size_type pos1, size_type n1,
120                            const charT* s, size_type n2) const;
121      constexpr size_type find(basic_string_view s, size_type pos = 0) const noexcept;
122      constexpr size_type find(charT c, size_type pos = 0) const noexcept;
123      constexpr size_type find(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
124      constexpr size_type find(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
125      constexpr size_type rfind(basic_string_view s, size_type pos = npos) const noexcept;
126      constexpr size_type rfind(charT c, size_type pos = npos) const noexcept;
127      constexpr size_type rfind(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
128      constexpr size_type rfind(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
129      constexpr size_type find_first_of(basic_string_view s, size_type pos = 0) const noexcept;
130      constexpr size_type find_first_of(charT c, size_type pos = 0) const noexcept;
131      constexpr size_type find_first_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
132      constexpr size_type find_first_of(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
133      constexpr size_type find_last_of(basic_string_view s, size_type pos = npos) const noexcept;
134      constexpr size_type find_last_of(charT c, size_type pos = npos) const noexcept;
135      constexpr size_type find_last_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
136      constexpr size_type find_last_of(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
137      constexpr size_type find_first_not_of(basic_string_view s, size_type pos = 0) const noexcept;
138      constexpr size_type find_first_not_of(charT c, size_type pos = 0) const noexcept;
139      constexpr size_type find_first_not_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
140      constexpr size_type find_first_not_of(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
141      constexpr size_type find_last_not_of(basic_string_view s, size_type pos = npos) const noexcept;
142      constexpr size_type find_last_not_of(charT c, size_type pos = npos) const noexcept;
143      constexpr size_type find_last_not_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
144      constexpr size_type find_last_not_of(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
145
146      constexpr bool starts_with(basic_string_view s) const noexcept; // C++20
147      constexpr bool starts_with(charT c) const noexcept;             // C++20
148      constexpr bool starts_with(const charT* s) const;               // C++20
149      constexpr bool ends_with(basic_string_view s) const noexcept;   // C++20
150      constexpr bool ends_with(charT c) const noexcept;               // C++20
151      constexpr bool ends_with(const charT* s) const;                 // C++20
152
153      constexpr bool contains(basic_string_view s) const noexcept; // C++2b
154      constexpr bool contains(charT c) const noexcept;             // C++2b
155      constexpr bool contains(const charT* s) const;               // C++2b
156
157     private:
158      const_pointer data_;  // exposition only
159      size_type     size_;  // exposition only
160    };
161
162  // 7.11, Hash support
163  template <class T> struct hash;
164  template <> struct hash<string_view>;
165  template <> struct hash<u8string_view>; // C++20
166  template <> struct hash<u16string_view>;
167  template <> struct hash<u32string_view>;
168  template <> struct hash<wstring_view>;
169
170  constexpr basic_string_view<char>     operator "" sv( const char *str,     size_t len ) noexcept;
171  constexpr basic_string_view<wchar_t>  operator "" sv( const wchar_t *str,  size_t len ) noexcept;
172  constexpr basic_string_view<char8_t>  operator "" sv( const char8_t *str,  size_t len ) noexcept; // C++20
173  constexpr basic_string_view<char16_t> operator "" sv( const char16_t *str, size_t len ) noexcept;
174  constexpr basic_string_view<char32_t> operator "" sv( const char32_t *str, size_t len ) noexcept;
175
176}  // namespace std
177
178
179*/
180
181#include <__config>
182#include <__string>
183#include <iosfwd>
184#include <algorithm>
185#include <compare>
186#include <iterator>
187#include <limits>
188#include <stdexcept>
189#include <version>
190#include <__debug>
191
192#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
193#pragma GCC system_header
194#endif
195
196_LIBCPP_PUSH_MACROS
197#include <__undef_macros>
198
199
200_LIBCPP_BEGIN_NAMESPACE_STD
201
202template<class _CharT, class _Traits = char_traits<_CharT> >
203    class _LIBCPP_TEMPLATE_VIS basic_string_view;
204
205typedef basic_string_view<char>     string_view;
206#ifndef _LIBCPP_NO_HAS_CHAR8_T
207typedef basic_string_view<char8_t>  u8string_view;
208#endif
209typedef basic_string_view<char16_t> u16string_view;
210typedef basic_string_view<char32_t> u32string_view;
211typedef basic_string_view<wchar_t>  wstring_view;
212
213template<class _CharT, class _Traits>
214class
215    _LIBCPP_PREFERRED_NAME(string_view)
216#ifndef _LIBCPP_NO_HAS_CHAR8_T
217    _LIBCPP_PREFERRED_NAME(u8string_view)
218#endif
219    _LIBCPP_PREFERRED_NAME(u16string_view)
220    _LIBCPP_PREFERRED_NAME(u32string_view)
221    _LIBCPP_PREFERRED_NAME(wstring_view)
222    basic_string_view {
223public:
224    // types
225    typedef _Traits                                    traits_type;
226    typedef _CharT                                     value_type;
227    typedef _CharT*                                    pointer;
228    typedef const _CharT*                              const_pointer;
229    typedef _CharT&                                    reference;
230    typedef const _CharT&                              const_reference;
231    typedef const_pointer                              const_iterator; // See [string.view.iterators]
232    typedef const_iterator                             iterator;
233    typedef _VSTD::reverse_iterator<const_iterator>    const_reverse_iterator;
234    typedef const_reverse_iterator                     reverse_iterator;
235    typedef size_t                                     size_type;
236    typedef ptrdiff_t                                  difference_type;
237    static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);
238
239    static_assert((!is_array<value_type>::value), "Character type of basic_string_view must not be an array");
240    static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string_view must be standard-layout");
241    static_assert(( is_trivial<value_type>::value), "Character type of basic_string_view must be trivial");
242    static_assert((is_same<_CharT, typename traits_type::char_type>::value),
243                  "traits_type::char_type must be the same type as CharT");
244
245    // [string.view.cons], construct/copy
246    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
247    basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {}
248
249    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
250    basic_string_view(const basic_string_view&) _NOEXCEPT = default;
251
252    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
253    basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;
254
255    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
256    basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT
257        : __data(__s), __size(__len)
258    {
259#if _LIBCPP_STD_VER > 11
260    _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr");
261#endif
262    }
263
264    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
265    basic_string_view(const _CharT* __s)
266        : __data(__s), __size(_VSTD::__char_traits_length_checked<_Traits>(__s)) {}
267
268    // [string.view.iterators], iterators
269    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
270    const_iterator begin()  const _NOEXCEPT { return cbegin(); }
271
272    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
273    const_iterator end()    const _NOEXCEPT { return cend(); }
274
275    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
276    const_iterator cbegin() const _NOEXCEPT { return __data; }
277
278    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
279    const_iterator cend()   const _NOEXCEPT { return __data + __size; }
280
281    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
282    const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
283
284    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
285    const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
286
287    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
288    const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
289
290    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
291    const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
292
293    // [string.view.capacity], capacity
294    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
295    size_type size()     const _NOEXCEPT { return __size; }
296
297    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
298    size_type length()   const _NOEXCEPT { return __size; }
299
300    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
301    size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max(); }
302
303    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
304    bool empty()         const _NOEXCEPT { return __size == 0; }
305
306    // [string.view.access], element access
307    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
308    const_reference operator[](size_type __pos) const _NOEXCEPT {
309      return _LIBCPP_ASSERT(__pos < size(), "string_view[] index out of bounds"), __data[__pos];
310    }
311
312    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
313    const_reference at(size_type __pos) const
314    {
315        return __pos >= size()
316            ? (__throw_out_of_range("string_view::at"), __data[0])
317            : __data[__pos];
318    }
319
320    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
321    const_reference front() const _NOEXCEPT
322    {
323        return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0];
324    }
325
326    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
327    const_reference back() const _NOEXCEPT
328    {
329        return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1];
330    }
331
332    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
333    const_pointer data() const _NOEXCEPT { return __data; }
334
335    // [string.view.modifiers], modifiers:
336    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
337    void remove_prefix(size_type __n) _NOEXCEPT
338    {
339        _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
340        __data += __n;
341        __size -= __n;
342    }
343
344    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
345    void remove_suffix(size_type __n) _NOEXCEPT
346    {
347        _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
348        __size -= __n;
349    }
350
351    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
352    void swap(basic_string_view& __other) _NOEXCEPT
353    {
354        const value_type *__p = __data;
355        __data = __other.__data;
356        __other.__data = __p;
357
358        size_type __sz = __size;
359        __size = __other.__size;
360        __other.__size = __sz;
361    }
362
363    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
364    size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
365    {
366        if (__pos > size())
367            __throw_out_of_range("string_view::copy");
368        size_type __rlen = _VSTD::min(__n, size() - __pos);
369        _Traits::copy(__s, data() + __pos, __rlen);
370        return __rlen;
371    }
372
373    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
374    basic_string_view substr(size_type __pos = 0, size_type __n = npos) const
375    {
376        return __pos > size()
377            ? (__throw_out_of_range("string_view::substr"), basic_string_view())
378            : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
379    }
380
381    _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT
382    {
383        size_type __rlen = _VSTD::min( size(), __sv.size());
384        int __retval = _Traits::compare(data(), __sv.data(), __rlen);
385        if ( __retval == 0 ) // first __rlen chars matched
386            __retval = size() == __sv.size() ? 0 : ( size() < __sv.size() ? -1 : 1 );
387        return __retval;
388    }
389
390    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
391    int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
392    {
393        return substr(__pos1, __n1).compare(__sv);
394    }
395
396    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
397    int compare(                       size_type __pos1, size_type __n1,
398                basic_string_view __sv, size_type __pos2, size_type __n2) const
399    {
400        return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
401    }
402
403    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
404    int compare(const _CharT* __s) const _NOEXCEPT
405    {
406        return compare(basic_string_view(__s));
407    }
408
409    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
410    int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
411    {
412        return substr(__pos1, __n1).compare(basic_string_view(__s));
413    }
414
415    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
416    int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
417    {
418        return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
419    }
420
421    // find
422    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
423    size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
424    {
425        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
426        return __str_find<value_type, size_type, traits_type, npos>
427            (data(), size(), __s.data(), __pos, __s.size());
428    }
429
430    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
431    size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
432    {
433        return __str_find<value_type, size_type, traits_type, npos>
434            (data(), size(), __c, __pos);
435    }
436
437    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
438    size_type find(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
439    {
440        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
441        return __str_find<value_type, size_type, traits_type, npos>
442            (data(), size(), __s, __pos, __n);
443    }
444
445    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
446    size_type find(const _CharT* __s, size_type __pos = 0) const _NOEXCEPT
447    {
448        _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr");
449        return __str_find<value_type, size_type, traits_type, npos>
450            (data(), size(), __s, __pos, traits_type::length(__s));
451    }
452
453    // rfind
454    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
455    size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
456    {
457        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
458        return __str_rfind<value_type, size_type, traits_type, npos>
459            (data(), size(), __s.data(), __pos, __s.size());
460    }
461
462    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
463    size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
464    {
465        return __str_rfind<value_type, size_type, traits_type, npos>
466            (data(), size(), __c, __pos);
467    }
468
469    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
470    size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
471    {
472        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
473        return __str_rfind<value_type, size_type, traits_type, npos>
474            (data(), size(), __s, __pos, __n);
475    }
476
477    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
478    size_type rfind(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
479    {
480        _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr");
481        return __str_rfind<value_type, size_type, traits_type, npos>
482            (data(), size(), __s, __pos, traits_type::length(__s));
483    }
484
485    // find_first_of
486    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
487    size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
488    {
489        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
490        return __str_find_first_of<value_type, size_type, traits_type, npos>
491            (data(), size(), __s.data(), __pos, __s.size());
492    }
493
494    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
495    size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
496    { return find(__c, __pos); }
497
498    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
499    size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
500    {
501        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
502        return __str_find_first_of<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_first_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
508    {
509        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr");
510        return __str_find_first_of<value_type, size_type, traits_type, npos>
511            (data(), size(), __s, __pos, traits_type::length(__s));
512    }
513
514    // find_last_of
515    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
516    size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
517    {
518        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
519        return __str_find_last_of<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 find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
525    { return rfind(__c, __pos); }
526
527    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
528    size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
529    {
530        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
531        return __str_find_last_of<value_type, size_type, traits_type, npos>
532            (data(), size(), __s, __pos, __n);
533    }
534
535    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
536    size_type find_last_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
537    {
538        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr");
539        return __str_find_last_of<value_type, size_type, traits_type, npos>
540            (data(), size(), __s, __pos, traits_type::length(__s));
541    }
542
543    // find_first_not_of
544    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
545    size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
546    {
547        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
548        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
549            (data(), size(), __s.data(), __pos, __s.size());
550    }
551
552    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
553    size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
554    {
555        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
556            (data(), size(), __c, __pos);
557    }
558
559    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
560    size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
561    {
562        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
563        return __str_find_first_not_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_not_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
569    {
570        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
571        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
572            (data(), size(), __s, __pos, traits_type::length(__s));
573    }
574
575    // find_last_not_of
576    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
577    size_type find_last_not_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_not_of(): received nullptr");
580        return __str_find_last_not_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_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
586    {
587        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
588            (data(), size(), __c, __pos);
589    }
590
591    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
592    size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
593    {
594        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
595        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
596            (data(), size(), __s, __pos, __n);
597    }
598
599    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
600    size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
601    {
602        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
603        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
604            (data(), size(), __s, __pos, traits_type::length(__s));
605    }
606
607#if _LIBCPP_STD_VER > 17
608    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
609    bool starts_with(basic_string_view __s) const _NOEXCEPT
610    { return size() >= __s.size() && compare(0, __s.size(), __s) == 0; }
611
612    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
613    bool starts_with(value_type __c) const _NOEXCEPT
614    { return !empty() && _Traits::eq(front(), __c); }
615
616    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
617    bool starts_with(const value_type* __s) const _NOEXCEPT
618    { return starts_with(basic_string_view(__s)); }
619
620    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
621    bool ends_with(basic_string_view __s) const _NOEXCEPT
622    { return size() >= __s.size() && compare(size() - __s.size(), npos, __s) == 0; }
623
624    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
625    bool ends_with(value_type __c) const _NOEXCEPT
626    { return !empty() && _Traits::eq(back(), __c); }
627
628    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
629    bool ends_with(const value_type* __s) const _NOEXCEPT
630    { return ends_with(basic_string_view(__s)); }
631#endif
632
633#if _LIBCPP_STD_VER > 20
634    constexpr _LIBCPP_INLINE_VISIBILITY
635    bool contains(basic_string_view __sv) const noexcept
636    { return find(__sv) != npos; }
637
638    constexpr _LIBCPP_INLINE_VISIBILITY
639    bool contains(value_type __c) const noexcept
640    { return find(__c) != npos; }
641
642    constexpr _LIBCPP_INLINE_VISIBILITY
643    bool contains(const value_type* __s) const
644    { return find(__s) != npos; }
645#endif
646
647private:
648    const   value_type* __data;
649    size_type           __size;
650};
651
652
653// [string.view.comparison]
654// operator ==
655template<class _CharT, class _Traits>
656_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
657bool operator==(basic_string_view<_CharT, _Traits> __lhs,
658                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
659{
660    if ( __lhs.size() != __rhs.size()) return false;
661    return __lhs.compare(__rhs) == 0;
662}
663
664template<class _CharT, class _Traits>
665_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
666bool operator==(basic_string_view<_CharT, _Traits> __lhs,
667                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
668{
669    if ( __lhs.size() != __rhs.size()) return false;
670    return __lhs.compare(__rhs) == 0;
671}
672
673template<class _CharT, class _Traits>
674_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
675bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
676                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
677{
678    if ( __lhs.size() != __rhs.size()) return false;
679    return __lhs.compare(__rhs) == 0;
680}
681
682
683// operator !=
684template<class _CharT, class _Traits>
685_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
686bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
687{
688    if ( __lhs.size() != __rhs.size())
689        return true;
690    return __lhs.compare(__rhs) != 0;
691}
692
693template<class _CharT, class _Traits>
694_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
695bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
696                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
697{
698    if ( __lhs.size() != __rhs.size())
699        return true;
700    return __lhs.compare(__rhs) != 0;
701}
702
703template<class _CharT, class _Traits>
704_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
705bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
706                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
707{
708    if ( __lhs.size() != __rhs.size())
709        return true;
710    return __lhs.compare(__rhs) != 0;
711}
712
713
714// operator <
715template<class _CharT, class _Traits>
716_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
717bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
718{
719    return __lhs.compare(__rhs) < 0;
720}
721
722template<class _CharT, class _Traits>
723_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
724bool operator<(basic_string_view<_CharT, _Traits> __lhs,
725                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
726{
727    return __lhs.compare(__rhs) < 0;
728}
729
730template<class _CharT, class _Traits>
731_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
732bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
733                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
734{
735    return __lhs.compare(__rhs) < 0;
736}
737
738
739// operator >
740template<class _CharT, class _Traits>
741_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
742bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
743{
744    return __lhs.compare(__rhs) > 0;
745}
746
747template<class _CharT, class _Traits>
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    return __lhs.compare(__rhs) > 0;
753}
754
755template<class _CharT, class _Traits>
756_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
757bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
758                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
759{
760    return __lhs.compare(__rhs) > 0;
761}
762
763
764// operator <=
765template<class _CharT, class _Traits>
766_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
767bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
768{
769    return __lhs.compare(__rhs) <= 0;
770}
771
772template<class _CharT, class _Traits>
773_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
774bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
775                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
776{
777    return __lhs.compare(__rhs) <= 0;
778}
779
780template<class _CharT, class _Traits>
781_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
782bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
783                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
784{
785    return __lhs.compare(__rhs) <= 0;
786}
787
788
789// operator >=
790template<class _CharT, class _Traits>
791_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
792bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
793{
794    return __lhs.compare(__rhs) >= 0;
795}
796
797
798template<class _CharT, class _Traits>
799_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
800bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
801                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
802{
803    return __lhs.compare(__rhs) >= 0;
804}
805
806template<class _CharT, class _Traits>
807_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
808bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
809                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
810{
811    return __lhs.compare(__rhs) >= 0;
812}
813
814
815template<class _CharT, class _Traits>
816basic_ostream<_CharT, _Traits>&
817operator<<(basic_ostream<_CharT, _Traits>& __os,
818           basic_string_view<_CharT, _Traits> __str);
819
820// [string.view.hash]
821template<class _CharT>
822struct _LIBCPP_TEMPLATE_VIS hash<basic_string_view<_CharT, char_traits<_CharT> > >
823    : public unary_function<basic_string_view<_CharT, char_traits<_CharT> >, size_t>
824{
825    _LIBCPP_INLINE_VISIBILITY
826    size_t operator()(const basic_string_view<_CharT, char_traits<_CharT> > __val) const _NOEXCEPT {
827        return __do_string_hash(__val.data(), __val.data() + __val.size());
828    }
829};
830
831
832#if _LIBCPP_STD_VER > 11
833inline namespace literals
834{
835  inline namespace string_view_literals
836  {
837    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
838    basic_string_view<char> operator "" sv(const char *__str, size_t __len) _NOEXCEPT
839    {
840        return basic_string_view<char> (__str, __len);
841    }
842
843    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
844    basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len) _NOEXCEPT
845    {
846        return basic_string_view<wchar_t> (__str, __len);
847    }
848
849#ifndef _LIBCPP_NO_HAS_CHAR8_T
850    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
851    basic_string_view<char8_t> operator "" sv(const char8_t *__str, size_t __len) _NOEXCEPT
852    {
853        return basic_string_view<char8_t> (__str, __len);
854    }
855#endif
856
857    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
858    basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len) _NOEXCEPT
859    {
860        return basic_string_view<char16_t> (__str, __len);
861    }
862
863    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
864    basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len) _NOEXCEPT
865    {
866        return basic_string_view<char32_t> (__str, __len);
867    }
868  }
869}
870#endif
871_LIBCPP_END_NAMESPACE_STD
872
873_LIBCPP_POP_MACROS
874
875#endif // _LIBCPP_STRING_VIEW
876