xref: /freebsd-src/contrib/llvm-project/libcxx/include/string_view (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
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<char16_t> u16string_view;
52    typedef basic_string_view<char32_t> u32string_view;
53    typedef basic_string_view<wchar_t> wstring_view;
54
55    template<class charT, class traits = char_traits<charT>>
56    class basic_string_view {
57      public:
58      // types
59      typedef traits traits_type;
60      typedef charT value_type;
61      typedef charT* pointer;
62      typedef const charT* const_pointer;
63      typedef charT& reference;
64      typedef const charT& const_reference;
65      typedef implementation-defined const_iterator;
66      typedef const_iterator iterator;
67      typedef reverse_iterator<const_iterator> const_reverse_iterator;
68      typedef const_reverse_iterator reverse_iterator;
69      typedef size_t size_type;
70      typedef ptrdiff_t difference_type;
71      static constexpr size_type npos = size_type(-1);
72
73      // 7.3, basic_string_view constructors and assignment operators
74      constexpr basic_string_view() noexcept;
75      constexpr basic_string_view(const basic_string_view&) noexcept = default;
76      basic_string_view& operator=(const basic_string_view&) noexcept = default;
77      template<class Allocator>
78      constexpr basic_string_view(const charT* str);
79      constexpr basic_string_view(const charT* str, size_type len);
80
81      // 7.4, basic_string_view iterator support
82      constexpr const_iterator begin() const noexcept;
83      constexpr const_iterator end() const noexcept;
84      constexpr const_iterator cbegin() const noexcept;
85      constexpr const_iterator cend() const noexcept;
86      const_reverse_iterator rbegin() const noexcept;
87      const_reverse_iterator rend() const noexcept;
88      const_reverse_iterator crbegin() const noexcept;
89      const_reverse_iterator crend() const noexcept;
90
91      // 7.5, basic_string_view capacity
92      constexpr size_type size() const noexcept;
93      constexpr size_type length() const noexcept;
94      constexpr size_type max_size() const noexcept;
95      constexpr bool empty() const noexcept;
96
97      // 7.6, basic_string_view element access
98      constexpr const_reference operator[](size_type pos) const;
99      constexpr const_reference at(size_type pos) const;
100      constexpr const_reference front() const;
101      constexpr const_reference back() const;
102      constexpr const_pointer data() const noexcept;
103
104      // 7.7, basic_string_view modifiers
105      constexpr void remove_prefix(size_type n);
106      constexpr void remove_suffix(size_type n);
107      constexpr void swap(basic_string_view& s) noexcept;
108
109      size_type copy(charT* s, size_type n, size_type pos = 0) const;
110
111      constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
112      constexpr int compare(basic_string_view s) const noexcept;
113      constexpr int compare(size_type pos1, size_type n1, basic_string_view s) const;
114      constexpr int compare(size_type pos1, size_type n1,
115                            basic_string_view s, size_type pos2, size_type n2) const;
116      constexpr int compare(const charT* s) const;
117      constexpr int compare(size_type pos1, size_type n1, const charT* s) const;
118      constexpr int compare(size_type pos1, size_type n1,
119                            const charT* s, size_type n2) const;
120      constexpr size_type find(basic_string_view s, size_type pos = 0) const noexcept;
121      constexpr size_type find(charT c, size_type pos = 0) const noexcept;
122      constexpr size_type find(const charT* s, size_type pos, size_type n) const;
123      constexpr size_type find(const charT* s, size_type pos = 0) const;
124      constexpr size_type rfind(basic_string_view s, size_type pos = npos) const noexcept;
125      constexpr size_type rfind(charT c, size_type pos = npos) const noexcept;
126      constexpr size_type rfind(const charT* s, size_type pos, size_type n) const;
127      constexpr size_type rfind(const charT* s, size_type pos = npos) const;
128      constexpr size_type find_first_of(basic_string_view s, size_type pos = 0) const noexcept;
129      constexpr size_type find_first_of(charT c, size_type pos = 0) const noexcept;
130      constexpr size_type find_first_of(const charT* s, size_type pos, size_type n) const;
131      constexpr size_type find_first_of(const charT* s, size_type pos = 0) const;
132      constexpr size_type find_last_of(basic_string_view s, size_type pos = npos) const noexcept;
133      constexpr size_type find_last_of(charT c, size_type pos = npos) const noexcept;
134      constexpr size_type find_last_of(const charT* s, size_type pos, size_type n) const;
135      constexpr size_type find_last_of(const charT* s, size_type pos = npos) const;
136      constexpr size_type find_first_not_of(basic_string_view s, size_type pos = 0) const noexcept;
137      constexpr size_type find_first_not_of(charT c, size_type pos = 0) const noexcept;
138      constexpr size_type find_first_not_of(const charT* s, size_type pos, size_type n) const;
139      constexpr size_type find_first_not_of(const charT* s, size_type pos = 0) const;
140      constexpr size_type find_last_not_of(basic_string_view s, size_type pos = npos) const noexcept;
141      constexpr size_type find_last_not_of(charT c, size_type pos = npos) const noexcept;
142      constexpr size_type find_last_not_of(const charT* s, size_type pos, size_type n) const;
143      constexpr size_type find_last_not_of(const charT* s, size_type pos = npos) const;
144
145      constexpr bool starts_with(basic_string_view s) const noexcept; // C++2a
146      constexpr bool starts_with(charT c) const noexcept;             // C++2a
147      constexpr bool starts_with(const charT* s) const;               // C++2a
148      constexpr bool ends_with(basic_string_view s) const noexcept;   // C++2a
149      constexpr bool ends_with(charT c) const noexcept;               // C++2a
150      constexpr bool ends_with(const charT* s) const;                 // C++2a
151
152     private:
153      const_pointer data_;  // exposition only
154      size_type     size_;  // exposition only
155    };
156
157  // 7.11, Hash support
158  template <class T> struct hash;
159  template <> struct hash<string_view>;
160  template <> struct hash<u16string_view>;
161  template <> struct hash<u32string_view>;
162  template <> struct hash<wstring_view>;
163
164  constexpr basic_string_view<char>     operator "" sv( const char *str,     size_t len ) noexcept;
165  constexpr basic_string_view<wchar_t>  operator "" sv( const wchar_t *str,  size_t len ) noexcept;
166  constexpr basic_string_view<char16_t> operator "" sv( const char16_t *str, size_t len ) noexcept;
167  constexpr basic_string_view<char32_t> operator "" sv( const char32_t *str, size_t len ) noexcept;
168
169}  // namespace std
170
171
172*/
173
174#include <__config>
175#include <__string>
176#include <algorithm>
177#include <iterator>
178#include <limits>
179#include <stdexcept>
180#include <version>
181#include <__debug>
182
183#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
184#pragma GCC system_header
185#endif
186
187_LIBCPP_PUSH_MACROS
188#include <__undef_macros>
189
190
191_LIBCPP_BEGIN_NAMESPACE_STD
192
193template<class _CharT, class _Traits = char_traits<_CharT> >
194class _LIBCPP_TEMPLATE_VIS basic_string_view {
195public:
196    // types
197    typedef _Traits                                    traits_type;
198    typedef _CharT                                     value_type;
199    typedef _CharT*                                    pointer;
200    typedef const _CharT*                              const_pointer;
201    typedef _CharT&                                    reference;
202    typedef const _CharT&                              const_reference;
203    typedef const_pointer                              const_iterator; // See [string.view.iterators]
204    typedef const_iterator                             iterator;
205    typedef _VSTD::reverse_iterator<const_iterator>    const_reverse_iterator;
206    typedef const_reverse_iterator                     reverse_iterator;
207    typedef size_t                                     size_type;
208    typedef ptrdiff_t                                  difference_type;
209    static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);
210
211    static_assert((!is_array<value_type>::value), "Character type of basic_string_view must not be an array");
212    static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string_view must be standard-layout");
213    static_assert(( is_trivial<value_type>::value), "Character type of basic_string_view must be trivial");
214    static_assert((is_same<_CharT, typename traits_type::char_type>::value),
215                  "traits_type::char_type must be the same type as CharT");
216
217    // [string.view.cons], construct/copy
218    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
219    basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {}
220
221    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
222    basic_string_view(const basic_string_view&) _NOEXCEPT = default;
223
224    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
225    basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;
226
227    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
228    basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT
229        : __data(__s), __size(__len)
230    {
231#if _LIBCPP_STD_VER > 11
232    _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr");
233#endif
234    }
235
236    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
237    basic_string_view(const _CharT* __s)
238        : __data(__s), __size(_Traits::length(__s)) {}
239
240    // [string.view.iterators], iterators
241    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
242    const_iterator begin()  const _NOEXCEPT { return cbegin(); }
243
244    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
245    const_iterator end()    const _NOEXCEPT { return cend(); }
246
247    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
248    const_iterator cbegin() const _NOEXCEPT { return __data; }
249
250    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
251    const_iterator cend()   const _NOEXCEPT { return __data + __size; }
252
253    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
254    const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
255
256    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
257    const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
258
259    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
260    const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
261
262    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
263    const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
264
265    // [string.view.capacity], capacity
266    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
267    size_type size()     const _NOEXCEPT { return __size; }
268
269    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
270    size_type length()   const _NOEXCEPT { return __size; }
271
272    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
273    size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max(); }
274
275    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
276    bool empty()         const _NOEXCEPT { return __size == 0; }
277
278    // [string.view.access], element access
279    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
280    const_reference operator[](size_type __pos) const _NOEXCEPT { return __data[__pos]; }
281
282    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
283    const_reference at(size_type __pos) const
284    {
285        return __pos >= size()
286            ? (__throw_out_of_range("string_view::at"), __data[0])
287            : __data[__pos];
288    }
289
290    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
291    const_reference front() const _NOEXCEPT
292    {
293        return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0];
294    }
295
296    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
297    const_reference back() const _NOEXCEPT
298    {
299        return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1];
300    }
301
302    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
303    const_pointer data() const _NOEXCEPT { return __data; }
304
305    // [string.view.modifiers], modifiers:
306    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
307    void remove_prefix(size_type __n) _NOEXCEPT
308    {
309        _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
310        __data += __n;
311        __size -= __n;
312    }
313
314    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
315    void remove_suffix(size_type __n) _NOEXCEPT
316    {
317        _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
318        __size -= __n;
319    }
320
321    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
322    void swap(basic_string_view& __other) _NOEXCEPT
323    {
324        const value_type *__p = __data;
325        __data = __other.__data;
326        __other.__data = __p;
327
328        size_type __sz = __size;
329        __size = __other.__size;
330        __other.__size = __sz;
331    }
332
333    _LIBCPP_INLINE_VISIBILITY
334    size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
335    {
336        if (__pos > size())
337            __throw_out_of_range("string_view::copy");
338        size_type __rlen = _VSTD::min(__n, size() - __pos);
339        _Traits::copy(__s, data() + __pos, __rlen);
340        return __rlen;
341    }
342
343    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
344    basic_string_view substr(size_type __pos = 0, size_type __n = npos) const
345    {
346        return __pos > size()
347            ? (__throw_out_of_range("string_view::substr"), basic_string_view())
348            : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
349    }
350
351    _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT
352    {
353        size_type __rlen = _VSTD::min( size(), __sv.size());
354        int __retval = _Traits::compare(data(), __sv.data(), __rlen);
355        if ( __retval == 0 ) // first __rlen chars matched
356            __retval = size() == __sv.size() ? 0 : ( size() < __sv.size() ? -1 : 1 );
357        return __retval;
358    }
359
360    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
361    int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
362    {
363        return substr(__pos1, __n1).compare(__sv);
364    }
365
366    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
367    int compare(                       size_type __pos1, size_type __n1,
368                basic_string_view __sv, size_type __pos2, size_type __n2) const
369    {
370        return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
371    }
372
373    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
374    int compare(const _CharT* __s) const _NOEXCEPT
375    {
376        return compare(basic_string_view(__s));
377    }
378
379    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
380    int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
381    {
382        return substr(__pos1, __n1).compare(basic_string_view(__s));
383    }
384
385    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
386    int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
387    {
388        return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
389    }
390
391    // find
392    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
393    size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
394    {
395        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
396        return __str_find<value_type, size_type, traits_type, npos>
397            (data(), size(), __s.data(), __pos, __s.size());
398    }
399
400    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
401    size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
402    {
403        return __str_find<value_type, size_type, traits_type, npos>
404            (data(), size(), __c, __pos);
405    }
406
407    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
408    size_type find(const _CharT* __s, size_type __pos, size_type __n) const
409    {
410        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
411        return __str_find<value_type, size_type, traits_type, npos>
412            (data(), size(), __s, __pos, __n);
413    }
414
415    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
416    size_type find(const _CharT* __s, size_type __pos = 0) const
417    {
418        _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr");
419        return __str_find<value_type, size_type, traits_type, npos>
420            (data(), size(), __s, __pos, traits_type::length(__s));
421    }
422
423    // rfind
424    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
425    size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
426    {
427        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
428        return __str_rfind<value_type, size_type, traits_type, npos>
429            (data(), size(), __s.data(), __pos, __s.size());
430    }
431
432    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
433    size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
434    {
435        return __str_rfind<value_type, size_type, traits_type, npos>
436            (data(), size(), __c, __pos);
437    }
438
439    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
440    size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const
441    {
442        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
443        return __str_rfind<value_type, size_type, traits_type, npos>
444            (data(), size(), __s, __pos, __n);
445    }
446
447    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
448    size_type rfind(const _CharT* __s, size_type __pos=npos) const
449    {
450        _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr");
451        return __str_rfind<value_type, size_type, traits_type, npos>
452            (data(), size(), __s, __pos, traits_type::length(__s));
453    }
454
455    // find_first_of
456    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
457    size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
458    {
459        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
460        return __str_find_first_of<value_type, size_type, traits_type, npos>
461            (data(), size(), __s.data(), __pos, __s.size());
462    }
463
464    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
465    size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
466    { return find(__c, __pos); }
467
468    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
469    size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
470    {
471        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
472        return __str_find_first_of<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_first_of(const _CharT* __s, size_type __pos=0) const
478    {
479        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr");
480        return __str_find_first_of<value_type, size_type, traits_type, npos>
481            (data(), size(), __s, __pos, traits_type::length(__s));
482    }
483
484    // find_last_of
485    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
486    size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
487    {
488        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
489        return __str_find_last_of<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 find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
495    { return rfind(__c, __pos); }
496
497    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
498    size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
499    {
500        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
501        return __str_find_last_of<value_type, size_type, traits_type, npos>
502            (data(), size(), __s, __pos, __n);
503    }
504
505    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
506    size_type find_last_of(const _CharT* __s, size_type __pos=npos) const
507    {
508        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr");
509        return __str_find_last_of<value_type, size_type, traits_type, npos>
510            (data(), size(), __s, __pos, traits_type::length(__s));
511    }
512
513    // find_first_not_of
514    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
515    size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
516    {
517        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
518        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
519            (data(), size(), __s.data(), __pos, __s.size());
520    }
521
522    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
523    size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
524    {
525        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
526            (data(), size(), __c, __pos);
527    }
528
529    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
530    size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
531    {
532        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
533        return __str_find_first_not_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_not_of(const _CharT* __s, size_type __pos=0) const
539    {
540        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
541        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
542            (data(), size(), __s, __pos, traits_type::length(__s));
543    }
544
545    // find_last_not_of
546    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
547    size_type find_last_not_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_not_of(): received nullptr");
550        return __str_find_last_not_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_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
556    {
557        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
558            (data(), size(), __c, __pos);
559    }
560
561    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
562    size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
563    {
564        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
565        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
566            (data(), size(), __s, __pos, __n);
567    }
568
569    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
570    size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const
571    {
572        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
573        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
574            (data(), size(), __s, __pos, traits_type::length(__s));
575    }
576
577#if _LIBCPP_STD_VER > 17
578    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
579    bool starts_with(basic_string_view __s) const _NOEXCEPT
580    { return size() >= __s.size() && compare(0, __s.size(), __s) == 0; }
581
582    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
583    bool starts_with(value_type __c) const _NOEXCEPT
584    { return !empty() && _Traits::eq(front(), __c); }
585
586    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
587    bool starts_with(const value_type* __s) const _NOEXCEPT
588    { return starts_with(basic_string_view(__s)); }
589
590    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
591    bool ends_with(basic_string_view __s) const _NOEXCEPT
592    { return size() >= __s.size() && compare(size() - __s.size(), npos, __s) == 0; }
593
594    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
595    bool ends_with(value_type __c) const _NOEXCEPT
596    { return !empty() && _Traits::eq(back(), __c); }
597
598    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
599    bool ends_with(const value_type* __s) const _NOEXCEPT
600    { return ends_with(basic_string_view(__s)); }
601#endif
602
603private:
604    const   value_type* __data;
605    size_type           __size;
606};
607
608
609// [string.view.comparison]
610// operator ==
611template<class _CharT, class _Traits>
612_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
613bool operator==(basic_string_view<_CharT, _Traits> __lhs,
614                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
615{
616    if ( __lhs.size() != __rhs.size()) return false;
617    return __lhs.compare(__rhs) == 0;
618}
619
620template<class _CharT, class _Traits>
621_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
622bool operator==(basic_string_view<_CharT, _Traits> __lhs,
623                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
624{
625    if ( __lhs.size() != __rhs.size()) return false;
626    return __lhs.compare(__rhs) == 0;
627}
628
629template<class _CharT, class _Traits>
630_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
631bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
632                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
633{
634    if ( __lhs.size() != __rhs.size()) return false;
635    return __lhs.compare(__rhs) == 0;
636}
637
638
639// operator !=
640template<class _CharT, class _Traits>
641_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
642bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
643{
644    if ( __lhs.size() != __rhs.size())
645        return true;
646    return __lhs.compare(__rhs) != 0;
647}
648
649template<class _CharT, class _Traits>
650_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
651bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
652                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
653{
654    if ( __lhs.size() != __rhs.size())
655        return true;
656    return __lhs.compare(__rhs) != 0;
657}
658
659template<class _CharT, class _Traits>
660_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
661bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
662                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
663{
664    if ( __lhs.size() != __rhs.size())
665        return true;
666    return __lhs.compare(__rhs) != 0;
667}
668
669
670// operator <
671template<class _CharT, class _Traits>
672_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
673bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
674{
675    return __lhs.compare(__rhs) < 0;
676}
677
678template<class _CharT, class _Traits>
679_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
680bool operator<(basic_string_view<_CharT, _Traits> __lhs,
681                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
682{
683    return __lhs.compare(__rhs) < 0;
684}
685
686template<class _CharT, class _Traits>
687_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
688bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
689                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
690{
691    return __lhs.compare(__rhs) < 0;
692}
693
694
695// operator >
696template<class _CharT, class _Traits>
697_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
698bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
699{
700    return __lhs.compare(__rhs) > 0;
701}
702
703template<class _CharT, class _Traits>
704_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
705bool operator>(basic_string_view<_CharT, _Traits> __lhs,
706                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
707{
708    return __lhs.compare(__rhs) > 0;
709}
710
711template<class _CharT, class _Traits>
712_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
713bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
714                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
715{
716    return __lhs.compare(__rhs) > 0;
717}
718
719
720// operator <=
721template<class _CharT, class _Traits>
722_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
723bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
724{
725    return __lhs.compare(__rhs) <= 0;
726}
727
728template<class _CharT, class _Traits>
729_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
730bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
731                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
732{
733    return __lhs.compare(__rhs) <= 0;
734}
735
736template<class _CharT, class _Traits>
737_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
738bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
739                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
740{
741    return __lhs.compare(__rhs) <= 0;
742}
743
744
745// operator >=
746template<class _CharT, class _Traits>
747_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
748bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
749{
750    return __lhs.compare(__rhs) >= 0;
751}
752
753
754template<class _CharT, class _Traits>
755_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
756bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
757                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
758{
759    return __lhs.compare(__rhs) >= 0;
760}
761
762template<class _CharT, class _Traits>
763_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
764bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
765                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
766{
767    return __lhs.compare(__rhs) >= 0;
768}
769
770typedef basic_string_view<char>     string_view;
771#ifndef _LIBCPP_NO_HAS_CHAR8_T
772typedef basic_string_view<char8_t>  u8string_view;
773#endif
774typedef basic_string_view<char16_t> u16string_view;
775typedef basic_string_view<char32_t> u32string_view;
776typedef basic_string_view<wchar_t>  wstring_view;
777
778// [string.view.hash]
779template<class _CharT>
780struct _LIBCPP_TEMPLATE_VIS hash<basic_string_view<_CharT, char_traits<_CharT> > >
781    : public unary_function<basic_string_view<_CharT, char_traits<_CharT> >, size_t>
782{
783    _LIBCPP_INLINE_VISIBILITY
784    size_t operator()(const basic_string_view<_CharT, char_traits<_CharT> > __val) const _NOEXCEPT {
785        return __do_string_hash(__val.data(), __val.data() + __val.size());
786    }
787};
788
789
790#if _LIBCPP_STD_VER > 11
791inline namespace literals
792{
793  inline namespace string_view_literals
794  {
795    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
796    basic_string_view<char> operator "" sv(const char *__str, size_t __len) _NOEXCEPT
797    {
798        return basic_string_view<char> (__str, __len);
799    }
800
801    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
802    basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len) _NOEXCEPT
803    {
804        return basic_string_view<wchar_t> (__str, __len);
805    }
806
807#ifndef _LIBCPP_NO_HAS_CHAR8_T
808    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
809    basic_string_view<char8_t> operator "" sv(const char8_t *__str, size_t __len) _NOEXCEPT
810    {
811        return basic_string_view<char8_t> (__str, __len);
812    }
813#endif
814
815    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
816    basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len) _NOEXCEPT
817    {
818        return basic_string_view<char16_t> (__str, __len);
819    }
820
821    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
822    basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len) _NOEXCEPT
823    {
824        return basic_string_view<char32_t> (__str, __len);
825    }
826  }
827}
828#endif
829_LIBCPP_END_NAMESPACE_STD
830
831_LIBCPP_POP_MACROS
832
833#endif // _LIBCPP_STRING_VIEW
834