1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_STRING_VIEW
11#define _LIBCPP_STRING_VIEW
12
13/*
14
15    string_view synopsis
16
17namespace std {
18
19    // 7.2, Class template basic_string_view
20    template<class charT, class traits = char_traits<charT>>
21        class basic_string_view;
22
23    template<class charT, class traits>
24    inline constexpr bool ranges::enable_view<basic_string_view<charT, traits>> = true;
25
26    template<class charT, class traits>
27    inline constexpr bool ranges::enable_borrowed_range<basic_string_view<charT, traits>> = true;  // C++20
28
29    // 7.9, basic_string_view non-member comparison functions
30    template<class charT, class traits>
31    constexpr bool operator==(basic_string_view<charT, traits> x,
32                              basic_string_view<charT, traits> y) noexcept;
33    template<class charT, class traits>
34    constexpr bool operator!=(basic_string_view<charT, traits> x,
35                              basic_string_view<charT, traits> y) noexcept;
36    template<class charT, class traits>
37    constexpr bool operator< (basic_string_view<charT, traits> x,
38                                 basic_string_view<charT, traits> y) noexcept;
39    template<class charT, class traits>
40    constexpr bool operator> (basic_string_view<charT, traits> x,
41                              basic_string_view<charT, traits> y) noexcept;
42    template<class charT, class traits>
43    constexpr bool operator<=(basic_string_view<charT, traits> x,
44                                 basic_string_view<charT, traits> y) noexcept;
45    template<class charT, class traits>
46    constexpr bool operator>=(basic_string_view<charT, traits> x,
47                              basic_string_view<charT, traits> y) noexcept;
48    // see below, sufficient additional overloads of comparison functions
49
50    // 7.10, Inserters and extractors
51    template<class charT, class traits>
52      basic_ostream<charT, traits>&
53        operator<<(basic_ostream<charT, traits>& os,
54                   basic_string_view<charT, traits> str);
55
56    // basic_string_view typedef names
57    typedef basic_string_view<char> string_view;
58    typedef basic_string_view<char8_t> u8string_view; // C++20
59    typedef basic_string_view<char16_t> u16string_view;
60    typedef basic_string_view<char32_t> u32string_view;
61    typedef basic_string_view<wchar_t> wstring_view;
62
63    template<class charT, class traits = char_traits<charT>>
64    class basic_string_view {
65      public:
66      // types
67      typedef traits traits_type;
68      typedef charT value_type;
69      typedef charT* pointer;
70      typedef const charT* const_pointer;
71      typedef charT& reference;
72      typedef const charT& const_reference;
73      typedef implementation-defined const_iterator;
74      typedef const_iterator iterator;
75      typedef reverse_iterator<const_iterator> const_reverse_iterator;
76      typedef const_reverse_iterator reverse_iterator;
77      typedef size_t size_type;
78      typedef ptrdiff_t difference_type;
79      static constexpr size_type npos = size_type(-1);
80
81      // 7.3, basic_string_view constructors and assignment operators
82      constexpr basic_string_view() noexcept;
83      constexpr basic_string_view(const basic_string_view&) noexcept = default;
84      basic_string_view& operator=(const basic_string_view&) noexcept = default;
85      template<class Allocator>
86      constexpr basic_string_view(const charT* str);
87      basic_string_view(nullptr_t) = delete; // C++2b
88      constexpr basic_string_view(const charT* str, size_type len);
89      template <class It, class End>
90      constexpr basic_string_view(It begin, End end); // C++20
91      template <class Range>
92      constexpr basic_string_view(Range&& r); // C++23
93
94      // 7.4, basic_string_view iterator support
95      constexpr const_iterator begin() const noexcept;
96      constexpr const_iterator end() const noexcept;
97      constexpr const_iterator cbegin() const noexcept;
98      constexpr const_iterator cend() const noexcept;
99      const_reverse_iterator rbegin() const noexcept;
100      const_reverse_iterator rend() const noexcept;
101      const_reverse_iterator crbegin() const noexcept;
102      const_reverse_iterator crend() const noexcept;
103
104      // 7.5, basic_string_view capacity
105      constexpr size_type size() const noexcept;
106      constexpr size_type length() const noexcept;
107      constexpr size_type max_size() const noexcept;
108      constexpr bool empty() const noexcept;
109
110      // 7.6, basic_string_view element access
111      constexpr const_reference operator[](size_type pos) const;
112      constexpr const_reference at(size_type pos) const;
113      constexpr const_reference front() const;
114      constexpr const_reference back() const;
115      constexpr const_pointer data() const noexcept;
116
117      // 7.7, basic_string_view modifiers
118      constexpr void remove_prefix(size_type n);
119      constexpr void remove_suffix(size_type n);
120      constexpr void swap(basic_string_view& s) noexcept;
121
122      size_type copy(charT* s, size_type n, size_type pos = 0) const;  // constexpr in C++20
123
124      constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
125      constexpr int compare(basic_string_view s) const noexcept;
126      constexpr int compare(size_type pos1, size_type n1, basic_string_view s) const;
127      constexpr int compare(size_type pos1, size_type n1,
128                            basic_string_view s, size_type pos2, size_type n2) const;
129      constexpr int compare(const charT* s) const;
130      constexpr int compare(size_type pos1, size_type n1, const charT* s) const;
131      constexpr int compare(size_type pos1, size_type n1,
132                            const charT* s, size_type n2) const;
133      constexpr size_type find(basic_string_view s, size_type pos = 0) const noexcept;
134      constexpr size_type find(charT c, size_type pos = 0) const noexcept;
135      constexpr size_type find(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
136      constexpr size_type find(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
137      constexpr size_type rfind(basic_string_view s, size_type pos = npos) const noexcept;
138      constexpr size_type rfind(charT c, size_type pos = npos) const noexcept;
139      constexpr size_type rfind(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
140      constexpr size_type rfind(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
141      constexpr size_type find_first_of(basic_string_view s, size_type pos = 0) const noexcept;
142      constexpr size_type find_first_of(charT c, size_type pos = 0) const noexcept;
143      constexpr size_type find_first_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
144      constexpr size_type find_first_of(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
145      constexpr size_type find_last_of(basic_string_view s, size_type pos = npos) const noexcept;
146      constexpr size_type find_last_of(charT c, size_type pos = npos) const noexcept;
147      constexpr size_type find_last_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
148      constexpr size_type find_last_of(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
149      constexpr size_type find_first_not_of(basic_string_view s, size_type pos = 0) const noexcept;
150      constexpr size_type find_first_not_of(charT c, size_type pos = 0) const noexcept;
151      constexpr size_type find_first_not_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
152      constexpr size_type find_first_not_of(const charT* s, size_type pos = 0) const noexcept; // noexcept as an extension
153      constexpr size_type find_last_not_of(basic_string_view s, size_type pos = npos) const noexcept;
154      constexpr size_type find_last_not_of(charT c, size_type pos = npos) const noexcept;
155      constexpr size_type find_last_not_of(const charT* s, size_type pos, size_type n) const noexcept; // noexcept as an extension
156      constexpr size_type find_last_not_of(const charT* s, size_type pos = npos) const noexcept; // noexcept as an extension
157
158      constexpr bool starts_with(basic_string_view s) const noexcept; // C++20
159      constexpr bool starts_with(charT c) const noexcept;             // C++20
160      constexpr bool starts_with(const charT* s) const;               // C++20
161      constexpr bool ends_with(basic_string_view s) const noexcept;   // C++20
162      constexpr bool ends_with(charT c) const noexcept;               // C++20
163      constexpr bool ends_with(const charT* s) const;                 // C++20
164
165      constexpr bool contains(basic_string_view s) const noexcept; // C++2b
166      constexpr bool contains(charT c) const noexcept;             // C++2b
167      constexpr bool contains(const charT* s) const;               // C++2b
168
169     private:
170      const_pointer data_;  // exposition only
171      size_type     size_;  // exposition only
172    };
173
174  // basic_string_view deduction guides
175  template<class It, class End>
176    basic_string_view(It, End) -> basic_string_view<iter_value_t<It>>; // C++20
177  template<class Range>
178    basic_string_view(Range&&) -> basic_string_view<ranges::range_value_t<Range>>; // C++23
179
180  // 7.11, Hash support
181  template <class T> struct hash;
182  template <> struct hash<string_view>;
183  template <> struct hash<u8string_view>; // C++20
184  template <> struct hash<u16string_view>;
185  template <> struct hash<u32string_view>;
186  template <> struct hash<wstring_view>;
187
188  constexpr basic_string_view<char>     operator "" sv( const char *str,     size_t len ) noexcept;
189  constexpr basic_string_view<wchar_t>  operator "" sv( const wchar_t *str,  size_t len ) noexcept;
190  constexpr basic_string_view<char8_t>  operator "" sv( const char8_t *str,  size_t len ) noexcept; // C++20
191  constexpr basic_string_view<char16_t> operator "" sv( const char16_t *str, size_t len ) noexcept;
192  constexpr basic_string_view<char32_t> operator "" sv( const char32_t *str, size_t len ) noexcept;
193
194}  // namespace std
195
196
197*/
198
199#include <__algorithm/min.h>
200#include <__assert> // all public C++ headers provide the assertion handler
201#include <__config>
202#include <__fwd/string_view.h>
203#include <__ranges/concepts.h>
204#include <__ranges/data.h>
205#include <__ranges/enable_borrowed_range.h>
206#include <__ranges/enable_view.h>
207#include <__ranges/size.h>
208#include <__string>
209#include <compare>
210#include <iosfwd>
211#include <iterator>
212#include <limits>
213#include <stdexcept>
214#include <type_traits>
215#include <version>
216
217#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
218#  pragma GCC system_header
219#endif
220
221_LIBCPP_PUSH_MACROS
222#include <__undef_macros>
223
224
225_LIBCPP_BEGIN_NAMESPACE_STD
226
227// TODO: This is a workaround for some vendors to carry a downstream diff to accept `nullptr` in
228//       string_view constructors. This can be refactored when this exact form isn't needed anymore.
229template <class _Traits>
230_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
231inline size_t __char_traits_length_checked(const typename _Traits::char_type* __s) _NOEXCEPT {
232  // This needs to be a single statement for C++11 constexpr
233  return _LIBCPP_ASSERT(__s != nullptr, "null pointer passed to non-null argument of char_traits<...>::length"), _Traits::length(__s);
234}
235
236template<class _CharT, class _Traits>
237class
238    _LIBCPP_PREFERRED_NAME(string_view)
239#ifndef _LIBCPP_HAS_NO_CHAR8_T
240    _LIBCPP_PREFERRED_NAME(u8string_view)
241#endif
242    _LIBCPP_PREFERRED_NAME(u16string_view)
243    _LIBCPP_PREFERRED_NAME(u32string_view)
244    _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wstring_view))
245    basic_string_view {
246public:
247    // types
248    typedef _Traits                                    traits_type;
249    typedef _CharT                                     value_type;
250    typedef _CharT*                                    pointer;
251    typedef const _CharT*                              const_pointer;
252    typedef _CharT&                                    reference;
253    typedef const _CharT&                              const_reference;
254    typedef const_pointer                              const_iterator; // See [string.view.iterators]
255    typedef const_iterator                             iterator;
256    typedef _VSTD::reverse_iterator<const_iterator>    const_reverse_iterator;
257    typedef const_reverse_iterator                     reverse_iterator;
258    typedef size_t                                     size_type;
259    typedef ptrdiff_t                                  difference_type;
260    static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);
261
262    static_assert((!is_array<value_type>::value), "Character type of basic_string_view must not be an array");
263    static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string_view must be standard-layout");
264    static_assert(( is_trivial<value_type>::value), "Character type of basic_string_view must be trivial");
265    static_assert((is_same<_CharT, typename traits_type::char_type>::value),
266                  "traits_type::char_type must be the same type as CharT");
267
268    // [string.view.cons], construct/copy
269    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
270    basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {}
271
272    _LIBCPP_INLINE_VISIBILITY
273    basic_string_view(const basic_string_view&) _NOEXCEPT = default;
274
275    _LIBCPP_INLINE_VISIBILITY
276    basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;
277
278    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
279    basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT
280        : __data(__s), __size(__len)
281    {
282#if _LIBCPP_STD_VER > 11
283    _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr");
284#endif
285    }
286
287#if _LIBCPP_STD_VER > 17
288    template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
289      requires (is_same_v<iter_value_t<_It>, _CharT> && !is_convertible_v<_End, size_type>)
290    constexpr _LIBCPP_HIDE_FROM_ABI basic_string_view(_It __begin, _End __end)
291       : __data(_VSTD::to_address(__begin)), __size(__end - __begin)
292    {
293      _LIBCPP_ASSERT((__end - __begin) >= 0, "std::string_view::string_view(iterator, sentinel) received invalid range");
294    }
295#endif // _LIBCPP_STD_VER > 17
296
297#if _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
298    template <class _Range>
299      requires (
300        !is_same_v<remove_cvref_t<_Range>, basic_string_view> &&
301        ranges::contiguous_range<_Range> &&
302        ranges::sized_range<_Range> &&
303        is_same_v<ranges::range_value_t<_Range>, _CharT> &&
304        !is_convertible_v<_Range, const _CharT*> &&
305        (!requires(remove_cvref_t<_Range>& d) {
306          d.operator _VSTD::basic_string_view<_CharT, _Traits>();
307        }) &&
308        (!requires {
309         typename remove_reference_t<_Range>::traits_type;
310        } || is_same_v<typename remove_reference_t<_Range>::traits_type, _Traits>)
311      )
312    constexpr _LIBCPP_HIDE_FROM_ABI
313    basic_string_view(_Range&& __r) : __data(ranges::data(__r)), __size(ranges::size(__r)) {}
314#endif // _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
315
316    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
317    basic_string_view(const _CharT* __s)
318        : __data(__s), __size(_VSTD::__char_traits_length_checked<_Traits>(__s)) {}
319
320#if _LIBCPP_STD_VER > 20
321    basic_string_view(nullptr_t) = delete;
322#endif
323
324    // [string.view.iterators], iterators
325    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
326    const_iterator begin()  const _NOEXCEPT { return cbegin(); }
327
328    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
329    const_iterator end()    const _NOEXCEPT { return cend(); }
330
331    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
332    const_iterator cbegin() const _NOEXCEPT { return __data; }
333
334    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
335    const_iterator cend()   const _NOEXCEPT { return __data + __size; }
336
337    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
338    const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
339
340    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
341    const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
342
343    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
344    const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
345
346    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
347    const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
348
349    // [string.view.capacity], capacity
350    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
351    size_type size()     const _NOEXCEPT { return __size; }
352
353    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
354    size_type length()   const _NOEXCEPT { return __size; }
355
356    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
357    size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max() / sizeof(value_type); }
358
359    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
360    bool empty()         const _NOEXCEPT { return __size == 0; }
361
362    // [string.view.access], element access
363    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
364    const_reference operator[](size_type __pos) const _NOEXCEPT {
365      return _LIBCPP_ASSERT(__pos < size(), "string_view[] index out of bounds"), __data[__pos];
366    }
367
368    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
369    const_reference at(size_type __pos) const
370    {
371        return __pos >= size()
372            ? (__throw_out_of_range("string_view::at"), __data[0])
373            : __data[__pos];
374    }
375
376    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
377    const_reference front() const _NOEXCEPT
378    {
379        return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0];
380    }
381
382    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
383    const_reference back() const _NOEXCEPT
384    {
385        return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1];
386    }
387
388    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
389    const_pointer data() const _NOEXCEPT { return __data; }
390
391    // [string.view.modifiers], modifiers:
392    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
393    void remove_prefix(size_type __n) _NOEXCEPT
394    {
395        _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
396        __data += __n;
397        __size -= __n;
398    }
399
400    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
401    void remove_suffix(size_type __n) _NOEXCEPT
402    {
403        _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
404        __size -= __n;
405    }
406
407    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
408    void swap(basic_string_view& __other) _NOEXCEPT
409    {
410        const value_type *__p = __data;
411        __data = __other.__data;
412        __other.__data = __p;
413
414        size_type __sz = __size;
415        __size = __other.__size;
416        __other.__size = __sz;
417    }
418
419    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
420    size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
421    {
422        if (__pos > size())
423            __throw_out_of_range("string_view::copy");
424        size_type __rlen = _VSTD::min(__n, size() - __pos);
425        _Traits::copy(__s, data() + __pos, __rlen);
426        return __rlen;
427    }
428
429    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
430    basic_string_view substr(size_type __pos = 0, size_type __n = npos) const
431    {
432        return __pos > size()
433            ? (__throw_out_of_range("string_view::substr"), basic_string_view())
434            : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
435    }
436
437    _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT
438    {
439        size_type __rlen = _VSTD::min( size(), __sv.size());
440        int __retval = _Traits::compare(data(), __sv.data(), __rlen);
441        if ( __retval == 0 ) // first __rlen chars matched
442            __retval = size() == __sv.size() ? 0 : ( size() < __sv.size() ? -1 : 1 );
443        return __retval;
444    }
445
446    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
447    int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
448    {
449        return substr(__pos1, __n1).compare(__sv);
450    }
451
452    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
453    int compare(                       size_type __pos1, size_type __n1,
454                basic_string_view __sv, size_type __pos2, size_type __n2) const
455    {
456        return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
457    }
458
459    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
460    int compare(const _CharT* __s) const _NOEXCEPT
461    {
462        return compare(basic_string_view(__s));
463    }
464
465    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
466    int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
467    {
468        return substr(__pos1, __n1).compare(basic_string_view(__s));
469    }
470
471    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
472    int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
473    {
474        return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
475    }
476
477    // find
478    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
479    size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
480    {
481        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
482        return __str_find<value_type, size_type, traits_type, npos>
483            (data(), size(), __s.data(), __pos, __s.size());
484    }
485
486    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
487    size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
488    {
489        return __str_find<value_type, size_type, traits_type, npos>
490            (data(), size(), __c, __pos);
491    }
492
493    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
494    size_type find(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
495    {
496        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
497        return __str_find<value_type, size_type, traits_type, npos>
498            (data(), size(), __s, __pos, __n);
499    }
500
501    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
502    size_type find(const _CharT* __s, size_type __pos = 0) const _NOEXCEPT
503    {
504        _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr");
505        return __str_find<value_type, size_type, traits_type, npos>
506            (data(), size(), __s, __pos, traits_type::length(__s));
507    }
508
509    // rfind
510    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
511    size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
512    {
513        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
514        return __str_rfind<value_type, size_type, traits_type, npos>
515            (data(), size(), __s.data(), __pos, __s.size());
516    }
517
518    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
519    size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
520    {
521        return __str_rfind<value_type, size_type, traits_type, npos>
522            (data(), size(), __c, __pos);
523    }
524
525    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
526    size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
527    {
528        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
529        return __str_rfind<value_type, size_type, traits_type, npos>
530            (data(), size(), __s, __pos, __n);
531    }
532
533    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
534    size_type rfind(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
535    {
536        _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr");
537        return __str_rfind<value_type, size_type, traits_type, npos>
538            (data(), size(), __s, __pos, traits_type::length(__s));
539    }
540
541    // find_first_of
542    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
543    size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
544    {
545        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
546        return __str_find_first_of<value_type, size_type, traits_type, npos>
547            (data(), size(), __s.data(), __pos, __s.size());
548    }
549
550    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
551    size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
552    { return find(__c, __pos); }
553
554    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
555    size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
556    {
557        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
558        return __str_find_first_of<value_type, size_type, traits_type, npos>
559            (data(), size(), __s, __pos, __n);
560    }
561
562    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
563    size_type find_first_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
564    {
565        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr");
566        return __str_find_first_of<value_type, size_type, traits_type, npos>
567            (data(), size(), __s, __pos, traits_type::length(__s));
568    }
569
570    // find_last_of
571    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
572    size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
573    {
574        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
575        return __str_find_last_of<value_type, size_type, traits_type, npos>
576            (data(), size(), __s.data(), __pos, __s.size());
577    }
578
579    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
580    size_type find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
581    { return rfind(__c, __pos); }
582
583    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
584    size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
585    {
586        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
587        return __str_find_last_of<value_type, size_type, traits_type, npos>
588            (data(), size(), __s, __pos, __n);
589    }
590
591    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
592    size_type find_last_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
593    {
594        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr");
595        return __str_find_last_of<value_type, size_type, traits_type, npos>
596            (data(), size(), __s, __pos, traits_type::length(__s));
597    }
598
599    // find_first_not_of
600    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
601    size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
602    {
603        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
604        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
605            (data(), size(), __s.data(), __pos, __s.size());
606    }
607
608    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
609    size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
610    {
611        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
612            (data(), size(), __c, __pos);
613    }
614
615    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
616    size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
617    {
618        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
619        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
620            (data(), size(), __s, __pos, __n);
621    }
622
623    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
624    size_type find_first_not_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
625    {
626        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
627        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
628            (data(), size(), __s, __pos, traits_type::length(__s));
629    }
630
631    // find_last_not_of
632    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
633    size_type find_last_not_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
634    {
635        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): received nullptr");
636        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
637            (data(), size(), __s.data(), __pos, __s.size());
638    }
639
640    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
641    size_type find_last_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
642    {
643        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
644            (data(), size(), __c, __pos);
645    }
646
647    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
648    size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
649    {
650        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
651        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
652            (data(), size(), __s, __pos, __n);
653    }
654
655    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
656    size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
657    {
658        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
659        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
660            (data(), size(), __s, __pos, traits_type::length(__s));
661    }
662
663#if _LIBCPP_STD_VER > 17
664    constexpr _LIBCPP_INLINE_VISIBILITY
665    bool starts_with(basic_string_view __s) const noexcept
666    { return size() >= __s.size() && compare(0, __s.size(), __s) == 0; }
667
668    constexpr _LIBCPP_INLINE_VISIBILITY
669    bool starts_with(value_type __c) const noexcept
670    { return !empty() && _Traits::eq(front(), __c); }
671
672    constexpr _LIBCPP_INLINE_VISIBILITY
673    bool starts_with(const value_type* __s) const noexcept
674    { return starts_with(basic_string_view(__s)); }
675
676    constexpr _LIBCPP_INLINE_VISIBILITY
677    bool ends_with(basic_string_view __s) const noexcept
678    { return size() >= __s.size() && compare(size() - __s.size(), npos, __s) == 0; }
679
680    constexpr _LIBCPP_INLINE_VISIBILITY
681    bool ends_with(value_type __c) const noexcept
682    { return !empty() && _Traits::eq(back(), __c); }
683
684    constexpr _LIBCPP_INLINE_VISIBILITY
685    bool ends_with(const value_type* __s) const noexcept
686    { return ends_with(basic_string_view(__s)); }
687#endif
688
689#if _LIBCPP_STD_VER > 20
690    constexpr _LIBCPP_INLINE_VISIBILITY
691    bool contains(basic_string_view __sv) const noexcept
692    { return find(__sv) != npos; }
693
694    constexpr _LIBCPP_INLINE_VISIBILITY
695    bool contains(value_type __c) const noexcept
696    { return find(__c) != npos; }
697
698    constexpr _LIBCPP_INLINE_VISIBILITY
699    bool contains(const value_type* __s) const
700    { return find(__s) != npos; }
701#endif
702
703private:
704    const   value_type* __data;
705    size_type           __size;
706};
707
708#if _LIBCPP_STD_VER > 17
709template <class _CharT, class _Traits>
710inline constexpr bool ranges::enable_view<basic_string_view<_CharT, _Traits>> = true;
711
712template <class _CharT, class _Traits>
713inline constexpr bool ranges::enable_borrowed_range<basic_string_view<_CharT, _Traits> > = true;
714#endif // _LIBCPP_STD_VER > 17
715
716// [string.view.deduct]
717
718#if _LIBCPP_STD_VER > 17
719template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
720  basic_string_view(_It, _End) -> basic_string_view<iter_value_t<_It>>;
721#endif // _LIBCPP_STD_VER > 17
722
723
724#if _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
725template <ranges::contiguous_range _Range>
726  basic_string_view(_Range) -> basic_string_view<ranges::range_value_t<_Range>>;
727#endif // _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
728
729// [string.view.comparison]
730// operator ==
731template<class _CharT, class _Traits>
732_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
733bool operator==(basic_string_view<_CharT, _Traits> __lhs,
734                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
735{
736    if ( __lhs.size() != __rhs.size()) return false;
737    return __lhs.compare(__rhs) == 0;
738}
739
740// The dummy default template parameters are used to work around a MSVC issue with mangling, see VSO-409326 for details.
741// This applies to the other sufficient overloads below for the other comparison operators.
742template<class _CharT, class _Traits, int = 1>
743_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
744bool operator==(basic_string_view<_CharT, _Traits> __lhs,
745                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
746{
747    if ( __lhs.size() != __rhs.size()) return false;
748    return __lhs.compare(__rhs) == 0;
749}
750
751template<class _CharT, class _Traits, int = 2>
752_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
753bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
754                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
755{
756    if ( __lhs.size() != __rhs.size()) return false;
757    return __lhs.compare(__rhs) == 0;
758}
759
760
761// operator !=
762template<class _CharT, class _Traits>
763_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
764bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
765{
766    if ( __lhs.size() != __rhs.size())
767        return true;
768    return __lhs.compare(__rhs) != 0;
769}
770
771template<class _CharT, class _Traits, int = 1>
772_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
773bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
774                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
775{
776    if ( __lhs.size() != __rhs.size())
777        return true;
778    return __lhs.compare(__rhs) != 0;
779}
780
781template<class _CharT, class _Traits, int = 2>
782_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
783bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
784                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
785{
786    if ( __lhs.size() != __rhs.size())
787        return true;
788    return __lhs.compare(__rhs) != 0;
789}
790
791
792// operator <
793template<class _CharT, class _Traits>
794_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
795bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
796{
797    return __lhs.compare(__rhs) < 0;
798}
799
800template<class _CharT, class _Traits, int = 1>
801_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
802bool operator<(basic_string_view<_CharT, _Traits> __lhs,
803                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
804{
805    return __lhs.compare(__rhs) < 0;
806}
807
808template<class _CharT, class _Traits, int = 2>
809_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
810bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
811                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
812{
813    return __lhs.compare(__rhs) < 0;
814}
815
816
817// operator >
818template<class _CharT, class _Traits>
819_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
820bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
821{
822    return __lhs.compare(__rhs) > 0;
823}
824
825template<class _CharT, class _Traits, int = 1>
826_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
827bool operator>(basic_string_view<_CharT, _Traits> __lhs,
828                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
829{
830    return __lhs.compare(__rhs) > 0;
831}
832
833template<class _CharT, class _Traits, int = 2>
834_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
835bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
836                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
837{
838    return __lhs.compare(__rhs) > 0;
839}
840
841
842// operator <=
843template<class _CharT, class _Traits>
844_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
845bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
846{
847    return __lhs.compare(__rhs) <= 0;
848}
849
850template<class _CharT, class _Traits, int = 1>
851_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
852bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
853                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
854{
855    return __lhs.compare(__rhs) <= 0;
856}
857
858template<class _CharT, class _Traits, int = 2>
859_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
860bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
861                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
862{
863    return __lhs.compare(__rhs) <= 0;
864}
865
866
867// operator >=
868template<class _CharT, class _Traits>
869_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
870bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
871{
872    return __lhs.compare(__rhs) >= 0;
873}
874
875
876template<class _CharT, class _Traits, int = 1>
877_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
878bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
879                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
880{
881    return __lhs.compare(__rhs) >= 0;
882}
883
884template<class _CharT, class _Traits, int = 2>
885_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
886bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
887                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
888{
889    return __lhs.compare(__rhs) >= 0;
890}
891
892
893template<class _CharT, class _Traits>
894basic_ostream<_CharT, _Traits>&
895operator<<(basic_ostream<_CharT, _Traits>& __os,
896           basic_string_view<_CharT, _Traits> __str);
897
898// [string.view.hash]
899template<class _CharT>
900struct _LIBCPP_TEMPLATE_VIS hash<basic_string_view<_CharT, char_traits<_CharT> > >
901    : public unary_function<basic_string_view<_CharT, char_traits<_CharT> >, size_t>
902{
903    _LIBCPP_INLINE_VISIBILITY
904    size_t operator()(const basic_string_view<_CharT, char_traits<_CharT> > __val) const _NOEXCEPT {
905        return __do_string_hash(__val.data(), __val.data() + __val.size());
906    }
907};
908
909
910#if _LIBCPP_STD_VER > 11
911inline namespace literals
912{
913  inline namespace string_view_literals
914  {
915    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
916    basic_string_view<char> operator "" sv(const char *__str, size_t __len) _NOEXCEPT
917    {
918        return basic_string_view<char> (__str, __len);
919    }
920
921#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
922    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
923    basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len) _NOEXCEPT
924    {
925        return basic_string_view<wchar_t> (__str, __len);
926    }
927#endif
928
929#ifndef _LIBCPP_HAS_NO_CHAR8_T
930    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
931    basic_string_view<char8_t> operator "" sv(const char8_t *__str, size_t __len) _NOEXCEPT
932    {
933        return basic_string_view<char8_t> (__str, __len);
934    }
935#endif
936
937    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
938    basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len) _NOEXCEPT
939    {
940        return basic_string_view<char16_t> (__str, __len);
941    }
942
943    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
944    basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len) _NOEXCEPT
945    {
946        return basic_string_view<char32_t> (__str, __len);
947    }
948  } // namespace string_view_literals
949} // namespace literals
950#endif
951_LIBCPP_END_NAMESPACE_STD
952
953_LIBCPP_POP_MACROS
954
955#endif // _LIBCPP_STRING_VIEW
956