1// Components for manipulating non-owning sequences of characters -*- C++ -*-
2
3// Copyright (C) 2013-2024 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file include/string_view
26 * This is a Standard C++ Library header.
27 */
28
29//
30// N3762 basic_string_view library
31//
32
33#ifndef _GLIBCXX_STRING_VIEW
34#define _GLIBCXX_STRING_VIEW 1
35
36#pragma GCC system_header
37
38#define __glibcxx_want_constexpr_char_traits
39#define __glibcxx_want_constexpr_string_view
40#define __glibcxx_want_freestanding_string_view
41#define __glibcxx_want_string_view
42#define __glibcxx_want_starts_ends_with
43#define __glibcxx_want_string_contains
44#include <bits/version.h>
45
46#if __cplusplus >= 201703L
47
48#include <bits/char_traits.h>
49#include <bits/functexcept.h>
50#include <bits/functional_hash.h>
51#include <bits/range_access.h>
52#include <bits/stl_algobase.h>
53#include <ext/numeric_traits.h>
54
55#if __cplusplus >= 202002L
56# include <bits/ranges_base.h>
57#endif
58
59#if _GLIBCXX_HOSTED
60# include <iosfwd>
61# include <bits/ostream_insert.h>
62#endif
63
64namespace std _GLIBCXX_VISIBILITY(default)
65{
66_GLIBCXX_BEGIN_NAMESPACE_VERSION
67
68 // Helper for basic_string and basic_string_view members.
69 constexpr size_t
70 __sv_check(size_t __size, size_t __pos, const char* __s)
71 {
72 if (__pos > __size)
73 __throw_out_of_range_fmt(__N("%s: __pos (which is %zu) > __size "
74 "(which is %zu)"), __s, __pos, __size);
75 return __pos;
76 }
77
78 // Helper for basic_string members.
79 // NB: __sv_limit doesn't check for a bad __pos value.
80 constexpr size_t
81 __sv_limit(size_t __size, size_t __pos, size_t __off) noexcept
82 {
83 const bool __testoff = __off < __size - __pos;
84 return __testoff ? __off : __size - __pos;
85 }
86
87 /**
88 * @class basic_string_view <string_view>
89 * @brief A non-owning reference to a string.
90 *
91 * @ingroup strings
92 * @ingroup sequences
93 *
94 * @tparam _CharT Type of character
95 * @tparam _Traits Traits for character type, defaults to
96 * char_traits<_CharT>.
97 *
98 * A basic_string_view looks like this:
99 *
100 * @code
101 * _CharT* _M_str
102 * size_t _M_len
103 * @endcode
104 */
105 template<typename _CharT, typename _Traits = std::char_traits<_CharT>>
106 class basic_string_view
107 {
108 static_assert(!is_array_v<_CharT>);
109 static_assert(is_trivial_v<_CharT> && is_standard_layout_v<_CharT>);
110 static_assert(is_same_v<_CharT, typename _Traits::char_type>);
111
112 public:
113
114 // types
115 using traits_type = _Traits;
116 using value_type = _CharT;
117 using pointer = value_type*;
118 using const_pointer = const value_type*;
119 using reference = value_type&;
120 using const_reference = const value_type&;
121 using const_iterator = const value_type*;
122 using iterator = const_iterator;
123 using const_reverse_iterator = std::reverse_iterator<const_iterator>;
124 using reverse_iterator = const_reverse_iterator;
125 using size_type = size_t;
126 using difference_type = ptrdiff_t;
127 static constexpr size_type npos = size_type(-1);
128
129 // [string.view.cons], construction and assignment
130
131 constexpr
132 basic_string_view() noexcept
133 : _M_len{0}, _M_str{nullptr}
134 { }
135
136 constexpr basic_string_view(const basic_string_view&) noexcept = default;
137
138 [[__gnu__::__nonnull__]]
139 constexpr
140 basic_string_view(const _CharT* __str) noexcept
141 : _M_len{traits_type::length(__str)},
142 _M_str{__str}
143 { }
144
145 constexpr
146 basic_string_view(const _CharT* __str, size_type __len) noexcept
147 : _M_len{__len}, _M_str{__str}
148 { }
149
150#if __cplusplus >= 202002L && __cpp_lib_concepts
151 template<contiguous_iterator _It, sized_sentinel_for<_It> _End>
152 requires same_as<iter_value_t<_It>, _CharT>
153 && (!convertible_to<_End, size_type>)
154 constexpr
155 basic_string_view(_It __first, _End __last)
156 noexcept(noexcept(__last - __first))
157 : _M_len(__last - __first), _M_str(std::to_address(__first))
158 { }
159
160#if __cplusplus > 202002L
161 template<typename _Range, typename _DRange = remove_cvref_t<_Range>>
162 requires (!is_same_v<_DRange, basic_string_view>)
163 && ranges::contiguous_range<_Range>
164 && ranges::sized_range<_Range>
165 && is_same_v<ranges::range_value_t<_Range>, _CharT>
166 && (!is_convertible_v<_Range, const _CharT*>)
167 && (!requires (_DRange& __d) {
168 __d.operator ::std::basic_string_view<_CharT, _Traits>();
169 })
170 constexpr explicit
171 basic_string_view(_Range&& __r)
172 noexcept(noexcept(ranges::size(__r)) && noexcept(ranges::data(__r)))
173 : _M_len(ranges::size(__r)), _M_str(ranges::data(__r))
174 { }
175
176 basic_string_view(nullptr_t) = delete;
177#endif // C++23
178#endif // C++20
179
180 constexpr basic_string_view&
181 operator=(const basic_string_view&) noexcept = default;
182
183 // [string.view.iterators], iterator support
184
185 [[nodiscard]]
186 constexpr const_iterator
187 begin() const noexcept
188 { return this->_M_str; }
189
190 [[nodiscard]]
191 constexpr const_iterator
192 end() const noexcept
193 { return this->_M_str + this->_M_len; }
194
195 [[nodiscard]]
196 constexpr const_iterator
197 cbegin() const noexcept
198 { return this->_M_str; }
199
200 [[nodiscard]]
201 constexpr const_iterator
202 cend() const noexcept
203 { return this->_M_str + this->_M_len; }
204
205 [[nodiscard]]
206 constexpr const_reverse_iterator
207 rbegin() const noexcept
208 { return const_reverse_iterator(this->end()); }
209
210 [[nodiscard]]
211 constexpr const_reverse_iterator
212 rend() const noexcept
213 { return const_reverse_iterator(this->begin()); }
214
215 [[nodiscard]]
216 constexpr const_reverse_iterator
217 crbegin() const noexcept
218 { return const_reverse_iterator(this->end()); }
219
220 [[nodiscard]]
221 constexpr const_reverse_iterator
222 crend() const noexcept
223 { return const_reverse_iterator(this->begin()); }
224
225 // [string.view.capacity], capacity
226
227 [[nodiscard]]
228 constexpr size_type
229 size() const noexcept
230 { return this->_M_len; }
231
232 [[nodiscard]]
233 constexpr size_type
234 length() const noexcept
235 { return _M_len; }
236
237 [[nodiscard]]
238 constexpr size_type
239 max_size() const noexcept
240 {
241 return (npos - sizeof(size_type) - sizeof(void*))
242 / sizeof(value_type) / 4;
243 }
244
245 [[nodiscard]]
246 constexpr bool
247 empty() const noexcept
248 { return this->_M_len == 0; }
249
250 // [string.view.access], element access
251
252 [[nodiscard]]
253 constexpr const_reference
254 operator[](size_type __pos) const noexcept
255 {
256 __glibcxx_assert(__pos < this->_M_len);
257 return *(this->_M_str + __pos);
258 }
259
260 [[nodiscard]]
261 constexpr const_reference
262 at(size_type __pos) const
263 {
264 if (__pos >= _M_len)
265 __throw_out_of_range_fmt(__N("basic_string_view::at: __pos "
266 "(which is %zu) >= this->size() "
267 "(which is %zu)"), __pos, this->size());
268 return *(this->_M_str + __pos);
269 }
270
271 [[nodiscard]]
272 constexpr const_reference
273 front() const noexcept
274 {
275 __glibcxx_assert(this->_M_len > 0);
276 return *this->_M_str;
277 }
278
279 [[nodiscard]]
280 constexpr const_reference
281 back() const noexcept
282 {
283 __glibcxx_assert(this->_M_len > 0);
284 return *(this->_M_str + this->_M_len - 1);
285 }
286
287 [[nodiscard]]
288 constexpr const_pointer
289 data() const noexcept
290 { return this->_M_str; }
291
292 // [string.view.modifiers], modifiers:
293
294 constexpr void
295 remove_prefix(size_type __n) noexcept
296 {
297 __glibcxx_assert(this->_M_len >= __n);
298 this->_M_str += __n;
299 this->_M_len -= __n;
300 }
301
302 constexpr void
303 remove_suffix(size_type __n) noexcept
304 {
305 __glibcxx_assert(this->_M_len >= __n);
306 this->_M_len -= __n;
307 }
308
309 constexpr void
310 swap(basic_string_view& __sv) noexcept
311 {
312 auto __tmp = *this;
313 *this = __sv;
314 __sv = __tmp;
315 }
316
317 // [string.view.ops], string operations:
318
319 _GLIBCXX20_CONSTEXPR
320 size_type
321 copy(_CharT* __str, size_type __n, size_type __pos = 0) const
322 {
323 __glibcxx_requires_string_len(__str, __n);
324 __pos = std::__sv_check(size: size(), __pos, s: "basic_string_view::copy");
325 const size_type __rlen = std::min<size_t>(a: __n, b: _M_len - __pos);
326 // _GLIBCXX_RESOLVE_LIB_DEFECTS
327 // 2777. basic_string_view::copy should use char_traits::copy
328 traits_type::copy(__str, data() + __pos, __rlen);
329 return __rlen;
330 }
331
332 [[nodiscard]]
333 constexpr basic_string_view
334 substr(size_type __pos = 0, size_type __n = npos) const noexcept(false)
335 {
336 __pos = std::__sv_check(size: size(), __pos, s: "basic_string_view::substr");
337 const size_type __rlen = std::min<size_t>(a: __n, b: _M_len - __pos);
338 return basic_string_view{_M_str + __pos, __rlen};
339 }
340
341 [[nodiscard]]
342 constexpr int
343 compare(basic_string_view __str) const noexcept
344 {
345 const size_type __rlen = std::min(this->_M_len, __str._M_len);
346 int __ret = traits_type::compare(this->_M_str, __str._M_str, __rlen);
347 if (__ret == 0)
348 __ret = _S_compare(n1: this->_M_len, n2: __str._M_len);
349 return __ret;
350 }
351
352 [[nodiscard]]
353 constexpr int
354 compare(size_type __pos1, size_type __n1, basic_string_view __str) const
355 { return this->substr(__pos1, __n1).compare(__str); }
356
357 [[nodiscard]]
358 constexpr int
359 compare(size_type __pos1, size_type __n1,
360 basic_string_view __str, size_type __pos2, size_type __n2) const
361 {
362 return this->substr(__pos1, __n1).compare(__str.substr(__pos2, __n2));
363 }
364
365 [[nodiscard, __gnu__::__nonnull__]]
366 constexpr int
367 compare(const _CharT* __str) const noexcept
368 { return this->compare(basic_string_view{__str}); }
369
370 [[nodiscard, __gnu__::__nonnull__]]
371 constexpr int
372 compare(size_type __pos1, size_type __n1, const _CharT* __str) const
373 { return this->substr(__pos1, __n1).compare(basic_string_view{__str}); }
374
375 [[nodiscard]]
376 constexpr int
377 compare(size_type __pos1, size_type __n1,
378 const _CharT* __str, size_type __n2) const noexcept(false)
379 {
380 return this->substr(__pos1, __n1)
381 .compare(basic_string_view(__str, __n2));
382 }
383
384#ifdef __cpp_lib_starts_ends_with // C++ >= 20
385 [[nodiscard]]
386 constexpr bool
387 starts_with(basic_string_view __x) const noexcept
388 { return this->substr(0, __x.size()) == __x; }
389
390 [[nodiscard]]
391 constexpr bool
392 starts_with(_CharT __x) const noexcept
393 { return !this->empty() && traits_type::eq(this->front(), __x); }
394
395 [[nodiscard, __gnu__::__nonnull__]]
396 constexpr bool
397 starts_with(const _CharT* __x) const noexcept
398 { return this->starts_with(basic_string_view(__x)); }
399
400 [[nodiscard]]
401 constexpr bool
402 ends_with(basic_string_view __x) const noexcept
403 {
404 const auto __len = this->size();
405 const auto __xlen = __x.size();
406 return __len >= __xlen
407 && traits_type::compare(end() - __xlen, __x.data(), __xlen) == 0;
408 }
409
410 [[nodiscard]]
411 constexpr bool
412 ends_with(_CharT __x) const noexcept
413 { return !this->empty() && traits_type::eq(this->back(), __x); }
414
415 [[nodiscard, __gnu__::__nonnull__]]
416 constexpr bool
417 ends_with(const _CharT* __x) const noexcept
418 { return this->ends_with(basic_string_view(__x)); }
419#endif // __cpp_lib_starts_ends_with
420
421#if __cplusplus > 202002L
422#if _GLIBCXX_HOSTED && !defined(__cpp_lib_string_contains)
423 // This FTM is not freestanding as it also implies matching <string>
424 // support, and <string> is omitted from the freestanding subset.
425# error "libstdc++ bug: string_contains not defined when it should be"
426#endif // HOSTED
427 [[nodiscard]]
428 constexpr bool
429 contains(basic_string_view __x) const noexcept
430 { return this->find(__x) != npos; }
431
432 [[nodiscard]]
433 constexpr bool
434 contains(_CharT __x) const noexcept
435 { return this->find(__x) != npos; }
436
437 [[nodiscard, __gnu__::__nonnull__]]
438 constexpr bool
439 contains(const _CharT* __x) const noexcept
440 { return this->find(__x) != npos; }
441#endif // C++23
442
443 // [string.view.find], searching
444
445 [[nodiscard]]
446 constexpr size_type
447 find(basic_string_view __str, size_type __pos = 0) const noexcept
448 { return this->find(__str._M_str, __pos, __str._M_len); }
449
450 [[nodiscard]]
451 constexpr size_type
452 find(_CharT __c, size_type __pos = 0) const noexcept;
453
454 [[nodiscard]]
455 constexpr size_type
456 find(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
457
458 [[nodiscard, __gnu__::__nonnull__]]
459 constexpr size_type
460 find(const _CharT* __str, size_type __pos = 0) const noexcept
461 { return this->find(__str, __pos, traits_type::length(__str)); }
462
463 [[nodiscard]]
464 constexpr size_type
465 rfind(basic_string_view __str, size_type __pos = npos) const noexcept
466 { return this->rfind(__str._M_str, __pos, __str._M_len); }
467
468 [[nodiscard]]
469 constexpr size_type
470 rfind(_CharT __c, size_type __pos = npos) const noexcept;
471
472 [[nodiscard]]
473 constexpr size_type
474 rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
475
476 [[nodiscard, __gnu__::__nonnull__]]
477 constexpr size_type
478 rfind(const _CharT* __str, size_type __pos = npos) const noexcept
479 { return this->rfind(__str, __pos, traits_type::length(__str)); }
480
481 [[nodiscard]]
482 constexpr size_type
483 find_first_of(basic_string_view __str, size_type __pos = 0) const noexcept
484 { return this->find_first_of(__str._M_str, __pos, __str._M_len); }
485
486 [[nodiscard]]
487 constexpr size_type
488 find_first_of(_CharT __c, size_type __pos = 0) const noexcept
489 { return this->find(__c, __pos); }
490
491 [[nodiscard]]
492 constexpr size_type
493 find_first_of(const _CharT* __str, size_type __pos,
494 size_type __n) const noexcept;
495
496 [[nodiscard, __gnu__::__nonnull__]]
497 constexpr size_type
498 find_first_of(const _CharT* __str, size_type __pos = 0) const noexcept
499 { return this->find_first_of(__str, __pos, traits_type::length(__str)); }
500
501 [[nodiscard]]
502 constexpr size_type
503 find_last_of(basic_string_view __str,
504 size_type __pos = npos) const noexcept
505 { return this->find_last_of(__str._M_str, __pos, __str._M_len); }
506
507 [[nodiscard]]
508 constexpr size_type
509 find_last_of(_CharT __c, size_type __pos=npos) const noexcept
510 { return this->rfind(__c, __pos); }
511
512 [[nodiscard]]
513 constexpr size_type
514 find_last_of(const _CharT* __str, size_type __pos,
515 size_type __n) const noexcept;
516
517 [[nodiscard, __gnu__::__nonnull__]]
518 constexpr size_type
519 find_last_of(const _CharT* __str, size_type __pos = npos) const noexcept
520 { return this->find_last_of(__str, __pos, traits_type::length(__str)); }
521
522 [[nodiscard]]
523 constexpr size_type
524 find_first_not_of(basic_string_view __str,
525 size_type __pos = 0) const noexcept
526 { return this->find_first_not_of(__str._M_str, __pos, __str._M_len); }
527
528 [[nodiscard]]
529 constexpr size_type
530 find_first_not_of(_CharT __c, size_type __pos = 0) const noexcept;
531
532 [[nodiscard]]
533 constexpr size_type
534 find_first_not_of(const _CharT* __str,
535 size_type __pos, size_type __n) const noexcept;
536
537 [[nodiscard, __gnu__::__nonnull__]]
538 constexpr size_type
539 find_first_not_of(const _CharT* __str, size_type __pos = 0) const noexcept
540 {
541 return this->find_first_not_of(__str, __pos,
542 traits_type::length(__str));
543 }
544
545 [[nodiscard]]
546 constexpr size_type
547 find_last_not_of(basic_string_view __str,
548 size_type __pos = npos) const noexcept
549 { return this->find_last_not_of(__str._M_str, __pos, __str._M_len); }
550
551 [[nodiscard]]
552 constexpr size_type
553 find_last_not_of(_CharT __c, size_type __pos = npos) const noexcept;
554
555 [[nodiscard]]
556 constexpr size_type
557 find_last_not_of(const _CharT* __str,
558 size_type __pos, size_type __n) const noexcept;
559
560 [[nodiscard, __gnu__::__nonnull__]]
561 constexpr size_type
562 find_last_not_of(const _CharT* __str,
563 size_type __pos = npos) const noexcept
564 {
565 return this->find_last_not_of(__str, __pos,
566 traits_type::length(__str));
567 }
568
569 private:
570
571 static constexpr int
572 _S_compare(size_type __n1, size_type __n2) noexcept
573 {
574 using __limits = __gnu_cxx::__int_traits<int>;
575 const difference_type __diff = __n1 - __n2;
576 if (__diff > __limits::__max)
577 return __limits::__max;
578 if (__diff < __limits::__min)
579 return __limits::__min;
580 return static_cast<int>(__diff);
581 }
582
583 size_t _M_len;
584 const _CharT* _M_str;
585 };
586
587#if __cplusplus > 201703L && __cpp_lib_concepts && __cpp_deduction_guides
588 template<contiguous_iterator _It, sized_sentinel_for<_It> _End>
589 basic_string_view(_It, _End) -> basic_string_view<iter_value_t<_It>>;
590
591#if __cplusplus > 202002L
592 template<ranges::contiguous_range _Range>
593 basic_string_view(_Range&&)
594 -> basic_string_view<ranges::range_value_t<_Range>>;
595#endif
596#endif
597
598 // [string.view.comparison], non-member basic_string_view comparison function
599
600 // Several of these functions use type_identity_t to create a non-deduced
601 // context, so that only one argument participates in template argument
602 // deduction and the other argument gets implicitly converted to the deduced
603 // type (see N3766).
604
605#if __cpp_lib_three_way_comparison
606 template<typename _CharT, typename _Traits>
607 [[nodiscard]]
608 constexpr bool
609 operator==(basic_string_view<_CharT, _Traits> __x,
610 type_identity_t<basic_string_view<_CharT, _Traits>> __y)
611 noexcept
612 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
613
614 template<typename _CharT, typename _Traits>
615 [[nodiscard]]
616 constexpr auto
617 operator<=>(basic_string_view<_CharT, _Traits> __x,
618 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
619 noexcept
620 -> decltype(__detail::__char_traits_cmp_cat<_Traits>(0))
621 { return __detail::__char_traits_cmp_cat<_Traits>(__x.compare(__y)); }
622#else
623 template<typename _CharT, typename _Traits>
624 [[nodiscard]]
625 constexpr bool
626 operator==(basic_string_view<_CharT, _Traits> __x,
627 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
628 noexcept
629 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
630
631 template<typename _CharT, typename _Traits>
632 [[nodiscard]]
633 constexpr bool
634 operator==(basic_string_view<_CharT, _Traits> __x,
635 basic_string_view<_CharT, _Traits> __y) noexcept
636 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
637
638 template<typename _CharT, typename _Traits>
639 [[nodiscard]]
640 constexpr bool
641 operator==(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
642 basic_string_view<_CharT, _Traits> __y) noexcept
643 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
644
645 template<typename _CharT, typename _Traits>
646 [[nodiscard]]
647 constexpr bool
648 operator!=(basic_string_view<_CharT, _Traits> __x,
649 basic_string_view<_CharT, _Traits> __y) noexcept
650 { return !(__x == __y); }
651
652 template<typename _CharT, typename _Traits>
653 [[nodiscard]]
654 constexpr bool
655 operator!=(basic_string_view<_CharT, _Traits> __x,
656 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
657 noexcept
658 { return !(__x == __y); }
659
660 template<typename _CharT, typename _Traits>
661 [[nodiscard]]
662 constexpr bool
663 operator!=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
664 basic_string_view<_CharT, _Traits> __y) noexcept
665 { return !(__x == __y); }
666
667 template<typename _CharT, typename _Traits>
668 [[nodiscard]]
669 constexpr bool
670 operator< (basic_string_view<_CharT, _Traits> __x,
671 basic_string_view<_CharT, _Traits> __y) noexcept
672 { return __x.compare(__y) < 0; }
673
674 template<typename _CharT, typename _Traits>
675 [[nodiscard]]
676 constexpr bool
677 operator< (basic_string_view<_CharT, _Traits> __x,
678 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
679 noexcept
680 { return __x.compare(__y) < 0; }
681
682 template<typename _CharT, typename _Traits>
683 [[nodiscard]]
684 constexpr bool
685 operator< (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
686 basic_string_view<_CharT, _Traits> __y) noexcept
687 { return __x.compare(__y) < 0; }
688
689 template<typename _CharT, typename _Traits>
690 [[nodiscard]]
691 constexpr bool
692 operator> (basic_string_view<_CharT, _Traits> __x,
693 basic_string_view<_CharT, _Traits> __y) noexcept
694 { return __x.compare(__y) > 0; }
695
696 template<typename _CharT, typename _Traits>
697 [[nodiscard]]
698 constexpr bool
699 operator> (basic_string_view<_CharT, _Traits> __x,
700 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
701 noexcept
702 { return __x.compare(__y) > 0; }
703
704 template<typename _CharT, typename _Traits>
705 [[nodiscard]]
706 constexpr bool
707 operator> (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
708 basic_string_view<_CharT, _Traits> __y) noexcept
709 { return __x.compare(__y) > 0; }
710
711 template<typename _CharT, typename _Traits>
712 [[nodiscard]]
713 constexpr bool
714 operator<=(basic_string_view<_CharT, _Traits> __x,
715 basic_string_view<_CharT, _Traits> __y) noexcept
716 { return __x.compare(__y) <= 0; }
717
718 template<typename _CharT, typename _Traits>
719 [[nodiscard]]
720 constexpr bool
721 operator<=(basic_string_view<_CharT, _Traits> __x,
722 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
723 noexcept
724 { return __x.compare(__y) <= 0; }
725
726 template<typename _CharT, typename _Traits>
727 [[nodiscard]]
728 constexpr bool
729 operator<=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
730 basic_string_view<_CharT, _Traits> __y) noexcept
731 { return __x.compare(__y) <= 0; }
732
733 template<typename _CharT, typename _Traits>
734 [[nodiscard]]
735 constexpr bool
736 operator>=(basic_string_view<_CharT, _Traits> __x,
737 basic_string_view<_CharT, _Traits> __y) noexcept
738 { return __x.compare(__y) >= 0; }
739
740 template<typename _CharT, typename _Traits>
741 [[nodiscard]]
742 constexpr bool
743 operator>=(basic_string_view<_CharT, _Traits> __x,
744 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
745 noexcept
746 { return __x.compare(__y) >= 0; }
747
748 template<typename _CharT, typename _Traits>
749 [[nodiscard]]
750 constexpr bool
751 operator>=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
752 basic_string_view<_CharT, _Traits> __y) noexcept
753 { return __x.compare(__y) >= 0; }
754#endif // three-way comparison
755
756#if _GLIBCXX_HOSTED
757 // [string.view.io], Inserters and extractors
758 template<typename _CharT, typename _Traits>
759 inline basic_ostream<_CharT, _Traits>&
760 operator<<(basic_ostream<_CharT, _Traits>& __os,
761 basic_string_view<_CharT,_Traits> __str)
762 { return __ostream_insert(__os, __str.data(), __str.size()); }
763#endif // HOSTED
764
765 // basic_string_view typedef names
766
767 using string_view = basic_string_view<char>;
768 using wstring_view = basic_string_view<wchar_t>;
769#ifdef _GLIBCXX_USE_CHAR8_T
770 using u8string_view = basic_string_view<char8_t>;
771#endif
772 using u16string_view = basic_string_view<char16_t>;
773 using u32string_view = basic_string_view<char32_t>;
774
775 // [string.view.hash], hash support:
776
777 template<typename _Tp>
778 struct hash;
779
780 template<>
781 struct hash<string_view>
782 : public __hash_base<size_t, string_view>
783 {
784 [[nodiscard]]
785 size_t
786 operator()(const string_view& __str) const noexcept
787 { return std::_Hash_impl::hash(ptr: __str.data(), clength: __str.length()); }
788 };
789
790 template<>
791 struct __is_fast_hash<hash<string_view>> : std::false_type
792 { };
793
794 template<>
795 struct hash<wstring_view>
796 : public __hash_base<size_t, wstring_view>
797 {
798 [[nodiscard]]
799 size_t
800 operator()(const wstring_view& __s) const noexcept
801 { return std::_Hash_impl::hash(ptr: __s.data(),
802 clength: __s.length() * sizeof(wchar_t)); }
803 };
804
805 template<>
806 struct __is_fast_hash<hash<wstring_view>> : std::false_type
807 { };
808
809#ifdef _GLIBCXX_USE_CHAR8_T
810 template<>
811 struct hash<u8string_view>
812 : public __hash_base<size_t, u8string_view>
813 {
814 [[nodiscard]]
815 size_t
816 operator()(const u8string_view& __str) const noexcept
817 { return std::_Hash_impl::hash(__str.data(), __str.length()); }
818 };
819
820 template<>
821 struct __is_fast_hash<hash<u8string_view>> : std::false_type
822 { };
823#endif
824
825 template<>
826 struct hash<u16string_view>
827 : public __hash_base<size_t, u16string_view>
828 {
829 [[nodiscard]]
830 size_t
831 operator()(const u16string_view& __s) const noexcept
832 { return std::_Hash_impl::hash(ptr: __s.data(),
833 clength: __s.length() * sizeof(char16_t)); }
834 };
835
836 template<>
837 struct __is_fast_hash<hash<u16string_view>> : std::false_type
838 { };
839
840 template<>
841 struct hash<u32string_view>
842 : public __hash_base<size_t, u32string_view>
843 {
844 [[nodiscard]]
845 size_t
846 operator()(const u32string_view& __s) const noexcept
847 { return std::_Hash_impl::hash(ptr: __s.data(),
848 clength: __s.length() * sizeof(char32_t)); }
849 };
850
851 template<>
852 struct __is_fast_hash<hash<u32string_view>> : std::false_type
853 { };
854
855 inline namespace literals
856 {
857 inline namespace string_view_literals
858 {
859#pragma GCC diagnostic push
860#pragma GCC diagnostic ignored "-Wliteral-suffix"
861 inline constexpr basic_string_view<char>
862 operator""sv(const char* __str, size_t __len) noexcept
863 { return basic_string_view<char>{__str, __len}; }
864
865 inline constexpr basic_string_view<wchar_t>
866 operator""sv(const wchar_t* __str, size_t __len) noexcept
867 { return basic_string_view<wchar_t>{__str, __len}; }
868
869#ifdef _GLIBCXX_USE_CHAR8_T
870 inline constexpr basic_string_view<char8_t>
871 operator""sv(const char8_t* __str, size_t __len) noexcept
872 { return basic_string_view<char8_t>{__str, __len}; }
873#endif
874
875 inline constexpr basic_string_view<char16_t>
876 operator""sv(const char16_t* __str, size_t __len) noexcept
877 { return basic_string_view<char16_t>{__str, __len}; }
878
879 inline constexpr basic_string_view<char32_t>
880 operator""sv(const char32_t* __str, size_t __len) noexcept
881 { return basic_string_view<char32_t>{__str, __len}; }
882
883#pragma GCC diagnostic pop
884 } // namespace string_literals
885 } // namespace literals
886
887#if __cpp_lib_concepts
888 namespace ranges
889 {
890 // Opt-in to borrowed_range concept
891 template<typename _CharT, typename _Traits>
892 inline constexpr bool
893 enable_borrowed_range<basic_string_view<_CharT, _Traits>> = true;
894
895 // Opt-in to view concept
896 template<typename _CharT, typename _Traits>
897 inline constexpr bool
898 enable_view<basic_string_view<_CharT, _Traits>> = true;
899 }
900#endif
901_GLIBCXX_END_NAMESPACE_VERSION
902} // namespace std
903
904#include <bits/string_view.tcc>
905
906#endif // __cplusplus <= 201402L
907
908#endif // _GLIBCXX_EXPERIMENTAL_STRING_VIEW
909