libstdc++
string_view
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1// Components for manipulating non-owning sequences of characters -*- C++ -*-
2
3// Copyright (C) 2013-2026 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#ifdef _GLIBCXX_SYSHDR
37#pragma GCC system_header
38#endif
39
40#define __glibcxx_want_constexpr_char_traits
41#define __glibcxx_want_constexpr_string_view
42#define __glibcxx_want_freestanding_string_view
43#define __glibcxx_want_starts_ends_with
44#define __glibcxx_want_string_contains
45#define __glibcxx_want_string_subview
46#define __glibcxx_want_string_view
47#include <bits/version.h>
48
49#if __cplusplus >= 201703L
50
51#include <bits/char_traits.h>
52#ifndef __glibcxx_exc_in_string
53#define __glibcxx_exc_in_string 2
54#include <bits/stdexcept_throw.h>
55#endif
56#include <bits/functional_hash.h>
57#include <bits/range_access.h>
58#include <bits/stl_algobase.h>
59#include <ext/numeric_traits.h>
60
61#if __cplusplus >= 202002L
62# include <bits/ranges_base.h>
63#endif
64
65#if _GLIBCXX_HOSTED
66# include <iosfwd>
67# include <bits/ostream_insert.h>
68#endif
69
70namespace std _GLIBCXX_VISIBILITY(default)
71{
72_GLIBCXX_BEGIN_NAMESPACE_VERSION
73
74 // Helper for basic_string and basic_string_view members.
75 constexpr size_t
76 __sv_check(size_t __size, size_t __pos, const char* __s)
77 {
78 if (__pos > __size)
79 __throw_out_of_range_fmt(__N("%s: __pos (which is %zu) > __size "
80 "(which is %zu)"), __s, __pos, __size);
81 return __pos;
82 }
83
84 // Helper for basic_string members.
85 // NB: __sv_limit doesn't check for a bad __pos value.
86 constexpr size_t
87 __sv_limit(size_t __size, size_t __pos, size_t __off) noexcept
88 {
89 const bool __testoff = __off < __size - __pos;
90 return __testoff ? __off : __size - __pos;
91 }
92
93 /**
94 * @class basic_string_view <string_view>
95 * @brief A non-owning reference to a string.
96 *
97 * @ingroup strings
98 * @ingroup sequences
99 *
100 * @tparam _CharT Type of character
101 * @tparam _Traits Traits for character type, defaults to
102 * char_traits<_CharT>.
103 *
104 * A basic_string_view looks like this:
105 *
106 * @code
107 * _CharT* _M_str
108 * size_t _M_len
109 * @endcode
110 */
111 template<typename _CharT, typename _Traits = std::char_traits<_CharT>>
112 class basic_string_view
113 {
114 static_assert(!is_array_v<_CharT>);
115 static_assert(is_trivially_copyable_v<_CharT>
116 && is_trivially_default_constructible_v<_CharT>
117 && is_standard_layout_v<_CharT>);
118 static_assert(is_same_v<_CharT, typename _Traits::char_type>);
119
120 public:
121
122 // types
123 using traits_type = _Traits;
124 using value_type = _CharT;
125 using pointer = value_type*;
126 using const_pointer = const value_type*;
127 using reference = value_type&;
128 using const_reference = const value_type&;
129 using const_iterator = const value_type*;
130 using iterator = const_iterator;
131 using const_reverse_iterator = std::reverse_iterator<const_iterator>;
132 using reverse_iterator = const_reverse_iterator;
133 using size_type = size_t;
134 using difference_type = ptrdiff_t;
135 static constexpr size_type npos = size_type(-1);
136
137 // [string.view.cons], construction and assignment
138
139 constexpr
140 basic_string_view() noexcept
141 : _M_len{0}, _M_str{nullptr}
142 { }
143
144 constexpr basic_string_view(const basic_string_view&) noexcept = default;
145
146 [[__gnu__::__nonnull__]]
147 constexpr
148 basic_string_view(const _CharT* __str) noexcept
149 : _M_len{traits_type::length(__str)},
150 _M_str{__str}
151 { }
152
153 constexpr
154 basic_string_view(const _CharT* __str, size_type __len) noexcept
155 : _M_len{__len}, _M_str{__str}
156 { }
157
158#if __cplusplus >= 202002L && __cpp_lib_concepts
159 template<contiguous_iterator _It, sized_sentinel_for<_It> _End>
160 requires same_as<iter_value_t<_It>, _CharT>
161 && (!convertible_to<_End, size_type>)
162 constexpr
163 basic_string_view(_It __first, _End __last)
164 noexcept(noexcept(__last - __first))
165 : _M_len(__last - __first), _M_str(std::to_address(__first))
166 { }
167
168#if __cplusplus > 202002L
169 template<typename _Range, typename _DRange = remove_cvref_t<_Range>>
170 requires (!is_same_v<_DRange, basic_string_view>)
171 && ranges::contiguous_range<_Range>
172 && ranges::sized_range<_Range>
173 && is_same_v<ranges::range_value_t<_Range>, _CharT>
174 && (!is_convertible_v<_Range, const _CharT*>)
175 && (!requires (_DRange& __d) {
176 __d.operator ::std::basic_string_view<_CharT, _Traits>();
177 })
178 constexpr explicit
179 basic_string_view(_Range&& __r)
180 noexcept(noexcept(ranges::size(__r)) && noexcept(ranges::data(__r)))
181 : _M_len(ranges::size(__r)), _M_str(ranges::data(__r))
182 { }
183
184 basic_string_view(nullptr_t) = delete;
185#endif // C++23
186#endif // C++20
187
188 constexpr basic_string_view&
189 operator=(const basic_string_view&) noexcept = default;
190
191 // [string.view.iterators], iterator support
192
193 [[nodiscard]]
194 constexpr const_iterator
195 begin() const noexcept
196 { return this->_M_str; }
197
198 [[nodiscard]]
199 constexpr const_iterator
200 end() const noexcept
201 { return this->_M_str + this->_M_len; }
202
203 [[nodiscard]]
204 constexpr const_iterator
205 cbegin() const noexcept
206 { return this->_M_str; }
207
208 [[nodiscard]]
209 constexpr const_iterator
210 cend() const noexcept
211 { return this->_M_str + this->_M_len; }
212
213 [[nodiscard]]
214 constexpr const_reverse_iterator
215 rbegin() const noexcept
216 { return const_reverse_iterator(this->end()); }
217
218 [[nodiscard]]
219 constexpr const_reverse_iterator
220 rend() const noexcept
221 { return const_reverse_iterator(this->begin()); }
222
223 [[nodiscard]]
224 constexpr const_reverse_iterator
225 crbegin() const noexcept
226 { return const_reverse_iterator(this->end()); }
227
228 [[nodiscard]]
229 constexpr const_reverse_iterator
230 crend() const noexcept
231 { return const_reverse_iterator(this->begin()); }
232
233 // [string.view.capacity], capacity
234
235 [[nodiscard]]
236 constexpr size_type
237 size() const noexcept
238 { return this->_M_len; }
239
240 [[nodiscard]]
241 constexpr size_type
242 length() const noexcept
243 { return _M_len; }
244
245 [[nodiscard]]
246 constexpr size_type
247 max_size() const noexcept
248 {
249 return (npos - sizeof(size_type) - sizeof(void*))
250 / sizeof(value_type) / 4;
251 }
252
253 [[nodiscard]]
254 constexpr bool
255 empty() const noexcept
256 { return this->_M_len == 0; }
257
258 // [string.view.access], element access
259
260 [[nodiscard]]
261 constexpr const_reference
262 operator[](size_type __pos) const noexcept
263 {
264 __glibcxx_assert(__pos < this->_M_len);
265 return *(this->_M_str + __pos);
266 }
267
268 [[nodiscard]]
269 constexpr const_reference
270 at(size_type __pos) const
271 {
272 if (__pos >= _M_len)
273 __throw_out_of_range_fmt(__N("basic_string_view::at: __pos "
274 "(which is %zu) >= this->size() "
275 "(which is %zu)"), __pos, this->size());
276 return *(this->_M_str + __pos);
277 }
278
279 [[nodiscard]]
280 constexpr const_reference
281 front() const noexcept
282 {
283 __glibcxx_assert(this->_M_len > 0);
284 return *this->_M_str;
285 }
286
287 [[nodiscard]]
288 constexpr const_reference
289 back() const noexcept
290 {
291 __glibcxx_assert(this->_M_len > 0);
292 return *(this->_M_str + this->_M_len - 1);
293 }
294
295 [[nodiscard]]
296 constexpr const_pointer
297 data() const noexcept
298 { return this->_M_str; }
299
300 // [string.view.modifiers], modifiers:
301
302 constexpr void
303 remove_prefix(size_type __n) noexcept
304 {
305 __glibcxx_assert(this->_M_len >= __n);
306 this->_M_str += __n;
307 this->_M_len -= __n;
308 }
309
310 constexpr void
311 remove_suffix(size_type __n) noexcept
312 {
313 __glibcxx_assert(this->_M_len >= __n);
314 this->_M_len -= __n;
315 }
316
317 constexpr void
318 swap(basic_string_view& __sv) noexcept
319 {
320 auto __tmp = *this;
321 *this = __sv;
322 __sv = __tmp;
323 }
324
325 // [string.view.ops], string operations:
326
327 _GLIBCXX20_CONSTEXPR
328 size_type
329 copy(_CharT* __str, size_type __n, size_type __pos = 0) const
330 {
331 __glibcxx_requires_string_len(__str, __n);
332 __pos = std::__sv_check(size(), __pos, "basic_string_view::copy");
333 const size_type __rlen = std::min<size_t>(__n, _M_len - __pos);
334 // _GLIBCXX_RESOLVE_LIB_DEFECTS
335 // 2777. basic_string_view::copy should use char_traits::copy
336 traits_type::copy(__str, data() + __pos, __rlen);
337 return __rlen;
338 }
339
340 [[nodiscard]]
341 constexpr basic_string_view
342 substr(size_type __pos = 0, size_type __n = npos) const noexcept(false)
343 {
344 __pos = std::__sv_check(size(), __pos, "basic_string_view::substr");
345 const size_type __rlen = std::min<size_t>(__n, _M_len - __pos);
346 return basic_string_view{_M_str + __pos, __rlen};
347 }
348
349#ifdef __glibcxx_string_subview // >= C++26
350 [[nodiscard]]
351 constexpr basic_string_view
352 subview(size_type __pos = 0, size_type __n = npos) const
353 { return substr(__pos, __n); }
354#endif
355
356 [[nodiscard]]
357 constexpr int
358 compare(basic_string_view __str) const noexcept
359 {
360 const size_type __rlen = std::min(this->_M_len, __str._M_len);
361 int __ret = traits_type::compare(this->_M_str, __str._M_str, __rlen);
362 if (__ret == 0)
363 __ret = _S_compare(this->_M_len, __str._M_len);
364 return __ret;
365 }
366
367 [[nodiscard]]
368 constexpr int
369 compare(size_type __pos1, size_type __n1, basic_string_view __str) const
370 { return this->substr(__pos1, __n1).compare(__str); }
371
372 [[nodiscard]]
373 constexpr int
374 compare(size_type __pos1, size_type __n1,
375 basic_string_view __str, size_type __pos2, size_type __n2) const
376 {
377 return this->substr(__pos1, __n1).compare(__str.substr(__pos2, __n2));
378 }
379
380 [[nodiscard, __gnu__::__nonnull__]]
381 constexpr int
382 compare(const _CharT* __str) const noexcept
383 { return this->compare(basic_string_view{__str}); }
384
385 [[nodiscard, __gnu__::__nonnull__]]
386 constexpr int
387 compare(size_type __pos1, size_type __n1, const _CharT* __str) const
388 { return this->substr(__pos1, __n1).compare(basic_string_view{__str}); }
389
390 [[nodiscard]]
391 constexpr int
392 compare(size_type __pos1, size_type __n1,
393 const _CharT* __str, size_type __n2) const noexcept(false)
394 {
395 return this->substr(__pos1, __n1)
396 .compare(basic_string_view(__str, __n2));
397 }
398
399#ifdef __cpp_lib_starts_ends_with // C++ >= 20
400 [[nodiscard]]
401 constexpr bool
402 starts_with(basic_string_view __x) const noexcept
403 {
404 return _M_len >= __x._M_len
405 && traits_type::compare(_M_str, __x._M_str, __x._M_len) == 0;
406 }
407
408 [[nodiscard]]
409 constexpr bool
410 starts_with(_CharT __x) const noexcept
411 { return !this->empty() && traits_type::eq(this->front(), __x); }
412
413 [[nodiscard, __gnu__::__nonnull__]]
414 constexpr bool
415 starts_with(const _CharT* __x) const noexcept
416 { return this->starts_with(basic_string_view(__x)); }
417
418 [[nodiscard]]
419 constexpr bool
420 ends_with(basic_string_view __x) const noexcept
421 {
422 const auto __len = this->size();
423 const auto __xlen = __x.size();
424 return __len >= __xlen
425 && traits_type::compare(end() - __xlen, __x.data(), __xlen) == 0;
426 }
427
428 [[nodiscard]]
429 constexpr bool
430 ends_with(_CharT __x) const noexcept
431 { return !this->empty() && traits_type::eq(this->back(), __x); }
432
433 [[nodiscard, __gnu__::__nonnull__]]
434 constexpr bool
435 ends_with(const _CharT* __x) const noexcept
436 { return this->ends_with(basic_string_view(__x)); }
437#endif // __cpp_lib_starts_ends_with
438
439#if __cplusplus > 202002L
440#if _GLIBCXX_HOSTED && !defined(__cpp_lib_string_contains)
441 // This FTM is not freestanding as it also implies matching <string>
442 // support, and <string> is omitted from the freestanding subset.
443# error "libstdc++ bug: string_contains not defined when it should be"
444#endif // HOSTED
445 [[nodiscard]]
446 constexpr bool
447 contains(basic_string_view __x) const noexcept
448 { return this->find(__x) != npos; }
449
450 [[nodiscard]]
451 constexpr bool
452 contains(_CharT __x) const noexcept
453 { return this->find(__x) != npos; }
454
455 [[nodiscard, __gnu__::__nonnull__]]
456 constexpr bool
457 contains(const _CharT* __x) const noexcept
458 { return this->find(__x) != npos; }
459#endif // C++23
460
461 // [string.view.find], searching
462
463 [[nodiscard]]
464 constexpr size_type
465 find(basic_string_view __str, size_type __pos = 0) const noexcept
466 { return this->find(__str._M_str, __pos, __str._M_len); }
467
468 [[nodiscard]]
469 constexpr size_type
470 find(_CharT __c, size_type __pos = 0) const noexcept;
471
472 [[nodiscard]]
473 constexpr size_type
474 find(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
475
476 [[nodiscard, __gnu__::__nonnull__]]
477 constexpr size_type
478 find(const _CharT* __str, size_type __pos = 0) const noexcept
479 { return this->find(__str, __pos, traits_type::length(__str)); }
480
481 [[nodiscard]]
482 constexpr size_type
483 rfind(basic_string_view __str, size_type __pos = npos) const noexcept
484 { return this->rfind(__str._M_str, __pos, __str._M_len); }
485
486 [[nodiscard]]
487 constexpr size_type
488 rfind(_CharT __c, size_type __pos = npos) const noexcept;
489
490 [[nodiscard]]
491 constexpr size_type
492 rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
493
494 [[nodiscard, __gnu__::__nonnull__]]
495 constexpr size_type
496 rfind(const _CharT* __str, size_type __pos = npos) const noexcept
497 { return this->rfind(__str, __pos, traits_type::length(__str)); }
498
499 [[nodiscard]]
500 constexpr size_type
501 find_first_of(basic_string_view __str, size_type __pos = 0) const noexcept
502 { return this->find_first_of(__str._M_str, __pos, __str._M_len); }
503
504 [[nodiscard]]
505 constexpr size_type
506 find_first_of(_CharT __c, size_type __pos = 0) const noexcept
507 { return this->find(__c, __pos); }
508
509 [[nodiscard]]
510 constexpr size_type
511 find_first_of(const _CharT* __str, size_type __pos,
512 size_type __n) const noexcept;
513
514 [[nodiscard, __gnu__::__nonnull__]]
515 constexpr size_type
516 find_first_of(const _CharT* __str, size_type __pos = 0) const noexcept
517 { return this->find_first_of(__str, __pos, traits_type::length(__str)); }
518
519 [[nodiscard]]
520 constexpr size_type
521 find_last_of(basic_string_view __str,
522 size_type __pos = npos) const noexcept
523 { return this->find_last_of(__str._M_str, __pos, __str._M_len); }
524
525 [[nodiscard]]
526 constexpr size_type
527 find_last_of(_CharT __c, size_type __pos=npos) const noexcept
528 { return this->rfind(__c, __pos); }
529
530 [[nodiscard]]
531 constexpr size_type
532 find_last_of(const _CharT* __str, size_type __pos,
533 size_type __n) const noexcept;
534
535 [[nodiscard, __gnu__::__nonnull__]]
536 constexpr size_type
537 find_last_of(const _CharT* __str, size_type __pos = npos) const noexcept
538 { return this->find_last_of(__str, __pos, traits_type::length(__str)); }
539
540 [[nodiscard]]
541 constexpr size_type
542 find_first_not_of(basic_string_view __str,
543 size_type __pos = 0) const noexcept
544 { return this->find_first_not_of(__str._M_str, __pos, __str._M_len); }
545
546 [[nodiscard]]
547 constexpr size_type
548 find_first_not_of(_CharT __c, size_type __pos = 0) const noexcept;
549
550 [[nodiscard]]
551 constexpr size_type
552 find_first_not_of(const _CharT* __str,
553 size_type __pos, size_type __n) const noexcept;
554
555 [[nodiscard, __gnu__::__nonnull__]]
556 constexpr size_type
557 find_first_not_of(const _CharT* __str, size_type __pos = 0) const noexcept
558 {
559 return this->find_first_not_of(__str, __pos,
560 traits_type::length(__str));
561 }
562
563 [[nodiscard]]
564 constexpr size_type
565 find_last_not_of(basic_string_view __str,
566 size_type __pos = npos) const noexcept
567 { return this->find_last_not_of(__str._M_str, __pos, __str._M_len); }
568
569 [[nodiscard]]
570 constexpr size_type
571 find_last_not_of(_CharT __c, size_type __pos = npos) const noexcept;
572
573 [[nodiscard]]
574 constexpr size_type
575 find_last_not_of(const _CharT* __str,
576 size_type __pos, size_type __n) const noexcept;
577
578 [[nodiscard, __gnu__::__nonnull__]]
579 constexpr size_type
580 find_last_not_of(const _CharT* __str,
581 size_type __pos = npos) const noexcept
582 {
583 return this->find_last_not_of(__str, __pos,
584 traits_type::length(__str));
585 }
586
587 private:
588
589 static constexpr int
590 _S_compare(size_type __n1, size_type __n2) noexcept
591 {
592 using __limits = __gnu_cxx::__int_traits<int>;
593 const difference_type __diff = __n1 - __n2;
594 if (__diff > __limits::__max)
595 return __limits::__max;
596 if (__diff < __limits::__min)
597 return __limits::__min;
598 return static_cast<int>(__diff);
599 }
600
601 size_t _M_len;
602 const _CharT* _M_str;
603 };
604
605#if __cplusplus > 201703L && __cpp_lib_concepts && __cpp_deduction_guides
606 template<contiguous_iterator _It, sized_sentinel_for<_It> _End>
607 basic_string_view(_It, _End) -> basic_string_view<iter_value_t<_It>>;
608
609#if __cplusplus > 202002L
610 template<ranges::contiguous_range _Range>
611 basic_string_view(_Range&&)
612 -> basic_string_view<ranges::range_value_t<_Range>>;
613#endif
614#endif
615
616 // [string.view.comparison], non-member basic_string_view comparison function
617
618 // Several of these functions use type_identity_t to create a non-deduced
619 // context, so that only one argument participates in template argument
620 // deduction and the other argument gets implicitly converted to the deduced
621 // type (see N3766).
622
623#if __cpp_lib_three_way_comparison
624 // _GLIBCXX_RESOLVE_LIB_DEFECTS
625 // 3950. std::basic_string_view comparison operators are overspecified
626
627 template<typename _CharT, typename _Traits>
628 [[nodiscard]]
629 constexpr bool
630 operator==(basic_string_view<_CharT, _Traits> __x,
631 type_identity_t<basic_string_view<_CharT, _Traits>> __y)
632 noexcept
633 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
634
635 template<typename _CharT, typename _Traits>
636 [[nodiscard]]
637 constexpr auto
638 operator<=>(basic_string_view<_CharT, _Traits> __x,
639 type_identity_t<basic_string_view<_CharT, _Traits>> __y)
640 noexcept
641 -> decltype(__detail::__char_traits_cmp_cat<_Traits>(0))
642 { return __detail::__char_traits_cmp_cat<_Traits>(__x.compare(__y)); }
643#else
644 template<typename _CharT, typename _Traits>
645 [[nodiscard]]
646 constexpr bool
647 operator==(basic_string_view<_CharT, _Traits> __x,
648 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
649 noexcept
650 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
651
652 template<typename _CharT, typename _Traits>
653 [[nodiscard]]
654 constexpr bool
655 operator==(basic_string_view<_CharT, _Traits> __x,
656 basic_string_view<_CharT, _Traits> __y) noexcept
657 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
658
659 template<typename _CharT, typename _Traits>
660 [[nodiscard]]
661 constexpr bool
662 operator==(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
663 basic_string_view<_CharT, _Traits> __y) noexcept
664 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
665
666 template<typename _CharT, typename _Traits>
667 [[nodiscard]]
668 constexpr bool
669 operator!=(basic_string_view<_CharT, _Traits> __x,
670 basic_string_view<_CharT, _Traits> __y) noexcept
671 { return !(__x == __y); }
672
673 template<typename _CharT, typename _Traits>
674 [[nodiscard]]
675 constexpr bool
676 operator!=(basic_string_view<_CharT, _Traits> __x,
677 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
678 noexcept
679 { return !(__x == __y); }
680
681 template<typename _CharT, typename _Traits>
682 [[nodiscard]]
683 constexpr bool
684 operator!=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
685 basic_string_view<_CharT, _Traits> __y) noexcept
686 { return !(__x == __y); }
687
688 template<typename _CharT, typename _Traits>
689 [[nodiscard]]
690 constexpr bool
691 operator< (basic_string_view<_CharT, _Traits> __x,
692 basic_string_view<_CharT, _Traits> __y) noexcept
693 { return __x.compare(__y) < 0; }
694
695 template<typename _CharT, typename _Traits>
696 [[nodiscard]]
697 constexpr bool
698 operator< (basic_string_view<_CharT, _Traits> __x,
699 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
700 noexcept
701 { return __x.compare(__y) < 0; }
702
703 template<typename _CharT, typename _Traits>
704 [[nodiscard]]
705 constexpr bool
706 operator< (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
707 basic_string_view<_CharT, _Traits> __y) noexcept
708 { return __x.compare(__y) < 0; }
709
710 template<typename _CharT, typename _Traits>
711 [[nodiscard]]
712 constexpr bool
713 operator> (basic_string_view<_CharT, _Traits> __x,
714 basic_string_view<_CharT, _Traits> __y) noexcept
715 { return __x.compare(__y) > 0; }
716
717 template<typename _CharT, typename _Traits>
718 [[nodiscard]]
719 constexpr bool
720 operator> (basic_string_view<_CharT, _Traits> __x,
721 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
722 noexcept
723 { return __x.compare(__y) > 0; }
724
725 template<typename _CharT, typename _Traits>
726 [[nodiscard]]
727 constexpr bool
728 operator> (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
729 basic_string_view<_CharT, _Traits> __y) noexcept
730 { return __x.compare(__y) > 0; }
731
732 template<typename _CharT, typename _Traits>
733 [[nodiscard]]
734 constexpr bool
735 operator<=(basic_string_view<_CharT, _Traits> __x,
736 basic_string_view<_CharT, _Traits> __y) noexcept
737 { return __x.compare(__y) <= 0; }
738
739 template<typename _CharT, typename _Traits>
740 [[nodiscard]]
741 constexpr bool
742 operator<=(basic_string_view<_CharT, _Traits> __x,
743 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
744 noexcept
745 { return __x.compare(__y) <= 0; }
746
747 template<typename _CharT, typename _Traits>
748 [[nodiscard]]
749 constexpr bool
750 operator<=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
751 basic_string_view<_CharT, _Traits> __y) noexcept
752 { return __x.compare(__y) <= 0; }
753
754 template<typename _CharT, typename _Traits>
755 [[nodiscard]]
756 constexpr bool
757 operator>=(basic_string_view<_CharT, _Traits> __x,
758 basic_string_view<_CharT, _Traits> __y) noexcept
759 { return __x.compare(__y) >= 0; }
760
761 template<typename _CharT, typename _Traits>
762 [[nodiscard]]
763 constexpr bool
764 operator>=(basic_string_view<_CharT, _Traits> __x,
765 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
766 noexcept
767 { return __x.compare(__y) >= 0; }
768
769 template<typename _CharT, typename _Traits>
770 [[nodiscard]]
771 constexpr bool
772 operator>=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
773 basic_string_view<_CharT, _Traits> __y) noexcept
774 { return __x.compare(__y) >= 0; }
775#endif // three-way comparison
776
777#if _GLIBCXX_HOSTED
778 // [string.view.io], Inserters and extractors
779 template<typename _CharT, typename _Traits>
780 inline basic_ostream<_CharT, _Traits>&
781 operator<<(basic_ostream<_CharT, _Traits>& __os,
782 basic_string_view<_CharT,_Traits> __str)
783 { return __ostream_insert(__os, __str.data(), __str.size()); }
784#endif // HOSTED
785
786 // basic_string_view typedef names
787
788 using string_view = basic_string_view<char>;
789 using wstring_view = basic_string_view<wchar_t>;
790#ifdef _GLIBCXX_USE_CHAR8_T
791 using u8string_view = basic_string_view<char8_t>;
792#endif
793 using u16string_view = basic_string_view<char16_t>;
794 using u32string_view = basic_string_view<char32_t>;
795
796 // [string.view.hash], hash support:
797
798 template<typename _Tp>
799 struct hash;
800
801 template<>
802 struct hash<string_view>
803 : public __hash_base<size_t, string_view>
804 {
805 [[nodiscard]]
806 size_t
807 operator()(const string_view& __str) const noexcept
808 { return std::_Hash_impl::hash(__str.data(), __str.length()); }
809 };
810
811 template<>
812 struct __is_fast_hash<hash<string_view>> : std::false_type
813 { };
814
815 template<>
816 struct hash<wstring_view>
817 : public __hash_base<size_t, wstring_view>
818 {
819 [[nodiscard]]
820 size_t
821 operator()(const wstring_view& __s) const noexcept
822 { return std::_Hash_impl::hash(__s.data(),
823 __s.length() * sizeof(wchar_t)); }
824 };
825
826 template<>
827 struct __is_fast_hash<hash<wstring_view>> : std::false_type
828 { };
829
830#ifdef _GLIBCXX_USE_CHAR8_T
831 template<>
832 struct hash<u8string_view>
833 : public __hash_base<size_t, u8string_view>
834 {
835 [[nodiscard]]
836 size_t
837 operator()(const u8string_view& __str) const noexcept
838 { return std::_Hash_impl::hash(__str.data(), __str.length()); }
839 };
840
841 template<>
842 struct __is_fast_hash<hash<u8string_view>> : std::false_type
843 { };
844#endif
845
846 template<>
847 struct hash<u16string_view>
848 : public __hash_base<size_t, u16string_view>
849 {
850 [[nodiscard]]
851 size_t
852 operator()(const u16string_view& __s) const noexcept
853 { return std::_Hash_impl::hash(__s.data(),
854 __s.length() * sizeof(char16_t)); }
855 };
856
857 template<>
858 struct __is_fast_hash<hash<u16string_view>> : std::false_type
859 { };
860
861 template<>
862 struct hash<u32string_view>
863 : public __hash_base<size_t, u32string_view>
864 {
865 [[nodiscard]]
866 size_t
867 operator()(const u32string_view& __s) const noexcept
868 { return std::_Hash_impl::hash(__s.data(),
869 __s.length() * sizeof(char32_t)); }
870 };
871
872 template<>
873 struct __is_fast_hash<hash<u32string_view>> : std::false_type
874 { };
875
876 inline namespace literals
877 {
878 inline namespace string_view_literals
879 {
880#pragma GCC diagnostic push
881#pragma GCC diagnostic ignored "-Wliteral-suffix"
882 inline constexpr basic_string_view<char>
883 operator""sv(const char* __str, size_t __len) noexcept
884 { return basic_string_view<char>{__str, __len}; }
885
886 inline constexpr basic_string_view<wchar_t>
887 operator""sv(const wchar_t* __str, size_t __len) noexcept
888 { return basic_string_view<wchar_t>{__str, __len}; }
889
890#ifdef _GLIBCXX_USE_CHAR8_T
891 inline constexpr basic_string_view<char8_t>
892 operator""sv(const char8_t* __str, size_t __len) noexcept
893 { return basic_string_view<char8_t>{__str, __len}; }
894#endif
895
896 inline constexpr basic_string_view<char16_t>
897 operator""sv(const char16_t* __str, size_t __len) noexcept
898 { return basic_string_view<char16_t>{__str, __len}; }
899
900 inline constexpr basic_string_view<char32_t>
901 operator""sv(const char32_t* __str, size_t __len) noexcept
902 { return basic_string_view<char32_t>{__str, __len}; }
903
904#pragma GCC diagnostic pop
905 } // namespace string_literals
906 } // namespace literals
907
908#if __cpp_lib_concepts
909 namespace ranges
910 {
911 // Opt-in to borrowed_range concept
912 template<typename _CharT, typename _Traits>
913 inline constexpr bool
914 enable_borrowed_range<basic_string_view<_CharT, _Traits>> = true;
915
916 // Opt-in to view concept
917 template<typename _CharT, typename _Traits>
918 inline constexpr bool
919 enable_view<basic_string_view<_CharT, _Traits>> = true;
920 }
921#endif
922_GLIBCXX_END_NAMESPACE_VERSION
923} // namespace std
924
925#include <bits/string_view.tcc>
926
927#if __glibcxx_exc_in_string == 2
928#undef __glibcxx_exc_in_string
929#if (_GLIBCXX_HOSTED && __cpp_exceptions && __cplusplus > 202302L \
930 && __cpp_constexpr_exceptions >= 202411L)
931#include <bits/stdexcept_throw.h>
932#endif
933#endif
934
935#endif // C++17
936
937#endif // _GLIBCXX_STRING_VIEW
std::ranges::enable_view
constexpr bool enable_view
[range.view] The ranges::enable_view boolean.
Definition ranges_base.h:582
std::to_address
constexpr _Tp * to_address(_Tp *__ptr) noexcept
Obtain address referenced by a pointer to an object.
Definition ptr_traits.h:234
std::false_type
__bool_constant< false > false_type
The type used as a compile-time boolean with false value.
Definition type_traits:122
std::min
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition stl_algobase.h:232
std
ISO C++ entities toplevel namespace is std.
std::operator<<
std::basic_ostream< _CharT, _Traits > & operator<<(std::basic_ostream< _CharT, _Traits > &__os, const bitset< _Nb > &__x)
Global I/O operators for bitsets.
Definition bitset:1754
std::literals
ISO C++ inline namespace for literal suffixes.
__gnu_cxx::__int_traits
__numeric_traits_integer< _Tp > __int_traits
Convenience alias for __numeric_traits<integer-type>.
Definition ext/numeric_traits.h:134
std::basic_ostream
Template class basic_ostream.
Definition ostream.h:67
std::basic_string_view
A non-owning reference to a string.
Definition string_view:113
std::hash
Primary class template hash.
Definition functional_hash.h:106
std::same_as
[concept.same], concept same_as
Definition concepts:65
std::convertible_to
[concept.convertible], concept convertible_to
Definition concepts:81
std::ranges::sized_range
[range.sized] The sized_range concept.
Definition ranges_base.h:553
std::ranges::contiguous_range
A range for which ranges::begin returns a contiguous iterator.
Definition ranges_base.h:619