libstdc++
string_view
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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(), __pos, "basic_string_view::copy");
325 const size_type __rlen = std::min<size_t>(__n, _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(), __pos, "basic_string_view::substr");
337 const size_type __rlen = std::min<size_t>(__n, _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(this->_M_len, __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 {
389 return _M_len >= __x._M_len
390 && traits_type::compare(_M_str, __x._M_str, __x._M_len) == 0;
391 }
392
393 [[nodiscard]]
394 constexpr bool
395 starts_with(_CharT __x) const noexcept
396 { return !this->empty() && traits_type::eq(this->front(), __x); }
397
398 [[nodiscard, __gnu__::__nonnull__]]
399 constexpr bool
400 starts_with(const _CharT* __x) const noexcept
401 { return this->starts_with(basic_string_view(__x)); }
402
403 [[nodiscard]]
404 constexpr bool
405 ends_with(basic_string_view __x) const noexcept
406 {
407 const auto __len = this->size();
408 const auto __xlen = __x.size();
409 return __len >= __xlen
410 && traits_type::compare(end() - __xlen, __x.data(), __xlen) == 0;
411 }
412
413 [[nodiscard]]
414 constexpr bool
415 ends_with(_CharT __x) const noexcept
416 { return !this->empty() && traits_type::eq(this->back(), __x); }
417
418 [[nodiscard, __gnu__::__nonnull__]]
419 constexpr bool
420 ends_with(const _CharT* __x) const noexcept
421 { return this->ends_with(basic_string_view(__x)); }
422#endif // __cpp_lib_starts_ends_with
423
424#if __cplusplus > 202002L
425#if _GLIBCXX_HOSTED && !defined(__cpp_lib_string_contains)
426 // This FTM is not freestanding as it also implies matching <string>
427 // support, and <string> is omitted from the freestanding subset.
428# error "libstdc++ bug: string_contains not defined when it should be"
429#endif // HOSTED
430 [[nodiscard]]
431 constexpr bool
432 contains(basic_string_view __x) const noexcept
433 { return this->find(__x) != npos; }
434
435 [[nodiscard]]
436 constexpr bool
437 contains(_CharT __x) const noexcept
438 { return this->find(__x) != npos; }
439
440 [[nodiscard, __gnu__::__nonnull__]]
441 constexpr bool
442 contains(const _CharT* __x) const noexcept
443 { return this->find(__x) != npos; }
444#endif // C++23
445
446 // [string.view.find], searching
447
448 [[nodiscard]]
449 constexpr size_type
450 find(basic_string_view __str, size_type __pos = 0) const noexcept
451 { return this->find(__str._M_str, __pos, __str._M_len); }
452
453 [[nodiscard]]
454 constexpr size_type
455 find(_CharT __c, size_type __pos = 0) const noexcept;
456
457 [[nodiscard]]
458 constexpr size_type
459 find(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
460
461 [[nodiscard, __gnu__::__nonnull__]]
462 constexpr size_type
463 find(const _CharT* __str, size_type __pos = 0) const noexcept
464 { return this->find(__str, __pos, traits_type::length(__str)); }
465
466 [[nodiscard]]
467 constexpr size_type
468 rfind(basic_string_view __str, size_type __pos = npos) const noexcept
469 { return this->rfind(__str._M_str, __pos, __str._M_len); }
470
471 [[nodiscard]]
472 constexpr size_type
473 rfind(_CharT __c, size_type __pos = npos) const noexcept;
474
475 [[nodiscard]]
476 constexpr size_type
477 rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
478
479 [[nodiscard, __gnu__::__nonnull__]]
480 constexpr size_type
481 rfind(const _CharT* __str, size_type __pos = npos) const noexcept
482 { return this->rfind(__str, __pos, traits_type::length(__str)); }
483
484 [[nodiscard]]
485 constexpr size_type
486 find_first_of(basic_string_view __str, size_type __pos = 0) const noexcept
487 { return this->find_first_of(__str._M_str, __pos, __str._M_len); }
488
489 [[nodiscard]]
490 constexpr size_type
491 find_first_of(_CharT __c, size_type __pos = 0) const noexcept
492 { return this->find(__c, __pos); }
493
494 [[nodiscard]]
495 constexpr size_type
496 find_first_of(const _CharT* __str, size_type __pos,
497 size_type __n) const noexcept;
498
499 [[nodiscard, __gnu__::__nonnull__]]
500 constexpr size_type
501 find_first_of(const _CharT* __str, size_type __pos = 0) const noexcept
502 { return this->find_first_of(__str, __pos, traits_type::length(__str)); }
503
504 [[nodiscard]]
505 constexpr size_type
506 find_last_of(basic_string_view __str,
507 size_type __pos = npos) const noexcept
508 { return this->find_last_of(__str._M_str, __pos, __str._M_len); }
509
510 [[nodiscard]]
511 constexpr size_type
512 find_last_of(_CharT __c, size_type __pos=npos) const noexcept
513 { return this->rfind(__c, __pos); }
514
515 [[nodiscard]]
516 constexpr size_type
517 find_last_of(const _CharT* __str, size_type __pos,
518 size_type __n) const noexcept;
519
520 [[nodiscard, __gnu__::__nonnull__]]
521 constexpr size_type
522 find_last_of(const _CharT* __str, size_type __pos = npos) const noexcept
523 { return this->find_last_of(__str, __pos, traits_type::length(__str)); }
524
525 [[nodiscard]]
526 constexpr size_type
527 find_first_not_of(basic_string_view __str,
528 size_type __pos = 0) const noexcept
529 { return this->find_first_not_of(__str._M_str, __pos, __str._M_len); }
530
531 [[nodiscard]]
532 constexpr size_type
533 find_first_not_of(_CharT __c, size_type __pos = 0) const noexcept;
534
535 [[nodiscard]]
536 constexpr size_type
537 find_first_not_of(const _CharT* __str,
538 size_type __pos, size_type __n) const noexcept;
539
540 [[nodiscard, __gnu__::__nonnull__]]
541 constexpr size_type
542 find_first_not_of(const _CharT* __str, size_type __pos = 0) const noexcept
543 {
544 return this->find_first_not_of(__str, __pos,
545 traits_type::length(__str));
546 }
547
548 [[nodiscard]]
549 constexpr size_type
550 find_last_not_of(basic_string_view __str,
551 size_type __pos = npos) const noexcept
552 { return this->find_last_not_of(__str._M_str, __pos, __str._M_len); }
553
554 [[nodiscard]]
555 constexpr size_type
556 find_last_not_of(_CharT __c, size_type __pos = npos) const noexcept;
557
558 [[nodiscard]]
559 constexpr size_type
560 find_last_not_of(const _CharT* __str,
561 size_type __pos, size_type __n) const noexcept;
562
563 [[nodiscard, __gnu__::__nonnull__]]
564 constexpr size_type
565 find_last_not_of(const _CharT* __str,
566 size_type __pos = npos) const noexcept
567 {
568 return this->find_last_not_of(__str, __pos,
569 traits_type::length(__str));
570 }
571
572 private:
573
574 static constexpr int
575 _S_compare(size_type __n1, size_type __n2) noexcept
576 {
577 using __limits = __gnu_cxx::__int_traits<int>;
578 const difference_type __diff = __n1 - __n2;
579 if (__diff > __limits::__max)
580 return __limits::__max;
581 if (__diff < __limits::__min)
582 return __limits::__min;
583 return static_cast<int>(__diff);
584 }
585
586 size_t _M_len;
587 const _CharT* _M_str;
588 };
589
590#if __cplusplus > 201703L && __cpp_lib_concepts && __cpp_deduction_guides
591 template<contiguous_iterator _It, sized_sentinel_for<_It> _End>
592 basic_string_view(_It, _End) -> basic_string_view<iter_value_t<_It>>;
593
594#if __cplusplus > 202002L
595 template<ranges::contiguous_range _Range>
596 basic_string_view(_Range&&)
597 -> basic_string_view<ranges::range_value_t<_Range>>;
598#endif
599#endif
600
601 // [string.view.comparison], non-member basic_string_view comparison function
602
603 // Several of these functions use type_identity_t to create a non-deduced
604 // context, so that only one argument participates in template argument
605 // deduction and the other argument gets implicitly converted to the deduced
606 // type (see N3766).
607
608#if __cpp_lib_three_way_comparison
609 // _GLIBCXX_RESOLVE_LIB_DEFECTS
610 // 3950. std::basic_string_view comparison operators are overspecified
611
612 template<typename _CharT, typename _Traits>
613 [[nodiscard]]
614 constexpr bool
615 operator==(basic_string_view<_CharT, _Traits> __x,
616 type_identity_t<basic_string_view<_CharT, _Traits>> __y)
617 noexcept
618 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
619
620 template<typename _CharT, typename _Traits>
621 [[nodiscard]]
622 constexpr auto
623 operator<=>(basic_string_view<_CharT, _Traits> __x,
624 type_identity_t<basic_string_view<_CharT, _Traits>> __y)
625 noexcept
626 -> decltype(__detail::__char_traits_cmp_cat<_Traits>(0))
627 { return __detail::__char_traits_cmp_cat<_Traits>(__x.compare(__y)); }
628#else
629 template<typename _CharT, typename _Traits>
630 [[nodiscard]]
631 constexpr bool
632 operator==(basic_string_view<_CharT, _Traits> __x,
633 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
634 noexcept
635 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
636
637 template<typename _CharT, typename _Traits>
638 [[nodiscard]]
639 constexpr bool
640 operator==(basic_string_view<_CharT, _Traits> __x,
641 basic_string_view<_CharT, _Traits> __y) noexcept
642 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
643
644 template<typename _CharT, typename _Traits>
645 [[nodiscard]]
646 constexpr bool
647 operator==(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
648 basic_string_view<_CharT, _Traits> __y) noexcept
649 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
650
651 template<typename _CharT, typename _Traits>
652 [[nodiscard]]
653 constexpr bool
654 operator!=(basic_string_view<_CharT, _Traits> __x,
655 basic_string_view<_CharT, _Traits> __y) noexcept
656 { return !(__x == __y); }
657
658 template<typename _CharT, typename _Traits>
659 [[nodiscard]]
660 constexpr bool
661 operator!=(basic_string_view<_CharT, _Traits> __x,
662 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
663 noexcept
664 { return !(__x == __y); }
665
666 template<typename _CharT, typename _Traits>
667 [[nodiscard]]
668 constexpr bool
669 operator!=(__type_identity_t<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 basic_string_view<_CharT, _Traits> __y) noexcept
678 { return __x.compare(__y) < 0; }
679
680 template<typename _CharT, typename _Traits>
681 [[nodiscard]]
682 constexpr bool
683 operator< (basic_string_view<_CharT, _Traits> __x,
684 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
685 noexcept
686 { return __x.compare(__y) < 0; }
687
688 template<typename _CharT, typename _Traits>
689 [[nodiscard]]
690 constexpr bool
691 operator< (__type_identity_t<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 basic_string_view<_CharT, _Traits> __y) noexcept
700 { return __x.compare(__y) > 0; }
701
702 template<typename _CharT, typename _Traits>
703 [[nodiscard]]
704 constexpr bool
705 operator> (basic_string_view<_CharT, _Traits> __x,
706 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
707 noexcept
708 { return __x.compare(__y) > 0; }
709
710 template<typename _CharT, typename _Traits>
711 [[nodiscard]]
712 constexpr bool
713 operator> (__type_identity_t<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 basic_string_view<_CharT, _Traits> __y) noexcept
722 { return __x.compare(__y) <= 0; }
723
724 template<typename _CharT, typename _Traits>
725 [[nodiscard]]
726 constexpr bool
727 operator<=(basic_string_view<_CharT, _Traits> __x,
728 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
729 noexcept
730 { return __x.compare(__y) <= 0; }
731
732 template<typename _CharT, typename _Traits>
733 [[nodiscard]]
734 constexpr bool
735 operator<=(__type_identity_t<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 basic_string_view<_CharT, _Traits> __y) noexcept
744 { return __x.compare(__y) >= 0; }
745
746 template<typename _CharT, typename _Traits>
747 [[nodiscard]]
748 constexpr bool
749 operator>=(basic_string_view<_CharT, _Traits> __x,
750 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
751 noexcept
752 { return __x.compare(__y) >= 0; }
753
754 template<typename _CharT, typename _Traits>
755 [[nodiscard]]
756 constexpr bool
757 operator>=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
758 basic_string_view<_CharT, _Traits> __y) noexcept
759 { return __x.compare(__y) >= 0; }
760#endif // three-way comparison
761
762#if _GLIBCXX_HOSTED
763 // [string.view.io], Inserters and extractors
764 template<typename _CharT, typename _Traits>
765 inline basic_ostream<_CharT, _Traits>&
766 operator<<(basic_ostream<_CharT, _Traits>& __os,
767 basic_string_view<_CharT,_Traits> __str)
768 { return __ostream_insert(__os, __str.data(), __str.size()); }
769#endif // HOSTED
770
771 // basic_string_view typedef names
772
773 using string_view = basic_string_view<char>;
774 using wstring_view = basic_string_view<wchar_t>;
775#ifdef _GLIBCXX_USE_CHAR8_T
776 using u8string_view = basic_string_view<char8_t>;
777#endif
778 using u16string_view = basic_string_view<char16_t>;
779 using u32string_view = basic_string_view<char32_t>;
780
781 // [string.view.hash], hash support:
782
783 template<typename _Tp>
784 struct hash;
785
786 template<>
787 struct hash<string_view>
788 : public __hash_base<size_t, string_view>
789 {
790 [[nodiscard]]
791 size_t
792 operator()(const string_view& __str) const noexcept
793 { return std::_Hash_impl::hash(__str.data(), __str.length()); }
794 };
795
796 template<>
797 struct __is_fast_hash<hash<string_view>> : std::false_type
798 { };
799
800 template<>
801 struct hash<wstring_view>
802 : public __hash_base<size_t, wstring_view>
803 {
804 [[nodiscard]]
805 size_t
806 operator()(const wstring_view& __s) const noexcept
807 { return std::_Hash_impl::hash(__s.data(),
808 __s.length() * sizeof(wchar_t)); }
809 };
810
811 template<>
812 struct __is_fast_hash<hash<wstring_view>> : std::false_type
813 { };
814
815#ifdef _GLIBCXX_USE_CHAR8_T
816 template<>
817 struct hash<u8string_view>
818 : public __hash_base<size_t, u8string_view>
819 {
820 [[nodiscard]]
821 size_t
822 operator()(const u8string_view& __str) const noexcept
823 { return std::_Hash_impl::hash(__str.data(), __str.length()); }
824 };
825
826 template<>
827 struct __is_fast_hash<hash<u8string_view>> : std::false_type
828 { };
829#endif
830
831 template<>
832 struct hash<u16string_view>
833 : public __hash_base<size_t, u16string_view>
834 {
835 [[nodiscard]]
836 size_t
837 operator()(const u16string_view& __s) const noexcept
838 { return std::_Hash_impl::hash(__s.data(),
839 __s.length() * sizeof(char16_t)); }
840 };
841
842 template<>
843 struct __is_fast_hash<hash<u16string_view>> : std::false_type
844 { };
845
846 template<>
847 struct hash<u32string_view>
848 : public __hash_base<size_t, u32string_view>
849 {
850 [[nodiscard]]
851 size_t
852 operator()(const u32string_view& __s) const noexcept
853 { return std::_Hash_impl::hash(__s.data(),
854 __s.length() * sizeof(char32_t)); }
855 };
856
857 template<>
858 struct __is_fast_hash<hash<u32string_view>> : std::false_type
859 { };
860
861 inline namespace literals
862 {
863 inline namespace string_view_literals
864 {
865#pragma GCC diagnostic push
866#pragma GCC diagnostic ignored "-Wliteral-suffix"
867 inline constexpr basic_string_view<char>
868 operator""sv(const char* __str, size_t __len) noexcept
869 { return basic_string_view<char>{__str, __len}; }
870
871 inline constexpr basic_string_view<wchar_t>
872 operator""sv(const wchar_t* __str, size_t __len) noexcept
873 { return basic_string_view<wchar_t>{__str, __len}; }
874
875#ifdef _GLIBCXX_USE_CHAR8_T
876 inline constexpr basic_string_view<char8_t>
877 operator""sv(const char8_t* __str, size_t __len) noexcept
878 { return basic_string_view<char8_t>{__str, __len}; }
879#endif
880
881 inline constexpr basic_string_view<char16_t>
882 operator""sv(const char16_t* __str, size_t __len) noexcept
883 { return basic_string_view<char16_t>{__str, __len}; }
884
885 inline constexpr basic_string_view<char32_t>
886 operator""sv(const char32_t* __str, size_t __len) noexcept
887 { return basic_string_view<char32_t>{__str, __len}; }
888
889#pragma GCC diagnostic pop
890 } // namespace string_literals
891 } // namespace literals
892
893#if __cpp_lib_concepts
894 namespace ranges
895 {
896 // Opt-in to borrowed_range concept
897 template<typename _CharT, typename _Traits>
898 inline constexpr bool
899 enable_borrowed_range<basic_string_view<_CharT, _Traits>> = true;
900
901 // Opt-in to view concept
902 template<typename _CharT, typename _Traits>
903 inline constexpr bool
904 enable_view<basic_string_view<_CharT, _Traits>> = true;
905 }
906#endif
907_GLIBCXX_END_NAMESPACE_VERSION
908} // namespace std
909
910#include <bits/string_view.tcc>
911
912#endif // C++17
913
914#endif // _GLIBCXX_STRING_VIEW
std::to_address
constexpr _Tp * to_address(_Tp *__ptr) noexcept
Obtain address referenced by a pointer to an object.
Definition ptr_traits.h:241
std::false_type
__bool_constant< false > false_type
The type used as a compile-time boolean with false value.
Definition type_traits:114
std::min
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition stl_algobase.h:233
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:1687
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:138
std::basic_ostream
Template class basic_ostream.
Definition ostream:67
std::basic_string_view
A non-owning reference to a string.
Definition string_view:107
std::hash
Primary class template hash.
Definition functional_hash.h:103