libstdc++
std/string_view
1// Components for manipulating non-owning sequences of characters -*- C++ -*-
2
3// Copyright (C) 2013-2023 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#if __cplusplus >= 201703L
39
40#include <bits/char_traits.h>
41#include <bits/functexcept.h>
43#include <bits/range_access.h>
44#include <bits/stl_algobase.h>
45#include <ext/numeric_traits.h>
46
47#if __cplusplus >= 202002L
48# include <bits/ranges_base.h>
49#endif
50
51#if _GLIBCXX_HOSTED
52# include <iosfwd>
53# include <bits/ostream_insert.h>
54#endif
55
56namespace std _GLIBCXX_VISIBILITY(default)
57{
58_GLIBCXX_BEGIN_NAMESPACE_VERSION
59
60#if _GLIBCXX_HOSTED
61# define __cpp_lib_string_view 201803L
62#endif
63
64#if __cplusplus > 201703L
65# define __cpp_lib_constexpr_string_view 201811L
66#endif
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>>
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;
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>
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>)
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 && (!requires { typename _DRange::traits_type; }
171 || is_same_v<typename _DRange::traits_type, _Traits>)
172 constexpr explicit
173 basic_string_view(_Range&& __r)
174 noexcept(noexcept(ranges::size(__r)) && noexcept(ranges::data(__r)))
175 : _M_len(ranges::size(__r)), _M_str(ranges::data(__r))
176 { }
177
178 basic_string_view(nullptr_t) = delete;
179#endif // C++23
180#endif // C++20
181
182 constexpr basic_string_view&
183 operator=(const basic_string_view&) noexcept = default;
184
185 // [string.view.iterators], iterator support
186
187 [[nodiscard]]
188 constexpr const_iterator
189 begin() const noexcept
190 { return this->_M_str; }
191
192 [[nodiscard]]
193 constexpr const_iterator
194 end() const noexcept
195 { return this->_M_str + this->_M_len; }
196
197 [[nodiscard]]
198 constexpr const_iterator
199 cbegin() const noexcept
200 { return this->_M_str; }
201
202 [[nodiscard]]
203 constexpr const_iterator
204 cend() const noexcept
205 { return this->_M_str + this->_M_len; }
206
207 [[nodiscard]]
208 constexpr const_reverse_iterator
209 rbegin() const noexcept
210 { return const_reverse_iterator(this->end()); }
211
212 [[nodiscard]]
213 constexpr const_reverse_iterator
214 rend() const noexcept
215 { return const_reverse_iterator(this->begin()); }
216
217 [[nodiscard]]
218 constexpr const_reverse_iterator
219 crbegin() const noexcept
220 { return const_reverse_iterator(this->end()); }
221
222 [[nodiscard]]
223 constexpr const_reverse_iterator
224 crend() const noexcept
225 { return const_reverse_iterator(this->begin()); }
226
227 // [string.view.capacity], capacity
228
229 [[nodiscard]]
230 constexpr size_type
231 size() const noexcept
232 { return this->_M_len; }
233
234 [[nodiscard]]
235 constexpr size_type
236 length() const noexcept
237 { return _M_len; }
238
239 [[nodiscard]]
240 constexpr size_type
241 max_size() const noexcept
242 {
243 return (npos - sizeof(size_type) - sizeof(void*))
244 / sizeof(value_type) / 4;
245 }
246
247 [[nodiscard]]
248 constexpr bool
249 empty() const noexcept
250 { return this->_M_len == 0; }
251
252 // [string.view.access], element access
253
254 [[nodiscard]]
255 constexpr const_reference
256 operator[](size_type __pos) const noexcept
257 {
258 __glibcxx_assert(__pos < this->_M_len);
259 return *(this->_M_str + __pos);
260 }
261
262 [[nodiscard]]
263 constexpr const_reference
264 at(size_type __pos) const
265 {
266 if (__pos >= _M_len)
267 __throw_out_of_range_fmt(__N("basic_string_view::at: __pos "
268 "(which is %zu) >= this->size() "
269 "(which is %zu)"), __pos, this->size());
270 return *(this->_M_str + __pos);
271 }
272
273 [[nodiscard]]
274 constexpr const_reference
275 front() const noexcept
276 {
277 __glibcxx_assert(this->_M_len > 0);
278 return *this->_M_str;
279 }
280
281 [[nodiscard]]
282 constexpr const_reference
283 back() const noexcept
284 {
285 __glibcxx_assert(this->_M_len > 0);
286 return *(this->_M_str + this->_M_len - 1);
287 }
288
289 [[nodiscard]]
290 constexpr const_pointer
291 data() const noexcept
292 { return this->_M_str; }
293
294 // [string.view.modifiers], modifiers:
295
296 constexpr void
297 remove_prefix(size_type __n) noexcept
298 {
299 __glibcxx_assert(this->_M_len >= __n);
300 this->_M_str += __n;
301 this->_M_len -= __n;
302 }
303
304 constexpr void
305 remove_suffix(size_type __n) noexcept
306 {
307 __glibcxx_assert(this->_M_len >= __n);
308 this->_M_len -= __n;
309 }
310
311 constexpr void
312 swap(basic_string_view& __sv) noexcept
313 {
314 auto __tmp = *this;
315 *this = __sv;
316 __sv = __tmp;
317 }
318
319 // [string.view.ops], string operations:
320
321 _GLIBCXX20_CONSTEXPR
322 size_type
323 copy(_CharT* __str, size_type __n, size_type __pos = 0) const
324 {
325 __glibcxx_requires_string_len(__str, __n);
326 __pos = std::__sv_check(size(), __pos, "basic_string_view::copy");
327 const size_type __rlen = std::min<size_t>(__n, _M_len - __pos);
328 // _GLIBCXX_RESOLVE_LIB_DEFECTS
329 // 2777. basic_string_view::copy should use char_traits::copy
330 traits_type::copy(__str, data() + __pos, __rlen);
331 return __rlen;
332 }
333
334 [[nodiscard]]
335 constexpr basic_string_view
336 substr(size_type __pos = 0, size_type __n = npos) const noexcept(false)
337 {
338 __pos = std::__sv_check(size(), __pos, "basic_string_view::substr");
339 const size_type __rlen = std::min<size_t>(__n, _M_len - __pos);
340 return basic_string_view{_M_str + __pos, __rlen};
341 }
342
343 [[nodiscard]]
344 constexpr int
345 compare(basic_string_view __str) const noexcept
346 {
347 const size_type __rlen = std::min(this->_M_len, __str._M_len);
348 int __ret = traits_type::compare(this->_M_str, __str._M_str, __rlen);
349 if (__ret == 0)
350 __ret = _S_compare(this->_M_len, __str._M_len);
351 return __ret;
352 }
353
354 [[nodiscard]]
355 constexpr int
356 compare(size_type __pos1, size_type __n1, basic_string_view __str) const
357 { return this->substr(__pos1, __n1).compare(__str); }
358
359 [[nodiscard]]
360 constexpr int
361 compare(size_type __pos1, size_type __n1,
362 basic_string_view __str, size_type __pos2, size_type __n2) const
363 {
364 return this->substr(__pos1, __n1).compare(__str.substr(__pos2, __n2));
365 }
366
367 [[nodiscard, __gnu__::__nonnull__]]
368 constexpr int
369 compare(const _CharT* __str) const noexcept
370 { return this->compare(basic_string_view{__str}); }
371
372 [[nodiscard, __gnu__::__nonnull__]]
373 constexpr int
374 compare(size_type __pos1, size_type __n1, const _CharT* __str) const
375 { return this->substr(__pos1, __n1).compare(basic_string_view{__str}); }
376
377 [[nodiscard]]
378 constexpr int
379 compare(size_type __pos1, size_type __n1,
380 const _CharT* __str, size_type __n2) const noexcept(false)
381 {
382 return this->substr(__pos1, __n1)
383 .compare(basic_string_view(__str, __n2));
384 }
385
386#if __cplusplus > 201703L
387#define __cpp_lib_starts_ends_with 201711L
388 [[nodiscard]]
389 constexpr bool
390 starts_with(basic_string_view __x) const noexcept
391 { return this->substr(0, __x.size()) == __x; }
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 // C++20
423
424#if __cplusplus > 202002L
425#if _GLIBCXX_HOSTED
426 // This FTM is not freestanding as it also implies matching <string>
427 // support, and <string> is omitted from the freestanding subset.
428# define __cpp_lib_string_contains 202011L
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>
593
594#if __cplusplus > 202002L
595 template<ranges::contiguous_range _Range>
596 basic_string_view(_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 template<typename _CharT, typename _Traits>
609 [[nodiscard]]
610 constexpr bool
613 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
614
615 template<typename _CharT, typename _Traits>
616 [[nodiscard]]
617 constexpr bool
618 operator==(basic_string_view<_CharT, _Traits> __x,
619 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
620 noexcept
621 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
622
623#if __cpp_lib_three_way_comparison
624 template<typename _CharT, typename _Traits>
625 [[nodiscard]]
626 constexpr auto
627 operator<=>(basic_string_view<_CharT, _Traits> __x,
628 basic_string_view<_CharT, _Traits> __y) noexcept
629 -> decltype(__detail::__char_traits_cmp_cat<_Traits>(0))
630 { return __detail::__char_traits_cmp_cat<_Traits>(__x.compare(__y)); }
631
632 template<typename _CharT, typename _Traits>
633 [[nodiscard]]
634 constexpr auto
635 operator<=>(basic_string_view<_CharT, _Traits> __x,
636 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
637 noexcept
638 -> decltype(__detail::__char_traits_cmp_cat<_Traits>(0))
639 { return __detail::__char_traits_cmp_cat<_Traits>(__x.compare(__y)); }
640#else
641 template<typename _CharT, typename _Traits>
642 [[nodiscard]]
643 constexpr bool
644 operator==(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
645 basic_string_view<_CharT, _Traits> __y) noexcept
646 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
647
648 template<typename _CharT, typename _Traits>
649 [[nodiscard]]
650 constexpr bool
651 operator!=(basic_string_view<_CharT, _Traits> __x,
652 basic_string_view<_CharT, _Traits> __y) noexcept
653 { return !(__x == __y); }
654
655 template<typename _CharT, typename _Traits>
656 [[nodiscard]]
657 constexpr bool
658 operator!=(basic_string_view<_CharT, _Traits> __x,
659 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
660 noexcept
661 { return !(__x == __y); }
662
663 template<typename _CharT, typename _Traits>
664 [[nodiscard]]
665 constexpr bool
666 operator!=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
667 basic_string_view<_CharT, _Traits> __y) noexcept
668 { return !(__x == __y); }
669
670 template<typename _CharT, typename _Traits>
671 [[nodiscard]]
672 constexpr bool
673 operator< (basic_string_view<_CharT, _Traits> __x,
674 basic_string_view<_CharT, _Traits> __y) noexcept
675 { return __x.compare(__y) < 0; }
676
677 template<typename _CharT, typename _Traits>
678 [[nodiscard]]
679 constexpr bool
680 operator< (basic_string_view<_CharT, _Traits> __x,
681 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
682 noexcept
683 { return __x.compare(__y) < 0; }
684
685 template<typename _CharT, typename _Traits>
686 [[nodiscard]]
687 constexpr bool
688 operator< (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
689 basic_string_view<_CharT, _Traits> __y) noexcept
690 { return __x.compare(__y) < 0; }
691
692 template<typename _CharT, typename _Traits>
693 [[nodiscard]]
694 constexpr bool
695 operator> (basic_string_view<_CharT, _Traits> __x,
696 basic_string_view<_CharT, _Traits> __y) noexcept
697 { return __x.compare(__y) > 0; }
698
699 template<typename _CharT, typename _Traits>
700 [[nodiscard]]
701 constexpr bool
702 operator> (basic_string_view<_CharT, _Traits> __x,
703 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
704 noexcept
705 { return __x.compare(__y) > 0; }
706
707 template<typename _CharT, typename _Traits>
708 [[nodiscard]]
709 constexpr bool
710 operator> (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
711 basic_string_view<_CharT, _Traits> __y) noexcept
712 { return __x.compare(__y) > 0; }
713
714 template<typename _CharT, typename _Traits>
715 [[nodiscard]]
716 constexpr bool
717 operator<=(basic_string_view<_CharT, _Traits> __x,
718 basic_string_view<_CharT, _Traits> __y) noexcept
719 { return __x.compare(__y) <= 0; }
720
721 template<typename _CharT, typename _Traits>
722 [[nodiscard]]
723 constexpr bool
724 operator<=(basic_string_view<_CharT, _Traits> __x,
725 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
726 noexcept
727 { return __x.compare(__y) <= 0; }
728
729 template<typename _CharT, typename _Traits>
730 [[nodiscard]]
731 constexpr bool
732 operator<=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
733 basic_string_view<_CharT, _Traits> __y) noexcept
734 { return __x.compare(__y) <= 0; }
735
736 template<typename _CharT, typename _Traits>
737 [[nodiscard]]
738 constexpr bool
739 operator>=(basic_string_view<_CharT, _Traits> __x,
740 basic_string_view<_CharT, _Traits> __y) noexcept
741 { return __x.compare(__y) >= 0; }
742
743 template<typename _CharT, typename _Traits>
744 [[nodiscard]]
745 constexpr bool
746 operator>=(basic_string_view<_CharT, _Traits> __x,
747 __type_identity_t<basic_string_view<_CharT, _Traits>> __y)
748 noexcept
749 { return __x.compare(__y) >= 0; }
750
751 template<typename _CharT, typename _Traits>
752 [[nodiscard]]
753 constexpr bool
754 operator>=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
755 basic_string_view<_CharT, _Traits> __y) noexcept
756 { return __x.compare(__y) >= 0; }
757#endif // three-way comparison
758
759#if _GLIBCXX_HOSTED
760 // [string.view.io], Inserters and extractors
761 template<typename _CharT, typename _Traits>
762 inline basic_ostream<_CharT, _Traits>&
763 operator<<(basic_ostream<_CharT, _Traits>& __os,
764 basic_string_view<_CharT,_Traits> __str)
765 { return __ostream_insert(__os, __str.data(), __str.size()); }
766#endif // HOSTED
767
768 // basic_string_view typedef names
769
770 using string_view = basic_string_view<char>;
771 using wstring_view = basic_string_view<wchar_t>;
772#ifdef _GLIBCXX_USE_CHAR8_T
773 using u8string_view = basic_string_view<char8_t>;
774#endif
775 using u16string_view = basic_string_view<char16_t>;
776 using u32string_view = basic_string_view<char32_t>;
777
778 // [string.view.hash], hash support:
779
780 template<typename _Tp>
781 struct hash;
782
783 template<>
784 struct hash<string_view>
785 : public __hash_base<size_t, string_view>
786 {
787 [[nodiscard]]
788 size_t
789 operator()(const string_view& __str) const noexcept
790 { return std::_Hash_impl::hash(__str.data(), __str.length()); }
791 };
792
793 template<>
794 struct __is_fast_hash<hash<string_view>> : std::false_type
795 { };
796
797 template<>
798 struct hash<wstring_view>
799 : public __hash_base<size_t, wstring_view>
800 {
801 [[nodiscard]]
802 size_t
803 operator()(const wstring_view& __s) const noexcept
804 { return std::_Hash_impl::hash(__s.data(),
805 __s.length() * sizeof(wchar_t)); }
806 };
807
808 template<>
809 struct __is_fast_hash<hash<wstring_view>> : std::false_type
810 { };
811
812#ifdef _GLIBCXX_USE_CHAR8_T
813 template<>
814 struct hash<u8string_view>
815 : public __hash_base<size_t, u8string_view>
816 {
817 [[nodiscard]]
818 size_t
819 operator()(const u8string_view& __str) const noexcept
820 { return std::_Hash_impl::hash(__str.data(), __str.length()); }
821 };
822
823 template<>
824 struct __is_fast_hash<hash<u8string_view>> : std::false_type
825 { };
826#endif
827
828 template<>
829 struct hash<u16string_view>
830 : public __hash_base<size_t, u16string_view>
831 {
832 [[nodiscard]]
833 size_t
834 operator()(const u16string_view& __s) const noexcept
835 { return std::_Hash_impl::hash(__s.data(),
836 __s.length() * sizeof(char16_t)); }
837 };
838
839 template<>
840 struct __is_fast_hash<hash<u16string_view>> : std::false_type
841 { };
842
843 template<>
844 struct hash<u32string_view>
845 : public __hash_base<size_t, u32string_view>
846 {
847 [[nodiscard]]
848 size_t
849 operator()(const u32string_view& __s) const noexcept
850 { return std::_Hash_impl::hash(__s.data(),
851 __s.length() * sizeof(char32_t)); }
852 };
853
854 template<>
855 struct __is_fast_hash<hash<u32string_view>> : std::false_type
856 { };
857
858 inline namespace literals
859 {
860 inline namespace string_view_literals
861 {
862#pragma GCC diagnostic push
863#pragma GCC diagnostic ignored "-Wliteral-suffix"
864 inline constexpr basic_string_view<char>
865 operator""sv(const char* __str, size_t __len) noexcept
866 { return basic_string_view<char>{__str, __len}; }
867
868 inline constexpr basic_string_view<wchar_t>
869 operator""sv(const wchar_t* __str, size_t __len) noexcept
870 { return basic_string_view<wchar_t>{__str, __len}; }
871
872#ifdef _GLIBCXX_USE_CHAR8_T
873 inline constexpr basic_string_view<char8_t>
874 operator""sv(const char8_t* __str, size_t __len) noexcept
875 { return basic_string_view<char8_t>{__str, __len}; }
876#endif
877
878 inline constexpr basic_string_view<char16_t>
879 operator""sv(const char16_t* __str, size_t __len) noexcept
880 { return basic_string_view<char16_t>{__str, __len}; }
881
882 inline constexpr basic_string_view<char32_t>
883 operator""sv(const char32_t* __str, size_t __len) noexcept
884 { return basic_string_view<char32_t>{__str, __len}; }
885
886#pragma GCC diagnostic pop
887 } // namespace string_literals
888 } // namespace literals
889
890#if __cpp_lib_concepts
891 namespace ranges
892 {
893 // Opt-in to borrowed_range concept
894 template<typename _CharT, typename _Traits>
895 inline constexpr bool
896 enable_borrowed_range<basic_string_view<_CharT, _Traits>> = true;
897
898 // Opt-in to view concept
899 template<typename _CharT, typename _Traits>
900 inline constexpr bool
901 enable_view<basic_string_view<_CharT, _Traits>> = true;
902 }
903#endif
904_GLIBCXX_END_NAMESPACE_VERSION
905} // namespace std
906
907#include <bits/string_view.tcc>
908
909#endif // __cplusplus <= 201402L
910
911#endif // _GLIBCXX_EXPERIMENTAL_STRING_VIEW
constexpr _Tp * to_address(_Tp *__ptr) noexcept
Obtain address referenced by a pointer to an object.
Definition: ptr_traits.h:250
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:233
ISO C++ entities toplevel namespace is std.
std::basic_ostream< _CharT, _Traits > & operator<<(std::basic_ostream< _CharT, _Traits > &__os, const bitset< _Nb > &__x)
Global I/O operators for bitsets.
Definition: std/bitset:1683
__numeric_traits_integer< _Tp > __int_traits
Convenience alias for __numeric_traits<integer-type>.
A non-owning reference to a string.
integral_constant
Definition: std/type_traits:63
[concept.same], concept same_as
Definition: concepts:63
[concept.convertible], concept convertible_to
Definition: concepts:72
[range.sized] The sized_range concept.
Definition: ranges_base.h:544
A range for which ranges::begin returns a contiguous iterator.
Definition: ranges_base.h:610