1// Components for manipulating non-owning sequences of characters -*- C++ -*-
2
3// Copyright (C) 2013-2019 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 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 <limits>
41#include <iosfwd>
42#include <bits/char_traits.h>
43#include <bits/functional_hash.h>
44#include <bits/range_access.h>
45
46namespace std _GLIBCXX_VISIBILITY(default)
47{
48_GLIBCXX_BEGIN_NAMESPACE_VERSION
49
50#define __cpp_lib_string_view 201603
51
52 // Helper for basic_string and basic_string_view members.
53 constexpr size_t
54 __sv_check(size_t __size, size_t __pos, const char* __s)
55 {
56 if (__pos > __size)
57 __throw_out_of_range_fmt(__N("%s: __pos (which is %zu) > __size "
58 "(which is %zu)"), __s, __pos, __size);
59 return __pos;
60 }
61
62 // Helper for basic_string members.
63 // NB: __sv_limit doesn't check for a bad __pos value.
64 constexpr size_t
65 __sv_limit(size_t __size, size_t __pos, size_t __off) noexcept
66 {
67 const bool __testoff = __off < __size - __pos;
68 return __testoff ? __off : __size - __pos;
69 }
70
71 /**
72 * @class basic_string_view <string_view>
73 * @brief A non-owning reference to a string.
74 *
75 * @ingroup strings
76 * @ingroup sequences
77 *
78 * @tparam _CharT Type of character
79 * @tparam _Traits Traits for character type, defaults to
80 * char_traits<_CharT>.
81 *
82 * A basic_string_view looks like this:
83 *
84 * @code
85 * _CharT* _M_str
86 * size_t _M_len
87 * @endcode
88 */
89 template<typename _CharT, typename _Traits = std::char_traits<_CharT>>
90 class basic_string_view
91 {
92 static_assert(!is_array_v<_CharT>);
93 static_assert(is_trivial_v<_CharT> && is_standard_layout_v<_CharT>);
94 static_assert(is_same_v<_CharT, typename _Traits::char_type>);
95
96 public:
97
98 // types
99 using traits_type = _Traits;
100 using value_type = _CharT;
101 using pointer = value_type*;
102 using const_pointer = const value_type*;
103 using reference = value_type&;
104 using const_reference = const value_type&;
105 using const_iterator = const value_type*;
106 using iterator = const_iterator;
107 using const_reverse_iterator = std::reverse_iterator<const_iterator>;
108 using reverse_iterator = const_reverse_iterator;
109 using size_type = size_t;
110 using difference_type = ptrdiff_t;
111 static constexpr size_type npos = size_type(-1);
112
113 // [string.view.cons], construction and assignment
114
115 constexpr
116 basic_string_view() noexcept
117 : _M_len{0}, _M_str{nullptr}
118 { }
119
120 constexpr basic_string_view(const basic_string_view&) noexcept = default;
121
122 __attribute__((__nonnull__)) constexpr
123 basic_string_view(const _CharT* __str) noexcept
124 : _M_len{traits_type::length(__str)},
125 _M_str{__str}
126 { }
127
128 constexpr
129 basic_string_view(const _CharT* __str, size_type __len) noexcept
130 : _M_len{__len}, _M_str{__str}
131 { }
132
133 constexpr basic_string_view&
134 operator=(const basic_string_view&) noexcept = default;
135
136 // [string.view.iterators], iterator support
137
138 constexpr const_iterator
139 begin() const noexcept
140 { return this->_M_str; }
141
142 constexpr const_iterator
143 end() const noexcept
144 { return this->_M_str + this->_M_len; }
145
146 constexpr const_iterator
147 cbegin() const noexcept
148 { return this->_M_str; }
149
150 constexpr const_iterator
151 cend() const noexcept
152 { return this->_M_str + this->_M_len; }
153
154 constexpr const_reverse_iterator
155 rbegin() const noexcept
156 { return const_reverse_iterator(this->end()); }
157
158 constexpr const_reverse_iterator
159 rend() const noexcept
160 { return const_reverse_iterator(this->begin()); }
161
162 constexpr const_reverse_iterator
163 crbegin() const noexcept
164 { return const_reverse_iterator(this->end()); }
165
166 constexpr const_reverse_iterator
167 crend() const noexcept
168 { return const_reverse_iterator(this->begin()); }
169
170 // [string.view.capacity], capacity
171
172 constexpr size_type
173 size() const noexcept
174 { return this->_M_len; }
175
176 constexpr size_type
177 length() const noexcept
178 { return _M_len; }
179
180 constexpr size_type
181 max_size() const noexcept
182 {
183 return (npos - sizeof(size_type) - sizeof(void*))
184 / sizeof(value_type) / 4;
185 }
186
187 [[nodiscard]] constexpr bool
188 empty() const noexcept
189 { return this->_M_len == 0; }
190
191 // [string.view.access], element access
192
193 constexpr const_reference
194 operator[](size_type __pos) const noexcept
195 {
196 // TODO: Assert to restore in a way compatible with the constexpr.
197 // __glibcxx_assert(__pos < this->_M_len);
198 return *(this->_M_str + __pos);
199 }
200
201 constexpr const_reference
202 at(size_type __pos) const
203 {
204 if (__pos >= _M_len)
205 __throw_out_of_range_fmt(__N("basic_string_view::at: __pos "
206 "(which is %zu) >= this->size() "
207 "(which is %zu)"), __pos, this->size());
208 return *(this->_M_str + __pos);
209 }
210
211 constexpr const_reference
212 front() const noexcept
213 {
214 // TODO: Assert to restore in a way compatible with the constexpr.
215 // __glibcxx_assert(this->_M_len > 0);
216 return *this->_M_str;
217 }
218
219 constexpr const_reference
220 back() const noexcept
221 {
222 // TODO: Assert to restore in a way compatible with the constexpr.
223 // __glibcxx_assert(this->_M_len > 0);
224 return *(this->_M_str + this->_M_len - 1);
225 }
226
227 constexpr const_pointer
228 data() const noexcept
229 { return this->_M_str; }
230
231 // [string.view.modifiers], modifiers:
232
233 constexpr void
234 remove_prefix(size_type __n) noexcept
235 {
236 __glibcxx_assert(this->_M_len >= __n);
237 this->_M_str += __n;
238 this->_M_len -= __n;
239 }
240
241 constexpr void
242 remove_suffix(size_type __n) noexcept
243 { this->_M_len -= __n; }
244
245 constexpr void
246 swap(basic_string_view& __sv) noexcept
247 {
248 auto __tmp = *this;
249 *this = __sv;
250 __sv = __tmp;
251 }
252
253 // [string.view.ops], string operations:
254
255 size_type
256 copy(_CharT* __str, size_type __n, size_type __pos = 0) const
257 {
258 __glibcxx_requires_string_len(__str, __n);
259 __pos = std::__sv_check(size(), __pos, "basic_string_view::copy");
260 const size_type __rlen = std::min(__n, _M_len - __pos);
261 // _GLIBCXX_RESOLVE_LIB_DEFECTS
262 // 2777. basic_string_view::copy should use char_traits::copy
263 traits_type::copy(__str, data() + __pos, __rlen);
264 return __rlen;
265 }
266
267 constexpr basic_string_view
268 substr(size_type __pos = 0, size_type __n = npos) const noexcept(false)
269 {
270 __pos = std::__sv_check(size(), __pos, "basic_string_view::substr");
271 const size_type __rlen = std::min(__n, _M_len - __pos);
272 return basic_string_view{_M_str + __pos, __rlen};
273 }
274
275 constexpr int
276 compare(basic_string_view __str) const noexcept
277 {
278 const size_type __rlen = std::min(this->_M_len, __str._M_len);
279 int __ret = traits_type::compare(this->_M_str, __str._M_str, __rlen);
280 if (__ret == 0)
281 __ret = _S_compare(this->_M_len, __str._M_len);
282 return __ret;
283 }
284
285 constexpr int
286 compare(size_type __pos1, size_type __n1, basic_string_view __str) const
287 { return this->substr(__pos1, __n1).compare(__str); }
288
289 constexpr int
290 compare(size_type __pos1, size_type __n1,
291 basic_string_view __str, size_type __pos2, size_type __n2) const
292 {
293 return this->substr(__pos1, __n1).compare(__str.substr(__pos2, __n2));
294 }
295
296 __attribute__((__nonnull__)) constexpr int
297 compare(const _CharT* __str) const noexcept
298 { return this->compare(basic_string_view{__str}); }
299
300 __attribute__((__nonnull__)) constexpr int
301 compare(size_type __pos1, size_type __n1, const _CharT* __str) const
302 { return this->substr(__pos1, __n1).compare(basic_string_view{__str}); }
303
304 constexpr int
305 compare(size_type __pos1, size_type __n1,
306 const _CharT* __str, size_type __n2) const noexcept(false)
307 {
308 return this->substr(__pos1, __n1)
309 .compare(basic_string_view(__str, __n2));
310 }
311
312#if __cplusplus > 201703L
313 constexpr bool
314 starts_with(basic_string_view __x) const noexcept
315 { return this->substr(0, __x.size()) == __x; }
316
317 constexpr bool
318 starts_with(_CharT __x) const noexcept
319 { return !this->empty() && traits_type::eq(this->front(), __x); }
320
321 constexpr bool
322 starts_with(const _CharT* __x) const noexcept
323 { return this->starts_with(basic_string_view(__x)); }
324
325 constexpr bool
326 ends_with(basic_string_view __x) const noexcept
327 {
328 return this->size() >= __x.size()
329 && this->compare(this->size() - __x.size(), npos, __x) == 0;
330 }
331
332 constexpr bool
333 ends_with(_CharT __x) const noexcept
334 { return !this->empty() && traits_type::eq(this->back(), __x); }
335
336 constexpr bool
337 ends_with(const _CharT* __x) const noexcept
338 { return this->ends_with(basic_string_view(__x)); }
339#endif // C++20
340
341 // [string.view.find], searching
342
343 constexpr size_type
344 find(basic_string_view __str, size_type __pos = 0) const noexcept
345 { return this->find(__str._M_str, __pos, __str._M_len); }
346
347 constexpr size_type
348 find(_CharT __c, size_type __pos = 0) const noexcept;
349
350 constexpr size_type
351 find(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
352
353 __attribute__((__nonnull__)) constexpr size_type
354 find(const _CharT* __str, size_type __pos = 0) const noexcept
355 { return this->find(__str, __pos, traits_type::length(__str)); }
356
357 constexpr size_type
358 rfind(basic_string_view __str, size_type __pos = npos) const noexcept
359 { return this->rfind(__str._M_str, __pos, __str._M_len); }
360
361 constexpr size_type
362 rfind(_CharT __c, size_type __pos = npos) const noexcept;
363
364 constexpr size_type
365 rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
366
367 __attribute__((__nonnull__)) constexpr size_type
368 rfind(const _CharT* __str, size_type __pos = npos) const noexcept
369 { return this->rfind(__str, __pos, traits_type::length(__str)); }
370
371 constexpr size_type
372 find_first_of(basic_string_view __str, size_type __pos = 0) const noexcept
373 { return this->find_first_of(__str._M_str, __pos, __str._M_len); }
374
375 constexpr size_type
376 find_first_of(_CharT __c, size_type __pos = 0) const noexcept
377 { return this->find(__c, __pos); }
378
379 constexpr size_type
380 find_first_of(const _CharT* __str, size_type __pos,
381 size_type __n) const noexcept;
382
383 __attribute__((__nonnull__)) constexpr size_type
384 find_first_of(const _CharT* __str, size_type __pos = 0) const noexcept
385 { return this->find_first_of(__str, __pos, traits_type::length(__str)); }
386
387 constexpr size_type
388 find_last_of(basic_string_view __str,
389 size_type __pos = npos) const noexcept
390 { return this->find_last_of(__str._M_str, __pos, __str._M_len); }
391
392 constexpr size_type
393 find_last_of(_CharT __c, size_type __pos=npos) const noexcept
394 { return this->rfind(__c, __pos); }
395
396 constexpr size_type
397 find_last_of(const _CharT* __str, size_type __pos,
398 size_type __n) const noexcept;
399
400 __attribute__((__nonnull__)) constexpr size_type
401 find_last_of(const _CharT* __str, size_type __pos = npos) const noexcept
402 { return this->find_last_of(__str, __pos, traits_type::length(__str)); }
403
404 constexpr size_type
405 find_first_not_of(basic_string_view __str,
406 size_type __pos = 0) const noexcept
407 { return this->find_first_not_of(__str._M_str, __pos, __str._M_len); }
408
409 constexpr size_type
410 find_first_not_of(_CharT __c, size_type __pos = 0) const noexcept;
411
412 constexpr size_type
413 find_first_not_of(const _CharT* __str,
414 size_type __pos, size_type __n) const noexcept;
415
416 __attribute__((__nonnull__)) constexpr size_type
417 find_first_not_of(const _CharT* __str, size_type __pos = 0) const noexcept
418 {
419 return this->find_first_not_of(__str, __pos,
420 traits_type::length(__str));
421 }
422
423 constexpr size_type
424 find_last_not_of(basic_string_view __str,
425 size_type __pos = npos) const noexcept
426 { return this->find_last_not_of(__str._M_str, __pos, __str._M_len); }
427
428 constexpr size_type
429 find_last_not_of(_CharT __c, size_type __pos = npos) const noexcept;
430
431 constexpr size_type
432 find_last_not_of(const _CharT* __str,
433 size_type __pos, size_type __n) const noexcept;
434
435 __attribute__((__nonnull__)) constexpr size_type
436 find_last_not_of(const _CharT* __str,
437 size_type __pos = npos) const noexcept
438 {
439 return this->find_last_not_of(__str, __pos,
440 traits_type::length(__str));
441 }
442
443 private:
444
445 static constexpr int
446 _S_compare(size_type __n1, size_type __n2) noexcept
447 {
448 const difference_type __diff = __n1 - __n2;
449 if (__diff > std::numeric_limits<int>::max())
450 return std::numeric_limits<int>::max();
451 if (__diff < std::numeric_limits<int>::min())
452 return std::numeric_limits<int>::min();
453 return static_cast<int>(__diff);
454 }
455
456 size_t _M_len;
457 const _CharT* _M_str;
458 };
459
460 // [string.view.comparison], non-member basic_string_view comparison function
461
462 namespace __detail
463 {
464 // Identity transform to create a non-deduced context, so that only one
465 // argument participates in template argument deduction and the other
466 // argument gets implicitly converted to the deduced type. See n3766.html.
467 template<typename _Tp>
468 using __idt = common_type_t<_Tp>;
469 }
470
471 template<typename _CharT, typename _Traits>
472 constexpr bool
473 operator==(basic_string_view<_CharT, _Traits> __x,
474 basic_string_view<_CharT, _Traits> __y) noexcept
475 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
476
477 template<typename _CharT, typename _Traits>
478 constexpr bool
479 operator==(basic_string_view<_CharT, _Traits> __x,
480 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
481 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
482
483 template<typename _CharT, typename _Traits>
484 constexpr bool
485 operator==(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
486 basic_string_view<_CharT, _Traits> __y) noexcept
487 { return __x.size() == __y.size() && __x.compare(__y) == 0; }
488
489 template<typename _CharT, typename _Traits>
490 constexpr bool
491 operator!=(basic_string_view<_CharT, _Traits> __x,
492 basic_string_view<_CharT, _Traits> __y) noexcept
493 { return !(__x == __y); }
494
495 template<typename _CharT, typename _Traits>
496 constexpr bool
497 operator!=(basic_string_view<_CharT, _Traits> __x,
498 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
499 { return !(__x == __y); }
500
501 template<typename _CharT, typename _Traits>
502 constexpr bool
503 operator!=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
504 basic_string_view<_CharT, _Traits> __y) noexcept
505 { return !(__x == __y); }
506
507 template<typename _CharT, typename _Traits>
508 constexpr bool
509 operator< (basic_string_view<_CharT, _Traits> __x,
510 basic_string_view<_CharT, _Traits> __y) noexcept
511 { return __x.compare(__y) < 0; }
512
513 template<typename _CharT, typename _Traits>
514 constexpr bool
515 operator< (basic_string_view<_CharT, _Traits> __x,
516 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
517 { return __x.compare(__y) < 0; }
518
519 template<typename _CharT, typename _Traits>
520 constexpr bool
521 operator< (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
522 basic_string_view<_CharT, _Traits> __y) noexcept
523 { return __x.compare(__y) < 0; }
524
525 template<typename _CharT, typename _Traits>
526 constexpr bool
527 operator> (basic_string_view<_CharT, _Traits> __x,
528 basic_string_view<_CharT, _Traits> __y) noexcept
529 { return __x.compare(__y) > 0; }
530
531 template<typename _CharT, typename _Traits>
532 constexpr bool
533 operator> (basic_string_view<_CharT, _Traits> __x,
534 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
535 { return __x.compare(__y) > 0; }
536
537 template<typename _CharT, typename _Traits>
538 constexpr bool
539 operator> (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
540 basic_string_view<_CharT, _Traits> __y) noexcept
541 { return __x.compare(__y) > 0; }
542
543 template<typename _CharT, typename _Traits>
544 constexpr bool
545 operator<=(basic_string_view<_CharT, _Traits> __x,
546 basic_string_view<_CharT, _Traits> __y) noexcept
547 { return __x.compare(__y) <= 0; }
548
549 template<typename _CharT, typename _Traits>
550 constexpr bool
551 operator<=(basic_string_view<_CharT, _Traits> __x,
552 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
553 { return __x.compare(__y) <= 0; }
554
555 template<typename _CharT, typename _Traits>
556 constexpr bool
557 operator<=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
558 basic_string_view<_CharT, _Traits> __y) noexcept
559 { return __x.compare(__y) <= 0; }
560
561 template<typename _CharT, typename _Traits>
562 constexpr bool
563 operator>=(basic_string_view<_CharT, _Traits> __x,
564 basic_string_view<_CharT, _Traits> __y) noexcept
565 { return __x.compare(__y) >= 0; }
566
567 template<typename _CharT, typename _Traits>
568 constexpr bool
569 operator>=(basic_string_view<_CharT, _Traits> __x,
570 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
571 { return __x.compare(__y) >= 0; }
572
573 template<typename _CharT, typename _Traits>
574 constexpr bool
575 operator>=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
576 basic_string_view<_CharT, _Traits> __y) noexcept
577 { return __x.compare(__y) >= 0; }
578
579 // [string.view.io], Inserters and extractors
580 template<typename _CharT, typename _Traits>
581 inline basic_ostream<_CharT, _Traits>&
582 operator<<(basic_ostream<_CharT, _Traits>& __os,
583 basic_string_view<_CharT,_Traits> __str)
584 { return __ostream_insert(__os, __str.data(), __str.size()); }
585
586
587 // basic_string_view typedef names
588
589 using string_view = basic_string_view<char>;
590#ifdef _GLIBCXX_USE_WCHAR_T
591 using wstring_view = basic_string_view<wchar_t>;
592#endif
593#ifdef _GLIBCXX_USE_CHAR8_T
594 using u8string_view = basic_string_view<char8_t>;
595#endif
596 using u16string_view = basic_string_view<char16_t>;
597 using u32string_view = basic_string_view<char32_t>;
598
599 // [string.view.hash], hash support:
600
601 template<typename _Tp>
602 struct hash;
603
604 template<>
605 struct hash<string_view>
606 : public __hash_base<size_t, string_view>
607 {
608 size_t
609 operator()(const string_view& __str) const noexcept
610 { return std::_Hash_impl::hash(__str.data(), __str.length()); }
611 };
612
613 template<>
614 struct __is_fast_hash<hash<string_view>> : std::false_type
615 { };
616
617#ifdef _GLIBCXX_USE_WCHAR_T
618 template<>
619 struct hash<wstring_view>
620 : public __hash_base<size_t, wstring_view>
621 {
622 size_t
623 operator()(const wstring_view& __s) const noexcept
624 { return std::_Hash_impl::hash(__s.data(),
625 __s.length() * sizeof(wchar_t)); }
626 };
627
628 template<>
629 struct __is_fast_hash<hash<wstring_view>> : std::false_type
630 { };
631#endif
632
633#ifdef _GLIBCXX_USE_CHAR8_T
634 template<>
635 struct hash<u8string_view>
636 : public __hash_base<size_t, u8string_view>
637 {
638 size_t
639 operator()(const u8string_view& __str) const noexcept
640 { return std::_Hash_impl::hash(__str.data(), __str.length()); }
641 };
642
643 template<>
644 struct __is_fast_hash<hash<u8string_view>> : std::false_type
645 { };
646#endif
647
648 template<>
649 struct hash<u16string_view>
650 : public __hash_base<size_t, u16string_view>
651 {
652 size_t
653 operator()(const u16string_view& __s) const noexcept
654 { return std::_Hash_impl::hash(__s.data(),
655 __s.length() * sizeof(char16_t)); }
656 };
657
658 template<>
659 struct __is_fast_hash<hash<u16string_view>> : std::false_type
660 { };
661
662 template<>
663 struct hash<u32string_view>
664 : public __hash_base<size_t, u32string_view>
665 {
666 size_t
667 operator()(const u32string_view& __s) const noexcept
668 { return std::_Hash_impl::hash(__s.data(),
669 __s.length() * sizeof(char32_t)); }
670 };
671
672 template<>
673 struct __is_fast_hash<hash<u32string_view>> : std::false_type
674 { };
675
676 inline namespace literals
677 {
678 inline namespace string_view_literals
679 {
680#pragma GCC diagnostic push
681#pragma GCC diagnostic ignored "-Wliteral-suffix"
682 inline constexpr basic_string_view<char>
683 operator""sv(const char* __str, size_t __len) noexcept
684 { return basic_string_view<char>{__str, __len}; }
685
686#ifdef _GLIBCXX_USE_WCHAR_T
687 inline constexpr basic_string_view<wchar_t>
688 operator""sv(const wchar_t* __str, size_t __len) noexcept
689 { return basic_string_view<wchar_t>{__str, __len}; }
690#endif
691
692#ifdef _GLIBCXX_USE_CHAR8_T
693 inline constexpr basic_string_view<char8_t>
694 operator""sv(const char8_t* __str, size_t __len) noexcept
695 { return basic_string_view<char8_t>{__str, __len}; }
696#endif
697
698 inline constexpr basic_string_view<char16_t>
699 operator""sv(const char16_t* __str, size_t __len) noexcept
700 { return basic_string_view<char16_t>{__str, __len}; }
701
702 inline constexpr basic_string_view<char32_t>
703 operator""sv(const char32_t* __str, size_t __len) noexcept
704 { return basic_string_view<char32_t>{__str, __len}; }
705
706#pragma GCC diagnostic pop
707 } // namespace string_literals
708 } // namespace literals
709
710_GLIBCXX_END_NAMESPACE_VERSION
711} // namespace std
712
713#include <bits/string_view.tcc>
714
715#endif // __cplusplus <= 201402L
716
717#endif // _GLIBCXX_EXPERIMENTAL_STRING_VIEW
718