xref: /netbsd-src/external/gpl3/gcc.old/dist/libstdc++-v3/include/std/string_view (revision 82d56013d7b633d116a93943de88e08335357a7c)
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