1 // Components for manipulating sequences of characters -*- C++ -*-
3 // Copyright (C) 1997-2023 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file bits/basic_string.tcc
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{string}
31 // ISO C++ 14882: 21 Strings library
34 // Written by Jason Merrill based upon the specification by Takanori Adachi
35 // in ANSI X3J16/94-0013R2. Rewritten by Nathan Myers to ISO-14882.
36 // Non-reference-counted implementation written by Paolo Carlini and
37 // updated by Jonathan Wakely for ISO-14882-2011.
39 #ifndef _BASIC_STRING_TCC
40 #define _BASIC_STRING_TCC 1
42 #pragma GCC system_header
44 #include <bits/cxxabi_forced.h>
46 namespace std _GLIBCXX_VISIBILITY(default)
48 _GLIBCXX_BEGIN_NAMESPACE_VERSION
50 #if _GLIBCXX_USE_CXX11_ABI
52 template<typename _CharT, typename _Traits, typename _Alloc>
53 const typename basic_string<_CharT, _Traits, _Alloc>::size_type
54 basic_string<_CharT, _Traits, _Alloc>::npos;
56 template<typename _CharT, typename _Traits, typename _Alloc>
59 basic_string<_CharT, _Traits, _Alloc>::
60 swap(basic_string& __s) _GLIBCXX_NOEXCEPT
62 if (this == std::__addressof(__s))
65 _Alloc_traits::_S_on_swap(_M_get_allocator(), __s._M_get_allocator());
68 if (__s._M_is_local())
70 if (length() && __s.length())
72 _CharT __tmp_data[_S_local_capacity + 1];
73 traits_type::copy(__tmp_data, __s._M_local_buf,
75 traits_type::copy(__s._M_local_buf, _M_local_buf,
77 traits_type::copy(_M_local_buf, __tmp_data,
80 else if (__s.length())
83 traits_type::copy(_M_local_buf, __s._M_local_buf,
85 _M_length(__s.length());
91 __s._M_init_local_buf();
92 traits_type::copy(__s._M_local_buf, _M_local_buf,
94 __s._M_length(length());
101 const size_type __tmp_capacity = __s._M_allocated_capacity;
102 __s._M_init_local_buf();
103 traits_type::copy(__s._M_local_buf, _M_local_buf,
105 _M_data(__s._M_data());
106 __s._M_data(__s._M_local_buf);
107 _M_capacity(__tmp_capacity);
111 const size_type __tmp_capacity = _M_allocated_capacity;
112 if (__s._M_is_local())
115 traits_type::copy(_M_local_buf, __s._M_local_buf,
117 __s._M_data(_M_data());
118 _M_data(_M_local_buf);
122 pointer __tmp_ptr = _M_data();
123 _M_data(__s._M_data());
124 __s._M_data(__tmp_ptr);
125 _M_capacity(__s._M_allocated_capacity);
127 __s._M_capacity(__tmp_capacity);
130 const size_type __tmp_length = length();
131 _M_length(__s.length());
132 __s._M_length(__tmp_length);
135 template<typename _CharT, typename _Traits, typename _Alloc>
137 typename basic_string<_CharT, _Traits, _Alloc>::pointer
138 basic_string<_CharT, _Traits, _Alloc>::
139 _M_create(size_type& __capacity, size_type __old_capacity)
141 // _GLIBCXX_RESOLVE_LIB_DEFECTS
142 // 83. String::npos vs. string::max_size()
143 if (__capacity > max_size())
144 std::__throw_length_error(__N("basic_string::_M_create"));
146 // The below implements an exponential growth policy, necessary to
147 // meet amortized linear time requirements of the library: see
148 // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
149 if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
151 __capacity = 2 * __old_capacity;
152 // Never allocate a string bigger than max_size.
153 if (__capacity > max_size())
154 __capacity = max_size();
157 // NB: Need an array of char_type[__capacity], plus a terminating
158 // null char_type() element.
159 return _S_allocate(_M_get_allocator(), __capacity + 1);
162 // NB: This is the special case for Input Iterators, used in
163 // istreambuf_iterators, etc.
164 // Input Iterators have a cost structure very different from
165 // pointers, calling for a different coding style.
166 template<typename _CharT, typename _Traits, typename _Alloc>
167 template<typename _InIterator>
170 basic_string<_CharT, _Traits, _Alloc>::
171 _M_construct(_InIterator __beg, _InIterator __end,
172 std::input_iterator_tag)
175 size_type __capacity = size_type(_S_local_capacity);
179 while (__beg != __end && __len < __capacity)
181 _M_local_buf[__len++] = *__beg;
188 explicit _Guard(basic_string* __s) : _M_guarded(__s) { }
191 ~_Guard() { if (_M_guarded) _M_guarded->_M_dispose(); }
193 basic_string* _M_guarded;
196 while (__beg != __end)
198 if (__len == __capacity)
200 // Allocate more space.
201 __capacity = __len + 1;
202 pointer __another = _M_create(__capacity, __len);
203 this->_S_copy(__another, _M_data(), __len);
206 _M_capacity(__capacity);
208 traits_type::assign(_M_data()[__len++], *__beg);
212 __guard._M_guarded = 0;
214 _M_set_length(__len);
217 template<typename _CharT, typename _Traits, typename _Alloc>
218 template<typename _InIterator>
221 basic_string<_CharT, _Traits, _Alloc>::
222 _M_construct(_InIterator __beg, _InIterator __end,
223 std::forward_iterator_tag)
225 size_type __dnew = static_cast<size_type>(std::distance(__beg, __end));
227 if (__dnew > size_type(_S_local_capacity))
229 _M_data(_M_create(__dnew, size_type(0)));
235 // Check for out_of_range and length_error exceptions.
239 explicit _Guard(basic_string* __s) : _M_guarded(__s) { }
242 ~_Guard() { if (_M_guarded) _M_guarded->_M_dispose(); }
244 basic_string* _M_guarded;
247 this->_S_copy_chars(_M_data(), __beg, __end);
249 __guard._M_guarded = 0;
251 _M_set_length(__dnew);
254 template<typename _CharT, typename _Traits, typename _Alloc>
257 basic_string<_CharT, _Traits, _Alloc>::
258 _M_construct(size_type __n, _CharT __c)
260 if (__n > size_type(_S_local_capacity))
262 _M_data(_M_create(__n, size_type(0)));
269 this->_S_assign(_M_data(), __n, __c);
274 template<typename _CharT, typename _Traits, typename _Alloc>
277 basic_string<_CharT, _Traits, _Alloc>::
278 _M_assign(const basic_string& __str)
280 if (this != std::__addressof(__str))
282 const size_type __rsize = __str.length();
283 const size_type __capacity = capacity();
285 if (__rsize > __capacity)
287 size_type __new_capacity = __rsize;
288 pointer __tmp = _M_create(__new_capacity, __capacity);
291 _M_capacity(__new_capacity);
295 this->_S_copy(_M_data(), __str._M_data(), __rsize);
297 _M_set_length(__rsize);
301 template<typename _CharT, typename _Traits, typename _Alloc>
304 basic_string<_CharT, _Traits, _Alloc>::
305 reserve(size_type __res)
307 const size_type __capacity = capacity();
308 // _GLIBCXX_RESOLVE_LIB_DEFECTS
309 // 2968. Inconsistencies between basic_string reserve and
310 // vector/unordered_map/unordered_set reserve functions
311 // P0966 reserve should not shrink
312 if (__res <= __capacity)
315 pointer __tmp = _M_create(__res, __capacity);
316 this->_S_copy(__tmp, _M_data(), length() + 1);
322 template<typename _CharT, typename _Traits, typename _Alloc>
325 basic_string<_CharT, _Traits, _Alloc>::
326 _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
329 const size_type __how_much = length() - __pos - __len1;
331 size_type __new_capacity = length() + __len2 - __len1;
332 pointer __r = _M_create(__new_capacity, capacity());
335 this->_S_copy(__r, _M_data(), __pos);
337 this->_S_copy(__r + __pos, __s, __len2);
339 this->_S_copy(__r + __pos + __len2,
340 _M_data() + __pos + __len1, __how_much);
344 _M_capacity(__new_capacity);
347 template<typename _CharT, typename _Traits, typename _Alloc>
350 basic_string<_CharT, _Traits, _Alloc>::
351 _M_erase(size_type __pos, size_type __n)
353 const size_type __how_much = length() - __pos - __n;
355 if (__how_much && __n)
356 this->_S_move(_M_data() + __pos, _M_data() + __pos + __n, __how_much);
358 _M_set_length(length() - __n);
361 template<typename _CharT, typename _Traits, typename _Alloc>
364 basic_string<_CharT, _Traits, _Alloc>::
370 const size_type __length = length();
371 const size_type __capacity = _M_allocated_capacity;
373 if (__length <= size_type(_S_local_capacity))
376 this->_S_copy(_M_local_buf, _M_data(), __length + 1);
377 _M_destroy(__capacity);
378 _M_data(_M_local_data());
381 else if (__length < __capacity)
384 pointer __tmp = _S_allocate(_M_get_allocator(), __length + 1);
385 this->_S_copy(__tmp, _M_data(), __length + 1);
388 _M_capacity(__length);
390 catch (const __cxxabiv1::__forced_unwind&)
393 { /* swallow the exception */ }
397 template<typename _CharT, typename _Traits, typename _Alloc>
400 basic_string<_CharT, _Traits, _Alloc>::
401 resize(size_type __n, _CharT __c)
403 const size_type __size = this->size();
405 this->append(__n - __size, __c);
406 else if (__n < __size)
407 this->_M_set_length(__n);
410 template<typename _CharT, typename _Traits, typename _Alloc>
412 basic_string<_CharT, _Traits, _Alloc>&
413 basic_string<_CharT, _Traits, _Alloc>::
414 _M_append(const _CharT* __s, size_type __n)
416 const size_type __len = __n + this->size();
418 if (__len <= this->capacity())
421 this->_S_copy(this->_M_data() + this->size(), __s, __n);
424 this->_M_mutate(this->size(), size_type(0), __s, __n);
426 this->_M_set_length(__len);
430 template<typename _CharT, typename _Traits, typename _Alloc>
431 template<typename _InputIterator>
433 basic_string<_CharT, _Traits, _Alloc>&
434 basic_string<_CharT, _Traits, _Alloc>::
435 _M_replace_dispatch(const_iterator __i1, const_iterator __i2,
436 _InputIterator __k1, _InputIterator __k2,
439 // _GLIBCXX_RESOLVE_LIB_DEFECTS
440 // 2788. unintentionally require a default constructible allocator
441 const basic_string __s(__k1, __k2, this->get_allocator());
442 const size_type __n1 = __i2 - __i1;
443 return _M_replace(__i1 - begin(), __n1, __s._M_data(),
447 template<typename _CharT, typename _Traits, typename _Alloc>
449 basic_string<_CharT, _Traits, _Alloc>&
450 basic_string<_CharT, _Traits, _Alloc>::
451 _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
454 _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
456 const size_type __old_size = this->size();
457 const size_type __new_size = __old_size + __n2 - __n1;
459 if (__new_size <= this->capacity())
461 pointer __p = this->_M_data() + __pos1;
463 const size_type __how_much = __old_size - __pos1 - __n1;
464 if (__how_much && __n1 != __n2)
465 this->_S_move(__p + __n2, __p + __n1, __how_much);
468 this->_M_mutate(__pos1, __n1, 0, __n2);
471 this->_S_assign(this->_M_data() + __pos1, __n2, __c);
473 this->_M_set_length(__new_size);
477 template<typename _CharT, typename _Traits, typename _Alloc>
478 __attribute__((__noinline__, __noclone__, __cold__)) void
479 basic_string<_CharT, _Traits, _Alloc>::
480 _M_replace_cold(pointer __p, size_type __len1, const _CharT* __s,
481 const size_type __len2, const size_type __how_much)
484 if (__len2 && __len2 <= __len1)
485 this->_S_move(__p, __s, __len2);
486 if (__how_much && __len1 != __len2)
487 this->_S_move(__p + __len2, __p + __len1, __how_much);
490 if (__s + __len2 <= __p + __len1)
491 this->_S_move(__p, __s, __len2);
492 else if (__s >= __p + __len1)
494 // Hint to middle end that __p and __s overlap
496 const size_type __poff = (__s - __p) + (__len2 - __len1);
497 this->_S_copy(__p, __p + __poff, __len2);
501 const size_type __nleft = (__p + __len1) - __s;
502 this->_S_move(__p, __s, __nleft);
503 this->_S_copy(__p + __nleft, __p + __len2, __len2 - __nleft);
508 template<typename _CharT, typename _Traits, typename _Alloc>
510 basic_string<_CharT, _Traits, _Alloc>&
511 basic_string<_CharT, _Traits, _Alloc>::
512 _M_replace(size_type __pos, size_type __len1, const _CharT* __s,
513 const size_type __len2)
515 _M_check_length(__len1, __len2, "basic_string::_M_replace");
517 const size_type __old_size = this->size();
518 const size_type __new_size = __old_size + __len2 - __len1;
520 if (__new_size <= this->capacity())
522 pointer __p = this->_M_data() + __pos;
524 const size_type __how_much = __old_size - __pos - __len1;
525 #if __cpp_lib_is_constant_evaluated
526 if (std::is_constant_evaluated())
528 auto __newp = _S_allocate(_M_get_allocator(), __new_size);
529 _S_copy(__newp, this->_M_data(), __pos);
530 _S_copy(__newp + __pos, __s, __len2);
531 _S_copy(__newp + __pos + __len2, __p + __len1, __how_much);
532 _S_copy(this->_M_data(), __newp, __new_size);
533 this->_M_get_allocator().deallocate(__newp, __new_size);
537 if (__builtin_expect(_M_disjunct(__s), true))
539 if (__how_much && __len1 != __len2)
540 this->_S_move(__p + __len2, __p + __len1, __how_much);
542 this->_S_copy(__p, __s, __len2);
545 _M_replace_cold(__p, __len1, __s, __len2, __how_much);
548 this->_M_mutate(__pos, __len1, __s, __len2);
550 this->_M_set_length(__new_size);
554 template<typename _CharT, typename _Traits, typename _Alloc>
556 typename basic_string<_CharT, _Traits, _Alloc>::size_type
557 basic_string<_CharT, _Traits, _Alloc>::
558 copy(_CharT* __s, size_type __n, size_type __pos) const
560 _M_check(__pos, "basic_string::copy");
561 __n = _M_limit(__pos, __n);
562 __glibcxx_requires_string_len(__s, __n);
564 _S_copy(__s, _M_data() + __pos, __n);
565 // 21.3.5.7 par 3: do not append null. (good.)
569 #ifdef __glibcxx_string_resize_and_overwrite // C++ >= 23
570 template<typename _CharT, typename _Traits, typename _Alloc>
571 template<typename _Operation>
572 [[__gnu__::__always_inline__]]
574 basic_string<_CharT, _Traits, _Alloc>::
575 __resize_and_overwrite(const size_type __n, _Operation __op)
576 { resize_and_overwrite<_Operation&>(__n, __op); }
579 #if __cplusplus >= 201103L
580 template<typename _CharT, typename _Traits, typename _Alloc>
581 template<typename _Operation>
582 _GLIBCXX20_CONSTEXPR void
583 basic_string<_CharT, _Traits, _Alloc>::
584 #ifdef __glibcxx_string_resize_and_overwrite // C++ >= 23
585 resize_and_overwrite(const size_type __n, _Operation __op)
587 __resize_and_overwrite(const size_type __n, _Operation __op)
591 _CharT* const __p = _M_data();
592 #if __cpp_lib_is_constant_evaluated
593 if (std::__is_constant_evaluated() && __n > size())
594 traits_type::assign(__p + size(), __n - size(), _CharT());
597 _GLIBCXX20_CONSTEXPR ~_Terminator() { _M_this->_M_set_length(_M_r); }
598 basic_string* _M_this;
601 _Terminator __term{this, 0};
602 auto __r = std::move(__op)(__p + 0, __n + 0);
603 #ifdef __cpp_lib_concepts
604 static_assert(ranges::__detail::__is_integer_like<decltype(__r)>);
606 static_assert(__gnu_cxx::__is_integer_nonstrict<decltype(__r)>::__value,
607 "resize_and_overwrite operation must return an integer");
609 _GLIBCXX_DEBUG_ASSERT(__r >= 0 && __r <= __n);
610 __term._M_r = size_type(__r);
611 if (__term._M_r > __n)
612 __builtin_unreachable();
616 #endif // _GLIBCXX_USE_CXX11_ABI
618 #if __glibcxx_constexpr_string >= 201907L
619 # define _GLIBCXX_STRING_CONSTEXPR constexpr
621 # define _GLIBCXX_STRING_CONSTEXPR
623 template<typename _CharT, typename _Traits, typename _Alloc>
624 _GLIBCXX_STRING_CONSTEXPR
625 typename basic_string<_CharT, _Traits, _Alloc>::size_type
626 basic_string<_CharT, _Traits, _Alloc>::
627 find(const _CharT* __s, size_type __pos, size_type __n) const
630 __glibcxx_requires_string_len(__s, __n);
631 const size_type __size = this->size();
634 return __pos <= __size ? __pos : npos;
638 const _CharT __elem0 = __s[0];
639 const _CharT* const __data = data();
640 const _CharT* __first = __data + __pos;
641 const _CharT* const __last = __data + __size;
642 size_type __len = __size - __pos;
646 // Find the first occurrence of __elem0:
647 __first = traits_type::find(__first, __len - __n + 1, __elem0);
650 // Compare the full strings from the first occurrence of __elem0.
651 // We already know that __first[0] == __s[0] but compare them again
652 // anyway because __s is probably aligned, which helps memcmp.
653 if (traits_type::compare(__first, __s, __n) == 0)
654 return __first - __data;
655 __len = __last - ++__first;
660 template<typename _CharT, typename _Traits, typename _Alloc>
661 _GLIBCXX_STRING_CONSTEXPR
662 typename basic_string<_CharT, _Traits, _Alloc>::size_type
663 basic_string<_CharT, _Traits, _Alloc>::
664 find(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
666 size_type __ret = npos;
667 const size_type __size = this->size();
670 const _CharT* __data = _M_data();
671 const size_type __n = __size - __pos;
672 const _CharT* __p = traits_type::find(__data + __pos, __n, __c);
674 __ret = __p - __data;
679 template<typename _CharT, typename _Traits, typename _Alloc>
680 _GLIBCXX_STRING_CONSTEXPR
681 typename basic_string<_CharT, _Traits, _Alloc>::size_type
682 basic_string<_CharT, _Traits, _Alloc>::
683 rfind(const _CharT* __s, size_type __pos, size_type __n) const
686 __glibcxx_requires_string_len(__s, __n);
687 const size_type __size = this->size();
690 __pos = std::min(size_type(__size - __n), __pos);
691 const _CharT* __data = _M_data();
694 if (traits_type::compare(__data + __pos, __s, __n) == 0)
702 template<typename _CharT, typename _Traits, typename _Alloc>
703 _GLIBCXX_STRING_CONSTEXPR
704 typename basic_string<_CharT, _Traits, _Alloc>::size_type
705 basic_string<_CharT, _Traits, _Alloc>::
706 rfind(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
708 size_type __size = this->size();
711 if (--__size > __pos)
713 for (++__size; __size-- > 0; )
714 if (traits_type::eq(_M_data()[__size], __c))
720 template<typename _CharT, typename _Traits, typename _Alloc>
721 _GLIBCXX_STRING_CONSTEXPR
722 typename basic_string<_CharT, _Traits, _Alloc>::size_type
723 basic_string<_CharT, _Traits, _Alloc>::
724 find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
727 __glibcxx_requires_string_len(__s, __n);
728 for (; __n && __pos < this->size(); ++__pos)
730 const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]);
737 template<typename _CharT, typename _Traits, typename _Alloc>
738 _GLIBCXX_STRING_CONSTEXPR
739 typename basic_string<_CharT, _Traits, _Alloc>::size_type
740 basic_string<_CharT, _Traits, _Alloc>::
741 find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
744 __glibcxx_requires_string_len(__s, __n);
745 size_type __size = this->size();
748 if (--__size > __pos)
752 if (traits_type::find(__s, __n, _M_data()[__size]))
755 while (__size-- != 0);
760 template<typename _CharT, typename _Traits, typename _Alloc>
761 _GLIBCXX_STRING_CONSTEXPR
762 typename basic_string<_CharT, _Traits, _Alloc>::size_type
763 basic_string<_CharT, _Traits, _Alloc>::
764 find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
767 __glibcxx_requires_string_len(__s, __n);
768 for (; __pos < this->size(); ++__pos)
769 if (!traits_type::find(__s, __n, _M_data()[__pos]))
774 template<typename _CharT, typename _Traits, typename _Alloc>
775 _GLIBCXX_STRING_CONSTEXPR
776 typename basic_string<_CharT, _Traits, _Alloc>::size_type
777 basic_string<_CharT, _Traits, _Alloc>::
778 find_first_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
780 for (; __pos < this->size(); ++__pos)
781 if (!traits_type::eq(_M_data()[__pos], __c))
786 template<typename _CharT, typename _Traits, typename _Alloc>
787 _GLIBCXX_STRING_CONSTEXPR
788 typename basic_string<_CharT, _Traits, _Alloc>::size_type
789 basic_string<_CharT, _Traits, _Alloc>::
790 find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
793 __glibcxx_requires_string_len(__s, __n);
794 size_type __size = this->size();
797 if (--__size > __pos)
801 if (!traits_type::find(__s, __n, _M_data()[__size]))
809 template<typename _CharT, typename _Traits, typename _Alloc>
810 _GLIBCXX_STRING_CONSTEXPR
811 typename basic_string<_CharT, _Traits, _Alloc>::size_type
812 basic_string<_CharT, _Traits, _Alloc>::
813 find_last_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
815 size_type __size = this->size();
818 if (--__size > __pos)
822 if (!traits_type::eq(_M_data()[__size], __c))
830 #undef _GLIBCXX_STRING_CONSTEXPR
832 // 21.3.7.9 basic_string::getline and operators
833 template<typename _CharT, typename _Traits, typename _Alloc>
834 basic_istream<_CharT, _Traits>&
835 operator>>(basic_istream<_CharT, _Traits>& __in,
836 basic_string<_CharT, _Traits, _Alloc>& __str)
838 typedef basic_istream<_CharT, _Traits> __istream_type;
839 typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
840 typedef typename __istream_type::ios_base __ios_base;
841 typedef typename __istream_type::int_type __int_type;
842 typedef typename __string_type::size_type __size_type;
843 typedef ctype<_CharT> __ctype_type;
844 typedef typename __ctype_type::ctype_base __ctype_base;
846 __size_type __extracted = 0;
847 typename __ios_base::iostate __err = __ios_base::goodbit;
848 typename __istream_type::sentry __cerb(__in, false);
853 // Avoid reallocation for common case.
856 __size_type __len = 0;
857 const streamsize __w = __in.width();
858 const __size_type __n = __w > 0 ? static_cast<__size_type>(__w)
860 const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
861 const __int_type __eof = _Traits::eof();
862 __int_type __c = __in.rdbuf()->sgetc();
864 while (__extracted < __n
865 && !_Traits::eq_int_type(__c, __eof)
866 && !__ct.is(__ctype_base::space,
867 _Traits::to_char_type(__c)))
869 if (__len == sizeof(__buf) / sizeof(_CharT))
871 __str.append(__buf, sizeof(__buf) / sizeof(_CharT));
874 __buf[__len++] = _Traits::to_char_type(__c);
876 __c = __in.rdbuf()->snextc();
878 __str.append(__buf, __len);
880 if (__extracted < __n && _Traits::eq_int_type(__c, __eof))
881 __err |= __ios_base::eofbit;
884 __catch(__cxxabiv1::__forced_unwind&)
886 __in._M_setstate(__ios_base::badbit);
887 __throw_exception_again;
891 // _GLIBCXX_RESOLVE_LIB_DEFECTS
892 // 91. Description of operator>> and getline() for string<>
893 // might cause endless loop
894 __in._M_setstate(__ios_base::badbit);
897 // 211. operator>>(istream&, string&) doesn't set failbit
899 __err |= __ios_base::failbit;
901 __in.setstate(__err);
905 template<typename _CharT, typename _Traits, typename _Alloc>
906 basic_istream<_CharT, _Traits>&
907 getline(basic_istream<_CharT, _Traits>& __in,
908 basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim)
910 typedef basic_istream<_CharT, _Traits> __istream_type;
911 typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
912 typedef typename __istream_type::ios_base __ios_base;
913 typedef typename __istream_type::int_type __int_type;
914 typedef typename __string_type::size_type __size_type;
916 __size_type __extracted = 0;
917 const __size_type __n = __str.max_size();
918 typename __ios_base::iostate __err = __ios_base::goodbit;
919 typename __istream_type::sentry __cerb(__in, true);
925 const __int_type __idelim = _Traits::to_int_type(__delim);
926 const __int_type __eof = _Traits::eof();
927 __int_type __c = __in.rdbuf()->sgetc();
929 while (__extracted < __n
930 && !_Traits::eq_int_type(__c, __eof)
931 && !_Traits::eq_int_type(__c, __idelim))
933 __str += _Traits::to_char_type(__c);
935 __c = __in.rdbuf()->snextc();
938 if (_Traits::eq_int_type(__c, __eof))
939 __err |= __ios_base::eofbit;
940 else if (_Traits::eq_int_type(__c, __idelim))
943 __in.rdbuf()->sbumpc();
946 __err |= __ios_base::failbit;
948 __catch(__cxxabiv1::__forced_unwind&)
950 __in._M_setstate(__ios_base::badbit);
951 __throw_exception_again;
955 // _GLIBCXX_RESOLVE_LIB_DEFECTS
956 // 91. Description of operator>> and getline() for string<>
957 // might cause endless loop
958 __in._M_setstate(__ios_base::badbit);
962 __err |= __ios_base::failbit;
964 __in.setstate(__err);
968 // Inhibit implicit instantiations for required instantiations,
969 // which are defined via explicit instantiations elsewhere.
970 #if _GLIBCXX_EXTERN_TEMPLATE
971 // The explicit instantiation definitions in src/c++11/string-inst.cc and
972 // src/c++17/string-inst.cc only instantiate the members required for C++17
973 // and earlier standards (so not C++20's starts_with and ends_with).
974 // Suppress the explicit instantiation declarations for C++20, so C++20
975 // code will implicitly instantiate std::string and std::wstring as needed.
976 # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0
977 extern template class basic_string<char>;
978 # elif ! _GLIBCXX_USE_CXX11_ABI
979 // Still need to prevent implicit instantiation of the COW empty rep,
980 // to ensure the definition in libstdc++.so is unique (PR 86138).
981 extern template basic_string<char>::size_type
982 basic_string<char>::_Rep::_S_empty_rep_storage[];
983 # elif _GLIBCXX_EXTERN_TEMPLATE > 0
984 // Export _M_replace_cold even for C++20.
986 basic_string<char>::_M_replace_cold(char *, size_type, const char*,
987 const size_type, const size_type);
992 operator>>(basic_istream<char>&, string&);
995 operator<<(basic_ostream<char>&, const string&);
998 getline(basic_istream<char>&, string&, char);
1000 basic_istream<char>&
1001 getline(basic_istream<char>&, string&);
1003 #ifdef _GLIBCXX_USE_WCHAR_T
1004 # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0
1005 extern template class basic_string<wchar_t>;
1006 # elif ! _GLIBCXX_USE_CXX11_ABI
1007 extern template basic_string<wchar_t>::size_type
1008 basic_string<wchar_t>::_Rep::_S_empty_rep_storage[];
1009 # elif _GLIBCXX_EXTERN_TEMPLATE > 0
1010 // Export _M_replace_cold even for C++20.
1011 extern template void
1012 basic_string<wchar_t>::_M_replace_cold(wchar_t*, size_type, const wchar_t*,
1013 const size_type, const size_type);
1017 basic_istream<wchar_t>&
1018 operator>>(basic_istream<wchar_t>&, wstring&);
1020 basic_ostream<wchar_t>&
1021 operator<<(basic_ostream<wchar_t>&, const wstring&);
1023 basic_istream<wchar_t>&
1024 getline(basic_istream<wchar_t>&, wstring&, wchar_t);
1026 basic_istream<wchar_t>&
1027 getline(basic_istream<wchar_t>&, wstring&);
1028 #endif // _GLIBCXX_USE_WCHAR_T
1029 #endif // _GLIBCXX_EXTERN_TEMPLATE
1031 _GLIBCXX_END_NAMESPACE_VERSION