libstdc++
bits/string_view.tcc
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1 // Components for manipulating non-owning sequences of characters -*- C++ -*-
2 
3 // Copyright (C) 2013-2025 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/bits/string_view.tcc
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly. @headername{string_view}
28  */
29 
30 //
31 // N3762 basic_string_view library
32 //
33 
34 #ifndef _GLIBCXX_STRING_VIEW_TCC
35 #define _GLIBCXX_STRING_VIEW_TCC 1
36 
37 #ifdef _GLIBCXX_SYSHDR
38 #pragma GCC system_header
39 #endif
40 
41 #if __cplusplus >= 201703L
42 
43 namespace std _GLIBCXX_VISIBILITY(default)
44 {
45 _GLIBCXX_BEGIN_NAMESPACE_VERSION
46 
47  template<typename _CharT, typename _Traits>
48  constexpr typename basic_string_view<_CharT, _Traits>::size_type
49  basic_string_view<_CharT, _Traits>::
50  find(const _CharT* __str, size_type __pos, size_type __n) const noexcept
51  {
52  __glibcxx_requires_string_len(__str, __n);
53 
54  if (__n == 0)
55  return __pos <= _M_len ? __pos : npos;
56  if (__pos >= _M_len)
57  return npos;
58 
59  const _CharT __elem0 = __str[0];
60  const _CharT* __first = _M_str + __pos;
61  const _CharT* const __last = _M_str + _M_len;
62  size_type __len = _M_len - __pos;
63 
64  while (__len >= __n)
65  {
66  // Find the first occurrence of __elem0:
67  __first = traits_type::find(__first, __len - __n + 1, __elem0);
68  if (!__first)
69  return npos;
70  // Compare the full strings from the first occurrence of __elem0.
71  // We already know that __first[0] == __s[0] but compare them again
72  // anyway because __s is probably aligned, which helps memcmp.
73  if (traits_type::compare(__first, __str, __n) == 0)
74  return __first - _M_str;
75  __len = __last - ++__first;
76  }
77  return npos;
78  }
79 
80  template<typename _CharT, typename _Traits>
81  constexpr typename basic_string_view<_CharT, _Traits>::size_type
82  basic_string_view<_CharT, _Traits>::
83  find(_CharT __c, size_type __pos) const noexcept
84  {
85  size_type __ret = npos;
86  if (__pos < this->_M_len)
87  {
88  const size_type __n = this->_M_len - __pos;
89  const _CharT* __p = traits_type::find(this->_M_str + __pos, __n, __c);
90  if (__p)
91  __ret = __p - this->_M_str;
92  }
93  return __ret;
94  }
95 
96  template<typename _CharT, typename _Traits>
97  constexpr typename basic_string_view<_CharT, _Traits>::size_type
98  basic_string_view<_CharT, _Traits>::
99  rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept
100  {
101  __glibcxx_requires_string_len(__str, __n);
102 
103  if (__n <= this->_M_len)
104  {
105  __pos = std::min(size_type(this->_M_len - __n), __pos);
106  do
107  {
108  if (traits_type::compare(this->_M_str + __pos, __str, __n) == 0)
109  return __pos;
110  }
111  while (__pos-- > 0);
112  }
113  return npos;
114  }
115 
116  template<typename _CharT, typename _Traits>
117  constexpr typename basic_string_view<_CharT, _Traits>::size_type
118  basic_string_view<_CharT, _Traits>::
119  rfind(_CharT __c, size_type __pos) const noexcept
120  {
121  size_type __size = this->_M_len;
122  if (__size > 0)
123  {
124  if (--__size > __pos)
125  __size = __pos;
126  for (++__size; __size-- > 0; )
127  if (traits_type::eq(this->_M_str[__size], __c))
128  return __size;
129  }
130  return npos;
131  }
132 
133  template<typename _CharT, typename _Traits>
134  constexpr typename basic_string_view<_CharT, _Traits>::size_type
135  basic_string_view<_CharT, _Traits>::
136  find_first_of(const _CharT* __str, size_type __pos,
137  size_type __n) const noexcept
138  {
139  __glibcxx_requires_string_len(__str, __n);
140  for (; __n && __pos < this->_M_len; ++__pos)
141  {
142  const _CharT* __p = traits_type::find(__str, __n,
143  this->_M_str[__pos]);
144  if (__p)
145  return __pos;
146  }
147  return npos;
148  }
149 
150  template<typename _CharT, typename _Traits>
151  constexpr typename basic_string_view<_CharT, _Traits>::size_type
152  basic_string_view<_CharT, _Traits>::
153  find_last_of(const _CharT* __str, size_type __pos,
154  size_type __n) const noexcept
155  {
156  __glibcxx_requires_string_len(__str, __n);
157  size_type __size = this->size();
158  if (__size && __n)
159  {
160  if (--__size > __pos)
161  __size = __pos;
162  do
163  {
164  if (traits_type::find(__str, __n, this->_M_str[__size]))
165  return __size;
166  }
167  while (__size-- != 0);
168  }
169  return npos;
170  }
171 
172  template<typename _CharT, typename _Traits>
173  constexpr typename basic_string_view<_CharT, _Traits>::size_type
174  basic_string_view<_CharT, _Traits>::
175  find_first_not_of(const _CharT* __str, size_type __pos,
176  size_type __n) const noexcept
177  {
178  __glibcxx_requires_string_len(__str, __n);
179  for (; __pos < this->_M_len; ++__pos)
180  if (!traits_type::find(__str, __n, this->_M_str[__pos]))
181  return __pos;
182  return npos;
183  }
184 
185  template<typename _CharT, typename _Traits>
186  constexpr typename basic_string_view<_CharT, _Traits>::size_type
187  basic_string_view<_CharT, _Traits>::
188  find_first_not_of(_CharT __c, size_type __pos) const noexcept
189  {
190  for (; __pos < this->_M_len; ++__pos)
191  if (!traits_type::eq(this->_M_str[__pos], __c))
192  return __pos;
193  return npos;
194  }
195 
196  template<typename _CharT, typename _Traits>
197  constexpr typename basic_string_view<_CharT, _Traits>::size_type
198  basic_string_view<_CharT, _Traits>::
199  find_last_not_of(const _CharT* __str, size_type __pos,
200  size_type __n) const noexcept
201  {
202  __glibcxx_requires_string_len(__str, __n);
203  size_type __size = this->_M_len;
204  if (__size)
205  {
206  if (--__size > __pos)
207  __size = __pos;
208  do
209  {
210  if (!traits_type::find(__str, __n, this->_M_str[__size]))
211  return __size;
212  }
213  while (__size--);
214  }
215  return npos;
216  }
217 
218  template<typename _CharT, typename _Traits>
219  constexpr typename basic_string_view<_CharT, _Traits>::size_type
220  basic_string_view<_CharT, _Traits>::
221  find_last_not_of(_CharT __c, size_type __pos) const noexcept
222  {
223  size_type __size = this->_M_len;
224  if (__size)
225  {
226  if (--__size > __pos)
227  __size = __pos;
228  do
229  {
230  if (!traits_type::eq(this->_M_str[__size], __c))
231  return __size;
232  }
233  while (__size--);
234  }
235  return npos;
236  }
237 
238 _GLIBCXX_END_NAMESPACE_VERSION
239 } // namespace std
240 
241 #endif // __cplusplus <= 201402L
242 
243 #endif // _GLIBCXX_STRING_VIEW_TCC
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:234
ISO C++ entities toplevel namespace is std.
constexpr auto size(const _Container &__cont) noexcept(noexcept(__cont.size())) -> decltype(__cont.size())
Return the size of a container.
Definition: range_access.h:274