libstdc++
bits/string_view.tcc
Go to the documentation of this file.
1 // Components for manipulating non-owning sequences of characters -*- C++ -*-
2 
3 // Copyright (C) 2013-2021 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 #pragma GCC system_header
38 
39 #if __cplusplus >= 201703L
40 
41 namespace std _GLIBCXX_VISIBILITY(default)
42 {
43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
44 
45  template<typename _CharT, typename _Traits>
46  constexpr typename basic_string_view<_CharT, _Traits>::size_type
47  basic_string_view<_CharT, _Traits>::
48  find(const _CharT* __str, size_type __pos, size_type __n) const noexcept
49  {
50  __glibcxx_requires_string_len(__str, __n);
51 
52  if (__n == 0)
53  return __pos <= _M_len ? __pos : npos;
54  if (__pos >= _M_len)
55  return npos;
56 
57  const _CharT __elem0 = __str[0];
58  const _CharT* __first = _M_str + __pos;
59  const _CharT* const __last = _M_str + _M_len;
60  size_type __len = _M_len - __pos;
61 
62  while (__len >= __n)
63  {
64  // Find the first occurrence of __elem0:
65  __first = traits_type::find(__first, __len - __n + 1, __elem0);
66  if (!__first)
67  return npos;
68  // Compare the full strings from the first occurrence of __elem0.
69  // We already know that __first[0] == __s[0] but compare them again
70  // anyway because __s is probably aligned, which helps memcmp.
71  if (traits_type::compare(__first, __str, __n) == 0)
72  return __first - _M_str;
73  __len = __last - ++__first;
74  }
75  return npos;
76  }
77 
78  template<typename _CharT, typename _Traits>
79  constexpr typename basic_string_view<_CharT, _Traits>::size_type
80  basic_string_view<_CharT, _Traits>::
81  find(_CharT __c, size_type __pos) const noexcept
82  {
83  size_type __ret = npos;
84  if (__pos < this->_M_len)
85  {
86  const size_type __n = this->_M_len - __pos;
87  const _CharT* __p = traits_type::find(this->_M_str + __pos, __n, __c);
88  if (__p)
89  __ret = __p - this->_M_str;
90  }
91  return __ret;
92  }
93 
94  template<typename _CharT, typename _Traits>
95  constexpr typename basic_string_view<_CharT, _Traits>::size_type
96  basic_string_view<_CharT, _Traits>::
97  rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept
98  {
99  __glibcxx_requires_string_len(__str, __n);
100 
101  if (__n <= this->_M_len)
102  {
103  __pos = std::min(size_type(this->_M_len - __n), __pos);
104  do
105  {
106  if (traits_type::compare(this->_M_str + __pos, __str, __n) == 0)
107  return __pos;
108  }
109  while (__pos-- > 0);
110  }
111  return npos;
112  }
113 
114  template<typename _CharT, typename _Traits>
115  constexpr typename basic_string_view<_CharT, _Traits>::size_type
116  basic_string_view<_CharT, _Traits>::
117  rfind(_CharT __c, size_type __pos) const noexcept
118  {
119  size_type __size = this->_M_len;
120  if (__size > 0)
121  {
122  if (--__size > __pos)
123  __size = __pos;
124  for (++__size; __size-- > 0; )
125  if (traits_type::eq(this->_M_str[__size], __c))
126  return __size;
127  }
128  return npos;
129  }
130 
131  template<typename _CharT, typename _Traits>
132  constexpr typename basic_string_view<_CharT, _Traits>::size_type
133  basic_string_view<_CharT, _Traits>::
134  find_first_of(const _CharT* __str, size_type __pos,
135  size_type __n) const noexcept
136  {
137  __glibcxx_requires_string_len(__str, __n);
138  for (; __n && __pos < this->_M_len; ++__pos)
139  {
140  const _CharT* __p = traits_type::find(__str, __n,
141  this->_M_str[__pos]);
142  if (__p)
143  return __pos;
144  }
145  return npos;
146  }
147 
148  template<typename _CharT, typename _Traits>
149  constexpr typename basic_string_view<_CharT, _Traits>::size_type
150  basic_string_view<_CharT, _Traits>::
151  find_last_of(const _CharT* __str, size_type __pos,
152  size_type __n) const noexcept
153  {
154  __glibcxx_requires_string_len(__str, __n);
155  size_type __size = this->size();
156  if (__size && __n)
157  {
158  if (--__size > __pos)
159  __size = __pos;
160  do
161  {
162  if (traits_type::find(__str, __n, this->_M_str[__size]))
163  return __size;
164  }
165  while (__size-- != 0);
166  }
167  return npos;
168  }
169 
170  template<typename _CharT, typename _Traits>
171  constexpr typename basic_string_view<_CharT, _Traits>::size_type
172  basic_string_view<_CharT, _Traits>::
173  find_first_not_of(const _CharT* __str, size_type __pos,
174  size_type __n) const noexcept
175  {
176  __glibcxx_requires_string_len(__str, __n);
177  for (; __pos < this->_M_len; ++__pos)
178  if (!traits_type::find(__str, __n, this->_M_str[__pos]))
179  return __pos;
180  return npos;
181  }
182 
183  template<typename _CharT, typename _Traits>
184  constexpr typename basic_string_view<_CharT, _Traits>::size_type
185  basic_string_view<_CharT, _Traits>::
186  find_first_not_of(_CharT __c, size_type __pos) const noexcept
187  {
188  for (; __pos < this->_M_len; ++__pos)
189  if (!traits_type::eq(this->_M_str[__pos], __c))
190  return __pos;
191  return npos;
192  }
193 
194  template<typename _CharT, typename _Traits>
195  constexpr typename basic_string_view<_CharT, _Traits>::size_type
196  basic_string_view<_CharT, _Traits>::
197  find_last_not_of(const _CharT* __str, size_type __pos,
198  size_type __n) const noexcept
199  {
200  __glibcxx_requires_string_len(__str, __n);
201  size_type __size = this->_M_len;
202  if (__size)
203  {
204  if (--__size > __pos)
205  __size = __pos;
206  do
207  {
208  if (!traits_type::find(__str, __n, this->_M_str[__size]))
209  return __size;
210  }
211  while (__size--);
212  }
213  return npos;
214  }
215 
216  template<typename _CharT, typename _Traits>
217  constexpr typename basic_string_view<_CharT, _Traits>::size_type
218  basic_string_view<_CharT, _Traits>::
219  find_last_not_of(_CharT __c, size_type __pos) const noexcept
220  {
221  size_type __size = this->_M_len;
222  if (__size)
223  {
224  if (--__size > __pos)
225  __size = __pos;
226  do
227  {
228  if (!traits_type::eq(this->_M_str[__size], __c))
229  return __size;
230  }
231  while (__size--);
232  }
233  return npos;
234  }
235 
236 _GLIBCXX_END_NAMESPACE_VERSION
237 } // namespace std
238 
239 #endif // __cplusplus <= 201402L
240 
241 #endif // _GLIBCXX_STRING_VIEW_TCC
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:230
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:245