libstdc++: string_view.tcc Source File

libstdc++

bits/string_view.tcc
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1// Components for manipulating non-owning sequences of characters -*- C++ -*-
2
3// Copyright (C) 2013-2026 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
43namespace 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
std::min
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition stl_algobase.h:232
std
ISO C++ entities toplevel namespace is std.
std::size
constexpr auto size(const _Container &__cont) noexcept(noexcept(__cont.size())) -> decltype(__cont.size())
Return the size of a container.
Definition range_access.h:292
std::basic_string_view
A non-owning reference to a string.
Definition string_view:113
std::size_type