1 // Components for manipulating non-owning sequences of characters -*- C++ -*-
2 
3 // Copyright (C) 2013-2022 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>::
find(const _CharT * __str,size_type __pos,size_type __n) const48     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>::
find(_CharT __c,size_type __pos) const81     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>::
rfind(const _CharT * __str,size_type __pos,size_type __n) const97     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>::
rfind(_CharT __c,size_type __pos) const117     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>::
find_first_of(const _CharT * __str,size_type __pos,size_type __n) const134     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>::
find_last_of(const _CharT * __str,size_type __pos,size_type __n) const151     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>::
find_first_not_of(const _CharT * __str,size_type __pos,size_type __n) const173     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>::
find_first_not_of(_CharT __c,size_type __pos) const186     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>::
find_last_not_of(const _CharT * __str,size_type __pos,size_type __n) const197     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>::
find_last_not_of(_CharT __c,size_type __pos) const219     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
242