1 // Versatile string utility -*- C++ -*-
2
3 // Copyright (C) 2005-2023 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 ext/vstring_util.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{ext/vstring.h}
28 */
29
30 #ifndef _VSTRING_UTIL_H
31 #define _VSTRING_UTIL_H 1
32
33 #pragma GCC system_header
34
35 #include <bits/requires_hosted.h> // GNU extensions are currently omitted
36
37 #include <ext/vstring_fwd.h>
38 #include <debug/debug.h>
39 #include <bits/stl_function.h> // For less
40 #include <bits/functexcept.h>
41 #include <bits/localefwd.h>
42 #include <bits/ostream_insert.h>
43 #include <bits/stl_iterator.h>
44 #include <ext/numeric_traits.h>
45 #include <ext/alloc_traits.h>
46 #include <bits/move.h>
47 #include <bits/range_access.h>
48
49 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
50 {
51 _GLIBCXX_BEGIN_NAMESPACE_VERSION
52
53 template<typename _CharT, typename _Traits, typename _Alloc>
54 struct __vstring_utility
55 {
56 typedef typename __alloc_traits<_Alloc>::template rebind<_CharT>::other
57 _CharT_alloc_type;
58 typedef __alloc_traits<_CharT_alloc_type> _CharT_alloc_traits;
59
60 typedef _Traits traits_type;
61 typedef typename _Traits::char_type value_type;
62 typedef typename _CharT_alloc_type::size_type size_type;
63 typedef typename _CharT_alloc_type::difference_type difference_type;
64 typedef typename _CharT_alloc_traits::pointer pointer;
65 typedef typename _CharT_alloc_traits::const_pointer const_pointer;
66
67 // For __sso_string.
68 typedef __gnu_cxx::
69 __normal_iterator<pointer, __gnu_cxx::
70 __versa_string<_CharT, _Traits, _Alloc,
71 __sso_string_base> >
72 __sso_iterator;
73 typedef __gnu_cxx::
74 __normal_iterator<const_pointer, __gnu_cxx::
75 __versa_string<_CharT, _Traits, _Alloc,
76 __sso_string_base> >
77 __const_sso_iterator;
78
79 // For __rc_string.
80 typedef __gnu_cxx::
81 __normal_iterator<pointer, __gnu_cxx::
82 __versa_string<_CharT, _Traits, _Alloc,
83 __rc_string_base> >
84 __rc_iterator;
85 typedef __gnu_cxx::
86 __normal_iterator<const_pointer, __gnu_cxx::
87 __versa_string<_CharT, _Traits, _Alloc,
88 __rc_string_base> >
89 __const_rc_iterator;
90
91 // NB: When the allocator is empty, deriving from it saves space
92 // (http://www.cantrip.org/emptyopt.html).
93 template<typename _Alloc1>
94 struct _Alloc_hider
95 : public _Alloc1
96 {
97 _Alloc_hider(_CharT* __ptr)
98 : _Alloc1(), _M_p(__ptr) { }
99
100 _Alloc_hider(const _Alloc1& __a, _CharT* __ptr)
101 : _Alloc1(__a), _M_p(__ptr) { }
102
103 _CharT* _M_p; // The actual data.
104 };
105
106 // When __n = 1 way faster than the general multichar
107 // traits_type::copy/move/assign.
108 static void
109 _S_copy(_CharT* __d, const _CharT* __s, size_type __n)
110 {
111 if (__n == 1)
112 traits_type::assign(*__d, *__s);
113 else
114 traits_type::copy(__d, __s, __n);
115 }
116
117 static void
118 _S_move(_CharT* __d, const _CharT* __s, size_type __n)
119 {
120 if (__n == 1)
121 traits_type::assign(*__d, *__s);
122 else
123 traits_type::move(__d, __s, __n);
124 }
125
126 static void
127 _S_assign(_CharT* __d, size_type __n, _CharT __c)
128 {
129 if (__n == 1)
130 traits_type::assign(*__d, __c);
131 else
132 traits_type::assign(__d, __n, __c);
133 }
134
135 // _S_copy_chars is a separate template to permit specialization
136 // to optimize for the common case of pointers as iterators.
137 template<typename _Iterator>
138 static void
139 _S_copy_chars(_CharT* __p, _Iterator __k1, _Iterator __k2)
140 {
141 for (; __k1 != __k2; ++__k1, ++__p)
142 traits_type::assign(*__p, *__k1); // These types are off.
143 }
144
145 static void
146 _S_copy_chars(_CharT* __p, __sso_iterator __k1, __sso_iterator __k2)
147 { _S_copy_chars(__p, __k1.base(), __k2.base()); }
148
149 static void
150 _S_copy_chars(_CharT* __p, __const_sso_iterator __k1,
151 __const_sso_iterator __k2)
152 { _S_copy_chars(__p, __k1.base(), __k2.base()); }
153
154 static void
155 _S_copy_chars(_CharT* __p, __rc_iterator __k1, __rc_iterator __k2)
156 { _S_copy_chars(__p, __k1.base(), __k2.base()); }
157
158 static void
159 _S_copy_chars(_CharT* __p, __const_rc_iterator __k1,
160 __const_rc_iterator __k2)
161 { _S_copy_chars(__p, __k1.base(), __k2.base()); }
162
163 static void
164 _S_copy_chars(_CharT* __p, _CharT* __k1, _CharT* __k2)
165 { _S_copy(__p, __k1, __k2 - __k1); }
166
167 static void
168 _S_copy_chars(_CharT* __p, const _CharT* __k1, const _CharT* __k2)
169 { _S_copy(__p, __k1, __k2 - __k1); }
170
171 static int
172 _S_compare(size_type __n1, size_type __n2)
173 {
174 const difference_type __d = difference_type(__n1 - __n2);
175
176 if (__d > __numeric_traits_integer<int>::__max)
177 return __numeric_traits_integer<int>::__max;
178 else if (__d < __numeric_traits_integer<int>::__min)
179 return __numeric_traits_integer<int>::__min;
180 else
181 return int(__d);
182 }
183 };
184
185 _GLIBCXX_END_NAMESPACE_VERSION
186 } // namespace
187
188 #endif /* _VSTRING_UTIL_H */