1 // POD character, std::char_traits specialization -*- C++ -*-
2
3 // Copyright (C) 2002-2023 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/pod_char_traits.h
26 * This file is a GNU extension to the Standard C++ Library.
27 */
28
29 // Gabriel Dos Reis <gdr@integrable-solutions.net>
30 // Benjamin Kosnik <bkoz@redhat.com>
31
32 #ifndef _POD_CHAR_TRAITS_H
33 #define _POD_CHAR_TRAITS_H 1
34
35 #pragma GCC system_header
36
37 #include <bits/requires_hosted.h> // GNU extensions are currently omitted
38
39 #include <string>
40
41 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
42 {
43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
44
45 // POD character abstraction.
46 // NB: The char_type parameter is a subset of int_type, as to allow
47 // int_type to properly hold the full range of char_type values as
48 // well as EOF.
49 /// @brief A POD class that serves as a character abstraction class.
50 template<typename _Value, typename _Int, typename _St = std::mbstate_t>
51 struct character
52 {
53 typedef _Value value_type;
54 typedef _Int int_type;
55 typedef _St state_type;
56 typedef character<_Value, _Int, _St> char_type;
57
58 value_type value;
59
60 template<typename V2>
61 static char_type
62 from(const V2& v)
63 {
64 char_type ret = { static_cast<value_type>(v) };
65 return ret;
66 }
67
68 template<typename V2>
69 static V2
70 to(const char_type& c)
71 {
72 V2 ret = { static_cast<V2>(c.value) };
73 return ret;
74 }
75
76 };
77
78 template<typename _Value, typename _Int, typename _St>
79 inline bool
80 operator==(const character<_Value, _Int, _St>& lhs,
81 const character<_Value, _Int, _St>& rhs)
82 { return lhs.value == rhs.value; }
83
84 template<typename _Value, typename _Int, typename _St>
85 inline bool
86 operator<(const character<_Value, _Int, _St>& lhs,
87 const character<_Value, _Int, _St>& rhs)
88 { return lhs.value < rhs.value; }
89
90 _GLIBCXX_END_NAMESPACE_VERSION
91 } // namespace
92
93 namespace std _GLIBCXX_VISIBILITY(default)
94 {
95 _GLIBCXX_BEGIN_NAMESPACE_VERSION
96
97 /// char_traits<__gnu_cxx::character> specialization.
98 template<typename _Value, typename _Int, typename _St>
99 struct char_traits<__gnu_cxx::character<_Value, _Int, _St> >
100 {
101 typedef __gnu_cxx::character<_Value, _Int, _St> char_type;
102 typedef typename char_type::int_type int_type;
103 typedef typename char_type::state_type state_type;
104 typedef fpos<state_type> pos_type;
105 typedef streamoff off_type;
106
107 static void
108 assign(char_type& __c1, const char_type& __c2)
109 { __c1 = __c2; }
110
111 static bool
112 eq(const char_type& __c1, const char_type& __c2)
113 { return __c1 == __c2; }
114
115 static bool
116 lt(const char_type& __c1, const char_type& __c2)
117 { return __c1 < __c2; }
118
119 static int
120 compare(const char_type* __s1, const char_type* __s2, size_t __n)
121 {
122 for (size_t __i = 0; __i < __n; ++__i)
123 if (!eq(__s1[__i], __s2[__i]))
124 return lt(__s1[__i], __s2[__i]) ? -1 : 1;
125 return 0;
126 }
127
128 static size_t
129 length(const char_type* __s)
130 {
131 const char_type* __p = __s;
132 while (__p->value)
133 ++__p;
134 return (__p - __s);
135 }
136
137 static const char_type*
138 find(const char_type* __s, size_t __n, const char_type& __a)
139 {
140 for (const char_type* __p = __s; size_t(__p - __s) < __n; ++__p)
141 if (*__p == __a)
142 return __p;
143 return 0;
144 }
145
146 static char_type*
147 move(char_type* __s1, const char_type* __s2, size_t __n)
148 {
149 if (__n == 0)
150 return __s1;
151 return static_cast<char_type*>
152 (__builtin_memmove(__s1, __s2, __n * sizeof(char_type)));
153 }
154
155 static char_type*
156 copy(char_type* __s1, const char_type* __s2, size_t __n)
157 {
158 if (__n == 0)
159 return __s1;
160 std::copy(__s2, __s2 + __n, __s1);
161 return __s1;
162 }
163
164 static char_type*
165 assign(char_type* __s, size_t __n, char_type __a)
166 {
167 std::fill_n(__s, __n, __a);
168 return __s;
169 }
170
171 static char_type
172 to_char_type(const int_type& __i)
173 { return char_type::template from(__i); }
174
175 static int_type
176 to_int_type(const char_type& __c)
177 { return char_type::template to<int_type>(__c); }
178
179 static bool
180 eq_int_type(const int_type& __c1, const int_type& __c2)
181 { return __c1 == __c2; }
182
183 static int_type
184 eof()
185 {
186 int_type __r = { static_cast<typename __gnu_cxx::__conditional_type
187 <std::__is_integer<int_type>::__value,
188 int_type, int>::__type>(-1) };
189 return __r;
190 }
191
192 static int_type
193 not_eof(const int_type& __c)
194 { return eq_int_type(__c, eof()) ? int_type() : __c; }
195 };
196
197 _GLIBCXX_END_NAMESPACE_VERSION
198 } // namespace
199
200 #endif