libstdc++
pod_char_traits.h
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1 // POD character, std::char_traits specialization -*- C++ -*-
2 
3 // Copyright (C) 2002-2024 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;
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,
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  {
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
ISO C++ entities toplevel namespace is std.
long long streamoff
Type used by fpos, char_traits<char>, and char_traits<wchar_t>.
Definition: postypes.h:64
Class representing stream positions.
Definition: postypes.h:82
A POD class that serves as a character abstraction class.
GNU extensions for public use.
constexpr _OI fill_n(_OI __first, _Size __n, const _Tp &__value)
Fills the range [first,first+n) with copies of value.
Basis for explicit traits specializations.
Definition: char_traits.h:323