char_traits.h revision 102782 
1// Character Traits for use by standard string and iostream -*- C++ -*-
2
3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
4// Free Software Foundation, Inc.
5//
6// This file is part of the GNU ISO C++ Library.  This library is free
7// software; you can redistribute it and/or modify it under the
8// terms of the GNU General Public License as published by the
9// Free Software Foundation; either version 2, or (at your option)
10// any later version.
11
12// This library is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15// GNU General Public License for more details.
16
17// You should have received a copy of the GNU General Public License along
18// with this library; see the file COPYING.  If not, write to the Free
19// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
20// USA.
21
22// As a special exception, you may use this file as part of a free software
23// library without restriction.  Specifically, if other files instantiate
24// templates or use macros or inline functions from this file, or you compile
25// this file and link it with other files to produce an executable, this
26// file does not by itself cause the resulting executable to be covered by
27// the GNU General Public License.  This exception does not however
28// invalidate any other reasons why the executable file might be covered by
29// the GNU General Public License.
30
31//
32// ISO C++ 14882: 21  Strings library
33//
34
35/** @file char_traits.h
36 *  This is an internal header file, included by other library headers.
37 *  You should not attempt to use it directly.
38 */
39
40#ifndef _CPP_BITS_CHAR_TRAITS_H
41#define _CPP_BITS_CHAR_TRAITS_H 1
42
43#pragma GCC system_header
44
45#include <cstring> 	// For memmove, memset, memchr
46#include <bits/fpos.h> 		// For streampos
47
48namespace std
49{
50  /// 21.1.2 Basis for explicit _Traits specialization
51  /// NB: That for any given actual character type this definition is
52  /// probably wrong.
53  template<class _CharT>
54    struct char_traits
55    {
56      typedef _CharT 		char_type;
57      // Unsigned as wint_t is unsigned.
58      typedef unsigned long  	int_type;
59      typedef streampos 	pos_type;
60      typedef streamoff 	off_type;
61      typedef mbstate_t 	state_type;
62
63      static void
64      assign(char_type& __c1, const char_type& __c2);
65
66      static bool
67      eq(const char_type& __c1, const char_type& __c2);
68
69      static bool
70      lt(const char_type& __c1, const char_type& __c2);
71
72      static int
73      compare(const char_type* __s1, const char_type* __s2, size_t __n);
74
75      static size_t
76      length(const char_type* __s);
77
78      static const char_type*
79      find(const char_type* __s, size_t __n, const char_type& __a);
80
81      static char_type*
82      move(char_type* __s1, const char_type* __s2, size_t __n);
83
84      static char_type*
85      copy(char_type* __s1, const char_type* __s2, size_t __n);
86
87      static char_type*
88      assign(char_type* __s, size_t __n, char_type __a);
89
90      static char_type
91      to_char_type(const int_type& __c);
92
93      static int_type
94      to_int_type(const char_type& __c);
95
96      static bool
97      eq_int_type(const int_type& __c1, const int_type& __c2);
98
99      static int_type
100      eof();
101
102      static int_type
103      not_eof(const int_type& __c);
104    };
105
106
107  /// 21.1.4  char_traits specializations
108  template<>
109    struct char_traits<char>
110    {
111      typedef char 		char_type;
112      typedef int 	        int_type;
113      typedef streampos 	pos_type;
114      typedef streamoff 	off_type;
115      typedef mbstate_t 	state_type;
116
117      static void
118      assign(char_type& __c1, const char_type& __c2)
119      { __c1 = __c2; }
120
121      static bool
122      eq(const char_type& __c1, const char_type& __c2)
123      { return __c1 == __c2; }
124
125      static bool
126      lt(const char_type& __c1, const char_type& __c2)
127      { return __c1 < __c2; }
128
129      static int
130      compare(const char_type* __s1, const char_type* __s2, size_t __n)
131      { return memcmp(__s1, __s2, __n); }
132
133      static size_t
134      length(const char_type* __s)
135      { return strlen(__s); }
136
137      static const char_type*
138      find(const char_type* __s, size_t __n, const char_type& __a)
139      { return static_cast<const char_type*>(memchr(__s, __a, __n)); }
140
141      static char_type*
142      move(char_type* __s1, const char_type* __s2, size_t __n)
143      { return static_cast<char_type*>(memmove(__s1, __s2, __n)); }
144
145      static char_type*
146      copy(char_type* __s1, const char_type* __s2, size_t __n)
147      {  return static_cast<char_type*>(memcpy(__s1, __s2, __n)); }
148
149      static char_type*
150      assign(char_type* __s, size_t __n, char_type __a)
151      { return static_cast<char_type*>(memset(__s, __a, __n)); }
152
153      static char_type
154      to_char_type(const int_type& __c)
155      { return static_cast<char_type>(__c); }
156
157      // To keep both the byte 0xff and the eof symbol 0xffffffff
158      // from ending up as 0xffffffff.
159      static int_type
160      to_int_type(const char_type& __c)
161      { return static_cast<int_type>(static_cast<unsigned char>(__c)); }
162
163      static bool
164      eq_int_type(const int_type& __c1, const int_type& __c2)
165      { return __c1 == __c2; }
166
167      static int_type
168      eof() { return static_cast<int_type>(EOF); }
169
170      static int_type
171      not_eof(const int_type& __c)
172      { return (__c == eof()) ? 0 : __c; }
173  };
174
175
176#ifdef _GLIBCPP_USE_WCHAR_T
177  template<>
178    struct char_traits<wchar_t>
179    {
180      typedef wchar_t 		char_type;
181      typedef wint_t 		int_type;
182      typedef streamoff 	off_type;
183      typedef wstreampos 	pos_type;
184      typedef mbstate_t 	state_type;
185
186      static void
187      assign(char_type& __c1, const char_type& __c2)
188      { __c1 = __c2; }
189
190      static bool
191      eq(const char_type& __c1, const char_type& __c2)
192      { return __c1 == __c2; }
193
194      static bool
195      lt(const char_type& __c1, const char_type& __c2)
196      { return __c1 < __c2; }
197
198      static int
199      compare(const char_type* __s1, const char_type* __s2, size_t __n)
200      { return wmemcmp(__s1, __s2, __n); }
201
202      static size_t
203      length(const char_type* __s)
204      { return wcslen(__s); }
205
206      static const char_type*
207      find(const char_type* __s, size_t __n, const char_type& __a)
208      { return wmemchr(__s, __a, __n); }
209
210      static char_type*
211      move(char_type* __s1, const char_type* __s2, int_type __n)
212      { return wmemmove(__s1, __s2, __n); }
213
214      static char_type*
215      copy(char_type* __s1, const char_type* __s2, size_t __n)
216      { return wmemcpy(__s1, __s2, __n); }
217
218      static char_type*
219      assign(char_type* __s, size_t __n, char_type __a)
220      { return wmemset(__s, __a, __n); }
221
222      static char_type
223      to_char_type(const int_type& __c) { return char_type(__c); }
224
225      static int_type
226      to_int_type(const char_type& __c) { return int_type(__c); }
227
228      static bool
229      eq_int_type(const int_type& __c1, const int_type& __c2)
230      { return __c1 == __c2; }
231
232      static int_type
233      eof() { return static_cast<int_type>(WEOF); }
234
235      static int_type
236      not_eof(const int_type& __c)
237      { return eq_int_type(__c, eof()) ? 0 : __c; }
238  };
239#endif //_GLIBCPP_USE_WCHAR_T
240
241  template<typename _CharT, typename _Traits>
242    struct _Char_traits_match
243    {
244      _CharT _M_c;
245      _Char_traits_match(_CharT const& __c) : _M_c(__c) { }
246
247      bool
248      operator()(_CharT const& __a) { return _Traits::eq(_M_c, __a); }
249    };
250} // namespace std
251
252#endif
253