libstdc++-v3/include/bits/char_traits.h

   1 // Character Traits for use by standard string and iostream -*- C++ -*-
   2
   3 // Copyright (C) 1997, 1998, 1999, 2000, 2001 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 2, 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 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 //
  31 // ISO C++ 14882: 21  Strings library
  32 //
  33
  34 #ifndef _CPP_BITS_CHAR_TRAITS_H
  35 #define _CPP_BITS_CHAR_TRAITS_H 1
  36
  37 #include <bits/std_cwchar.h>    // For mbstate_t.
  38 #include <bits/std_cstring.h>   // For memmove, memset, memchr
  39 #include <bits/fpos.h>          // For streamoff, streamsize
  40
  41 namespace std {
  42
  43   // Same as iosfwd
  44 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
  45   // Can't have self-recursive types for streampos.
  46   // 21.1.3.1 char_traits sets size_type to streampos
  47   // 27.4.1
  48   // And here, where streampos is typedefed to fpos<traits::state_type>
  49     typedef fpos<mbstate_t>     streampos;
  50 #  ifdef _GLIBCPP_USE_WCHAR_T
  51     typedef fpos<mbstate_t>     wstreampos;
  52 #  endif
  53 #endif
  54
  55   // 21.1.2 Basis for explicit _Traits specialization
  56   // NB: That for any given actual character type this definition is
  57   // probably wrong.
  58
  59   template<class _CharT>
  60     struct char_traits
  61     {
  62       typedef _CharT            char_type;
  63       // Unsigned as wint_t in unsigned.
  64       typedef unsigned long     int_type;
  65       typedef streampos         pos_type;
  66       typedef streamoff         off_type;
  67       typedef mbstate_t         state_type;
  68
  69       static void
  70       assign(char_type& __c1, const char_type& __c2)
  71       { __c1 = __c2; }
  72
  73       static bool
  74       eq(const char_type& __c1, const char_type& __c2)
  75       { return __c1 == __c2; }
  76
  77       static bool
  78       lt(const char_type& __c1, const char_type& __c2)
  79       { return __c1 < __c2; }
  80
  81       static int
  82       compare(const char_type* __s1, const char_type* __s2, size_t __n)
  83       {
  84         for (size_t __i = 0; __i < __n; ++__i)
  85           if (!eq(__s1[__i], __s2[__i]))
  86             return lt(__s1[__i], __s2[__i]) ? -1 : 1;
  87         return 0;
  88       }
  89
  90       static size_t
  91       length(const char_type* __s)
  92       {
  93         const char_type* __p = __s;
  94         while (*__p) ++__p;
  95         return (__p - __s);
  96       }
  97
  98       static const char_type*
  99       find(const char_type* __s, size_t __n, const char_type& __a)
 100       {
 101         for (const char_type* __p = __s; size_t(__p - __s) < __n; ++__p)
 102           if (*__p == __a) return __p;
 103         return 0;
 104       }
 105
 106       static char_type*
 107       move(char_type* __s1, const char_type* __s2, size_t __n)
 108       { return (char_type*) memmove(__s1, __s2, __n * sizeof(char_type)); }
 109
 110       static char_type*
 111       copy(char_type* __s1, const char_type* __s2, size_t __n)
 112       { return (char_type*) memcpy(__s1, __s2, __n * sizeof(char_type)); }
 113
 114       static char_type*
 115       assign(char_type* __s, size_t __n, char_type __a)
 116       {
 117         for (char_type* __p = __s; __p < __s + __n; ++__p)
 118           assign(*__p, __a);
 119         return __s;
 120       }
 121
 122       static char_type
 123       to_char_type(const int_type& __c)
 124       { return char_type(__c); }
 125
 126       static int_type
 127       to_int_type(const char_type& __c) { return int_type(__c); }
 128
 129       static bool
 130       eq_int_type(const int_type& __c1, const int_type& __c2)
 131       { return __c1 == __c2; }
 132
 133       static state_type
 134       _S_get_state(const pos_type& __pos) { return __pos.state(); }
 135
 136       static int_type
 137       eof() { return static_cast<int_type>(-1); }
 138
 139       static int_type
 140       _S_eos() { return char_type(); }
 141
 142       static int_type
 143       not_eof(const int_type& __c)
 144       { return eq_int_type(__c, eof()) ? int_type(0) : __c; }
 145     };
 146
 147
 148   // 21.1.4  char_traits specializations
 149   template<>
 150     struct char_traits<char>
 151     {
 152       typedef char              char_type;
 153       typedef int               int_type;
 154       typedef streampos         pos_type;
 155       typedef streamoff         off_type;
 156       typedef mbstate_t         state_type;
 157
 158       static void
 159       assign(char_type& __c1, const char_type& __c2)
 160       { __c1 = __c2; }
 161
 162       static bool
 163       eq(const char_type& __c1, const char_type& __c2)
 164       { return __c1 == __c2; }
 165
 166       static bool
 167       lt(const char_type& __c1, const char_type& __c2)
 168       { return __c1 < __c2; }
 169
 170       static int
 171       compare(const char_type* __s1, const char_type* __s2, size_t __n)
 172       { return memcmp(__s1, __s2, __n); }
 173
 174       static size_t
 175       length(const char_type* __s)
 176       { return strlen(__s); }
 177
 178       static const char_type*
 179       find(const char_type* __s, size_t __n, const char_type& __a)
 180       { return static_cast<const char_type*>(memchr(__s, __a, __n)); }
 181
 182       static char_type*
 183       move(char_type* __s1, const char_type* __s2, size_t __n)
 184       { return static_cast<char_type*>(memmove(__s1, __s2, __n)); }
 185
 186       static char_type*
 187       copy(char_type* __s1, const char_type* __s2, size_t __n)
 188       {  return static_cast<char_type*>(memcpy(__s1, __s2, __n)); }
 189
 190       static char_type*
 191       assign(char_type* __s, size_t __n, char_type __a)
 192       { return static_cast<char_type*>(memset(__s, __a, __n)); }
 193
 194       static char_type
 195       to_char_type(const int_type& __c)
 196       { return static_cast<char_type>(__c); }
 197
 198       // To keep both the byte 0xff and the eof symbol 0xffffffff
 199       // from ending up as 0xffffffff.
 200       static int_type
 201       to_int_type(const char_type& __c)
 202       { return static_cast<int_type>(static_cast<unsigned char>(__c)); }
 203
 204       static bool
 205       eq_int_type(const int_type& __c1, const int_type& __c2)
 206       { return __c1 == __c2; }
 207
 208       static state_type
 209       _S_get_state(const pos_type& __pos) { return __pos.state(); }
 210
 211       static int_type
 212       eof() { return static_cast<int_type>(EOF); }
 213
 214       static int_type
 215       _S_eos() { return char_type(); }
 216
 217       static int_type
 218       not_eof(const int_type& __c)
 219       { return (__c == eof()) ? 0 : __c; }
 220   };
 221
 222
 223 #ifdef _GLIBCPP_USE_WCHAR_T
 224   template<>
 225     struct char_traits<wchar_t>
 226     {
 227       typedef wchar_t           char_type;
 228       typedef wint_t            int_type;
 229       typedef wstreamoff        off_type;
 230       typedef wstreampos        pos_type;
 231       typedef mbstate_t         state_type;
 232
 233       static void
 234       assign(char_type& __c1, const char_type& __c2)
 235       { __c1 = __c2; }
 236
 237       static bool
 238       eq(const char_type& __c1, const char_type& __c2)
 239       { return __c1 == __c2; }
 240
 241       static bool
 242       lt(const char_type& __c1, const char_type& __c2)
 243       { return __c1 < __c2; }
 244
 245       static int
 246       compare(const char_type* __s1, const char_type* __s2, size_t __n)
 247       { return wmemcmp(__s1, __s2, __n); }
 248
 249       static size_t
 250       length(const char_type* __s)
 251       { return wcslen(__s); }
 252
 253       static const char_type*
 254       find(const char_type* __s, size_t __n, const char_type& __a)
 255       { return wmemchr(__s, __a, __n); }
 256
 257       static char_type*
 258       move(char_type* __s1, const char_type* __s2, int_type __n)
 259       { return wmemmove(__s1, __s2, __n); }
 260
 261       static char_type*
 262       copy(char_type* __s1, const char_type* __s2, size_t __n)
 263       { return wmemcpy(__s1, __s2, __n); }
 264
 265       static char_type*
 266       assign(char_type* __s, size_t __n, char_type __a)
 267       { return wmemset(__s, __a, __n); }
 268
 269       static char_type
 270       to_char_type(const int_type& __c) { return char_type(__c); }
 271
 272       static int_type
 273       to_int_type(const char_type& __c) { return int_type(__c); }
 274
 275       static bool
 276       eq_int_type(const int_type& __c1, const int_type& __c2)
 277       { return __c1 == __c2; }
 278
 279       static state_type
 280       _S_get_state(const pos_type& __pos) { return __pos.state(); }
 281
 282       static int_type
 283       eof() { return static_cast<int_type>(WEOF); }
 284
 285       static int_type
 286       _S_eos() { return char_type(); }
 287
 288       static int_type
 289       not_eof(const int_type& __c)
 290       { return eq_int_type(__c, eof()) ? 0 : __c; }
 291   };
 292 #endif //_GLIBCPP_USE_WCHAR_T
 293
 294   template<typename _CharT, typename _Traits>
 295     struct _Char_traits_match
 296     {
 297       _CharT _M_c;
 298       _Char_traits_match(_CharT const& __c) : _M_c(__c) { }
 299
 300       bool
 301       operator()(_CharT const& __a) { return _Traits::eq(_M_c, __a); }
 302     };
 303
 304 } // namespace std
 305
 306
 307 #endif /* _CPP_BITS_CHAR_TRAITS_H */
 308