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

   1 // Character Traits for use by standard string and iostream -*- C++ -*-
   2
   3 // Copyright (C) 1997-1999, 2000 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   // 21.1.4  char_traits specializations
 148   template<>
 149     struct char_traits<char>
 150     {
 151       typedef char              char_type;
 152       typedef unsigned int      int_type;
 153       typedef streampos         pos_type;
 154       typedef streamoff         off_type;
 155       typedef mbstate_t         state_type;
 156
 157       static void
 158       assign(char_type& __c1, const char_type& __c2)
 159       { __c1 = __c2; }
 160
 161       static bool
 162       eq(const char_type& __c1, const char_type& __c2)
 163       { return __c1 == __c2; }
 164
 165       static bool
 166       lt(const char_type& __c1, const char_type& __c2)
 167       { return __c1 < __c2; }
 168
 169       static int
 170       compare(const char_type* __s1, const char_type* __s2, size_t __n)
 171       { return memcmp(__s1, __s2, __n); }
 172
 173       static size_t
 174       length(const char_type* __s)
 175       { return strlen(__s); }
 176
 177       static const char_type*
 178       find(const char_type* __s, size_t __n, const char_type& __a)
 179       { return static_cast<const char_type*>(memchr(__s, __a, __n)); }
 180
 181       static char_type*
 182       move(char_type* __s1, const char_type* __s2, size_t __n)
 183       { return static_cast<char_type*>(memmove(__s1, __s2, __n)); }
 184
 185       static char_type*
 186       copy(char_type* __s1, const char_type* __s2, size_t __n)
 187       {  return static_cast<char_type*>(memcpy(__s1, __s2, __n)); }
 188
 189       static char_type*
 190       assign(char_type* __s, size_t __n, char_type __a)
 191       { return static_cast<char_type*>(memset(__s, __a, __n)); }
 192
 193       static char_type
 194       to_char_type(const int_type& __c)
 195       { return static_cast<char_type>(__c); }
 196
 197       // To keep both the byte 0xff and the eof symbol 0xffffffff
 198       // from ending up as 0xffffffff.
 199       static int_type
 200       to_int_type(const char_type& __c)
 201       { return static_cast<int_type>(static_cast<unsigned char>(__c)); }
 202
 203       static bool
 204       eq_int_type(const int_type& __c1, const int_type& __c2)
 205       { return __c1 == __c2; }
 206
 207       static state_type
 208       _S_get_state(const pos_type& __pos) { return __pos.state(); }
 209
 210       static int_type
 211       eof() { return static_cast<int_type>(EOF); }
 212
 213       static int_type
 214       _S_eos() { return char_type(); }
 215
 216       static int_type
 217       not_eof(const int_type& __c)
 218       { return (__c == eof()) ? 0 : __c; }
 219   };
 220
 221
 222 #ifdef _GLIBCPP_USE_WCHAR_T
 223   template<>
 224     struct char_traits<wchar_t>
 225     {
 226       typedef wchar_t           char_type;
 227       typedef wint_t            int_type;
 228       typedef wstreamoff        off_type;
 229       typedef wstreampos        pos_type;
 230       typedef mbstate_t         state_type;
 231
 232       static void
 233       assign(char_type& __c1, const char_type& __c2)
 234       { __c1 = __c2; }
 235
 236       static bool
 237       eq(const char_type& __c1, const char_type& __c2)
 238       { return __c1 == __c2; }
 239
 240       static bool
 241       lt(const char_type& __c1, const char_type& __c2)
 242       { return __c1 < __c2; }
 243
 244       static int
 245       compare(const char_type* __s1, const char_type* __s2, size_t __n)
 246       { return wmemcmp(__s1, __s2, __n); }
 247
 248       static size_t
 249       length(const char_type* __s)
 250       { return wcslen(__s); }
 251
 252       static const char_type*
 253       find(const char_type* __s, size_t __n, const char_type& __a)
 254       { return wmemchr(__s, __a, __n); }
 255
 256       static char_type*
 257       move(char_type* __s1, const char_type* __s2, int_type __n)
 258       { return wmemmove(__s1, __s2, __n); }
 259
 260       static char_type*
 261       copy(char_type* __s1, const char_type* __s2, size_t __n)
 262       { return wmemcpy(__s1, __s2, __n); }
 263
 264       static char_type*
 265       assign(char_type* __s, size_t __n, char_type __a)
 266       { return wmemset(__s, __a, __n); }
 267
 268       static char_type
 269       to_char_type(const int_type& __c) { return char_type(__c); }
 270
 271       static int_type
 272       to_int_type(const char_type& __c) { return int_type(__c); }
 273
 274       static bool
 275       eq_int_type(const int_type& __c1, const int_type& __c2)
 276       { return __c1 == __c2; }
 277
 278       static state_type
 279       _S_get_state(const pos_type& __pos) { return __pos.state(); }
 280
 281       static int_type
 282       eof() { return static_cast<int_type>(WEOF); }
 283
 284       static int_type
 285       _S_eos() { return char_type(); }
 286
 287       static int_type
 288       not_eof(const int_type& __c)
 289       { return eq_int_type(__c, eof()) ? 0 : __c; }
 290   };
 291 #endif //_GLIBCPP_USE_WCHAR_T
 292
 293   template<typename _CharT, typename _Traits>
 294     struct _Char_traits_match
 295     {
 296       _CharT _M_c;
 297       _Char_traits_match(_CharT const& __c) : _M_c(__c) { }
 298
 299       bool
 300       operator()(_CharT const& __a) { return _Traits::eq(_M_c,__a); }
 301     };
 302
 303 } // namespace std
 304
 305
 306 #endif /* _CPP_BITS_CHAR_TRAITS_H */
 307