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 #pragma GCC system_header
  38
  39 #include <bits/std_cwchar.h>    // For mbstate_t.
  40 #include <bits/std_cstring.h>   // For memmove, memset, memchr
  41 #include <bits/fpos.h>          // For streamoff, streamsize
  42
  43 namespace std {
  44
  45   // Same as iosfwd
  46 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
  47   // Can't have self-recursive types for streampos.
  48   // 21.1.3.1 char_traits sets size_type to streampos
  49   // 27.4.1
  50   // And here, where streampos is typedefed to fpos<traits::state_type>
  51     typedef fpos<mbstate_t>     streampos;
  52 #  ifdef _GLIBCPP_USE_WCHAR_T
  53     typedef fpos<mbstate_t>     wstreampos;
  54 #  endif
  55 #endif
  56
  57   // 21.1.2 Basis for explicit _Traits specialization
  58   // NB: That for any given actual character type this definition is
  59   // probably wrong.
  60
  61   template<class _CharT>
  62     struct char_traits
  63     {
  64       typedef _CharT            char_type;
  65       // Unsigned as wint_t in unsigned.
  66       typedef unsigned long     int_type;
  67       typedef streampos         pos_type;
  68       typedef streamoff         off_type;
  69       typedef mbstate_t         state_type;
  70
  71       static void
  72       assign(char_type& __c1, const char_type& __c2)
  73       { __c1 = __c2; }
  74
  75       static bool
  76       eq(const char_type& __c1, const char_type& __c2)
  77       { return __c1 == __c2; }
  78
  79       static bool
  80       lt(const char_type& __c1, const char_type& __c2)
  81       { return __c1 < __c2; }
  82
  83       static int
  84       compare(const char_type* __s1, const char_type* __s2, size_t __n)
  85       {
  86         for (size_t __i = 0; __i < __n; ++__i)
  87           if (!eq(__s1[__i], __s2[__i]))
  88             return lt(__s1[__i], __s2[__i]) ? -1 : 1;
  89         return 0;
  90       }
  91
  92       static size_t
  93       length(const char_type* __s)
  94       {
  95         const char_type* __p = __s;
  96         while (*__p) ++__p;
  97         return (__p - __s);
  98       }
  99
 100       static const char_type*
 101       find(const char_type* __s, size_t __n, const char_type& __a)
 102       {
 103         for (const char_type* __p = __s; size_t(__p - __s) < __n; ++__p)
 104           if (*__p == __a) return __p;
 105         return 0;
 106       }
 107
 108       static char_type*
 109       move(char_type* __s1, const char_type* __s2, size_t __n)
 110       { return (char_type*) memmove(__s1, __s2, __n * sizeof(char_type)); }
 111
 112       static char_type*
 113       copy(char_type* __s1, const char_type* __s2, size_t __n)
 114       { return (char_type*) memcpy(__s1, __s2, __n * sizeof(char_type)); }
 115
 116       static char_type*
 117       assign(char_type* __s, size_t __n, char_type __a)
 118       {
 119         for (char_type* __p = __s; __p < __s + __n; ++__p)
 120           assign(*__p, __a);
 121         return __s;
 122       }
 123
 124       static char_type
 125       to_char_type(const int_type& __c)
 126       { return char_type(__c); }
 127
 128       static int_type
 129       to_int_type(const char_type& __c) { return int_type(__c); }
 130
 131       static bool
 132       eq_int_type(const int_type& __c1, const int_type& __c2)
 133       { return __c1 == __c2; }
 134
 135       static int_type
 136       eof() { return static_cast<int_type>(-1); }
 137
 138       static int_type
 139       not_eof(const int_type& __c)
 140       { return eq_int_type(__c, eof()) ? int_type(0) : __c; }
 141     };
 142
 143
 144   // 21.1.4  char_traits specializations
 145   template<>
 146     struct char_traits<char>
 147     {
 148       typedef char              char_type;
 149       typedef int               int_type;
 150       typedef streampos         pos_type;
 151       typedef streamoff         off_type;
 152       typedef mbstate_t         state_type;
 153
 154       static void
 155       assign(char_type& __c1, const char_type& __c2)
 156       { __c1 = __c2; }
 157
 158       static bool
 159       eq(const char_type& __c1, const char_type& __c2)
 160       { return __c1 == __c2; }
 161
 162       static bool
 163       lt(const char_type& __c1, const char_type& __c2)
 164       { return __c1 < __c2; }
 165
 166       static int
 167       compare(const char_type* __s1, const char_type* __s2, size_t __n)
 168       { return memcmp(__s1, __s2, __n); }
 169
 170       static size_t
 171       length(const char_type* __s)
 172       { return strlen(__s); }
 173
 174       static const char_type*
 175       find(const char_type* __s, size_t __n, const char_type& __a)
 176       { return static_cast<const char_type*>(memchr(__s, __a, __n)); }
 177
 178       static char_type*
 179       move(char_type* __s1, const char_type* __s2, size_t __n)
 180       { return static_cast<char_type*>(memmove(__s1, __s2, __n)); }
 181
 182       static char_type*
 183       copy(char_type* __s1, const char_type* __s2, size_t __n)
 184       {  return static_cast<char_type*>(memcpy(__s1, __s2, __n)); }
 185
 186       static char_type*
 187       assign(char_type* __s, size_t __n, char_type __a)
 188       { return static_cast<char_type*>(memset(__s, __a, __n)); }
 189
 190       static char_type
 191       to_char_type(const int_type& __c)
 192       { return static_cast<char_type>(__c); }
 193
 194       // To keep both the byte 0xff and the eof symbol 0xffffffff
 195       // from ending up as 0xffffffff.
 196       static int_type
 197       to_int_type(const char_type& __c)
 198       { return static_cast<int_type>(static_cast<unsigned char>(__c)); }
 199
 200       static bool
 201       eq_int_type(const int_type& __c1, const int_type& __c2)
 202       { return __c1 == __c2; }
 203
 204       static int_type
 205       eof() { return static_cast<int_type>(EOF); }
 206
 207       static int_type
 208       not_eof(const int_type& __c)
 209       { return (__c == eof()) ? 0 : __c; }
 210   };
 211
 212
 213 #ifdef _GLIBCPP_USE_WCHAR_T
 214   template<>
 215     struct char_traits<wchar_t>
 216     {
 217       typedef wchar_t           char_type;
 218       typedef wint_t            int_type;
 219       typedef wstreamoff        off_type;
 220       typedef wstreampos        pos_type;
 221       typedef mbstate_t         state_type;
 222
 223       static void
 224       assign(char_type& __c1, const char_type& __c2)
 225       { __c1 = __c2; }
 226
 227       static bool
 228       eq(const char_type& __c1, const char_type& __c2)
 229       { return __c1 == __c2; }
 230
 231       static bool
 232       lt(const char_type& __c1, const char_type& __c2)
 233       { return __c1 < __c2; }
 234
 235       static int
 236       compare(const char_type* __s1, const char_type* __s2, size_t __n)
 237       { return wmemcmp(__s1, __s2, __n); }
 238
 239       static size_t
 240       length(const char_type* __s)
 241       { return wcslen(__s); }
 242
 243       static const char_type*
 244       find(const char_type* __s, size_t __n, const char_type& __a)
 245       { return wmemchr(__s, __a, __n); }
 246
 247       static char_type*
 248       move(char_type* __s1, const char_type* __s2, int_type __n)
 249       { return wmemmove(__s1, __s2, __n); }
 250
 251       static char_type*
 252       copy(char_type* __s1, const char_type* __s2, size_t __n)
 253       { return wmemcpy(__s1, __s2, __n); }
 254
 255       static char_type*
 256       assign(char_type* __s, size_t __n, char_type __a)
 257       { return wmemset(__s, __a, __n); }
 258
 259       static char_type
 260       to_char_type(const int_type& __c) { return char_type(__c); }
 261
 262       static int_type
 263       to_int_type(const char_type& __c) { return int_type(__c); }
 264
 265       static bool
 266       eq_int_type(const int_type& __c1, const int_type& __c2)
 267       { return __c1 == __c2; }
 268
 269       static int_type
 270       eof() { return static_cast<int_type>(WEOF); }
 271
 272       static int_type
 273       not_eof(const int_type& __c)
 274       { return eq_int_type(__c, eof()) ? 0 : __c; }
 275   };
 276 #endif //_GLIBCPP_USE_WCHAR_T
 277
 278   template<typename _CharT, typename _Traits>
 279     struct _Char_traits_match
 280     {
 281       _CharT _M_c;
 282       _Char_traits_match(_CharT const& __c) : _M_c(__c) { }
 283
 284       bool
 285       operator()(_CharT const& __a) { return _Traits::eq(_M_c, __a); }
 286     };
 287
 288 } // namespace std
 289
 290
 291 #endif /* _CPP_BITS_CHAR_TRAITS_H */
 292