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_cstring.h>   // For memmove, memset, memchr
  40 #include <bits/fpos.h>          // For streampos
  41
  42 namespace std
  43 {
  44   /// 21.1.2 Basis for explicit _Traits specialization
  45   /// NB: That for any given actual character type this definition is
  46   /// probably wrong.
  47   template<class _CharT>
  48     struct char_traits
  49     {
  50       typedef _CharT            char_type;
  51       // Unsigned as wint_t in unsigned.
  52       typedef unsigned long     int_type;
  53       typedef streampos         pos_type;
  54       typedef streamoff         off_type;
  55       typedef mbstate_t         state_type;
  56
  57       static void
  58       assign(char_type& __c1, const char_type& __c2)
  59       { __c1 = __c2; }
  60
  61       static bool
  62       eq(const char_type& __c1, const char_type& __c2)
  63       { return __c1 == __c2; }
  64
  65       static bool
  66       lt(const char_type& __c1, const char_type& __c2)
  67       { return __c1 < __c2; }
  68
  69       static int
  70       compare(const char_type* __s1, const char_type* __s2, size_t __n)
  71       {
  72         for (size_t __i = 0; __i < __n; ++__i)
  73           if (!eq(__s1[__i], __s2[__i]))
  74             return lt(__s1[__i], __s2[__i]) ? -1 : 1;
  75         return 0;
  76       }
  77
  78       static size_t
  79       length(const char_type* __s)
  80       {
  81         const char_type* __p = __s;
  82         while (*__p) ++__p;
  83         return (__p - __s);
  84       }
  85
  86       static const char_type*
  87       find(const char_type* __s, size_t __n, const char_type& __a)
  88       {
  89         for (const char_type* __p = __s; size_t(__p - __s) < __n; ++__p)
  90           if (*__p == __a) return __p;
  91         return 0;
  92       }
  93
  94       static char_type*
  95       move(char_type* __s1, const char_type* __s2, size_t __n)
  96       { return (char_type*) memmove(__s1, __s2, __n * sizeof(char_type)); }
  97
  98       static char_type*
  99       copy(char_type* __s1, const char_type* __s2, size_t __n)
 100       { return (char_type*) memcpy(__s1, __s2, __n * sizeof(char_type)); }
 101
 102       static char_type*
 103       assign(char_type* __s, size_t __n, char_type __a)
 104       {
 105         for (char_type* __p = __s; __p < __s + __n; ++__p)
 106           assign(*__p, __a);
 107         return __s;
 108       }
 109
 110       static char_type
 111       to_char_type(const int_type& __c)
 112       { return char_type(__c); }
 113
 114       static int_type
 115       to_int_type(const char_type& __c) { return int_type(__c); }
 116
 117       static bool
 118       eq_int_type(const int_type& __c1, const int_type& __c2)
 119       { return __c1 == __c2; }
 120
 121       static int_type
 122       eof() { return static_cast<int_type>(-1); }
 123
 124       static int_type
 125       not_eof(const int_type& __c)
 126       { return eq_int_type(__c, eof()) ? int_type(0) : __c; }
 127     };
 128
 129
 130   /// 21.1.4  char_traits specializations
 131   template<>
 132     struct char_traits<char>
 133     {
 134       typedef char              char_type;
 135       typedef int               int_type;
 136       typedef streampos         pos_type;
 137       typedef streamoff         off_type;
 138       typedef mbstate_t         state_type;
 139
 140       static void
 141       assign(char_type& __c1, const char_type& __c2)
 142       { __c1 = __c2; }
 143
 144       static bool
 145       eq(const char_type& __c1, const char_type& __c2)
 146       { return __c1 == __c2; }
 147
 148       static bool
 149       lt(const char_type& __c1, const char_type& __c2)
 150       { return __c1 < __c2; }
 151
 152       static int
 153       compare(const char_type* __s1, const char_type* __s2, size_t __n)
 154       { return memcmp(__s1, __s2, __n); }
 155
 156       static size_t
 157       length(const char_type* __s)
 158       { return strlen(__s); }
 159
 160       static const char_type*
 161       find(const char_type* __s, size_t __n, const char_type& __a)
 162       { return static_cast<const char_type*>(memchr(__s, __a, __n)); }
 163
 164       static char_type*
 165       move(char_type* __s1, const char_type* __s2, size_t __n)
 166       { return static_cast<char_type*>(memmove(__s1, __s2, __n)); }
 167
 168       static char_type*
 169       copy(char_type* __s1, const char_type* __s2, size_t __n)
 170       {  return static_cast<char_type*>(memcpy(__s1, __s2, __n)); }
 171
 172       static char_type*
 173       assign(char_type* __s, size_t __n, char_type __a)
 174       { return static_cast<char_type*>(memset(__s, __a, __n)); }
 175
 176       static char_type
 177       to_char_type(const int_type& __c)
 178       { return static_cast<char_type>(__c); }
 179
 180       // To keep both the byte 0xff and the eof symbol 0xffffffff
 181       // from ending up as 0xffffffff.
 182       static int_type
 183       to_int_type(const char_type& __c)
 184       { return static_cast<int_type>(static_cast<unsigned char>(__c)); }
 185
 186       static bool
 187       eq_int_type(const int_type& __c1, const int_type& __c2)
 188       { return __c1 == __c2; }
 189
 190       static int_type
 191       eof() { return static_cast<int_type>(EOF); }
 192
 193       static int_type
 194       not_eof(const int_type& __c)
 195       { return (__c == eof()) ? 0 : __c; }
 196   };
 197
 198
 199 #ifdef _GLIBCPP_USE_WCHAR_T
 200   template<>
 201     struct char_traits<wchar_t>
 202     {
 203       typedef wchar_t           char_type;
 204       typedef wint_t            int_type;
 205       typedef streamoff         off_type;
 206       typedef wstreampos        pos_type;
 207       typedef mbstate_t         state_type;
 208
 209       static void
 210       assign(char_type& __c1, const char_type& __c2)
 211       { __c1 = __c2; }
 212
 213       static bool
 214       eq(const char_type& __c1, const char_type& __c2)
 215       { return __c1 == __c2; }
 216
 217       static bool
 218       lt(const char_type& __c1, const char_type& __c2)
 219       { return __c1 < __c2; }
 220
 221       static int
 222       compare(const char_type* __s1, const char_type* __s2, size_t __n)
 223       { return wmemcmp(__s1, __s2, __n); }
 224
 225       static size_t
 226       length(const char_type* __s)
 227       { return wcslen(__s); }
 228
 229       static const char_type*
 230       find(const char_type* __s, size_t __n, const char_type& __a)
 231       { return wmemchr(__s, __a, __n); }
 232
 233       static char_type*
 234       move(char_type* __s1, const char_type* __s2, int_type __n)
 235       { return wmemmove(__s1, __s2, __n); }
 236
 237       static char_type*
 238       copy(char_type* __s1, const char_type* __s2, size_t __n)
 239       { return wmemcpy(__s1, __s2, __n); }
 240
 241       static char_type*
 242       assign(char_type* __s, size_t __n, char_type __a)
 243       { return wmemset(__s, __a, __n); }
 244
 245       static char_type
 246       to_char_type(const int_type& __c) { return char_type(__c); }
 247
 248       static int_type
 249       to_int_type(const char_type& __c) { return int_type(__c); }
 250
 251       static bool
 252       eq_int_type(const int_type& __c1, const int_type& __c2)
 253       { return __c1 == __c2; }
 254
 255       static int_type
 256       eof() { return static_cast<int_type>(WEOF); }
 257
 258       static int_type
 259       not_eof(const int_type& __c)
 260       { return eq_int_type(__c, eof()) ? 0 : __c; }
 261   };
 262 #endif //_GLIBCPP_USE_WCHAR_T
 263
 264   template<typename _CharT, typename _Traits>
 265     struct _Char_traits_match
 266     {
 267       _CharT _M_c;
 268       _Char_traits_match(_CharT const& __c) : _M_c(__c) { }
 269
 270       bool
 271       operator()(_CharT const& __a) { return _Traits::eq(_M_c, __a); }
 272     };
 273 } // namespace std
 274
 275 #endif