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 /** @file char_traits.h
  35  *  This is an internal header file, included by other library headers.
  36  *  You should not attempt to use it directly.
  37  */
  38
  39 #ifndef _CPP_BITS_CHAR_TRAITS_H
  40 #define _CPP_BITS_CHAR_TRAITS_H 1
  41
  42 #pragma GCC system_header
  43
  44 #include <bits/std_cstring.h>   // For memmove, memset, memchr
  45 #include <bits/fpos.h>          // For streampos
  46
  47 namespace std
  48 {
  49   /// 21.1.2 Basis for explicit _Traits specialization
  50   /// NB: That for any given actual character type this definition is
  51   /// probably wrong.
  52   template<class _CharT>
  53     struct char_traits
  54     {
  55       typedef _CharT            char_type;
  56       // Unsigned as wint_t in unsigned.
  57       typedef unsigned long     int_type;
  58       typedef streampos         pos_type;
  59       typedef streamoff         off_type;
  60       typedef mbstate_t         state_type;
  61
  62       static void
  63       assign(char_type& __c1, const char_type& __c2)
  64       { __c1 = __c2; }
  65
  66       static bool
  67       eq(const char_type& __c1, const char_type& __c2)
  68       { return __c1 == __c2; }
  69
  70       static bool
  71       lt(const char_type& __c1, const char_type& __c2)
  72       { return __c1 < __c2; }
  73
  74       static int
  75       compare(const char_type* __s1, const char_type* __s2, size_t __n)
  76       {
  77         for (size_t __i = 0; __i < __n; ++__i)
  78           if (!eq(__s1[__i], __s2[__i]))
  79             return lt(__s1[__i], __s2[__i]) ? -1 : 1;
  80         return 0;
  81       }
  82
  83       static size_t
  84       length(const char_type* __s)
  85       {
  86         const char_type* __p = __s;
  87         while (*__p) ++__p;
  88         return (__p - __s);
  89       }
  90
  91       static const char_type*
  92       find(const char_type* __s, size_t __n, const char_type& __a)
  93       {
  94         for (const char_type* __p = __s; size_t(__p - __s) < __n; ++__p)
  95           if (*__p == __a) return __p;
  96         return 0;
  97       }
  98
  99       static char_type*
 100       move(char_type* __s1, const char_type* __s2, size_t __n)
 101       { return (char_type*) memmove(__s1, __s2, __n * sizeof(char_type)); }
 102
 103       static char_type*
 104       copy(char_type* __s1, const char_type* __s2, size_t __n)
 105       { return (char_type*) memcpy(__s1, __s2, __n * sizeof(char_type)); }
 106
 107       static char_type*
 108       assign(char_type* __s, size_t __n, char_type __a)
 109       {
 110         for (char_type* __p = __s; __p < __s + __n; ++__p)
 111           assign(*__p, __a);
 112         return __s;
 113       }
 114
 115       static char_type
 116       to_char_type(const int_type& __c)
 117       { return char_type(__c); }
 118
 119       static int_type
 120       to_int_type(const char_type& __c) { return int_type(__c); }
 121
 122       static bool
 123       eq_int_type(const int_type& __c1, const int_type& __c2)
 124       { return __c1 == __c2; }
 125
 126       static int_type
 127       eof() { return static_cast<int_type>(-1); }
 128
 129       static int_type
 130       not_eof(const int_type& __c)
 131       { return eq_int_type(__c, eof()) ? int_type(0) : __c; }
 132     };
 133
 134
 135   /// 21.1.4  char_traits specializations
 136   template<>
 137     struct char_traits<char>
 138     {
 139       typedef char              char_type;
 140       typedef int               int_type;
 141       typedef streampos         pos_type;
 142       typedef streamoff         off_type;
 143       typedef mbstate_t         state_type;
 144
 145       static void
 146       assign(char_type& __c1, const char_type& __c2)
 147       { __c1 = __c2; }
 148
 149       static bool
 150       eq(const char_type& __c1, const char_type& __c2)
 151       { return __c1 == __c2; }
 152
 153       static bool
 154       lt(const char_type& __c1, const char_type& __c2)
 155       { return __c1 < __c2; }
 156
 157       static int
 158       compare(const char_type* __s1, const char_type* __s2, size_t __n)
 159       { return memcmp(__s1, __s2, __n); }
 160
 161       static size_t
 162       length(const char_type* __s)
 163       { return strlen(__s); }
 164
 165       static const char_type*
 166       find(const char_type* __s, size_t __n, const char_type& __a)
 167       { return static_cast<const char_type*>(memchr(__s, __a, __n)); }
 168
 169       static char_type*
 170       move(char_type* __s1, const char_type* __s2, size_t __n)
 171       { return static_cast<char_type*>(memmove(__s1, __s2, __n)); }
 172
 173       static char_type*
 174       copy(char_type* __s1, const char_type* __s2, size_t __n)
 175       {  return static_cast<char_type*>(memcpy(__s1, __s2, __n)); }
 176
 177       static char_type*
 178       assign(char_type* __s, size_t __n, char_type __a)
 179       { return static_cast<char_type*>(memset(__s, __a, __n)); }
 180
 181       static char_type
 182       to_char_type(const int_type& __c)
 183       { return static_cast<char_type>(__c); }
 184
 185       // To keep both the byte 0xff and the eof symbol 0xffffffff
 186       // from ending up as 0xffffffff.
 187       static int_type
 188       to_int_type(const char_type& __c)
 189       { return static_cast<int_type>(static_cast<unsigned char>(__c)); }
 190
 191       static bool
 192       eq_int_type(const int_type& __c1, const int_type& __c2)
 193       { return __c1 == __c2; }
 194
 195       static int_type
 196       eof() { return static_cast<int_type>(EOF); }
 197
 198       static int_type
 199       not_eof(const int_type& __c)
 200       { return (__c == eof()) ? 0 : __c; }
 201   };
 202
 203
 204 #ifdef _GLIBCPP_USE_WCHAR_T
 205   template<>
 206     struct char_traits<wchar_t>
 207     {
 208       typedef wchar_t           char_type;
 209       typedef wint_t            int_type;
 210       typedef streamoff         off_type;
 211       typedef wstreampos        pos_type;
 212       typedef mbstate_t         state_type;
 213
 214       static void
 215       assign(char_type& __c1, const char_type& __c2)
 216       { __c1 = __c2; }
 217
 218       static bool
 219       eq(const char_type& __c1, const char_type& __c2)
 220       { return __c1 == __c2; }
 221
 222       static bool
 223       lt(const char_type& __c1, const char_type& __c2)
 224       { return __c1 < __c2; }
 225
 226       static int
 227       compare(const char_type* __s1, const char_type* __s2, size_t __n)
 228       { return wmemcmp(__s1, __s2, __n); }
 229
 230       static size_t
 231       length(const char_type* __s)
 232       { return wcslen(__s); }
 233
 234       static const char_type*
 235       find(const char_type* __s, size_t __n, const char_type& __a)
 236       { return wmemchr(__s, __a, __n); }
 237
 238       static char_type*
 239       move(char_type* __s1, const char_type* __s2, int_type __n)
 240       { return wmemmove(__s1, __s2, __n); }
 241
 242       static char_type*
 243       copy(char_type* __s1, const char_type* __s2, size_t __n)
 244       { return wmemcpy(__s1, __s2, __n); }
 245
 246       static char_type*
 247       assign(char_type* __s, size_t __n, char_type __a)
 248       { return wmemset(__s, __a, __n); }
 249
 250       static char_type
 251       to_char_type(const int_type& __c) { return char_type(__c); }
 252
 253       static int_type
 254       to_int_type(const char_type& __c) { return int_type(__c); }
 255
 256       static bool
 257       eq_int_type(const int_type& __c1, const int_type& __c2)
 258       { return __c1 == __c2; }
 259
 260       static int_type
 261       eof() { return static_cast<int_type>(WEOF); }
 262
 263       static int_type
 264       not_eof(const int_type& __c)
 265       { return eq_int_type(__c, eof()) ? 0 : __c; }
 266   };
 267 #endif //_GLIBCPP_USE_WCHAR_T
 268
 269   template<typename _CharT, typename _Traits>
 270     struct _Char_traits_match
 271     {
 272       _CharT _M_c;
 273       _Char_traits_match(_CharT const& __c) : _M_c(__c) { }
 274
 275       bool
 276       operator()(_CharT const& __a) { return _Traits::eq(_M_c, __a); }
 277     };
 278 } // namespace std
 279
 280 #endif