char_traits.h

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00001 // Character Traits for use by standard string and iostream -*- C++ -*-
00002 
00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 2, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // You should have received a copy of the GNU General Public License along
00017 // with this library; see the file COPYING.  If not, write to the Free
00018 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
00019 // USA.
00020 
00021 // As a special exception, you may use this file as part of a free software
00022 // library without restriction.  Specifically, if other files instantiate
00023 // templates or use macros or inline functions from this file, or you compile
00024 // this file and link it with other files to produce an executable, this
00025 // file does not by itself cause the resulting executable to be covered by
00026 // the GNU General Public License.  This exception does not however
00027 // invalidate any other reasons why the executable file might be covered by
00028 // the GNU General Public License.
00029 
00030 //
00031 // ISO C++ 14882: 21  Strings library
00032 //
00033 
00039 #ifndef _CPP_BITS_CHAR_TRAITS_H
00040 #define _CPP_BITS_CHAR_TRAITS_H 1
00041 
00042 #pragma GCC system_header
00043 
00044 #include <cstring>  // For memmove, memset, memchr
00045 #include <bits/fpos.h>      // For streampos
00046 
00047 namespace std 
00048 {
00052   template<class _CharT>
00053     struct char_traits
00054     {
00055       typedef _CharT        char_type;
00056       // Unsigned as wint_t in unsigned.
00057       typedef unsigned long     int_type;
00058       typedef streampos     pos_type;
00059       typedef streamoff     off_type;
00060       typedef mbstate_t     state_type;
00061       
00062       static void 
00063       assign(char_type& __c1, const char_type& __c2)
00064       { __c1 = __c2; }
00065 
00066       static bool 
00067       eq(const char_type& __c1, const char_type& __c2)
00068       { return __c1 == __c2; }
00069 
00070       static bool 
00071       lt(const char_type& __c1, const char_type& __c2)
00072       { return __c1 < __c2; }
00073 
00074       static int 
00075       compare(const char_type* __s1, const char_type* __s2, size_t __n)
00076       { 
00077     for (size_t __i = 0; __i < __n; ++__i)
00078       if (!eq(__s1[__i], __s2[__i]))
00079         return lt(__s1[__i], __s2[__i]) ? -1 : 1;
00080     return 0; 
00081       }
00082 
00083       static size_t
00084       length(const char_type* __s)
00085       { 
00086     const char_type* __p = __s; 
00087     while (*__p) ++__p; 
00088     return (__p - __s); 
00089       }
00090 
00091       static const char_type* 
00092       find(const char_type* __s, size_t __n, const char_type& __a)
00093       { 
00094     for (const char_type* __p = __s; size_t(__p - __s) < __n; ++__p)
00095       if (*__p == __a) return __p;
00096     return 0;
00097       }
00098 
00099       static char_type* 
00100       move(char_type* __s1, const char_type* __s2, size_t __n)
00101       { return (char_type*) memmove(__s1, __s2, __n * sizeof(char_type)); }
00102 
00103       static char_type* 
00104       copy(char_type* __s1, const char_type* __s2, size_t __n)
00105       { return (char_type*) memcpy(__s1, __s2, __n * sizeof(char_type)); }
00106 
00107       static char_type* 
00108       assign(char_type* __s, size_t __n, char_type __a)
00109       { 
00110     for (char_type* __p = __s; __p < __s + __n; ++__p) 
00111       assign(*__p, __a);
00112         return __s; 
00113       }
00114 
00115       static char_type 
00116       to_char_type(const int_type& __c)
00117       { return char_type(__c); }
00118 
00119       static int_type 
00120       to_int_type(const char_type& __c) { return int_type(__c); }
00121 
00122       static bool 
00123       eq_int_type(const int_type& __c1, const int_type& __c2)
00124       { return __c1 == __c2; }
00125 
00126       static int_type 
00127       eof() { return static_cast<int_type>(-1); }
00128 
00129       static int_type 
00130       not_eof(const int_type& __c)
00131       { return eq_int_type(__c, eof()) ? int_type(0) : __c; }
00132     };
00133 
00134 
00136   template<>
00137     struct char_traits<char>
00138     {
00139       typedef char      char_type;
00140       typedef int           int_type;
00141       typedef streampos     pos_type;
00142       typedef streamoff     off_type;
00143       typedef mbstate_t     state_type;
00144 
00145       static void 
00146       assign(char_type& __c1, const char_type& __c2)
00147       { __c1 = __c2; }
00148 
00149       static bool 
00150       eq(const char_type& __c1, const char_type& __c2)
00151       { return __c1 == __c2; }
00152 
00153       static bool 
00154       lt(const char_type& __c1, const char_type& __c2)
00155       { return __c1 < __c2; }
00156 
00157       static int 
00158       compare(const char_type* __s1, const char_type* __s2, size_t __n)
00159       { return memcmp(__s1, __s2, __n); }
00160 
00161       static size_t
00162       length(const char_type* __s)
00163       { return strlen(__s); }
00164 
00165       static const char_type* 
00166       find(const char_type* __s, size_t __n, const char_type& __a)
00167       { return static_cast<const char_type*>(memchr(__s, __a, __n)); }
00168 
00169       static char_type* 
00170       move(char_type* __s1, const char_type* __s2, size_t __n)
00171       { return static_cast<char_type*>(memmove(__s1, __s2, __n)); }
00172 
00173       static char_type* 
00174       copy(char_type* __s1, const char_type* __s2, size_t __n)
00175       {  return static_cast<char_type*>(memcpy(__s1, __s2, __n)); }
00176 
00177       static char_type* 
00178       assign(char_type* __s, size_t __n, char_type __a)
00179       { return static_cast<char_type*>(memset(__s, __a, __n)); }
00180 
00181       static char_type 
00182       to_char_type(const int_type& __c)
00183       { return static_cast<char_type>(__c); }
00184 
00185       // To keep both the byte 0xff and the eof symbol 0xffffffff
00186       // from ending up as 0xffffffff.
00187       static int_type 
00188       to_int_type(const char_type& __c)
00189       { return static_cast<int_type>(static_cast<unsigned char>(__c)); }
00190 
00191       static bool 
00192       eq_int_type(const int_type& __c1, const int_type& __c2)
00193       { return __c1 == __c2; }
00194 
00195       static int_type 
00196       eof() { return static_cast<int_type>(EOF); }
00197 
00198       static int_type 
00199       not_eof(const int_type& __c)
00200       { return (__c == eof()) ? 0 : __c; }
00201   };
00202 
00203 
00204 #ifdef _GLIBCPP_USE_WCHAR_T
00205   template<>
00206     struct char_traits<wchar_t>
00207     {
00208       typedef wchar_t       char_type;
00209       typedef wint_t        int_type;
00210       typedef streamoff     off_type;
00211       typedef wstreampos    pos_type;
00212       typedef mbstate_t     state_type;
00213       
00214       static void 
00215       assign(char_type& __c1, const char_type& __c2)
00216       { __c1 = __c2; }
00217 
00218       static bool 
00219       eq(const char_type& __c1, const char_type& __c2)
00220       { return __c1 == __c2; }
00221 
00222       static bool 
00223       lt(const char_type& __c1, const char_type& __c2)
00224       { return __c1 < __c2; }
00225 
00226       static int 
00227       compare(const char_type* __s1, const char_type* __s2, size_t __n)
00228       { return wmemcmp(__s1, __s2, __n); }
00229 
00230       static size_t
00231       length(const char_type* __s)
00232       { return wcslen(__s); }
00233 
00234       static const char_type* 
00235       find(const char_type* __s, size_t __n, const char_type& __a)
00236       { return wmemchr(__s, __a, __n); }
00237 
00238       static char_type* 
00239       move(char_type* __s1, const char_type* __s2, int_type __n)
00240       { return wmemmove(__s1, __s2, __n); }
00241 
00242       static char_type* 
00243       copy(char_type* __s1, const char_type* __s2, size_t __n)
00244       { return wmemcpy(__s1, __s2, __n); }
00245 
00246       static char_type* 
00247       assign(char_type* __s, size_t __n, char_type __a)
00248       { return wmemset(__s, __a, __n); }
00249 
00250       static char_type 
00251       to_char_type(const int_type& __c) { return char_type(__c); }
00252 
00253       static int_type 
00254       to_int_type(const char_type& __c) { return int_type(__c); }
00255 
00256       static bool 
00257       eq_int_type(const int_type& __c1, const int_type& __c2)
00258       { return __c1 == __c2; }
00259 
00260       static int_type 
00261       eof() { return static_cast<int_type>(WEOF); }
00262 
00263       static int_type 
00264       not_eof(const int_type& __c)
00265       { return eq_int_type(__c, eof()) ? 0 : __c; }
00266   };
00267 #endif //_GLIBCPP_USE_WCHAR_T
00268 
00269   template<typename _CharT, typename _Traits>
00270     struct _Char_traits_match
00271     {
00272       _CharT _M_c;
00273       _Char_traits_match(_CharT const& __c) : _M_c(__c) { }
00274 
00275       bool 
00276       operator()(_CharT const& __a) { return _Traits::eq(_M_c, __a); }
00277     };
00278 } // namespace std
00279 
00280 #endif

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