libstdc++-v3/include/bits/sstream.tcc

   1 // String based streams -*- C++ -*-
   2
   3 // Copyright (C) 1997-1999, 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: 27.7  String-based streams
  32 //
  33
  34 #ifndef _CPP_BITS_SSTREAM_TCC
  35 #define _CPP_BITS_SSTREAM_TCC   1
  36
  37 #include <sstream>
  38
  39 namespace std
  40 {
  41
  42   template <class _CharT, class _Traits, class _Alloc>
  43     typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
  44     basic_stringbuf<_CharT, _Traits, _Alloc>::
  45     pbackfail(int_type __c)
  46     {
  47       int_type __ret = traits_type::eof();
  48       bool __testeof = traits_type::eq_int_type(__c, traits_type::eof());
  49       bool __testpos = _M_in_cur && _M_in_beg < _M_in_cur;
  50
  51       // Try to put back __c into input sequence in one of three ways.
  52       // Order these tests done in is unspecified by the standard.
  53       if (__testpos)
  54         {
  55           if (traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1])
  56               && !__testeof)
  57             {
  58               --_M_in_cur;
  59               __ret = __c;
  60             }
  61           else if (!__testeof)
  62             {
  63               --_M_in_cur;
  64               *_M_in_cur = traits_type::to_char_type(__c);
  65               __ret = __c;
  66             }
  67           else if (__testeof)
  68             {
  69               --_M_in_cur;
  70               __ret = traits_type::not_eof(__c);
  71             }
  72         }
  73       return __ret;
  74     }
  75
  76   template <class _CharT, class _Traits, class _Alloc>
  77     typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
  78     basic_stringbuf<_CharT, _Traits, _Alloc>::
  79     overflow(int_type __c)
  80     {
  81       int_type __ret = traits_type::eof();
  82       bool __testeof = traits_type::eq_int_type(__c, __ret);
  83       bool __testwrite = _M_out_cur < _M_buf + _M_buf_size;
  84       bool __testout = _M_mode & ios_base::out;
  85
  86       // Try to append __c into output sequence in one of two ways.
  87       // Order these tests done in is unspecified by the standard.
  88       if (__testout)
  89         {
  90           if (!__testeof)
  91             {
  92               __size_type __len = max(_M_buf_size, _M_buf_size_opt);
  93               __len *= 2;
  94
  95               if (__testwrite)
  96                 __ret = this->sputc(__c);
  97               else if (__len <= _M_string.max_size())
  98                 {
  99                   // Force-allocate, re-sync.
 100                   _M_string = this->str();
 101                   _M_string.reserve(__len);
 102                   _M_buf_size = static_cast<int_type>(__len);
 103                   _M_really_sync(_M_in_cur - _M_in_beg,
 104                                  _M_out_cur - _M_out_beg);
 105                   *_M_out_cur = traits_type::to_char_type(__c);
 106                   _M_out_cur_move(1);
 107                   __ret = __c;
 108                 }
 109             }
 110           else
 111             __ret = traits_type::not_eof(__c);
 112         }
 113       return __ret;
 114     }
 115
 116   template <class _CharT, class _Traits, class _Alloc>
 117     typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
 118     basic_stringbuf<_CharT, _Traits, _Alloc>::
 119     seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
 120     {
 121       pos_type __ret =  pos_type(off_type(-1));
 122       bool __testin = __mode & ios_base::in && _M_mode & ios_base::in;
 123       bool __testout = __mode & ios_base::out && _M_mode & ios_base::out;
 124       bool __testboth = __testin && __testout && __way != ios_base::cur;
 125
 126       if (_M_buf_size && ((__testin != __testout) || __testboth))
 127         {
 128           char_type* __beg = _M_buf;
 129           char_type* __curi = NULL;
 130           char_type* __curo = NULL;
 131           char_type* __endi = NULL;
 132           char_type* __endo = NULL;
 133
 134           if (__testin)
 135             {
 136               __curi = this->gptr();
 137               __endi = this->egptr();
 138             }
 139           if (__testout)
 140             {
 141               __curo = this->pptr();
 142               __endo = this->epptr();
 143             }
 144
 145           off_type __newoffi = 0;
 146           off_type __newoffo = 0;
 147           if (__way == ios_base::cur)
 148             {
 149               __newoffi = __curi - __beg;
 150               __newoffo = __curo - __beg;
 151             }
 152           else if (__way == ios_base::end)
 153             {
 154               __newoffi = __endi - __beg;
 155               __newoffo = __endo - __beg;
 156             }
 157
 158           if (__testin
 159               && __newoffi + __off >= 0 && __endi - __beg >= __newoffi + __off)
 160             {
 161               _M_in_cur = __beg + __newoffi + __off;
 162               __ret = pos_type(__newoffi);
 163             }
 164           if (__testout
 165               && __newoffo + __off >= 0 && __endo - __beg >= __newoffo + __off)
 166             {
 167               _M_out_cur_move(__newoffo + __off - (_M_out_cur - __beg));
 168               __ret = pos_type(__newoffo);
 169             }
 170         }
 171       return __ret;
 172     }
 173
 174   template <class _CharT, class _Traits, class _Alloc>
 175     typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
 176     basic_stringbuf<_CharT, _Traits, _Alloc>::
 177     seekpos(pos_type __sp, ios_base::openmode __mode)
 178     {
 179       pos_type __ret =  pos_type(off_type(-1));
 180       off_type __pos = __sp._M_position();
 181       char_type* __beg = NULL;
 182       char_type* __end = NULL;
 183       bool __testin = __mode & ios_base::in && _M_mode & ios_base::in;
 184       bool __testout = __mode & ios_base::out && _M_mode & ios_base::out;
 185
 186       if (__testin)
 187         {
 188           __beg = this->eback();
 189           __end = this->egptr();
 190         }
 191       if (__testout)
 192         {
 193           __beg = this->pbase();
 194           __end = _M_buf + _M_buf_size;
 195         }
 196
 197       if (0 <= __pos && __pos <= __end - __beg)
 198         {
 199           // Need to set both of these if applicable
 200           if (__testin)
 201             _M_in_cur = _M_in_beg + __pos;
 202           if (__testout)
 203             _M_out_cur_move((__pos) - (_M_out_cur - __beg));
 204           __ret = pos_type(off_type(__pos));
 205         }
 206
 207       return __ret;
 208     }
 209
 210 } // namespace std
 211
 212 #endif  /* _CPP_BITS_SSTREAM_TCC */
 213