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

   1 // Stream buffer classes -*- C++ -*-
   2
   3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 //
  32 // ISO C++ 14882: 27.5  Stream buffers
  33 //
  34
  35 #ifndef _STREAMBUF_TCC
  36 #define _STREAMBUF_TCC 1
  37
  38 #pragma GCC system_header
  39
  40 namespace std
  41 {
  42   template<typename _CharT, typename _Traits>
  43     streamsize
  44     basic_streambuf<_CharT, _Traits>::
  45     xsgetn(char_type* __s, streamsize __n)
  46     {
  47       streamsize __ret = 0;
  48       while (__ret < __n)
  49         {
  50           const size_t __buf_len = this->egptr() - this->gptr();
  51           if (__buf_len)
  52             {
  53               const size_t __remaining = __n - __ret;
  54               const size_t __len = std::min(__buf_len, __remaining);
  55               traits_type::copy(__s, this->gptr(), __len);
  56               __ret += __len;
  57               __s += __len;
  58               this->gbump(__len);
  59             }
  60
  61           if (__ret < __n)
  62             {
  63               const int_type __c = this->uflow();
  64               if (!traits_type::eq_int_type(__c, traits_type::eof()))
  65                 {
  66                   traits_type::assign(*__s++, traits_type::to_char_type(__c));
  67                   ++__ret;
  68                 }
  69               else
  70                 break;
  71             }
  72         }
  73       return __ret;
  74     }
  75
  76   template<typename _CharT, typename _Traits>
  77     streamsize
  78     basic_streambuf<_CharT, _Traits>::
  79     xsputn(const char_type* __s, streamsize __n)
  80     {
  81       streamsize __ret = 0;
  82       while (__ret < __n)
  83         {
  84           const size_t __buf_len = this->epptr() - this->pptr();
  85           if (__buf_len)
  86             {
  87               const size_t __remaining = __n - __ret;
  88               const size_t __len = std::min(__buf_len, __remaining);
  89               traits_type::copy(this->pptr(), __s, __len);
  90               __ret += __len;
  91               __s += __len;
  92               this->pbump(__len);
  93             }
  94
  95           if (__ret < __n)
  96             {
  97               int_type __c = this->overflow(traits_type::to_int_type(*__s));
  98               if (!traits_type::eq_int_type(__c, traits_type::eof()))
  99                 {
 100                   ++__ret;
 101                   ++__s;
 102                 }
 103               else
 104                 break;
 105             }
 106         }
 107       return __ret;
 108     }
 109
 110   // Conceivably, this could be used to implement buffer-to-buffer
 111   // copies, if this was ever desired in an un-ambiguous way by the
 112   // standard. If so, then checks for __ios being zero would be
 113   // necessary.
 114   template<typename _CharT, typename _Traits>
 115     streamsize
 116     __copy_streambufs(basic_ios<_CharT, _Traits>& __ios,
 117                       basic_streambuf<_CharT, _Traits>* __sbin,
 118                       basic_streambuf<_CharT, _Traits>* __sbout)
 119     {
 120       streamsize __ret = 0;
 121       try
 122         {
 123           typename _Traits::int_type __c = __sbin->sgetc();
 124           while (!_Traits::eq_int_type(__c, _Traits::eof()))
 125             {
 126               const size_t __n = __sbin->egptr() - __sbin->gptr();
 127               if (__n > 1)
 128                 {
 129                   const size_t __wrote = __sbout->sputn(__sbin->gptr(), __n);
 130                   __sbin->gbump(__wrote);
 131                   __ret += __wrote;
 132                   if (__wrote < __n)
 133                     break;
 134                   __c = __sbin->underflow();
 135                 }
 136               else
 137                 {
 138                   __c = __sbout->sputc(_Traits::to_char_type(__c));
 139                   if (_Traits::eq_int_type(__c, _Traits::eof()))
 140                     break;
 141                   ++__ret;
 142                   __c = __sbin->snextc();
 143                 }
 144             }
 145         }
 146       catch(...)
 147         { __throw_exception_again; }
 148       return __ret;
 149     }
 150
 151   // Inhibit implicit instantiations for required instantiations,
 152   // which are defined via explicit instantiations elsewhere.
 153   // NB:  This syntax is a GNU extension.
 154 #if _GLIBCXX_EXTERN_TEMPLATE
 155   extern template class basic_streambuf<char>;
 156   extern template
 157     streamsize
 158     __copy_streambufs(basic_ios<char>&, basic_streambuf<char>*,
 159                       basic_streambuf<char>*);
 160
 161 #ifdef _GLIBCXX_USE_WCHAR_T
 162   extern template class basic_streambuf<wchar_t>;
 163   extern template
 164     streamsize
 165     __copy_streambufs(basic_ios<wchar_t>&, basic_streambuf<wchar_t>*,
 166                       basic_streambuf<wchar_t>*);
 167 #endif
 168 #endif
 169 } // namespace std
 170
 171 #endif