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      1 // Stream buffer classes -*- C++ -*-
      2 
      3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
      4 // 2006, 2009  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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
     18 // permissions described in the GCC Runtime Library Exception, version
     19 // 3.1, as published by the Free Software Foundation.
     20 
     21 // You should have received a copy of the GNU General Public License and
     22 // a copy of the GCC Runtime Library Exception along with this program;
     23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
     24 // <http://www.gnu.org/licenses/>.
     25 
     26 /** @file streambuf.tcc
     27  *  This is an internal header file, included by other library headers.
     28  *  You should not attempt to use it directly.
     29  */
     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 _GLIBCXX_BEGIN_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 streamsize __buf_len = this->egptr() - this->gptr();
     51 	  if (__buf_len)
     52 	    {
     53 	      const streamsize __remaining = __n - __ret;
     54 	      const streamsize __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 streamsize __buf_len = this->epptr() - this->pptr();
     85 	  if (__buf_len)
     86 	    {
     87 	      const streamsize __remaining = __n - __ret;
     88 	      const streamsize __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.
    113   template<typename _CharT, typename _Traits>
    114     streamsize
    115     __copy_streambufs_eof(basic_streambuf<_CharT, _Traits>* __sbin,
    116 			  basic_streambuf<_CharT, _Traits>* __sbout,
    117 			  bool& __ineof)
    118     {
    119       streamsize __ret = 0;
    120       __ineof = true;
    121       typename _Traits::int_type __c = __sbin->sgetc();
    122       while (!_Traits::eq_int_type(__c, _Traits::eof()))
    123 	{
    124 	  __c = __sbout->sputc(_Traits::to_char_type(__c));
    125 	  if (_Traits::eq_int_type(__c, _Traits::eof()))
    126 	    {
    127 	      __ineof = false;
    128 	      break;
    129 	    }
    130 	  ++__ret;
    131 	  __c = __sbin->snextc();
    132 	}
    133       return __ret;
    134     }
    135 
    136   template<typename _CharT, typename _Traits>
    137     inline streamsize
    138     __copy_streambufs(basic_streambuf<_CharT, _Traits>* __sbin,
    139 		      basic_streambuf<_CharT, _Traits>* __sbout)
    140     {
    141       bool __ineof;
    142       return __copy_streambufs_eof(__sbin, __sbout, __ineof);
    143     }
    144 
    145   // Inhibit implicit instantiations for required instantiations,
    146   // which are defined via explicit instantiations elsewhere.
    147   // NB:  This syntax is a GNU extension.
    148 #if _GLIBCXX_EXTERN_TEMPLATE
    149   extern template class basic_streambuf<char>;
    150   extern template
    151     streamsize
    152     __copy_streambufs(basic_streambuf<char>*,
    153 		      basic_streambuf<char>*);
    154   extern template
    155     streamsize
    156     __copy_streambufs_eof(basic_streambuf<char>*,
    157 			  basic_streambuf<char>*, bool&);
    158 
    159 #ifdef _GLIBCXX_USE_WCHAR_T
    160   extern template class basic_streambuf<wchar_t>;
    161   extern template
    162     streamsize
    163     __copy_streambufs(basic_streambuf<wchar_t>*,
    164 		      basic_streambuf<wchar_t>*);
    165   extern template
    166     streamsize
    167     __copy_streambufs_eof(basic_streambuf<wchar_t>*,
    168 			  basic_streambuf<wchar_t>*, bool&);
    169 #endif
    170 #endif
    171 
    172 _GLIBCXX_END_NAMESPACE
    173 
    174 #endif
    175