sstream.tcc

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00001 // String based streams -*- C++ -*-
00002 
00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
00004 // 2006, 2007
00005 // Free Software Foundation, Inc.
00006 //
00007 // This file is part of the GNU ISO C++ Library.  This library is free
00008 // software; you can redistribute it and/or modify it under the
00009 // terms of the GNU General Public License as published by the
00010 // Free Software Foundation; either version 2, or (at your option)
00011 // any later version.
00012 
00013 // This library is distributed in the hope that it will be useful,
00014 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00015 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00016 // GNU General Public License for more details.
00017 
00018 // You should have received a copy of the GNU General Public License along
00019 // with this library; see the file COPYING.  If not, write to the Free
00020 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
00021 // USA.
00022 
00023 // As a special exception, you may use this file as part of a free software
00024 // library without restriction.  Specifically, if other files instantiate
00025 // templates or use macros or inline functions from this file, or you compile
00026 // this file and link it with other files to produce an executable, this
00027 // file does not by itself cause the resulting executable to be covered by
00028 // the GNU General Public License.  This exception does not however
00029 // invalidate any other reasons why the executable file might be covered by
00030 // the GNU General Public License.
00031 
00032 /** @file sstream.tcc
00033  *  This is an internal header file, included by other library headers.
00034  *  You should not attempt to use it directly.
00035  */
00036 
00037 //
00038 // ISO C++ 14882: 27.7  String-based streams
00039 //
00040 
00041 #ifndef _SSTREAM_TCC
00042 #define _SSTREAM_TCC 1
00043 
00044 #pragma GCC system_header
00045 
00046 _GLIBCXX_BEGIN_NAMESPACE(std)
00047 
00048   template <class _CharT, class _Traits, class _Alloc>
00049     typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
00050     basic_stringbuf<_CharT, _Traits, _Alloc>::
00051     pbackfail(int_type __c)
00052     {
00053       int_type __ret = traits_type::eof();
00054       if (this->eback() < this->gptr())
00055     {
00056       // Try to put back __c into input sequence in one of three ways.
00057       // Order these tests done in is unspecified by the standard.
00058       const bool __testeof = traits_type::eq_int_type(__c, __ret);
00059       if (!__testeof)
00060         {
00061           const bool __testeq = traits_type::eq(traits_type::
00062                             to_char_type(__c),
00063                             this->gptr()[-1]);    
00064           const bool __testout = this->_M_mode & ios_base::out;
00065           if (__testeq || __testout)
00066         {
00067           this->gbump(-1);
00068           if (!__testeq)
00069             *this->gptr() = traits_type::to_char_type(__c);
00070           __ret = __c;
00071         }
00072         }
00073       else
00074         {
00075           this->gbump(-1);
00076           __ret = traits_type::not_eof(__c);
00077         }
00078     }
00079       return __ret;
00080     }
00081 
00082   template <class _CharT, class _Traits, class _Alloc>
00083     typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
00084     basic_stringbuf<_CharT, _Traits, _Alloc>::
00085     overflow(int_type __c)
00086     {
00087       const bool __testout = this->_M_mode & ios_base::out;
00088       if (__builtin_expect(!__testout, false))
00089     return traits_type::eof();
00090 
00091       const bool __testeof = traits_type::eq_int_type(__c, traits_type::eof());
00092       if (__builtin_expect(__testeof, false))
00093     return traits_type::not_eof(__c);
00094 
00095       const __size_type __capacity = _M_string.capacity();
00096       const __size_type __max_size = _M_string.max_size();
00097       const bool __testput = this->pptr() < this->epptr();
00098       if (__builtin_expect(!__testput && __capacity == __max_size, false))
00099     return traits_type::eof();
00100 
00101       // Try to append __c into output sequence in one of two ways.
00102       // Order these tests done in is unspecified by the standard.
00103       const char_type __conv = traits_type::to_char_type(__c);
00104       if (!__testput)
00105     {
00106       // NB: Start ostringstream buffers at 512 chars.  This is an
00107       // experimental value (pronounced "arbitrary" in some of the
00108       // hipper English-speaking countries), and can be changed to
00109       // suit particular needs.
00110       //
00111       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00112       // 169. Bad efficiency of overflow() mandated
00113       // 432. stringbuf::overflow() makes only one write position
00114       //      available
00115       const __size_type __opt_len = std::max(__size_type(2 * __capacity),
00116                          __size_type(512));
00117       const __size_type __len = std::min(__opt_len, __max_size);
00118       __string_type __tmp;
00119       __tmp.reserve(__len);
00120       if (this->pbase())
00121         __tmp.assign(this->pbase(), this->epptr() - this->pbase());
00122       __tmp.push_back(__conv);
00123       _M_string.swap(__tmp);
00124       _M_sync(const_cast<char_type*>(_M_string.data()),
00125           this->gptr() - this->eback(), this->pptr() - this->pbase());
00126     }
00127       else
00128     *this->pptr() = __conv;
00129       this->pbump(1);
00130       return __c;
00131     }
00132 
00133   template <class _CharT, class _Traits, class _Alloc>
00134     typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
00135     basic_stringbuf<_CharT, _Traits, _Alloc>::
00136     underflow()
00137     {
00138       int_type __ret = traits_type::eof();
00139       const bool __testin = this->_M_mode & ios_base::in;
00140       if (__testin)
00141     {
00142       // Update egptr() to match the actual string end.
00143       _M_update_egptr();
00144 
00145       if (this->gptr() < this->egptr())
00146         __ret = traits_type::to_int_type(*this->gptr());
00147     }
00148       return __ret;
00149     }
00150 
00151   template <class _CharT, class _Traits, class _Alloc>
00152     typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
00153     basic_stringbuf<_CharT, _Traits, _Alloc>::
00154     seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
00155     {
00156       pos_type __ret =  pos_type(off_type(-1));
00157       bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
00158       bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
00159       const bool __testboth = __testin && __testout && __way != ios_base::cur;
00160       __testin &= !(__mode & ios_base::out);
00161       __testout &= !(__mode & ios_base::in);
00162 
00163       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00164       // 453. basic_stringbuf::seekoff need not always fail for an empty stream.
00165       const char_type* __beg = __testin ? this->eback() : this->pbase();
00166       if ((__beg || !__off) && (__testin || __testout || __testboth))
00167     {
00168       _M_update_egptr();
00169 
00170       off_type __newoffi = __off;
00171       off_type __newoffo = __newoffi;
00172       if (__way == ios_base::cur)
00173         {
00174           __newoffi += this->gptr() - __beg;
00175           __newoffo += this->pptr() - __beg;
00176         }
00177       else if (__way == ios_base::end)
00178         __newoffo = __newoffi += this->egptr() - __beg;
00179 
00180       if ((__testin || __testboth)
00181           && __newoffi >= 0
00182           && this->egptr() - __beg >= __newoffi)
00183         {
00184           this->gbump((__beg + __newoffi) - this->gptr());
00185           __ret = pos_type(__newoffi);
00186         }
00187       if ((__testout || __testboth)
00188           && __newoffo >= 0
00189           && this->egptr() - __beg >= __newoffo)
00190         {
00191           this->pbump((__beg + __newoffo) - this->pptr());
00192           __ret = pos_type(__newoffo);
00193         }
00194     }
00195       return __ret;
00196     }
00197 
00198   template <class _CharT, class _Traits, class _Alloc>
00199     typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
00200     basic_stringbuf<_CharT, _Traits, _Alloc>::
00201     seekpos(pos_type __sp, ios_base::openmode __mode)
00202     {
00203       pos_type __ret =  pos_type(off_type(-1));
00204       const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
00205       const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
00206 
00207       const char_type* __beg = __testin ? this->eback() : this->pbase();
00208       if ((__beg || !off_type(__sp)) && (__testin || __testout))
00209     {
00210       _M_update_egptr();
00211 
00212       const off_type __pos(__sp);
00213       const bool __testpos = (0 <= __pos
00214                   && __pos <= this->egptr() - __beg);
00215       if (__testpos)
00216         {
00217           if (__testin)
00218         this->gbump((__beg + __pos) - this->gptr());
00219           if (__testout)
00220                 this->pbump((__beg + __pos) - this->pptr());
00221           __ret = __sp;
00222         }
00223     }
00224       return __ret;
00225     }
00226 
00227   template <class _CharT, class _Traits, class _Alloc>
00228     void
00229     basic_stringbuf<_CharT, _Traits, _Alloc>::
00230     _M_sync(char_type* __base, __size_type __i, __size_type __o)
00231     {
00232       const bool __testin = _M_mode & ios_base::in;
00233       const bool __testout = _M_mode & ios_base::out;
00234       char_type* __endg = __base + _M_string.size();
00235       char_type* __endp = __base + _M_string.capacity();
00236 
00237       if (__base != _M_string.data())
00238     {
00239       // setbuf: __i == size of buffer area (_M_string.size() == 0).
00240       __endg += __i;
00241       __i = 0;
00242       __endp = __endg;
00243     }
00244 
00245       if (__testin)
00246     this->setg(__base, __base + __i, __endg);
00247       if (__testout)
00248     {
00249       this->setp(__base, __endp);
00250       this->pbump(__o);
00251       // egptr() always tracks the string end.  When !__testin,
00252       // for the correct functioning of the streambuf inlines
00253       // the other get area pointers are identical.
00254       if (!__testin)
00255         this->setg(__endg, __endg, __endg);
00256     }
00257     }
00258 
00259   // Inhibit implicit instantiations for required instantiations,
00260   // which are defined via explicit instantiations elsewhere.
00261   // NB:  This syntax is a GNU extension.
00262 #if _GLIBCXX_EXTERN_TEMPLATE
00263   extern template class basic_stringbuf<char>;
00264   extern template class basic_istringstream<char>;
00265   extern template class basic_ostringstream<char>;
00266   extern template class basic_stringstream<char>;
00267 
00268 #ifdef _GLIBCXX_USE_WCHAR_T
00269   extern template class basic_stringbuf<wchar_t>;
00270   extern template class basic_istringstream<wchar_t>;
00271   extern template class basic_ostringstream<wchar_t>;
00272   extern template class basic_stringstream<wchar_t>;
00273 #endif
00274 #endif
00275 
00276 _GLIBCXX_END_NAMESPACE
00277 
00278 #endif

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