sstream.tcc

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00001 // String based streams -*- C++ -*-
00002 
00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
00004 // Free Software Foundation, Inc.
00005 //
00006 // This file is part of the GNU ISO C++ Library.  This library is free
00007 // software; you can redistribute it and/or modify it under the
00008 // terms of the GNU General Public License as published by the
00009 // Free Software Foundation; either version 2, or (at your option)
00010 // any later version.
00011 
00012 // This library is distributed in the hope that it will be useful,
00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015 // GNU General Public License for more details.
00016 
00017 // You should have received a copy of the GNU General Public License along
00018 // with this library; see the file COPYING.  If not, write to the Free
00019 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
00020 // USA.
00021 
00022 // As a special exception, you may use this file as part of a free software
00023 // library without restriction.  Specifically, if other files instantiate
00024 // templates or use macros or inline functions from this file, or you compile
00025 // this file and link it with other files to produce an executable, this
00026 // file does not by itself cause the resulting executable to be covered by
00027 // the GNU General Public License.  This exception does not however
00028 // invalidate any other reasons why the executable file might be covered by
00029 // the GNU General Public License.
00030 
00031 /** @file sstream.tcc
00032  *  This is an internal header file, included by other library headers.
00033  *  You should not attempt to use it directly.
00034  */
00035 
00036 //
00037 // ISO C++ 14882: 27.7  String-based streams
00038 //
00039 
00040 #ifndef _SSTREAM_TCC
00041 #define _SSTREAM_TCC 1
00042 
00043 #pragma GCC system_header
00044 
00045 #include <sstream>
00046 
00047 _GLIBCXX_BEGIN_NAMESPACE(std)
00048 
00049   template <class _CharT, class _Traits, class _Alloc>
00050     typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
00051     basic_stringbuf<_CharT, _Traits, _Alloc>::
00052     pbackfail(int_type __c)
00053     {
00054       int_type __ret = traits_type::eof();
00055       if (this->eback() < this->gptr())
00056     {
00057       // Try to put back __c into input sequence in one of three ways.
00058       // Order these tests done in is unspecified by the standard.
00059       const bool __testeof = traits_type::eq_int_type(__c, __ret);
00060       if (!__testeof)
00061         {
00062           const bool __testeq = traits_type::eq(traits_type::
00063                             to_char_type(__c),
00064                             this->gptr()[-1]);    
00065           const bool __testout = this->_M_mode & ios_base::out;
00066           if (__testeq || __testout)
00067         {
00068           this->gbump(-1);
00069           if (!__testeq)
00070             *this->gptr() = traits_type::to_char_type(__c);
00071           __ret = __c;
00072         }
00073         }
00074       else
00075         {
00076           this->gbump(-1);
00077           __ret = traits_type::not_eof(__c);
00078         }
00079     }
00080       return __ret;
00081     }
00082 
00083   template <class _CharT, class _Traits, class _Alloc>
00084     typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
00085     basic_stringbuf<_CharT, _Traits, _Alloc>::
00086     overflow(int_type __c)
00087     {
00088       const bool __testout = this->_M_mode & ios_base::out;
00089       if (__builtin_expect(!__testout, false))
00090     return traits_type::eof();
00091 
00092       const bool __testeof = traits_type::eq_int_type(__c, traits_type::eof());
00093       if (__builtin_expect(__testeof, false))
00094     return traits_type::not_eof(__c);
00095 
00096       const __size_type __capacity = _M_string.capacity();
00097       const __size_type __max_size = _M_string.max_size();
00098       const bool __testput = this->pptr() < this->epptr();
00099       if (__builtin_expect(!__testput && __capacity == __max_size, false))
00100     return traits_type::eof();
00101 
00102       // Try to append __c into output sequence in one of two ways.
00103       // Order these tests done in is unspecified by the standard.
00104       const char_type __conv = traits_type::to_char_type(__c);
00105       if (!__testput)
00106     {
00107       // NB: Start ostringstream buffers at 512 chars.  This is an
00108       // experimental value (pronounced "arbitrary" in some of the
00109       // hipper english-speaking countries), and can be changed to
00110       // suit particular needs.
00111       //
00112       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00113       // 169. Bad efficiency of overflow() mandated
00114       // 432. stringbuf::overflow() makes only one write position
00115       //      available
00116       const __size_type __opt_len = std::max(__size_type(2 * __capacity),
00117                          __size_type(512));
00118       const __size_type __len = std::min(__opt_len, __max_size);
00119       __string_type __tmp;
00120       __tmp.reserve(__len);
00121       if (this->pbase())
00122         __tmp.assign(this->pbase(), this->epptr() - this->pbase());
00123       __tmp.push_back(__conv);
00124       _M_string.swap(__tmp);
00125       _M_sync(const_cast<char_type*>(_M_string.data()),
00126           this->gptr() - this->eback(), this->pptr() - this->pbase());
00127     }
00128       else
00129     *this->pptr() = __conv;
00130       this->pbump(1);
00131       return __c;
00132     }
00133 
00134   template <class _CharT, class _Traits, class _Alloc>
00135     typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
00136     basic_stringbuf<_CharT, _Traits, _Alloc>::
00137     underflow()
00138     {
00139       int_type __ret = traits_type::eof();
00140       const bool __testin = this->_M_mode & ios_base::in;
00141       if (__testin)
00142     {
00143       // Update egptr() to match the actual string end.
00144       _M_update_egptr();
00145 
00146       if (this->gptr() < this->egptr())
00147         __ret = traits_type::to_int_type(*this->gptr());
00148     }
00149       return __ret;
00150     }
00151 
00152   template <class _CharT, class _Traits, class _Alloc>
00153     typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
00154     basic_stringbuf<_CharT, _Traits, _Alloc>::
00155     seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
00156     {
00157       pos_type __ret =  pos_type(off_type(-1));
00158       bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
00159       bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
00160       const bool __testboth = __testin && __testout && __way != ios_base::cur;
00161       __testin &= !(__mode & ios_base::out);
00162       __testout &= !(__mode & ios_base::in);
00163 
00164       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00165       // 453. basic_stringbuf::seekoff need not always fail for an empty stream.
00166       const char_type* __beg = __testin ? this->eback() : this->pbase();
00167       if ((__beg || !__off) && (__testin || __testout || __testboth))
00168     {
00169       _M_update_egptr();
00170 
00171       off_type __newoffi = __off;
00172       off_type __newoffo = __newoffi;
00173       if (__way == ios_base::cur)
00174         {
00175           __newoffi += this->gptr() - __beg;
00176           __newoffo += this->pptr() - __beg;
00177         }
00178       else if (__way == ios_base::end)
00179         __newoffo = __newoffi += this->egptr() - __beg;
00180 
00181       if ((__testin || __testboth)
00182           && __newoffi >= 0
00183           && this->egptr() - __beg >= __newoffi)
00184         {
00185           this->gbump((__beg + __newoffi) - this->gptr());
00186           __ret = pos_type(__newoffi);
00187         }
00188       if ((__testout || __testboth)
00189           && __newoffo >= 0
00190           && this->egptr() - __beg >= __newoffo)
00191         {
00192           this->pbump((__beg + __newoffo) - this->pptr());
00193           __ret = pos_type(__newoffo);
00194         }
00195     }
00196       return __ret;
00197     }
00198 
00199   template <class _CharT, class _Traits, class _Alloc>
00200     typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
00201     basic_stringbuf<_CharT, _Traits, _Alloc>::
00202     seekpos(pos_type __sp, ios_base::openmode __mode)
00203     {
00204       pos_type __ret =  pos_type(off_type(-1));
00205       const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
00206       const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
00207 
00208       const char_type* __beg = __testin ? this->eback() : this->pbase();
00209       if ((__beg || !off_type(__sp)) && (__testin || __testout))
00210     {
00211       _M_update_egptr();
00212 
00213       const off_type __pos(__sp);
00214       const bool __testpos = (0 <= __pos
00215                   && __pos <= this->egptr() - __beg);
00216       if (__testpos)
00217         {
00218           if (__testin)
00219         this->gbump((__beg + __pos) - this->gptr());
00220           if (__testout)
00221                 this->pbump((__beg + __pos) - this->pptr());
00222           __ret = __sp;
00223         }
00224     }
00225       return __ret;
00226     }
00227 
00228   template <class _CharT, class _Traits, class _Alloc>
00229     void
00230     basic_stringbuf<_CharT, _Traits, _Alloc>::
00231     _M_sync(char_type* __base, __size_type __i, __size_type __o)
00232     {
00233       const bool __testin = _M_mode & ios_base::in;
00234       const bool __testout = _M_mode & ios_base::out;
00235       char_type* __endg = __base + _M_string.size();
00236       char_type* __endp = __base + _M_string.capacity();
00237 
00238       if (__base != _M_string.data())
00239     {
00240       // setbuf: __i == size of buffer area (_M_string.size() == 0).
00241       __endg += __i;
00242       __i = 0;
00243       __endp = __endg;
00244     }
00245 
00246       if (__testin)
00247     this->setg(__base, __base + __i, __endg);
00248       if (__testout)
00249     {
00250       this->setp(__base, __endp);
00251       this->pbump(__o);
00252       // egptr() always tracks the string end.  When !__testin,
00253       // for the correct functioning of the streambuf inlines
00254       // the other get area pointers are identical.
00255       if (!__testin)
00256         this->setg(__endg, __endg, __endg);
00257     }
00258     }
00259 
00260   // Inhibit implicit instantiations for required instantiations,
00261   // which are defined via explicit instantiations elsewhere.
00262   // NB:  This syntax is a GNU extension.
00263 #if _GLIBCXX_EXTERN_TEMPLATE
00264   extern template class basic_stringbuf<char>;
00265   extern template class basic_istringstream<char>;
00266   extern template class basic_ostringstream<char>;
00267   extern template class basic_stringstream<char>;
00268 
00269 #ifdef _GLIBCXX_USE_WCHAR_T
00270   extern template class basic_stringbuf<wchar_t>;
00271   extern template class basic_istringstream<wchar_t>;
00272   extern template class basic_ostringstream<wchar_t>;
00273   extern template class basic_stringstream<wchar_t>;
00274 #endif
00275 #endif
00276 
00277 _GLIBCXX_END_NAMESPACE
00278 
00279 #endif

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