sstream

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00001 // String based streams -*- C++ -*-
00002 
00003 // Copyright (C) 1997, 1998, 1999, 2002 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 2, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // You should have received a copy of the GNU General Public License along
00017 // with this library; see the file COPYING.  If not, write to the Free
00018 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
00019 // USA.
00020 
00021 // As a special exception, you may use this file as part of a free software
00022 // library without restriction.  Specifically, if other files instantiate
00023 // templates or use macros or inline functions from this file, or you compile
00024 // this file and link it with other files to produce an executable, this
00025 // file does not by itself cause the resulting executable to be covered by
00026 // the GNU General Public License.  This exception does not however
00027 // invalidate any other reasons why the executable file might be covered by
00028 // the GNU General Public License.
00029 
00030 //
00031 // ISO C++ 14882: 27.7  String-based streams
00032 //
00033 
00039 #ifndef _CPP_SSTREAM
00040 #define _CPP_SSTREAM    1
00041 
00042 #pragma GCC system_header
00043 
00044 #include <istream>
00045 #include <ostream>
00046 
00047 namespace std
00048 {
00049   // [27.7.1] template class basic_stringbuf
00061   template<typename _CharT, typename _Traits, typename _Alloc>
00062     class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
00063     {
00064     public:
00065       // Types:
00066       typedef _CharT                    char_type;
00067       typedef _Traits                   traits_type;
00068 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
00069 // 251. basic_stringbuf missing allocator_type
00070       typedef _Alloc                        allocator_type;
00071 #endif
00072       typedef typename traits_type::int_type        int_type;
00073       typedef typename traits_type::pos_type        pos_type;
00074       typedef typename traits_type::off_type        off_type;
00075 
00077 
00082       typedef basic_streambuf<char_type, traits_type>   __streambuf_type;
00083       typedef basic_string<char_type, _Traits, _Alloc>  __string_type;
00084       typedef typename __string_type::size_type     __size_type;
00086 
00087     protected:
00088       // Data Members:
00094       __string_type         _M_string;
00095 
00096     public:
00097       // Constructors:
00105       explicit
00106       basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)
00107       : __streambuf_type(), _M_string()
00108       { _M_stringbuf_init(__mode); }
00109 
00118       explicit
00119       basic_stringbuf(const __string_type& __str,
00120               ios_base::openmode __mode = ios_base::in | ios_base::out)
00121       : __streambuf_type(), _M_string(__str.data(), __str.size())
00122       { _M_stringbuf_init(__mode); }
00123 
00124       // Get and set:
00133       __string_type
00134       str() const
00135       {
00136     if (_M_mode & ios_base::out)
00137       {
00138         // This is the deal: _M_string.size() is a value that
00139         // represents the size of the initial string that makes
00140         // _M_string, and may not be the correct size of the
00141         // current stringbuf internal buffer.
00142         __size_type __len = _M_string.size();
00143         if (_M_out_cur > _M_out_beg)
00144           __len = max(__size_type(_M_out_end - _M_out_beg), __len);
00145         return __string_type(_M_out_beg, _M_out_beg + __len);
00146       }
00147     else
00148       return _M_string;
00149       }
00150 
00158       void
00159       str(const __string_type& __s)
00160       {
00161     // Cannot use _M_string = __s, since v3 strings are COW.
00162     _M_string.assign(__s.data(), __s.size());
00163     _M_stringbuf_init(_M_mode);
00164       }
00165 
00166     protected:
00167       // Common initialization code for both ctors goes here.
00173       void
00174       _M_stringbuf_init(ios_base::openmode __mode)
00175       {
00176     // _M_buf_size is a convenient alias for "what the streambuf
00177     // thinks the allocated size of the string really is." This is
00178     // necessary as ostringstreams are implemented with the
00179     // streambufs having control of the allocation and
00180     // re-allocation of the internal string object, _M_string.
00181     _M_buf_size = _M_string.size();
00182 
00183     // NB: Start ostringstream buffers at 512 bytes. This is an
00184     // experimental value (pronounced "arbitrary" in some of the
00185     // hipper english-speaking countries), and can be changed to
00186     // suit particular needs.
00187     _M_buf_size_opt = 512;
00188     _M_mode = __mode;
00189     if (_M_mode & (ios_base::ate | ios_base::app))
00190       _M_really_sync(0, _M_buf_size);
00191     else
00192       _M_really_sync(0, 0);
00193       }
00194 
00195       // Overridden virtual functions:
00196       // [documentation is inherited]
00197       virtual int_type
00198       underflow()
00199       {
00200     if (_M_in_cur && _M_in_cur < _M_in_end)
00201       return traits_type::to_int_type(*gptr());
00202     else
00203       return traits_type::eof();
00204       }
00205 
00206       // [documentation is inherited]
00207       virtual int_type
00208       pbackfail(int_type __c = traits_type::eof());
00209 
00210       // [documentation is inherited]
00211       virtual int_type
00212       overflow(int_type __c = traits_type::eof());
00213 
00225       virtual __streambuf_type*
00226       setbuf(char_type* __s, streamsize __n)
00227       {
00228     if (__s && __n)
00229       {
00230         _M_string = __string_type(__s, __n);
00231         _M_really_sync(0, 0);
00232       }
00233     return this;
00234       }
00235 
00236       // [documentation is inherited]
00237       virtual pos_type
00238       seekoff(off_type __off, ios_base::seekdir __way,
00239           ios_base::openmode __mode = ios_base::in | ios_base::out);
00240 
00241       // [documentation is inherited]
00242       virtual pos_type
00243       seekpos(pos_type __sp,
00244           ios_base::openmode __mode = ios_base::in | ios_base::out);
00245 
00246       // Internal function for correctly updating the internal buffer
00247       // for a particular _M_string, due to initialization or
00248       // re-sizing of an existing _M_string.
00249       // Assumes: contents of _M_string and internal buffer match exactly.
00250       // __i == _M_in_cur - _M_in_beg
00251       // __o == _M_out_cur - _M_out_beg
00257       virtual int
00258       _M_really_sync(__size_type __i, __size_type __o)
00259       {
00260     char_type* __base = const_cast<char_type*>(_M_string.data());
00261     bool __testin = _M_mode & ios_base::in;
00262     bool __testout = _M_mode & ios_base::out;
00263     __size_type __len = _M_string.size();
00264 
00265     _M_buf = __base;
00266     if (__testin)
00267         this->setg(__base, __base + __i, __base + __len);
00268     if (__testout)
00269       {
00270         this->setp(__base, __base + __len);
00271         _M_out_cur += __o;
00272       }
00273     return 0;
00274       }
00275     };
00276 
00277 
00278   // [27.7.2] Template class basic_istringstream
00287   template<typename _CharT, typename _Traits, typename _Alloc>
00288     class basic_istringstream : public basic_istream<_CharT, _Traits>
00289     {
00290     public:
00291       // Types:
00292       typedef _CharT                    char_type;
00293       typedef _Traits                   traits_type;
00294 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
00295 // 251. basic_stringbuf missing allocator_type
00296       typedef _Alloc                        allocator_type;
00297 #endif
00298       typedef typename traits_type::int_type        int_type;
00299       typedef typename traits_type::pos_type        pos_type;
00300       typedef typename traits_type::off_type        off_type;
00301 
00302       // Non-standard types:
00303       typedef basic_string<_CharT, _Traits, _Alloc>     __string_type;
00304       typedef basic_stringbuf<_CharT, _Traits, _Alloc>  __stringbuf_type;
00305       typedef basic_istream<char_type, traits_type> __istream_type;
00306 
00307     private:
00313       __stringbuf_type  _M_stringbuf;
00314 
00315     public:
00316       // Constructors:
00331       explicit
00332       basic_istringstream(ios_base::openmode __mode = ios_base::in)
00333       : __istream_type(NULL), _M_stringbuf(__mode | ios_base::in)
00334       { this->init(&_M_stringbuf); }
00335 
00351       explicit
00352       basic_istringstream(const __string_type& __str,
00353               ios_base::openmode __mode = ios_base::in)
00354       : __istream_type(NULL), _M_stringbuf(__str, __mode | ios_base::in)
00355       { this->init(&_M_stringbuf); }
00356 
00363       ~basic_istringstream()
00364       { }
00365 
00366       // Members:
00373       __stringbuf_type*
00374       rdbuf() const
00375       { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
00376 
00381       __string_type
00382       str() const
00383       { return _M_stringbuf.str(); }
00384 
00391       void
00392       str(const __string_type& __s)
00393       { _M_stringbuf.str(__s); }
00394     };
00395 
00396 
00397   // [27.7.3] Template class basic_ostringstream
00406   template <typename _CharT, typename _Traits, typename _Alloc>
00407     class basic_ostringstream : public basic_ostream<_CharT, _Traits>
00408     {
00409     public:
00410       // Types:
00411       typedef _CharT                    char_type;
00412       typedef _Traits                   traits_type;
00413 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
00414 // 251. basic_stringbuf missing allocator_type
00415       typedef _Alloc                        allocator_type;
00416 #endif
00417       typedef typename traits_type::int_type        int_type;
00418       typedef typename traits_type::pos_type        pos_type;
00419       typedef typename traits_type::off_type        off_type;
00420 
00421       // Non-standard types:
00422       typedef basic_string<_CharT, _Traits, _Alloc>     __string_type;
00423       typedef basic_stringbuf<_CharT, _Traits, _Alloc>  __stringbuf_type;
00424       typedef basic_ostream<char_type, traits_type> __ostream_type;
00425 
00426     private:
00432       __stringbuf_type  _M_stringbuf;
00433 
00434     public:
00435       // Constructors/destructor:
00450       explicit
00451       basic_ostringstream(ios_base::openmode __mode = ios_base::out)
00452       : __ostream_type(NULL), _M_stringbuf(__mode | ios_base::out)
00453       { this->init(&_M_stringbuf); }
00454 
00470       explicit
00471       basic_ostringstream(const __string_type& __str,
00472               ios_base::openmode __mode = ios_base::out)
00473       : __ostream_type(NULL), _M_stringbuf(__str, __mode | ios_base::out)
00474       { this->init(&_M_stringbuf); }
00475 
00482       ~basic_ostringstream()
00483       { }
00484 
00485       // Members:
00492       __stringbuf_type*
00493       rdbuf() const
00494       { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
00495 
00500       __string_type
00501       str() const
00502       { return _M_stringbuf.str(); }
00503 
00510       void
00511       str(const __string_type& __s)
00512       { _M_stringbuf.str(__s); }
00513     };
00514 
00515 
00516   // [27.7.4] Template class basic_stringstream
00525   template <typename _CharT, typename _Traits, typename _Alloc>
00526     class basic_stringstream : public basic_iostream<_CharT, _Traits>
00527     {
00528     public:
00529       // Types:
00530       typedef _CharT                    char_type;
00531       typedef _Traits                   traits_type;
00532 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
00533 // 251. basic_stringbuf missing allocator_type
00534       typedef _Alloc                        allocator_type;
00535 #endif
00536       typedef typename traits_type::int_type        int_type;
00537       typedef typename traits_type::pos_type        pos_type;
00538       typedef typename traits_type::off_type        off_type;
00539 
00540       // Non-standard Types:
00541       typedef basic_string<_CharT, _Traits, _Alloc>     __string_type;
00542       typedef basic_stringbuf<_CharT, _Traits, _Alloc>  __stringbuf_type;
00543       typedef basic_iostream<char_type, traits_type>    __iostream_type;
00544 
00545     private:
00551       __stringbuf_type  _M_stringbuf;
00552 
00553     public:
00554       // Constructors/destructors
00567       explicit
00568       basic_stringstream(ios_base::openmode __m = ios_base::out | ios_base::in)
00569       : __iostream_type(NULL), _M_stringbuf(__m)
00570       { this->init(&_M_stringbuf); }
00571 
00585       explicit
00586       basic_stringstream(const __string_type& __str,
00587              ios_base::openmode __m = ios_base::out | ios_base::in)
00588       : __iostream_type(NULL), _M_stringbuf(__str, __m)
00589       { this->init(&_M_stringbuf); }
00590 
00597       ~basic_stringstream()
00598       { }
00599 
00600       // Members:
00607       __stringbuf_type*
00608       rdbuf() const
00609       { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
00610 
00615       __string_type
00616       str() const
00617       { return _M_stringbuf.str(); }
00618 
00625       void
00626       str(const __string_type& __s)
00627       { _M_stringbuf.str(__s); }
00628     };
00629 } // namespace std
00630 
00631 #ifdef _GLIBCPP_NO_TEMPLATE_EXPORT
00632 # define export
00633 #endif
00634 #ifdef  _GLIBCPP_FULLY_COMPLIANT_HEADERS
00635 # include <bits/sstream.tcc>
00636 #endif
00637 
00638 #endif

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