libstdc++-v3/include/bits/std_sstream.h

   1 // String based streams -*- C++ -*-
   2
   3 // Copyright (C) 1997-1999 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 //
  31 // ISO C++ 14882: 27.7  String-based streams
  32 //
  33
  34 #ifndef _CPP_SSTREAM
  35 #define _CPP_SSTREAM    1
  36
  37 #include <bits/std_istream.h>
  38 #include <bits/std_ostream.h>
  39
  40 namespace std {
  41
  42   template<typename _CharT, typename _Traits, typename _Alloc>
  43     class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
  44     {
  45     public:
  46       // Types:
  47       typedef _CharT                                    char_type;
  48       typedef _Traits                                   traits_type;
  49       typedef typename traits_type::int_type            int_type;
  50       typedef typename traits_type::pos_type            pos_type;
  51       typedef typename traits_type::off_type            off_type;
  52
  53       // Non-standard Types:
  54       typedef basic_streambuf<char_type, traits_type>   __streambuf_type;
  55       typedef basic_string<char_type, _Traits, _Alloc>  __string_type;
  56       typedef typename __string_type::size_type         __size_type;
  57
  58     private:
  59       // Data Members:
  60       __string_type             _M_string;
  61
  62     public:
  63       // Constructors:
  64       explicit
  65       basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)
  66       : __streambuf_type(), _M_string()
  67       { _M_stringbuf_init(__mode); }
  68
  69       explicit
  70       basic_stringbuf(const __string_type& __str,
  71                       ios_base::openmode __mode = ios_base::in | ios_base::out)
  72       : __streambuf_type(), _M_string(__str)
  73       { _M_stringbuf_init(__mode); }
  74
  75       // Get and set:
  76       __string_type
  77       str() const
  78       {
  79         if (_M_mode & ios_base::in && !(_M_mode & ios_base::out))
  80           return _M_string;
  81         else
  82           {
  83             // This is the deal: _M_string.size() is value that
  84             // represents the size of the intial string that makes
  85             // _M_string, and may not be the correct size of the
  86             // current stringbuf internal buffer.
  87             __size_type __len = _M_string.size();
  88             if (_M_out_cur > _M_out_beg)
  89               __len = max(__size_type(_M_out_end - _M_out_beg), __len);
  90             return __string_type(_M_out_beg, _M_out_beg + __len);
  91           }
  92       }
  93
  94       void
  95       str(const __string_type& __s)
  96       {
  97         _M_string = __s;
  98         _M_stringbuf_init(_M_mode);
  99       }
 100
 101     protected:
 102       // Common initialization code for both ctors goes here.
 103       void
 104       _M_stringbuf_init(ios_base::openmode __mode)
 105       {
 106         // _M_buf_size is a convenient alias for "what the streambuf
 107         // thinks the allocated size of the string really is." This is
 108         // necessary as ostringstreams are implemented with the
 109         // streambufs having control of the allocation and
 110         // re-allocation of the internal string object, _M_string.
 111         _M_buf_size = _M_string.size();
 112
 113         // NB: Start ostringstream buffers at 1024 bytes. This is an
 114         // experimental value (pronounced "arbitrary" in some of the
 115         // hipper english-speaking countries), and can be changed to
 116         // suite particular needs.
 117         _M_buf_size_opt = 512;
 118         _M_mode = __mode;
 119         if (_M_mode & ios_base::ate)
 120           _M_really_sync(0, _M_buf_size);
 121         else
 122           _M_really_sync(0, 0);
 123       }
 124
 125       // Overridden virtual functions:
 126       virtual int_type
 127       underflow()
 128       {
 129         if (_M_in_cur && _M_in_cur < _M_in_end)
 130           return traits_type::to_int_type(*gptr());
 131         else
 132           return traits_type::eof();
 133       }
 134
 135       virtual int_type
 136       pbackfail(int_type __c = traits_type::eof());
 137
 138       virtual int_type
 139       overflow(int_type __c = traits_type::eof());
 140
 141       virtual __streambuf_type*
 142       setbuf(char_type* __s, streamsize __n)
 143       {
 144         if (__n)
 145           {
 146             _M_string = __string_type(__s, __n);
 147             _M_really_sync(0, 0);
 148           }
 149         return this;
 150       }
 151
 152       virtual pos_type
 153       seekoff(off_type __off, ios_base::seekdir __way,
 154               ios_base::openmode __mode = ios_base::in | ios_base::out);
 155
 156       virtual pos_type
 157       seekpos(pos_type __sp,
 158               ios_base::openmode __mode = ios_base::in | ios_base::out);
 159
 160       // Internal function for correctly updating the internal buffer
 161       // for a particular _M_string, due to initialization or
 162       // re-sizing of an existing _M_string.
 163       // Assumes: contents of _M_string and internal buffer match exactly.
 164       // __i == _M_in_cur - _M_in_beg
 165       // __o == _M_out_cur - _M_out_beg
 166       virtual int
 167       _M_really_sync(__size_type __i, __size_type __o)
 168       {
 169         char_type* __base = const_cast<char_type*>(_M_string.data());
 170         bool __testin = _M_mode & ios_base::in;
 171         bool __testout = _M_mode & ios_base::out;
 172         __size_type __len = _M_string.size();
 173
 174         _M_buf = __base;
 175         if (__testin)
 176             this->setg(__base, __base + __i, __base + __len);
 177         if (__testout)
 178           {
 179             this->setp(__base, __base + __len);
 180             _M_out_cur += __o;
 181           }
 182         return 0;
 183       }
 184     };
 185
 186
 187   // 27.7.2  Template class basic_istringstream
 188   template<typename _CharT, typename _Traits, typename _Alloc>
 189     class basic_istringstream : public basic_istream<_CharT, _Traits>
 190     {
 191     public:
 192       // Types:
 193       typedef _CharT                                    char_type;
 194       typedef _Traits                                   traits_type;
 195       typedef typename traits_type::int_type            int_type;
 196       typedef typename traits_type::pos_type            pos_type;
 197       typedef typename traits_type::off_type            off_type;
 198
 199       // Non-standard types:
 200       typedef basic_string<_CharT, _Traits, _Alloc>     __string_type;
 201       typedef basic_stringbuf<_CharT, _Traits, _Alloc>  __stringbuf_type;
 202       typedef basic_istream<char_type, traits_type>     __istream_type;
 203
 204       // Constructors:
 205       explicit
 206       basic_istringstream(ios_base::openmode __mode = ios_base::in)
 207       : __istream_type(new __stringbuf_type(__mode | ios_base::in))
 208       { }
 209
 210       explicit
 211       basic_istringstream(const __string_type& __str,
 212                           ios_base::openmode __mode = ios_base::in)
 213       : __istream_type(new __stringbuf_type(__str, __mode | ios_base::in))
 214       { }
 215
 216       ~basic_istringstream()
 217       {
 218         delete _M_streambuf;
 219         _M_streambuf = NULL;
 220       }
 221
 222       // Members:
 223       __stringbuf_type*
 224       rdbuf() const
 225       { return static_cast<__stringbuf_type*>(_M_streambuf); }
 226
 227       __string_type
 228       str() const
 229       { return this->rdbuf()->str(); }
 230
 231       void
 232       str(const __string_type& __s)
 233       { rdbuf()->str(__s); }
 234
 235     };
 236
 237
 238   // 27.7.3  Template class basic_ostringstream
 239   template <typename _CharT, typename _Traits, typename _Alloc>
 240     class basic_ostringstream : public basic_ostream<_CharT, _Traits>
 241     {
 242     public:
 243       // Types:
 244       typedef _CharT                                    char_type;
 245       typedef _Traits                                   traits_type;
 246       typedef typename traits_type::int_type            int_type;
 247       typedef typename traits_type::pos_type            pos_type;
 248       typedef typename traits_type::off_type            off_type;
 249
 250       // Non-standard types:
 251       typedef basic_string<_CharT, _Traits, _Alloc>     __string_type;
 252       typedef basic_stringbuf<_CharT, _Traits, _Alloc>  __stringbuf_type;
 253       typedef basic_ostream<char_type, traits_type>     __ostream_type;
 254
 255       // Constructors/destructor:
 256       explicit
 257       basic_ostringstream(ios_base::openmode __mode = ios_base::out)
 258       : __ostream_type(new __stringbuf_type(__mode | ios_base::out))
 259       { }
 260
 261       explicit
 262       basic_ostringstream(const __string_type __str,
 263                           ios_base::openmode __mode = ios_base::out)
 264       : __ostream_type(new __stringbuf_type(__str, __mode | ios_base::out))
 265       { }
 266
 267       ~basic_ostringstream()
 268       {
 269         delete _M_streambuf;
 270         _M_streambuf = NULL;
 271       }
 272
 273       // Members:
 274       __stringbuf_type*
 275       rdbuf() const
 276       { return static_cast<__stringbuf_type*>(_M_streambuf); }
 277
 278       __string_type
 279       str() const
 280       { return this->rdbuf()->str(); }
 281
 282       void
 283       str(const __string_type& __s)
 284       { rdbuf()->str(__s); }
 285
 286     };
 287
 288
 289   // 27.7.4  Template class basic_stringstream
 290   template <typename _CharT, typename _Traits, typename _Alloc>
 291     class basic_stringstream : public basic_iostream<_CharT, _Traits>
 292     {
 293     public:
 294       // Types:
 295       typedef _CharT                                    char_type;
 296       typedef _Traits                                   traits_type;
 297       typedef typename traits_type::int_type            int_type;
 298       typedef typename traits_type::pos_type            pos_type;
 299       typedef typename traits_type::off_type            off_type;
 300
 301       // Non-standard Types:
 302       typedef basic_string<_CharT, _Traits, _Alloc>     __string_type;
 303       typedef basic_stringbuf<_CharT, _Traits, _Alloc>  __stringbuf_type;
 304       typedef basic_iostream<char_type, traits_type>    __iostream_type;
 305
 306       // Constructors/destructors
 307       explicit
 308       basic_stringstream(ios_base::openmode __mode =
 309                          ios_base::out | ios_base::in)
 310       : __iostream_type(new __stringbuf_type(__mode))
 311       { }
 312
 313       explicit
 314       basic_stringstream(const __string_type& __str,
 315                          ios_base::openmode __mode =
 316                          ios_base::out | ios_base::in)
 317       : __iostream_type(new __stringbuf_type(__str, __mode))
 318       { }
 319
 320       ~basic_stringstream()
 321       {
 322         delete _M_streambuf;
 323         _M_streambuf = NULL;
 324       }
 325
 326       // Members:
 327       __stringbuf_type*
 328       rdbuf() const
 329       { return static_cast<__stringbuf_type*>(_M_streambuf); }
 330
 331       __string_type
 332       str() const
 333       { return rdbuf()->str(); }
 334
 335       void
 336       str(const __string_type& __s)
 337       { rdbuf()->str(__s); }
 338     };
 339
 340 } // namespace std
 341
 342
 343
 344 #ifdef _GLIBCPP_NO_TEMPLATE_EXPORT
 345 # define export
 346 #ifdef  _GLIBCPP_FULLY_COMPLIANT_HEADERS
 347 # include <bits/sstream.tcc>
 348 #endif
 349 #endif
 350
 351
 352 #endif  /* _CPP_SSTREAM */
 353
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