1 // String based streams -*- C++ -*-
2 
3 // Copyright (C) 1997, 1998, 1999, 2002 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 /** @file sstream
35  *  This is a Standard C++ Library header.  You should @c #include this header
36  *  in your programs, rather than any of the "st[dl]_*.h" implementation files.
37  */
38 
39 #ifndef _CPP_SSTREAM
40 #define _CPP_SSTREAM	1
41 
42 #pragma GCC system_header
43 
44 #include <istream>
45 #include <ostream>
46 
47 namespace std
48 {
49   template<typename _CharT, typename _Traits, typename _Alloc>
50     class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
51     {
52     public:
53       // Types:
54       typedef _CharT 					char_type;
55       typedef _Traits 					traits_type;
56 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
57 // 251. basic_stringbuf missing allocator_type
58       typedef _Alloc				       	allocator_type;
59 #endif
60       typedef typename traits_type::int_type 		int_type;
61       typedef typename traits_type::pos_type 		pos_type;
62       typedef typename traits_type::off_type 		off_type;
63 
64       // Non-standard Types:
65       typedef basic_streambuf<char_type, traits_type>  	__streambuf_type;
66       typedef basic_string<char_type, _Traits, _Alloc> 	__string_type;
67       typedef typename __string_type::size_type		__size_type;
68 
69     protected:
70       // Data Members:
71       __string_type 		_M_string;
72 
73     public:
74       // Constructors:
75       explicit
76       basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)
77       : __streambuf_type(), _M_string()
78       { _M_stringbuf_init(__mode); }
79 
80       explicit
81       basic_stringbuf(const __string_type& __str,
82 		      ios_base::openmode __mode = ios_base::in | ios_base::out)
83       : __streambuf_type(), _M_string(__str.data(), __str.size())
84       { _M_stringbuf_init(__mode); }
85 
86       // Get and set:
87       __string_type
88       str() const
89       {
90 	if (_M_mode & ios_base::out)
91 	  {
92 	    // This is the deal: _M_string.size() is a value that
93 	    // represents the size of the initial string that makes
94 	    // _M_string, and may not be the correct size of the
95 	    // current stringbuf internal buffer.
96 	    __size_type __len = _M_string.size();
97 	    if (_M_out_cur > _M_out_beg)
98 	      __len = max(__size_type(_M_out_end - _M_out_beg), __len);
99 	    return __string_type(_M_out_beg, _M_out_beg + __len);
100 	  }
101 	else
102 	  return _M_string;
103       }
104 
105       void
106       str(const __string_type& __s)
107       {
108 	_M_string = __s;
109 	_M_stringbuf_init(_M_mode);
110       }
111 
112     protected:
113       // Common initialization code for both ctors goes here.
114       void
115       _M_stringbuf_init(ios_base::openmode __mode)
116       {
117 	// _M_buf_size is a convenient alias for "what the streambuf
118 	// thinks the allocated size of the string really is." This is
119 	// necessary as ostringstreams are implemented with the
120 	// streambufs having control of the allocation and
121 	// re-allocation of the internal string object, _M_string.
122 	_M_buf_size = _M_string.size();
123 
124 	// NB: Start ostringstream buffers at 512 bytes. This is an
125 	// experimental value (pronounced "arbitrary" in some of the
126 	// hipper english-speaking countries), and can be changed to
127 	// suit particular needs.
128 	_M_buf_size_opt = 512;
129 	_M_mode = __mode;
130 	if (_M_mode & (ios_base::ate | ios_base::app))
131 	  _M_really_sync(0, _M_buf_size);
132 	else
133 	  _M_really_sync(0, 0);
134       }
135 
136       // Overridden virtual functions:
137       virtual int_type
138       underflow()
139       {
140 	if (_M_in_cur && _M_in_cur < _M_in_end)
141 	  return traits_type::to_int_type(*gptr());
142 	else
143 	  return traits_type::eof();
144       }
145 
146       virtual int_type
147       pbackfail(int_type __c = traits_type::eof());
148 
149       virtual int_type
150       overflow(int_type __c = traits_type::eof());
151 
152       virtual __streambuf_type*
153       setbuf(char_type* __s, streamsize __n)
154       {
155 	if (__s && __n)
156 	  {
157 	    _M_string = __string_type(__s, __n);
158 	    _M_really_sync(0, 0);
159 	  }
160 	return this;
161       }
162 
163       virtual pos_type
164       seekoff(off_type __off, ios_base::seekdir __way,
165 	      ios_base::openmode __mode = ios_base::in | ios_base::out);
166 
167       virtual pos_type
168       seekpos(pos_type __sp,
169 	      ios_base::openmode __mode = ios_base::in | ios_base::out);
170 
171       // Internal function for correctly updating the internal buffer
172       // for a particular _M_string, due to initialization or
173       // re-sizing of an existing _M_string.
174       // Assumes: contents of _M_string and internal buffer match exactly.
175       // __i == _M_in_cur - _M_in_beg
176       // __o == _M_out_cur - _M_out_beg
177       virtual int
178       _M_really_sync(__size_type __i, __size_type __o)
179       {
180 	char_type* __base = const_cast<char_type*>(_M_string.data());
181 	bool __testin = _M_mode & ios_base::in;
182 	bool __testout = _M_mode & ios_base::out;
183 	__size_type __len = _M_string.size();
184 
185 	_M_buf = __base;
186 	if (__testin)
187 	    this->setg(__base, __base + __i, __base + __len);
188 	if (__testout)
189 	  {
190 	    this->setp(__base, __base + __len);
191 	    _M_out_cur += __o;
192 	  }
193 	return 0;
194       }
195     };
196 
197 
198   // 27.7.2  Template class basic_istringstream
199   template<typename _CharT, typename _Traits, typename _Alloc>
200     class basic_istringstream : public basic_istream<_CharT, _Traits>
201     {
202     public:
203       // Types:
204       typedef _CharT 					char_type;
205       typedef _Traits 					traits_type;
206 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
207 // 251. basic_stringbuf missing allocator_type
208       typedef _Alloc				       	allocator_type;
209 #endif
210       typedef typename traits_type::int_type 		int_type;
211       typedef typename traits_type::pos_type 		pos_type;
212       typedef typename traits_type::off_type 		off_type;
213 
214       // Non-standard types:
215       typedef basic_string<_CharT, _Traits, _Alloc> 	__string_type;
216       typedef basic_stringbuf<_CharT, _Traits, _Alloc> 	__stringbuf_type;
217       typedef basic_istream<char_type, traits_type>	__istream_type;
218 
219     private:
220       __stringbuf_type	_M_stringbuf;
221 
222     public:
223       // Constructors:
224       explicit
225       basic_istringstream(ios_base::openmode __mode = ios_base::in)
226       : __istream_type(NULL), _M_stringbuf(__mode | ios_base::in)
227       { this->init(&_M_stringbuf); }
228 
229       explicit
230       basic_istringstream(const __string_type& __str,
231 			  ios_base::openmode __mode = ios_base::in)
232       : __istream_type(NULL), _M_stringbuf(__str, __mode | ios_base::in)
233       { this->init(&_M_stringbuf); }
234 
235       ~basic_istringstream()
236       { }
237 
238       // Members:
239       __stringbuf_type*
240       rdbuf() const
241       { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
242 
243       __string_type
244       str() const
245       { return _M_stringbuf.str(); }
246 
247       void
248       str(const __string_type& __s)
249       { _M_stringbuf.str(__s); }
250     };
251 
252 
253   // 27.7.3  Template class basic_ostringstream
254   template <typename _CharT, typename _Traits, typename _Alloc>
255     class basic_ostringstream : public basic_ostream<_CharT, _Traits>
256     {
257     public:
258       // Types:
259       typedef _CharT 					char_type;
260       typedef _Traits 					traits_type;
261 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
262 // 251. basic_stringbuf missing allocator_type
263       typedef _Alloc				       	allocator_type;
264 #endif
265       typedef typename traits_type::int_type 		int_type;
266       typedef typename traits_type::pos_type 		pos_type;
267       typedef typename traits_type::off_type 		off_type;
268 
269       // Non-standard types:
270       typedef basic_string<_CharT, _Traits, _Alloc> 	__string_type;
271       typedef basic_stringbuf<_CharT, _Traits, _Alloc> 	__stringbuf_type;
272       typedef basic_ostream<char_type, traits_type>	__ostream_type;
273 
274     private:
275       __stringbuf_type	_M_stringbuf;
276 
277     public:
278      // Constructors/destructor:
279       explicit
280       basic_ostringstream(ios_base::openmode __mode = ios_base::out)
281       : __ostream_type(NULL), _M_stringbuf(__mode | ios_base::out)
282       { this->init(&_M_stringbuf); }
283 
284       explicit
285       basic_ostringstream(const __string_type& __str,
286 			  ios_base::openmode __mode = ios_base::out)
287       : __ostream_type(NULL), _M_stringbuf(__str, __mode | ios_base::out)
288       { this->init(&_M_stringbuf); }
289 
290       ~basic_ostringstream()
291       { }
292 
293       // Members:
294       __stringbuf_type*
295       rdbuf() const
296       { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
297 
298       __string_type
299       str() const
300       { return _M_stringbuf.str(); }
301 
302       void
303       str(const __string_type& __s)
304       { _M_stringbuf.str(__s); }
305     };
306 
307 
308   // 27.7.4  Template class basic_stringstream
309   template <typename _CharT, typename _Traits, typename _Alloc>
310     class basic_stringstream : public basic_iostream<_CharT, _Traits>
311     {
312     public:
313       // Types:
314       typedef _CharT 					char_type;
315       typedef _Traits 					traits_type;
316 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
317 // 251. basic_stringbuf missing allocator_type
318       typedef _Alloc				       	allocator_type;
319 #endif
320       typedef typename traits_type::int_type 		int_type;
321       typedef typename traits_type::pos_type 		pos_type;
322       typedef typename traits_type::off_type 		off_type;
323 
324       // Non-standard Types:
325       typedef basic_string<_CharT, _Traits, _Alloc> 	__string_type;
326       typedef basic_stringbuf<_CharT, _Traits, _Alloc> 	__stringbuf_type;
327       typedef basic_iostream<char_type, traits_type>	__iostream_type;
328 
329     private:
330       __stringbuf_type	_M_stringbuf;
331 
332     public:
333       // Constructors/destructors
334       explicit
335       basic_stringstream(ios_base::openmode __m = ios_base::out | ios_base::in)
336       : __iostream_type(NULL), _M_stringbuf(__m)
337       { this->init(&_M_stringbuf); }
338 
339       explicit
340       basic_stringstream(const __string_type& __str,
341 			 ios_base::openmode __m = ios_base::out | ios_base::in)
342       : __iostream_type(NULL), _M_stringbuf(__str, __m)
343       { this->init(&_M_stringbuf); }
344 
345       ~basic_stringstream()
346       { }
347 
348       // Members:
349       __stringbuf_type*
350       rdbuf() const
351       { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
352 
353       __string_type
354       str() const
355       { return _M_stringbuf.str(); }
356 
357       void
358       str(const __string_type& __s)
359       { _M_stringbuf.str(__s); }
360     };
361 } // namespace std
362 
363 #ifdef _GLIBCPP_NO_TEMPLATE_EXPORT
364 # define export
365 #endif
366 #ifdef  _GLIBCPP_FULLY_COMPLIANT_HEADERS
367 # include <bits/sstream.tcc>
368 #endif
369 
370 #endif
371