OpenCores
URL https://opencores.org/ocsvn/openrisc/openrisc/trunk

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libstdc++-v3/] [include/] [std/] [streambuf] - Blame information for rev 791

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 742 jeremybenn
// Stream buffer classes -*- C++ -*-
2
 
3
// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4
// 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
5
//
6
// This file is part of the GNU ISO C++ Library.  This library is free
7
// software; you can redistribute it and/or modify it under the
8
// terms of the GNU General Public License as published by the
9
// Free Software Foundation; either version 3, or (at your option)
10
// any later version.
11
 
12
// This library is distributed in the hope that it will be useful,
13
// but WITHOUT ANY WARRANTY; without even the implied warranty of
14
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15
// GNU General Public License for more details.
16
 
17
// Under Section 7 of GPL version 3, you are granted additional
18
// permissions described in the GCC Runtime Library Exception, version
19
// 3.1, as published by the Free Software Foundation.
20
 
21
// You should have received a copy of the GNU General Public License and
22
// a copy of the GCC Runtime Library Exception along with this program;
23
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
24
// .
25
 
26
/** @file include/streambuf
27
 *  This is a Standard C++ Library header.
28
 */
29
 
30
//
31
// ISO C++ 14882: 27.5  Stream buffers
32
//
33
 
34
#ifndef _GLIBXX_STREAMBUF
35
#define _GLIBXX_STREAMBUF 1
36
 
37
#pragma GCC system_header
38
 
39
#include 
40
#include 
41
#include 
42
#include 
43
#include 
44
#include 
45
 
46
namespace std _GLIBCXX_VISIBILITY(default)
47
{
48
_GLIBCXX_BEGIN_NAMESPACE_VERSION
49
 
50
  template
51
    streamsize
52
    __copy_streambufs_eof(basic_streambuf<_CharT, _Traits>*,
53
                          basic_streambuf<_CharT, _Traits>*, bool&);
54
 
55
  /**
56
   *  @brief  The actual work of input and output (interface).
57
   *  @ingroup io
58
   *
59
   *  This is a base class.  Derived stream buffers each control a
60
   *  pair of character sequences:  one for input, and one for output.
61
   *
62
   *  Section [27.5.1] of the standard describes the requirements and
63
   *  behavior of stream buffer classes.  That section (three paragraphs)
64
   *  is reproduced here, for simplicity and accuracy.
65
   *
66
   *  -# Stream buffers can impose various constraints on the sequences
67
   *     they control.  Some constraints are:
68
   *     - The controlled input sequence can be not readable.
69
   *     - The controlled output sequence can be not writable.
70
   *     - The controlled sequences can be associated with the contents of
71
   *       other representations for character sequences, such as external
72
   *       files.
73
   *     - The controlled sequences can support operations @e directly to or
74
   *       from associated sequences.
75
   *     - The controlled sequences can impose limitations on how the
76
   *       program can read characters from a sequence, write characters to
77
   *       a sequence, put characters back into an input sequence, or alter
78
   *       the stream position.
79
   *     .
80
   *  -# Each sequence is characterized by three pointers which, if non-null,
81
   *     all point into the same @c charT array object.  The array object
82
   *     represents, at any moment, a (sub)sequence of characters from the
83
   *     sequence.  Operations performed on a sequence alter the values
84
   *     stored in these pointers, perform reads and writes directly to or
85
   *     from associated sequences, and alter the stream position and
86
   *     conversion state as needed to maintain this subsequence relationship.
87
   *     The three pointers are:
88
   *     - the beginning pointer, or lowest element address in the
89
   *       array (called @e xbeg here);
90
   *     - the next pointer, or next element address that is a
91
   *       current candidate for reading or writing (called @e xnext here);
92
   *     - the end pointer, or first element address beyond the
93
   *       end of the array (called @e xend here).
94
   *     .
95
   *  -# The following semantic constraints shall always apply for any set
96
   *     of three pointers for a sequence, using the pointer names given
97
   *     immediately above:
98
   *     - If @e xnext is not a null pointer, then @e xbeg and @e xend shall
99
   *       also be non-null pointers into the same @c charT array, as
100
   *       described above; otherwise, @e xbeg and @e xend shall also be null.
101
   *     - If @e xnext is not a null pointer and @e xnext < @e xend for an
102
   *       output sequence, then a write position is available.
103
   *       In this case, @e *xnext shall be assignable as the next element
104
   *       to write (to put, or to store a character value, into the sequence).
105
   *     - If @e xnext is not a null pointer and @e xbeg < @e xnext for an
106
   *       input sequence, then a putback position is available.
107
   *       In this case, @e xnext[-1] shall have a defined value and is the
108
   *       next (preceding) element to store a character that is put back
109
   *       into the input sequence.
110
   *     - If @e xnext is not a null pointer and @e xnext< @e xend for an
111
   *       input sequence, then a read position is available.
112
   *       In this case, @e *xnext shall have a defined value and is the
113
   *       next element to read (to get, or to obtain a character value,
114
   *       from the sequence).
115
  */
116
  template
117
    class basic_streambuf
118
    {
119
    public:
120
      //@{
121
      /**
122
       *  These are standard types.  They permit a standardized way of
123
       *  referring to names of (or names dependant on) the template
124
       *  parameters, which are specific to the implementation.
125
      */
126
      typedef _CharT                                    char_type;
127
      typedef _Traits                                   traits_type;
128
      typedef typename traits_type::int_type            int_type;
129
      typedef typename traits_type::pos_type            pos_type;
130
      typedef typename traits_type::off_type            off_type;
131
      //@}
132
 
133
      //@{
134
      /// This is a non-standard type.
135
      typedef basic_streambuf   __streambuf_type;
136
      //@}
137
 
138
      friend class basic_ios;
139
      friend class basic_istream;
140
      friend class basic_ostream;
141
      friend class istreambuf_iterator;
142
      friend class ostreambuf_iterator;
143
 
144
      friend streamsize
145
      __copy_streambufs_eof<>(__streambuf_type*, __streambuf_type*, bool&);
146
 
147
      template
148
        friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
149
                                               _CharT2*>::__type
150
        __copy_move_a2(istreambuf_iterator<_CharT2>,
151
                       istreambuf_iterator<_CharT2>, _CharT2*);
152
 
153
      template
154
        friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
155
                                  istreambuf_iterator<_CharT2> >::__type
156
        find(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
157
             const _CharT2&);
158
 
159
      template
160
        friend basic_istream<_CharT2, _Traits2>&
161
        operator>>(basic_istream<_CharT2, _Traits2>&, _CharT2*);
162
 
163
      template
164
        friend basic_istream<_CharT2, _Traits2>&
165
        operator>>(basic_istream<_CharT2, _Traits2>&,
166
                   basic_string<_CharT2, _Traits2, _Alloc>&);
167
 
168
      template
169
        friend basic_istream<_CharT2, _Traits2>&
170
        getline(basic_istream<_CharT2, _Traits2>&,
171
                basic_string<_CharT2, _Traits2, _Alloc>&, _CharT2);
172
 
173
    protected:
174
      //@{
175
      /**
176
       *  This is based on _IO_FILE, just reordered to be more consistent,
177
       *  and is intended to be the most minimal abstraction for an
178
       *  internal buffer.
179
       *  -  get == input == read
180
       *  -  put == output == write
181
      */
182
      char_type*                _M_in_beg;     // Start of get area.
183
      char_type*                _M_in_cur;     // Current read area.
184
      char_type*                _M_in_end;     // End of get area.
185
      char_type*                _M_out_beg;    // Start of put area.
186
      char_type*                _M_out_cur;    // Current put area.
187
      char_type*                _M_out_end;    // End of put area.
188
 
189
      /// Current locale setting.
190
      locale                    _M_buf_locale;
191
 
192
  public:
193
      /// Destructor deallocates no buffer space.
194
      virtual
195
      ~basic_streambuf()
196
      { }
197
 
198
      // [27.5.2.2.1] locales
199
      /**
200
       *  @brief  Entry point for imbue().
201
       *  @param  __loc  The new locale.
202
       *  @return  The previous locale.
203
       *
204
       *  Calls the derived imbue(__loc).
205
      */
206
      locale
207
      pubimbue(const locale& __loc)
208
      {
209
        locale __tmp(this->getloc());
210
        this->imbue(__loc);
211
        _M_buf_locale = __loc;
212
        return __tmp;
213
      }
214
 
215
      /**
216
       *  @brief  Locale access.
217
       *  @return  The current locale in effect.
218
       *
219
       *  If pubimbue(loc) has been called, then the most recent @c loc
220
       *  is returned.  Otherwise the global locale in effect at the time
221
       *  of construction is returned.
222
      */
223
      locale
224
      getloc() const
225
      { return _M_buf_locale; }
226
 
227
      // [27.5.2.2.2] buffer management and positioning
228
      //@{
229
      /**
230
       *  @brief  Entry points for derived buffer functions.
231
       *
232
       *  The public versions of @c pubfoo dispatch to the protected
233
       *  derived @c foo member functions, passing the arguments (if any)
234
       *  and returning the result unchanged.
235
      */
236
      __streambuf_type*
237
      pubsetbuf(char_type* __s, streamsize __n)
238
      { return this->setbuf(__s, __n); }
239
 
240
      /**
241
       *  @brief  Alters the stream position.
242
       *  @param  __off  Offset.
243
       *  @param  __way  Value for ios_base::seekdir.
244
       *  @param  __mode Value for ios_base::openmode.
245
       *
246
       *  Calls virtual seekoff function.
247
      */
248
      pos_type
249
      pubseekoff(off_type __off, ios_base::seekdir __way,
250
                 ios_base::openmode __mode = ios_base::in | ios_base::out)
251
      { return this->seekoff(__off, __way, __mode); }
252
 
253
      /**
254
       *  @brief  Alters the stream position.
255
       *  @param  __sp  Position
256
       *  @param  __mode Value for ios_base::openmode.
257
       *
258
       *  Calls virtual seekpos function.
259
      */
260
      pos_type
261
      pubseekpos(pos_type __sp,
262
                 ios_base::openmode __mode = ios_base::in | ios_base::out)
263
      { return this->seekpos(__sp, __mode); }
264
 
265
      /**
266
       *  @brief  Calls virtual sync function.
267
      */
268
      int
269
      pubsync() { return this->sync(); }
270
      //@}
271
 
272
      // [27.5.2.2.3] get area
273
      /**
274
       *  @brief  Looking ahead into the stream.
275
       *  @return  The number of characters available.
276
       *
277
       *  If a read position is available, returns the number of characters
278
       *  available for reading before the buffer must be refilled.
279
       *  Otherwise returns the derived @c showmanyc().
280
      */
281
      streamsize
282
      in_avail()
283
      {
284
        const streamsize __ret = this->egptr() - this->gptr();
285
        return __ret ? __ret : this->showmanyc();
286
      }
287
 
288
      /**
289
       *  @brief  Getting the next character.
290
       *  @return  The next character, or eof.
291
       *
292
       *  Calls @c sbumpc(), and if that function returns
293
       *  @c traits::eof(), so does this function.  Otherwise, @c sgetc().
294
      */
295
      int_type
296
      snextc()
297
      {
298
        int_type __ret = traits_type::eof();
299
        if (__builtin_expect(!traits_type::eq_int_type(this->sbumpc(),
300
                                                       __ret), true))
301
          __ret = this->sgetc();
302
        return __ret;
303
      }
304
 
305
      /**
306
       *  @brief  Getting the next character.
307
       *  @return  The next character, or eof.
308
       *
309
       *  If the input read position is available, returns that character
310
       *  and increments the read pointer, otherwise calls and returns
311
       *  @c uflow().
312
      */
313
      int_type
314
      sbumpc()
315
      {
316
        int_type __ret;
317
        if (__builtin_expect(this->gptr() < this->egptr(), true))
318
          {
319
            __ret = traits_type::to_int_type(*this->gptr());
320
            this->gbump(1);
321
          }
322
        else
323
          __ret = this->uflow();
324
        return __ret;
325
      }
326
 
327
      /**
328
       *  @brief  Getting the next character.
329
       *  @return  The next character, or eof.
330
       *
331
       *  If the input read position is available, returns that character,
332
       *  otherwise calls and returns @c underflow().  Does not move the
333
       *  read position after fetching the character.
334
      */
335
      int_type
336
      sgetc()
337
      {
338
        int_type __ret;
339
        if (__builtin_expect(this->gptr() < this->egptr(), true))
340
          __ret = traits_type::to_int_type(*this->gptr());
341
        else
342
          __ret = this->underflow();
343
        return __ret;
344
      }
345
 
346
      /**
347
       *  @brief  Entry point for xsgetn.
348
       *  @param  __s  A buffer area.
349
       *  @param  __n  A count.
350
       *
351
       *  Returns xsgetn(__s,__n).  The effect is to fill @a __s[0] through
352
       *  @a __s[__n-1] with characters from the input sequence, if possible.
353
      */
354
      streamsize
355
      sgetn(char_type* __s, streamsize __n)
356
      { return this->xsgetn(__s, __n); }
357
 
358
      // [27.5.2.2.4] putback
359
      /**
360
       *  @brief  Pushing characters back into the input stream.
361
       *  @param  __c  The character to push back.
362
       *  @return  The previous character, if possible.
363
       *
364
       *  Similar to sungetc(), but @a __c is pushed onto the stream
365
       *  instead of the previous character. If successful,
366
       *  the next character fetched from the input stream will be @a
367
       *  __c.
368
      */
369
      int_type
370
      sputbackc(char_type __c)
371
      {
372
        int_type __ret;
373
        const bool __testpos = this->eback() < this->gptr();
374
        if (__builtin_expect(!__testpos ||
375
                             !traits_type::eq(__c, this->gptr()[-1]), false))
376
          __ret = this->pbackfail(traits_type::to_int_type(__c));
377
        else
378
          {
379
            this->gbump(-1);
380
            __ret = traits_type::to_int_type(*this->gptr());
381
          }
382
        return __ret;
383
      }
384
 
385
      /**
386
       *  @brief  Moving backwards in the input stream.
387
       *  @return  The previous character, if possible.
388
       *
389
       *  If a putback position is available, this function decrements
390
       *  the input pointer and returns that character.  Otherwise,
391
       *  calls and returns pbackfail().  The effect is to @a unget
392
       *  the last character @a gotten.
393
      */
394
      int_type
395
      sungetc()
396
      {
397
        int_type __ret;
398
        if (__builtin_expect(this->eback() < this->gptr(), true))
399
          {
400
            this->gbump(-1);
401
            __ret = traits_type::to_int_type(*this->gptr());
402
          }
403
        else
404
          __ret = this->pbackfail();
405
        return __ret;
406
      }
407
 
408
      // [27.5.2.2.5] put area
409
      /**
410
       *  @brief  Entry point for all single-character output functions.
411
       *  @param  __c  A character to output.
412
       *  @return  @a __c, if possible.
413
       *
414
       *  One of two public output functions.
415
       *
416
       *  If a write position is available for the output sequence (i.e.,
417
       *  the buffer is not full), stores @a __c in that position, increments
418
       *  the position, and returns @c traits::to_int_type(__c).  If a write
419
       *  position is not available, returns @c overflow(__c).
420
      */
421
      int_type
422
      sputc(char_type __c)
423
      {
424
        int_type __ret;
425
        if (__builtin_expect(this->pptr() < this->epptr(), true))
426
          {
427
            *this->pptr() = __c;
428
            this->pbump(1);
429
            __ret = traits_type::to_int_type(__c);
430
          }
431
        else
432
          __ret = this->overflow(traits_type::to_int_type(__c));
433
        return __ret;
434
      }
435
 
436
      /**
437
       *  @brief  Entry point for all single-character output functions.
438
       *  @param  __s  A buffer read area.
439
       *  @param  __n  A count.
440
       *
441
       *  One of two public output functions.
442
       *
443
       *
444
       *  Returns xsputn(__s,__n).  The effect is to write @a __s[0] through
445
       *  @a __s[__n-1] to the output sequence, if possible.
446
      */
447
      streamsize
448
      sputn(const char_type* __s, streamsize __n)
449
      { return this->xsputn(__s, __n); }
450
 
451
    protected:
452
      /**
453
       *  @brief  Base constructor.
454
       *
455
       *  Only called from derived constructors, and sets up all the
456
       *  buffer data to zero, including the pointers described in the
457
       *  basic_streambuf class description.  Note that, as a result,
458
       *  - the class starts with no read nor write positions available,
459
       *  - this is not an error
460
      */
461
      basic_streambuf()
462
      : _M_in_beg(0), _M_in_cur(0), _M_in_end(0),
463
      _M_out_beg(0), _M_out_cur(0), _M_out_end(0),
464
      _M_buf_locale(locale())
465
      { }
466
 
467
      // [27.5.2.3.1] get area access
468
      //@{
469
      /**
470
       *  @brief  Access to the get area.
471
       *
472
       *  These functions are only available to other protected functions,
473
       *  including derived classes.
474
       *
475
       *  - eback() returns the beginning pointer for the input sequence
476
       *  - gptr() returns the next pointer for the input sequence
477
       *  - egptr() returns the end pointer for the input sequence
478
      */
479
      char_type*
480
      eback() const { return _M_in_beg; }
481
 
482
      char_type*
483
      gptr()  const { return _M_in_cur;  }
484
 
485
      char_type*
486
      egptr() const { return _M_in_end; }
487
      //@}
488
 
489
      /**
490
       *  @brief  Moving the read position.
491
       *  @param  __n  The delta by which to move.
492
       *
493
       *  This just advances the read position without returning any data.
494
      */
495
      void
496
      gbump(int __n) { _M_in_cur += __n; }
497
 
498
      /**
499
       *  @brief  Setting the three read area pointers.
500
       *  @param  __gbeg  A pointer.
501
       *  @param  __gnext  A pointer.
502
       *  @param  __gend  A pointer.
503
       *  @post  @a __gbeg == @c eback(), @a __gnext == @c gptr(), and
504
       *         @a __gend == @c egptr()
505
      */
506
      void
507
      setg(char_type* __gbeg, char_type* __gnext, char_type* __gend)
508
      {
509
        _M_in_beg = __gbeg;
510
        _M_in_cur = __gnext;
511
        _M_in_end = __gend;
512
      }
513
 
514
      // [27.5.2.3.2] put area access
515
      //@{
516
      /**
517
       *  @brief  Access to the put area.
518
       *
519
       *  These functions are only available to other protected functions,
520
       *  including derived classes.
521
       *
522
       *  - pbase() returns the beginning pointer for the output sequence
523
       *  - pptr() returns the next pointer for the output sequence
524
       *  - epptr() returns the end pointer for the output sequence
525
      */
526
      char_type*
527
      pbase() const { return _M_out_beg; }
528
 
529
      char_type*
530
      pptr() const { return _M_out_cur; }
531
 
532
      char_type*
533
      epptr() const { return _M_out_end; }
534
      //@}
535
 
536
      /**
537
       *  @brief  Moving the write position.
538
       *  @param  __n  The delta by which to move.
539
       *
540
       *  This just advances the write position without returning any data.
541
      */
542
      void
543
      pbump(int __n) { _M_out_cur += __n; }
544
 
545
      /**
546
       *  @brief  Setting the three write area pointers.
547
       *  @param  __pbeg  A pointer.
548
       *  @param  __pend  A pointer.
549
       *  @post  @a __pbeg == @c pbase(), @a __pbeg == @c pptr(), and
550
       *         @a __pend == @c epptr()
551
      */
552
      void
553
      setp(char_type* __pbeg, char_type* __pend)
554
      {
555
        _M_out_beg = _M_out_cur = __pbeg;
556
        _M_out_end = __pend;
557
      }
558
 
559
      // [27.5.2.4] virtual functions
560
      // [27.5.2.4.1] locales
561
      /**
562
       *  @brief  Changes translations.
563
       *  @param  __loc  A new locale.
564
       *
565
       *  Translations done during I/O which depend on the current
566
       *  locale are changed by this call.  The standard adds,
567
       *  Between invocations of this function a class derived
568
       *  from streambuf can safely cache results of calls to locale
569
       *  functions and to members of facets so obtained.
570
       *
571
       *  @note  Base class version does nothing.
572
      */
573
      virtual void
574
      imbue(const locale& __loc)
575
      { }
576
 
577
      // [27.5.2.4.2] buffer management and positioning
578
      /**
579
       *  @brief  Manipulates the buffer.
580
       *
581
       *  Each derived class provides its own appropriate behavior.  See
582
       *  the next-to-last paragraph of
583
       *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html
584
       *  for more on this function.
585
       *
586
       *  @note  Base class version does nothing, returns @c this.
587
      */
588
      virtual basic_streambuf*
589
      setbuf(char_type*, streamsize)
590
      { return this; }
591
 
592
      /**
593
       *  @brief  Alters the stream positions.
594
       *
595
       *  Each derived class provides its own appropriate behavior.
596
       *  @note  Base class version does nothing, returns a @c pos_type
597
       *         that represents an invalid stream position.
598
      */
599
      virtual pos_type
600
      seekoff(off_type, ios_base::seekdir,
601
              ios_base::openmode /*__mode*/ = ios_base::in | ios_base::out)
602
      { return pos_type(off_type(-1)); }
603
 
604
      /**
605
       *  @brief  Alters the stream positions.
606
       *
607
       *  Each derived class provides its own appropriate behavior.
608
       *  @note  Base class version does nothing, returns a @c pos_type
609
       *         that represents an invalid stream position.
610
      */
611
      virtual pos_type
612
      seekpos(pos_type,
613
              ios_base::openmode /*__mode*/ = ios_base::in | ios_base::out)
614
      { return pos_type(off_type(-1)); }
615
 
616
      /**
617
       *  @brief  Synchronizes the buffer arrays with the controlled sequences.
618
       *  @return  -1 on failure.
619
       *
620
       *  Each derived class provides its own appropriate behavior,
621
       *  including the definition of @a failure.
622
       *  @note  Base class version does nothing, returns zero.
623
      */
624
      virtual int
625
      sync() { return 0; }
626
 
627
      // [27.5.2.4.3] get area
628
      /**
629
       *  @brief  Investigating the data available.
630
       *  @return  An estimate of the number of characters available in the
631
       *           input sequence, or -1.
632
       *
633
       *  If it returns a positive value, then successive calls to
634
       *  @c underflow() will not return @c traits::eof() until at
635
       *  least that number of characters have been supplied.  If @c
636
       *  showmanyc() returns -1, then calls to @c underflow() or @c
637
       *  uflow() will fail. [27.5.2.4.3]/1
638
       *
639
       *  @note  Base class version does nothing, returns zero.
640
       *  @note  The standard adds that the intention is not only that the
641
       *         calls [to underflow or uflow] will not return @c eof() but
642
       *         that they will return immediately.
643
       *  @note  The standard adds that the morphemes of @c showmanyc are
644
       *         @b es-how-many-see, not @b show-manic.
645
      */
646
      virtual streamsize
647
      showmanyc() { return 0; }
648
 
649
      /**
650
       *  @brief  Multiple character extraction.
651
       *  @param  __s  A buffer area.
652
       *  @param  __n  Maximum number of characters to assign.
653
       *  @return  The number of characters assigned.
654
       *
655
       *  Fills @a __s[0] through @a __s[__n-1] with characters from the input
656
       *  sequence, as if by @c sbumpc().  Stops when either @a __n characters
657
       *  have been copied, or when @c traits::eof() would be copied.
658
       *
659
       *  It is expected that derived classes provide a more efficient
660
       *  implementation by overriding this definition.
661
      */
662
      virtual streamsize
663
      xsgetn(char_type* __s, streamsize __n);
664
 
665
      /**
666
       *  @brief  Fetches more data from the controlled sequence.
667
       *  @return  The first character from the pending sequence.
668
       *
669
       *  Informally, this function is called when the input buffer is
670
       *  exhausted (or does not exist, as buffering need not actually be
671
       *  done).  If a buffer exists, it is @a refilled.  In either case, the
672
       *  next available character is returned, or @c traits::eof() to
673
       *  indicate a null pending sequence.
674
       *
675
       *  For a formal definition of the pending sequence, see a good text
676
       *  such as Langer & Kreft, or [27.5.2.4.3]/7-14.
677
       *
678
       *  A functioning input streambuf can be created by overriding only
679
       *  this function (no buffer area will be used).  For an example, see
680
       *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25.html
681
       *
682
       *  @note  Base class version does nothing, returns eof().
683
      */
684
      virtual int_type
685
      underflow()
686
      { return traits_type::eof(); }
687
 
688
      /**
689
       *  @brief  Fetches more data from the controlled sequence.
690
       *  @return  The first character from the pending sequence.
691
       *
692
       *  Informally, this function does the same thing as @c underflow(),
693
       *  and in fact is required to call that function.  It also returns
694
       *  the new character, like @c underflow() does.  However, this
695
       *  function also moves the read position forward by one.
696
      */
697
      virtual int_type
698
      uflow()
699
      {
700
        int_type __ret = traits_type::eof();
701
        const bool __testeof = traits_type::eq_int_type(this->underflow(),
702
                                                        __ret);
703
        if (!__testeof)
704
          {
705
            __ret = traits_type::to_int_type(*this->gptr());
706
            this->gbump(1);
707
          }
708
        return __ret;
709
      }
710
 
711
      // [27.5.2.4.4] putback
712
      /**
713
       *  @brief  Tries to back up the input sequence.
714
       *  @param  __c  The character to be inserted back into the sequence.
715
       *  @return  eof() on failure, some other value on success
716
       *  @post  The constraints of @c gptr(), @c eback(), and @c pptr()
717
       *         are the same as for @c underflow().
718
       *
719
       *  @note  Base class version does nothing, returns eof().
720
      */
721
      virtual int_type
722
      pbackfail(int_type __c  = traits_type::eof())
723
      { return traits_type::eof(); }
724
 
725
      // Put area:
726
      /**
727
       *  @brief  Multiple character insertion.
728
       *  @param  __s  A buffer area.
729
       *  @param  __n  Maximum number of characters to write.
730
       *  @return  The number of characters written.
731
       *
732
       *  Writes @a __s[0] through @a __s[__n-1] to the output sequence, as if
733
       *  by @c sputc().  Stops when either @a n characters have been
734
       *  copied, or when @c sputc() would return @c traits::eof().
735
       *
736
       *  It is expected that derived classes provide a more efficient
737
       *  implementation by overriding this definition.
738
      */
739
      virtual streamsize
740
      xsputn(const char_type* __s, streamsize __n);
741
 
742
      /**
743
       *  @brief  Consumes data from the buffer; writes to the
744
       *          controlled sequence.
745
       *  @param  __c  An additional character to consume.
746
       *  @return  eof() to indicate failure, something else (usually
747
       *           @a __c, or not_eof())
748
       *
749
       *  Informally, this function is called when the output buffer
750
       *  is full (or does not exist, as buffering need not actually
751
       *  be done).  If a buffer exists, it is @a consumed, with
752
       *  some effect on the controlled sequence.
753
       *  (Typically, the buffer is written out to the sequence
754
       *  verbatim.)  In either case, the character @a c is also
755
       *  written out, if @a __c is not @c eof().
756
       *
757
       *  For a formal definition of this function, see a good text
758
       *  such as Langer & Kreft, or [27.5.2.4.5]/3-7.
759
       *
760
       *  A functioning output streambuf can be created by overriding only
761
       *  this function (no buffer area will be used).
762
       *
763
       *  @note  Base class version does nothing, returns eof().
764
      */
765
      virtual int_type
766
      overflow(int_type __c  = traits_type::eof())
767
      { return traits_type::eof(); }
768
 
769
#if _GLIBCXX_USE_DEPRECATED
770
    // Annex D.6
771
    public:
772
      /**
773
       *  @brief  Tosses a character.
774
       *
775
       *  Advances the read pointer, ignoring the character that would have
776
       *  been read.
777
       *
778
       *  See http://gcc.gnu.org/ml/libstdc++/2002-05/msg00168.html
779
       */
780
      void
781
      stossc()
782
      {
783
        if (this->gptr() < this->egptr())
784
          this->gbump(1);
785
        else
786
          this->uflow();
787
      }
788
#endif
789
 
790
      // Also used by specializations for char and wchar_t in src.
791
      void
792
      __safe_gbump(streamsize __n) { _M_in_cur += __n; }
793
 
794
      void
795
      __safe_pbump(streamsize __n) { _M_out_cur += __n; }
796
 
797
    private:
798
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
799
      // Side effect of DR 50.
800
      basic_streambuf(const __streambuf_type& __sb)
801
      : _M_in_beg(__sb._M_in_beg), _M_in_cur(__sb._M_in_cur),
802
      _M_in_end(__sb._M_in_end), _M_out_beg(__sb._M_out_beg),
803
      _M_out_cur(__sb._M_out_cur), _M_out_end(__sb._M_out_cur),
804
      _M_buf_locale(__sb._M_buf_locale)
805
      { }
806
 
807
      __streambuf_type&
808
      operator=(const __streambuf_type&) { return *this; };
809
    };
810
 
811
  // Explicit specialization declarations, defined in src/streambuf.cc.
812
  template<>
813
    streamsize
814
    __copy_streambufs_eof(basic_streambuf* __sbin,
815
                          basic_streambuf* __sbout, bool& __ineof);
816
#ifdef _GLIBCXX_USE_WCHAR_T
817
  template<>
818
    streamsize
819
    __copy_streambufs_eof(basic_streambuf* __sbin,
820
                          basic_streambuf* __sbout, bool& __ineof);
821
#endif
822
 
823
_GLIBCXX_END_NAMESPACE_VERSION
824
} // namespace
825
 
826
#include 
827
 
828
#endif /* _GLIBCXX_STREAMBUF */

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.