libstdc++
streambuf_iterator.h
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1 // Streambuf iterators
2 
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 // 2006, 2007, 2009, 2010, 2011
5 // Free Software Foundation, Inc.
6 //
7 // This file is part of the GNU ISO C++ Library. This library is free
8 // software; you can redistribute it and/or modify it under the
9 // terms of the GNU General Public License as published by the
10 // Free Software Foundation; either version 3, or (at your option)
11 // any later version.
12 
13 // This library is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
17 
18 // Under Section 7 of GPL version 3, you are granted additional
19 // permissions described in the GCC Runtime Library Exception, version
20 // 3.1, as published by the Free Software Foundation.
21 
22 // You should have received a copy of the GNU General Public License and
23 // a copy of the GCC Runtime Library Exception along with this program;
24 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
25 // <http://www.gnu.org/licenses/>.
26 
27 /** @file bits/streambuf_iterator.h
28  * This is an internal header file, included by other library headers.
29  * Do not attempt to use it directly. @headername{iterator}
30  */
31 
32 #ifndef _STREAMBUF_ITERATOR_H
33 #define _STREAMBUF_ITERATOR_H 1
34 
35 #pragma GCC system_header
36 
37 #include <streambuf>
38 #include <debug/debug.h>
39 
40 namespace std _GLIBCXX_VISIBILITY(default)
41 {
42 _GLIBCXX_BEGIN_NAMESPACE_VERSION
43 
44  /**
45  * @addtogroup iterators
46  * @{
47  */
48 
49  // 24.5.3 Template class istreambuf_iterator
50  /// Provides input iterator semantics for streambufs.
51  template<typename _CharT, typename _Traits>
52  class istreambuf_iterator
53  : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type,
54  _CharT*, _CharT&>
55  {
56  public:
57  // Types:
58  //@{
59  /// Public typedefs
60  typedef _CharT char_type;
61  typedef _Traits traits_type;
62  typedef typename _Traits::int_type int_type;
63  typedef basic_streambuf<_CharT, _Traits> streambuf_type;
64  typedef basic_istream<_CharT, _Traits> istream_type;
65  //@}
66 
67  template<typename _CharT2>
68  friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
69  ostreambuf_iterator<_CharT2> >::__type
70  copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
71  ostreambuf_iterator<_CharT2>);
72 
73  template<bool _IsMove, typename _CharT2>
74  friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
75  _CharT2*>::__type
76  __copy_move_a2(istreambuf_iterator<_CharT2>,
77  istreambuf_iterator<_CharT2>, _CharT2*);
78 
79  template<typename _CharT2>
80  friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
81  istreambuf_iterator<_CharT2> >::__type
82  find(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
83  const _CharT2&);
84 
85  private:
86  // 24.5.3 istreambuf_iterator
87  // p 1
88  // If the end of stream is reached (streambuf_type::sgetc()
89  // returns traits_type::eof()), the iterator becomes equal to
90  // the "end of stream" iterator value.
91  // NB: This implementation assumes the "end of stream" value
92  // is EOF, or -1.
93  mutable streambuf_type* _M_sbuf;
94  mutable int_type _M_c;
95 
96  public:
97  /// Construct end of input stream iterator.
98  _GLIBCXX_CONSTEXPR istreambuf_iterator() throw()
99  : _M_sbuf(0), _M_c(traits_type::eof()) { }
100 
101  /// Construct start of input stream iterator.
102  istreambuf_iterator(istream_type& __s) throw()
103  : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }
104 
105  /// Construct start of streambuf iterator.
106  istreambuf_iterator(streambuf_type* __s) throw()
107  : _M_sbuf(__s), _M_c(traits_type::eof()) { }
108 
109  /// Return the current character pointed to by iterator. This returns
110  /// streambuf.sgetc(). It cannot be assigned. NB: The result of
111  /// operator*() on an end of stream is undefined.
112  char_type
113  operator*() const
114  {
115 #ifdef _GLIBCXX_DEBUG_PEDANTIC
116  // Dereferencing a past-the-end istreambuf_iterator is a
117  // libstdc++ extension
118  __glibcxx_requires_cond(!_M_at_eof(),
119  _M_message(__gnu_debug::__msg_deref_istreambuf)
120  ._M_iterator(*this));
121 #endif
122  return traits_type::to_char_type(_M_get());
123  }
124 
125  /// Advance the iterator. Calls streambuf.sbumpc().
126  istreambuf_iterator&
127  operator++()
128  {
129  __glibcxx_requires_cond(!_M_at_eof(),
130  _M_message(__gnu_debug::__msg_inc_istreambuf)
131  ._M_iterator(*this));
132  if (_M_sbuf)
133  {
134  _M_sbuf->sbumpc();
135  _M_c = traits_type::eof();
136  }
137  return *this;
138  }
139 
140  /// Advance the iterator. Calls streambuf.sbumpc().
141  istreambuf_iterator
142  operator++(int)
143  {
144  __glibcxx_requires_cond(!_M_at_eof(),
145  _M_message(__gnu_debug::__msg_inc_istreambuf)
146  ._M_iterator(*this));
147 
148  istreambuf_iterator __old = *this;
149  if (_M_sbuf)
150  {
151  __old._M_c = _M_sbuf->sbumpc();
152  _M_c = traits_type::eof();
153  }
154  return __old;
155  }
156 
157  // _GLIBCXX_RESOLVE_LIB_DEFECTS
158  // 110 istreambuf_iterator::equal not const
159  // NB: there is also number 111 (NAD, Future) pending on this function.
160  /// Return true both iterators are end or both are not end.
161  bool
162  equal(const istreambuf_iterator& __b) const
163  { return _M_at_eof() == __b._M_at_eof(); }
164 
165  private:
166  int_type
167  _M_get() const
168  {
169  const int_type __eof = traits_type::eof();
170  int_type __ret = __eof;
171  if (_M_sbuf)
172  {
173  if (!traits_type::eq_int_type(_M_c, __eof))
174  __ret = _M_c;
175  else if (!traits_type::eq_int_type((__ret = _M_sbuf->sgetc()),
176  __eof))
177  _M_c = __ret;
178  else
179  _M_sbuf = 0;
180  }
181  return __ret;
182  }
183 
184  bool
185  _M_at_eof() const
186  {
187  const int_type __eof = traits_type::eof();
188  return traits_type::eq_int_type(_M_get(), __eof);
189  }
190  };
191 
192  template<typename _CharT, typename _Traits>
193  inline bool
194  operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
195  const istreambuf_iterator<_CharT, _Traits>& __b)
196  { return __a.equal(__b); }
197 
198  template<typename _CharT, typename _Traits>
199  inline bool
200  operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
201  const istreambuf_iterator<_CharT, _Traits>& __b)
202  { return !__a.equal(__b); }
203 
204  /// Provides output iterator semantics for streambufs.
205  template<typename _CharT, typename _Traits>
206  class ostreambuf_iterator
207  : public iterator<output_iterator_tag, void, void, void, void>
208  {
209  public:
210  // Types:
211  //@{
212  /// Public typedefs
213  typedef _CharT char_type;
214  typedef _Traits traits_type;
215  typedef basic_streambuf<_CharT, _Traits> streambuf_type;
216  typedef basic_ostream<_CharT, _Traits> ostream_type;
217  //@}
218 
219  template<typename _CharT2>
220  friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
221  ostreambuf_iterator<_CharT2> >::__type
222  copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
223  ostreambuf_iterator<_CharT2>);
224 
225  private:
226  streambuf_type* _M_sbuf;
227  bool _M_failed;
228 
229  public:
230  /// Construct output iterator from ostream.
231  ostreambuf_iterator(ostream_type& __s) throw ()
232  : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }
233 
234  /// Construct output iterator from streambuf.
235  ostreambuf_iterator(streambuf_type* __s) throw ()
236  : _M_sbuf(__s), _M_failed(!_M_sbuf) { }
237 
238  /// Write character to streambuf. Calls streambuf.sputc().
239  ostreambuf_iterator&
240  operator=(_CharT __c)
241  {
242  if (!_M_failed &&
243  _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof()))
244  _M_failed = true;
245  return *this;
246  }
247 
248  /// Return *this.
249  ostreambuf_iterator&
250  operator*()
251  { return *this; }
252 
253  /// Return *this.
254  ostreambuf_iterator&
255  operator++(int)
256  { return *this; }
257 
258  /// Return *this.
259  ostreambuf_iterator&
260  operator++()
261  { return *this; }
262 
263  /// Return true if previous operator=() failed.
264  bool
265  failed() const throw()
266  { return _M_failed; }
267 
268  ostreambuf_iterator&
269  _M_put(const _CharT* __ws, streamsize __len)
270  {
271  if (__builtin_expect(!_M_failed, true)
272  && __builtin_expect(this->_M_sbuf->sputn(__ws, __len) != __len,
273  false))
274  _M_failed = true;
275  return *this;
276  }
277  };
278 
279  // Overloads for streambuf iterators.
280  template<typename _CharT>
281  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
282  ostreambuf_iterator<_CharT> >::__type
283  copy(istreambuf_iterator<_CharT> __first,
284  istreambuf_iterator<_CharT> __last,
285  ostreambuf_iterator<_CharT> __result)
286  {
287  if (__first._M_sbuf && !__last._M_sbuf && !__result._M_failed)
288  {
289  bool __ineof;
290  __copy_streambufs_eof(__first._M_sbuf, __result._M_sbuf, __ineof);
291  if (!__ineof)
292  __result._M_failed = true;
293  }
294  return __result;
295  }
296 
297  template<bool _IsMove, typename _CharT>
298  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
299  ostreambuf_iterator<_CharT> >::__type
300  __copy_move_a2(_CharT* __first, _CharT* __last,
301  ostreambuf_iterator<_CharT> __result)
302  {
303  const streamsize __num = __last - __first;
304  if (__num > 0)
305  __result._M_put(__first, __num);
306  return __result;
307  }
308 
309  template<bool _IsMove, typename _CharT>
310  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
311  ostreambuf_iterator<_CharT> >::__type
312  __copy_move_a2(const _CharT* __first, const _CharT* __last,
313  ostreambuf_iterator<_CharT> __result)
314  {
315  const streamsize __num = __last - __first;
316  if (__num > 0)
317  __result._M_put(__first, __num);
318  return __result;
319  }
320 
321  template<bool _IsMove, typename _CharT>
322  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
323  _CharT*>::__type
324  __copy_move_a2(istreambuf_iterator<_CharT> __first,
325  istreambuf_iterator<_CharT> __last, _CharT* __result)
326  {
327  typedef istreambuf_iterator<_CharT> __is_iterator_type;
328  typedef typename __is_iterator_type::traits_type traits_type;
329  typedef typename __is_iterator_type::streambuf_type streambuf_type;
330  typedef typename traits_type::int_type int_type;
331 
332  if (__first._M_sbuf && !__last._M_sbuf)
333  {
334  streambuf_type* __sb = __first._M_sbuf;
335  int_type __c = __sb->sgetc();
336  while (!traits_type::eq_int_type(__c, traits_type::eof()))
337  {
338  const streamsize __n = __sb->egptr() - __sb->gptr();
339  if (__n > 1)
340  {
341  traits_type::copy(__result, __sb->gptr(), __n);
342  __sb->__safe_gbump(__n);
343  __result += __n;
344  __c = __sb->underflow();
345  }
346  else
347  {
348  *__result++ = traits_type::to_char_type(__c);
349  __c = __sb->snextc();
350  }
351  }
352  }
353  return __result;
354  }
355 
356  template<typename _CharT>
357  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
358  istreambuf_iterator<_CharT> >::__type
359  find(istreambuf_iterator<_CharT> __first,
360  istreambuf_iterator<_CharT> __last, const _CharT& __val)
361  {
362  typedef istreambuf_iterator<_CharT> __is_iterator_type;
363  typedef typename __is_iterator_type::traits_type traits_type;
364  typedef typename __is_iterator_type::streambuf_type streambuf_type;
365  typedef typename traits_type::int_type int_type;
366 
367  if (__first._M_sbuf && !__last._M_sbuf)
368  {
369  const int_type __ival = traits_type::to_int_type(__val);
370  streambuf_type* __sb = __first._M_sbuf;
371  int_type __c = __sb->sgetc();
372  while (!traits_type::eq_int_type(__c, traits_type::eof())
373  && !traits_type::eq_int_type(__c, __ival))
374  {
375  streamsize __n = __sb->egptr() - __sb->gptr();
376  if (__n > 1)
377  {
378  const _CharT* __p = traits_type::find(__sb->gptr(),
379  __n, __val);
380  if (__p)
381  __n = __p - __sb->gptr();
382  __sb->__safe_gbump(__n);
383  __c = __sb->sgetc();
384  }
385  else
386  __c = __sb->snextc();
387  }
388 
389  if (!traits_type::eq_int_type(__c, traits_type::eof()))
390  __first._M_c = __c;
391  else
392  __first._M_sbuf = 0;
393  }
394  return __first;
395  }
396 
397 // @} group iterators
398 
399 _GLIBCXX_END_NAMESPACE_VERSION
400 } // namespace
401 
402 #endif