libstdc++
streambuf_iterator.h
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1 // Streambuf iterators
2 
3 // Copyright (C) 1997-2017 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file bits/streambuf_iterator.h
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly. @headername{iterator}
28  */
29 
30 #ifndef _STREAMBUF_ITERATOR_H
31 #define _STREAMBUF_ITERATOR_H 1
32 
33 #pragma GCC system_header
34 
35 #include <streambuf>
36 #include <debug/debug.h>
37 
38 namespace std _GLIBCXX_VISIBILITY(default)
39 {
40 _GLIBCXX_BEGIN_NAMESPACE_VERSION
41 
42  /**
43  * @addtogroup iterators
44  * @{
45  */
46 
47  // 24.5.3 Template class istreambuf_iterator
48  /// Provides input iterator semantics for streambufs.
49  template<typename _CharT, typename _Traits>
50  class istreambuf_iterator
51  : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type,
52  _CharT*,
53 #if __cplusplus >= 201103L
54  // LWG 445.
55  _CharT>
56 #else
57  _CharT&>
58 #endif
59  {
60  public:
61  // Types:
62  //@{
63  /// Public typedefs
64  typedef _CharT char_type;
65  typedef _Traits traits_type;
66  typedef typename _Traits::int_type int_type;
69  //@}
70 
71  template<typename _CharT2>
72  friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
76 
77  template<bool _IsMove, typename _CharT2>
78  friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
79  _CharT2*>::__type
80  __copy_move_a2(istreambuf_iterator<_CharT2>,
82 
83  template<typename _CharT2>
84  friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
87  const _CharT2&);
88 
89  private:
90  // 24.5.3 istreambuf_iterator
91  // p 1
92  // If the end of stream is reached (streambuf_type::sgetc()
93  // returns traits_type::eof()), the iterator becomes equal to
94  // the "end of stream" iterator value.
95  // NB: This implementation assumes the "end of stream" value
96  // is EOF, or -1.
97  mutable streambuf_type* _M_sbuf;
98  mutable int_type _M_c;
99 
100  public:
101  /// Construct end of input stream iterator.
102  _GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT
103  : _M_sbuf(0), _M_c(traits_type::eof()) { }
104 
105 #if __cplusplus >= 201103L
106  istreambuf_iterator(const istreambuf_iterator&) noexcept = default;
107 
108  ~istreambuf_iterator() = default;
109 #endif
110 
111  /// Construct start of input stream iterator.
112  istreambuf_iterator(istream_type& __s) _GLIBCXX_USE_NOEXCEPT
113  : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }
114 
115  /// Construct start of streambuf iterator.
116  istreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT
117  : _M_sbuf(__s), _M_c(traits_type::eof()) { }
118 
119  /// Return the current character pointed to by iterator. This returns
120  /// streambuf.sgetc(). It cannot be assigned. NB: The result of
121  /// operator*() on an end of stream is undefined.
122  char_type
123  operator*() const
124  {
125 #ifdef _GLIBCXX_DEBUG_PEDANTIC
126  // Dereferencing a past-the-end istreambuf_iterator is a
127  // libstdc++ extension
128  __glibcxx_requires_cond(!_M_at_eof(),
129  _M_message(__gnu_debug::__msg_deref_istreambuf)
130  ._M_iterator(*this));
131 #endif
132  return traits_type::to_char_type(_M_get());
133  }
134 
135  /// Advance the iterator. Calls streambuf.sbumpc().
138  {
139  __glibcxx_requires_cond(!_M_at_eof(),
140  _M_message(__gnu_debug::__msg_inc_istreambuf)
141  ._M_iterator(*this));
142  if (_M_sbuf)
143  {
144  _M_sbuf->sbumpc();
145  _M_c = traits_type::eof();
146  }
147  return *this;
148  }
149 
150  /// Advance the iterator. Calls streambuf.sbumpc().
153  {
154  __glibcxx_requires_cond(!_M_at_eof(),
155  _M_message(__gnu_debug::__msg_inc_istreambuf)
156  ._M_iterator(*this));
157 
158  istreambuf_iterator __old = *this;
159  if (_M_sbuf)
160  {
161  __old._M_c = _M_sbuf->sbumpc();
162  _M_c = traits_type::eof();
163  }
164  return __old;
165  }
166 
167  // _GLIBCXX_RESOLVE_LIB_DEFECTS
168  // 110 istreambuf_iterator::equal not const
169  // NB: there is also number 111 (NAD, Future) pending on this function.
170  /// Return true both iterators are end or both are not end.
171  bool
172  equal(const istreambuf_iterator& __b) const
173  { return _M_at_eof() == __b._M_at_eof(); }
174 
175  private:
176  int_type
177  _M_get() const
178  {
179  const int_type __eof = traits_type::eof();
180  int_type __ret = __eof;
181  if (_M_sbuf)
182  {
183  if (!traits_type::eq_int_type(_M_c, __eof))
184  __ret = _M_c;
185  else if (!traits_type::eq_int_type((__ret = _M_sbuf->sgetc()),
186  __eof))
187  _M_c = __ret;
188  else
189  _M_sbuf = 0;
190  }
191  return __ret;
192  }
193 
194  bool
195  _M_at_eof() const
196  {
197  const int_type __eof = traits_type::eof();
198  return traits_type::eq_int_type(_M_get(), __eof);
199  }
200  };
201 
202  template<typename _CharT, typename _Traits>
203  inline bool
204  operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
206  { return __a.equal(__b); }
207 
208  template<typename _CharT, typename _Traits>
209  inline bool
210  operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
212  { return !__a.equal(__b); }
213 
214  /// Provides output iterator semantics for streambufs.
215  template<typename _CharT, typename _Traits>
216  class ostreambuf_iterator
217  : public iterator<output_iterator_tag, void, void, void, void>
218  {
219  public:
220  // Types:
221  //@{
222  /// Public typedefs
223  typedef _CharT char_type;
224  typedef _Traits traits_type;
227  //@}
228 
229  template<typename _CharT2>
230  friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
234 
235  private:
236  streambuf_type* _M_sbuf;
237  bool _M_failed;
238 
239  public:
240  /// Construct output iterator from ostream.
241  ostreambuf_iterator(ostream_type& __s) _GLIBCXX_USE_NOEXCEPT
242  : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }
243 
244  /// Construct output iterator from streambuf.
245  ostreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT
246  : _M_sbuf(__s), _M_failed(!_M_sbuf) { }
247 
248  /// Write character to streambuf. Calls streambuf.sputc().
250  operator=(_CharT __c)
251  {
252  if (!_M_failed &&
253  _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof()))
254  _M_failed = true;
255  return *this;
256  }
257 
258  /// Return *this.
261  { return *this; }
262 
263  /// Return *this.
266  { return *this; }
267 
268  /// Return *this.
271  { return *this; }
272 
273  /// Return true if previous operator=() failed.
274  bool
275  failed() const _GLIBCXX_USE_NOEXCEPT
276  { return _M_failed; }
277 
279  _M_put(const _CharT* __ws, streamsize __len)
280  {
281  if (__builtin_expect(!_M_failed, true)
282  && __builtin_expect(this->_M_sbuf->sputn(__ws, __len) != __len,
283  false))
284  _M_failed = true;
285  return *this;
286  }
287  };
288 
289  // Overloads for streambuf iterators.
290  template<typename _CharT>
291  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
293  copy(istreambuf_iterator<_CharT> __first,
296  {
297  if (__first._M_sbuf && !__last._M_sbuf && !__result._M_failed)
298  {
299  bool __ineof;
300  __copy_streambufs_eof(__first._M_sbuf, __result._M_sbuf, __ineof);
301  if (!__ineof)
302  __result._M_failed = true;
303  }
304  return __result;
305  }
306 
307  template<bool _IsMove, typename _CharT>
308  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
310  __copy_move_a2(_CharT* __first, _CharT* __last,
312  {
313  const streamsize __num = __last - __first;
314  if (__num > 0)
315  __result._M_put(__first, __num);
316  return __result;
317  }
318 
319  template<bool _IsMove, typename _CharT>
320  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
322  __copy_move_a2(const _CharT* __first, const _CharT* __last,
324  {
325  const streamsize __num = __last - __first;
326  if (__num > 0)
327  __result._M_put(__first, __num);
328  return __result;
329  }
330 
331  template<bool _IsMove, typename _CharT>
332  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
333  _CharT*>::__type
334  __copy_move_a2(istreambuf_iterator<_CharT> __first,
335  istreambuf_iterator<_CharT> __last, _CharT* __result)
336  {
337  typedef istreambuf_iterator<_CharT> __is_iterator_type;
338  typedef typename __is_iterator_type::traits_type traits_type;
339  typedef typename __is_iterator_type::streambuf_type streambuf_type;
340  typedef typename traits_type::int_type int_type;
341 
342  if (__first._M_sbuf && !__last._M_sbuf)
343  {
344  streambuf_type* __sb = __first._M_sbuf;
345  int_type __c = __sb->sgetc();
346  while (!traits_type::eq_int_type(__c, traits_type::eof()))
347  {
348  const streamsize __n = __sb->egptr() - __sb->gptr();
349  if (__n > 1)
350  {
351  traits_type::copy(__result, __sb->gptr(), __n);
352  __sb->__safe_gbump(__n);
353  __result += __n;
354  __c = __sb->underflow();
355  }
356  else
357  {
358  *__result++ = traits_type::to_char_type(__c);
359  __c = __sb->snextc();
360  }
361  }
362  }
363  return __result;
364  }
365 
366  template<typename _CharT>
367  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
369  find(istreambuf_iterator<_CharT> __first,
370  istreambuf_iterator<_CharT> __last, const _CharT& __val)
371  {
372  typedef istreambuf_iterator<_CharT> __is_iterator_type;
373  typedef typename __is_iterator_type::traits_type traits_type;
374  typedef typename __is_iterator_type::streambuf_type streambuf_type;
375  typedef typename traits_type::int_type int_type;
376 
377  if (__first._M_sbuf && !__last._M_sbuf)
378  {
379  const int_type __ival = traits_type::to_int_type(__val);
380  streambuf_type* __sb = __first._M_sbuf;
381  int_type __c = __sb->sgetc();
382  while (!traits_type::eq_int_type(__c, traits_type::eof())
383  && !traits_type::eq_int_type(__c, __ival))
384  {
385  streamsize __n = __sb->egptr() - __sb->gptr();
386  if (__n > 1)
387  {
388  const _CharT* __p = traits_type::find(__sb->gptr(),
389  __n, __val);
390  if (__p)
391  __n = __p - __sb->gptr();
392  __sb->__safe_gbump(__n);
393  __c = __sb->sgetc();
394  }
395  else
396  __c = __sb->snextc();
397  }
398 
399  if (!traits_type::eq_int_type(__c, traits_type::eof()))
400  __first._M_c = __c;
401  else
402  __first._M_sbuf = 0;
403  }
404  return __first;
405  }
406 
407 // @} group iterators
408 
409 _GLIBCXX_END_NAMESPACE_VERSION
410 } // namespace
411 
412 #endif
ostreambuf_iterator(streambuf_type *__s) noexcept
Construct output iterator from streambuf.
int_type sputc(char_type __c)
Entry point for all single-character output functions.
Definition: streambuf:424
_Traits::int_type int_type
Public typedefs.
char_type * egptr() const
Access to the get area.
Definition: streambuf:488
ostreambuf_iterator & operator*()
Return *this.
ostreambuf_iterator & operator++(int)
Return *this.
Provides output iterator semantics for streambufs.
Definition: iosfwd:128
char_type * gptr() const
Access to the get area.
Definition: streambuf:485
_CharT char_type
Public typedefs.
char_type operator*() const
Return the current character pointed to by iterator. This returns streambuf.sgetc(). It cannot be assigned. NB: The result of operator*() on an end of stream is undefined.
Template class basic_ostream.
Definition: iosfwd:86
ostreambuf_iterator & operator++()
Return *this.
constexpr istreambuf_iterator() noexcept
Construct end of input stream iterator.
istreambuf_iterator(istream_type &__s) noexcept
Construct start of input stream iterator.
bool failed() const noexcept
Return true if previous operator=() failed.
The actual work of input and output (interface).
Definition: iosfwd:80
ISO C++ entities toplevel namespace is std.
Template class basic_istream.
Definition: iosfwd:83
basic_streambuf< _CharT, _Traits > streambuf_type
Public typedefs.
int_type sbumpc()
Getting the next character.
Definition: streambuf:316
int_type snextc()
Getting the next character.
Definition: streambuf:298
istreambuf_iterator & operator++()
Advance the iterator. Calls streambuf.sbumpc().
int_type sgetc()
Getting the next character.
Definition: streambuf:338
ostreambuf_iterator(ostream_type &__s) noexcept
Construct output iterator from ostream.
bool equal(const istreambuf_iterator &__b) const
Return true both iterators are end or both are not end.
basic_streambuf< _CharT, _Traits > streambuf_type
Public typedefs.
_CharT char_type
Public typedefs.
basic_istream< _CharT, _Traits > istream_type
Public typedefs.
ostreambuf_iterator & operator=(_CharT __c)
Write character to streambuf. Calls streambuf.sputc().
basic_ostream< _CharT, _Traits > ostream_type
Public typedefs.
istreambuf_iterator operator++(int)
Advance the iterator. Calls streambuf.sbumpc().
streamsize sputn(const char_type *__s, streamsize __n)
Entry point for all single-character output functions.
Definition: streambuf:450
_Traits traits_type
Public typedefs.
istreambuf_iterator(streambuf_type *__s) noexcept
Construct start of streambuf iterator.
ptrdiff_t streamsize
Integral type for I/O operation counts and buffer sizes.
Definition: postypes.h:98
Common iterator class.
virtual int_type underflow()
Fetches more data from the controlled sequence.
Definition: streambuf:687
_Traits traits_type
Public typedefs.
Provides input iterator semantics for streambufs.
Definition: iosfwd:125