1 // Streambuf iterators
2
3 // Copyright (C) 1997-2016 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
_GLIBCXX_VISIBILITY(default)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;
67 typedef basic_streambuf<_CharT, _Traits> streambuf_type;
68 typedef basic_istream<_CharT, _Traits> istream_type;
69 //@}
70
71 template<typename _CharT2>
72 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
73 ostreambuf_iterator<_CharT2> >::__type
74 copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
75 ostreambuf_iterator<_CharT2>);
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>,
81 istreambuf_iterator<_CharT2>, _CharT2*);
82
83 template<typename _CharT2>
84 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
85 istreambuf_iterator<_CharT2> >::__type
86 find(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
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().
136 istreambuf_iterator&
137 operator++()
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().
151 istreambuf_iterator
152 operator++(int)
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,
205 const istreambuf_iterator<_CharT, _Traits>& __b)
206 { return __a.equal(__b); }
207
208 template<typename _CharT, typename _Traits>
209 inline bool
210 operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
211 const istreambuf_iterator<_CharT, _Traits>& __b)
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;
225 typedef basic_streambuf<_CharT, _Traits> streambuf_type;
226 typedef basic_ostream<_CharT, _Traits> ostream_type;
227 //@}
228
229 template<typename _CharT2>
230 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
231 ostreambuf_iterator<_CharT2> >::__type
232 copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
233 ostreambuf_iterator<_CharT2>);
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().
249 ostreambuf_iterator&
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.
259 ostreambuf_iterator&
260 operator*()
261 { return *this; }
262
263 /// Return *this.
264 ostreambuf_iterator&
265 operator++(int)
266 { return *this; }
267
268 /// Return *this.
269 ostreambuf_iterator&
270 operator++()
271 { return *this; }
272
273 /// Return true if previous operator=() failed.
274 bool
275 failed() const _GLIBCXX_USE_NOEXCEPT
276 { return _M_failed; }
277
278 ostreambuf_iterator&
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,
292 ostreambuf_iterator<_CharT> >::__type
293 copy(istreambuf_iterator<_CharT> __first,
294 istreambuf_iterator<_CharT> __last,
295 ostreambuf_iterator<_CharT> __result)
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,
309 ostreambuf_iterator<_CharT> >::__type
310 __copy_move_a2(_CharT* __first, _CharT* __last,
311 ostreambuf_iterator<_CharT> __result)
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,
321 ostreambuf_iterator<_CharT> >::__type
322 __copy_move_a2(const _CharT* __first, const _CharT* __last,
323 ostreambuf_iterator<_CharT> __result)
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,
368 istreambuf_iterator<_CharT> >::__type
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
413