1    	// Streambuf iterators
2    	
3    	// Copyright (C) 1997-2013 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;
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