xref: /netbsd-src/external/gpl3/gcc.old/dist/libstdc++-v3/include/debug/safe_iterator.h (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 // Safe iterator implementation  -*- C++ -*-
2 
3 // Copyright (C) 2003-2015 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 debug/safe_iterator.h
26  *  This file is a GNU debug extension to the Standard C++ Library.
27  */
28 
29 #ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_H
30 #define _GLIBCXX_DEBUG_SAFE_ITERATOR_H 1
31 
32 #include <debug/debug.h>
33 #include <debug/macros.h>
34 #include <debug/functions.h>
35 #include <debug/safe_base.h>
36 #include <bits/stl_pair.h>
37 #include <ext/type_traits.h>
38 
39 namespace __gnu_debug
40 {
41   /** Helper struct to deal with sequence offering a before_begin
42    *  iterator.
43    **/
44   template <typename _Sequence>
45     struct _BeforeBeginHelper
46     {
47       template<typename _Iterator>
48 	static bool
49 	_S_Is(const _Safe_iterator<_Iterator, _Sequence>&)
50 	{ return false; }
51 
52       template<typename _Iterator>
53 	static bool
54 	_S_Is_Beginnest(const _Safe_iterator<_Iterator, _Sequence>& __it)
55 	{ return __it.base() == __it._M_get_sequence()->_M_base().begin(); }
56     };
57 
58   /** Iterators that derive from _Safe_iterator_base can be determined singular
59    *  or non-singular.
60    **/
61   inline bool
62   __check_singular_aux(const _Safe_iterator_base* __x)
63   { return __x->_M_singular(); }
64 
65   /** The precision to which we can calculate the distance between
66    *  two iterators.
67    */
68   enum _Distance_precision
69     {
70       __dp_equality, //< Can compare iterator equality, only
71       __dp_sign,     //< Can determine equality and ordering
72       __dp_exact     //< Can determine distance precisely
73     };
74 
75   /** Determine the distance between two iterators with some known
76    *	precision.
77   */
78   template<typename _Iterator>
79     inline std::pair<typename std::iterator_traits<_Iterator>::difference_type,
80 		     _Distance_precision>
81     __get_distance(const _Iterator& __lhs, const _Iterator& __rhs,
82 		   std::random_access_iterator_tag)
83     { return std::make_pair(__rhs - __lhs, __dp_exact); }
84 
85   template<typename _Iterator>
86     inline std::pair<typename std::iterator_traits<_Iterator>::difference_type,
87 		     _Distance_precision>
88     __get_distance(const _Iterator& __lhs, const _Iterator& __rhs,
89 		   std::forward_iterator_tag)
90     { return std::make_pair(__lhs == __rhs? 0 : 1, __dp_equality); }
91 
92   template<typename _Iterator>
93     inline std::pair<typename std::iterator_traits<_Iterator>::difference_type,
94 		     _Distance_precision>
95     __get_distance(const _Iterator& __lhs, const _Iterator& __rhs)
96     {
97       typedef typename std::iterator_traits<_Iterator>::iterator_category
98 	  _Category;
99       return __get_distance(__lhs, __rhs, _Category());
100     }
101 
102   /** \brief Safe iterator wrapper.
103    *
104    *  The class template %_Safe_iterator is a wrapper around an
105    *  iterator that tracks the iterator's movement among sequences and
106    *  checks that operations performed on the "safe" iterator are
107    *  legal. In additional to the basic iterator operations (which are
108    *  validated, and then passed to the underlying iterator),
109    *  %_Safe_iterator has member functions for iterator invalidation,
110    *  attaching/detaching the iterator from sequences, and querying
111    *  the iterator's state.
112    *
113    *  Note that _Iterator must be the first base class so that it gets
114    *  initialized before the iterator is being attached to the container's list
115    *  of iterators and it is being detached before _Iterator get
116    *  destroyed. Otherwise it would result in a data race.
117    */
118   template<typename _Iterator, typename _Sequence>
119     class _Safe_iterator
120     : private _Iterator,
121       public _Safe_iterator_base
122     {
123       typedef _Iterator _Iter_base;
124       typedef _Safe_iterator_base _Safe_base;
125       typedef typename _Sequence::const_iterator _Const_iterator;
126 
127       /// Determine if this is a constant iterator.
128       bool
129       _M_constant() const
130       { return std::__are_same<_Const_iterator, _Safe_iterator>::__value; }
131 
132       typedef std::iterator_traits<_Iterator> _Traits;
133 
134       struct _Attach_single
135       { };
136 
137       _Safe_iterator(const _Iterator& __i, _Safe_sequence_base* __seq,
138 		     _Attach_single)
139       _GLIBCXX_NOEXCEPT
140       : _Iter_base(__i)
141       { _M_attach_single(__seq); }
142 
143     public:
144       typedef _Iterator					iterator_type;
145       typedef typename _Traits::iterator_category	iterator_category;
146       typedef typename _Traits::value_type		value_type;
147       typedef typename _Traits::difference_type		difference_type;
148       typedef typename _Traits::reference		reference;
149       typedef typename _Traits::pointer			pointer;
150 
151       /// @post the iterator is singular and unattached
152       _Safe_iterator() _GLIBCXX_NOEXCEPT : _Iter_base() { }
153 
154       /**
155        * @brief Safe iterator construction from an unsafe iterator and
156        * its sequence.
157        *
158        * @pre @p seq is not NULL
159        * @post this is not singular
160        */
161       _Safe_iterator(const _Iterator& __i, const _Safe_sequence_base* __seq)
162       _GLIBCXX_NOEXCEPT
163       : _Iter_base(__i), _Safe_base(__seq, _M_constant())
164       {
165 	_GLIBCXX_DEBUG_VERIFY(!this->_M_singular(),
166 			      _M_message(__msg_init_singular)
167 			      ._M_iterator(*this, "this"));
168       }
169 
170       /**
171        * @brief Copy construction.
172        */
173       _Safe_iterator(const _Safe_iterator& __x) _GLIBCXX_NOEXCEPT
174       : _Iter_base(__x.base())
175       {
176 	// _GLIBCXX_RESOLVE_LIB_DEFECTS
177 	// DR 408. Is vector<reverse_iterator<char*> > forbidden?
178 	_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
179 			      || __x.base() == _Iterator(),
180 			      _M_message(__msg_init_copy_singular)
181 			      ._M_iterator(*this, "this")
182 			      ._M_iterator(__x, "other"));
183 	_M_attach(__x._M_sequence);
184       }
185 
186 #if __cplusplus >= 201103L
187       /**
188        * @brief Move construction.
189        * @post __x is singular and unattached
190        */
191       _Safe_iterator(_Safe_iterator&& __x) noexcept
192       : _Iter_base()
193       {
194 	_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
195 			      || __x.base() == _Iterator(),
196 			      _M_message(__msg_init_copy_singular)
197 			      ._M_iterator(*this, "this")
198 			      ._M_iterator(__x, "other"));
199 	_Safe_sequence_base* __seq = __x._M_sequence;
200 	__x._M_detach();
201 	std::swap(base(), __x.base());
202 	_M_attach(__seq);
203       }
204 #endif
205 
206       /**
207        *  @brief Converting constructor from a mutable iterator to a
208        *  constant iterator.
209       */
210       template<typename _MutableIterator>
211 	_Safe_iterator(
212 	  const _Safe_iterator<_MutableIterator,
213 	  typename __gnu_cxx::__enable_if<(std::__are_same<_MutableIterator,
214 		      typename _Sequence::iterator::iterator_type>::__value),
215 		   _Sequence>::__type>& __x) _GLIBCXX_NOEXCEPT
216 	: _Iter_base(__x.base())
217 	{
218 	  // _GLIBCXX_RESOLVE_LIB_DEFECTS
219 	  // DR 408. Is vector<reverse_iterator<char*> > forbidden?
220 	  _GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
221 				|| __x.base() == _Iterator(),
222 				_M_message(__msg_init_const_singular)
223 				._M_iterator(*this, "this")
224 				._M_iterator(__x, "other"));
225 	  _M_attach(__x._M_sequence);
226 	}
227 
228       /**
229        * @brief Copy assignment.
230        */
231       _Safe_iterator&
232       operator=(const _Safe_iterator& __x) _GLIBCXX_NOEXCEPT
233       {
234 	// _GLIBCXX_RESOLVE_LIB_DEFECTS
235 	// DR 408. Is vector<reverse_iterator<char*> > forbidden?
236 	_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
237 			      || __x.base() == _Iterator(),
238 			      _M_message(__msg_copy_singular)
239 			      ._M_iterator(*this, "this")
240 			      ._M_iterator(__x, "other"));
241 
242 	if (this->_M_sequence && this->_M_sequence == __x._M_sequence)
243 	  {
244 	    __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
245 	    base() = __x.base();
246 	    _M_version = __x._M_sequence->_M_version;
247 	  }
248 	else
249 	  {
250 	    _M_detach();
251 	    base() = __x.base();
252 	    _M_attach(__x._M_sequence);
253 	  }
254 
255 	return *this;
256       }
257 
258 #if __cplusplus >= 201103L
259       /**
260        * @brief Move assignment.
261        * @post __x is singular and unattached
262        */
263       _Safe_iterator&
264       operator=(_Safe_iterator&& __x) noexcept
265       {
266 	_GLIBCXX_DEBUG_VERIFY(this != &__x,
267 			      _M_message(__msg_self_move_assign)
268 			      ._M_iterator(*this, "this"));
269 	_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
270 			      || __x.base() == _Iterator(),
271 			      _M_message(__msg_copy_singular)
272 			      ._M_iterator(*this, "this")
273 			      ._M_iterator(__x, "other"));
274 
275 	if (this->_M_sequence && this->_M_sequence == __x._M_sequence)
276 	  {
277 	    __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
278 	    base() = __x.base();
279 	    _M_version = __x._M_sequence->_M_version;
280 	  }
281 	else
282 	  {
283 	    _M_detach();
284 	    base() = __x.base();
285 	    _M_attach(__x._M_sequence);
286 	  }
287 
288 	__x._M_detach();
289 	__x.base() = _Iterator();
290 	return *this;
291       }
292 #endif
293 
294       /**
295        *  @brief Iterator dereference.
296        *  @pre iterator is dereferenceable
297        */
298       reference
299       operator*() const _GLIBCXX_NOEXCEPT
300       {
301 	_GLIBCXX_DEBUG_VERIFY(this->_M_dereferenceable(),
302 			      _M_message(__msg_bad_deref)
303 			      ._M_iterator(*this, "this"));
304 	return *base();
305       }
306 
307       /**
308        *  @brief Iterator dereference.
309        *  @pre iterator is dereferenceable
310        *  @todo Make this correct w.r.t. iterators that return proxies
311        */
312       pointer
313       operator->() const _GLIBCXX_NOEXCEPT
314       {
315 	_GLIBCXX_DEBUG_VERIFY(this->_M_dereferenceable(),
316 			      _M_message(__msg_bad_deref)
317 			      ._M_iterator(*this, "this"));
318 	return std::__addressof(*base());
319       }
320 
321       // ------ Input iterator requirements ------
322       /**
323        *  @brief Iterator preincrement
324        *  @pre iterator is incrementable
325        */
326       _Safe_iterator&
327       operator++() _GLIBCXX_NOEXCEPT
328       {
329 	_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
330 			      _M_message(__msg_bad_inc)
331 			      ._M_iterator(*this, "this"));
332 	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
333 	++base();
334 	return *this;
335       }
336 
337       /**
338        *  @brief Iterator postincrement
339        *  @pre iterator is incrementable
340        */
341       _Safe_iterator
342       operator++(int) _GLIBCXX_NOEXCEPT
343       {
344 	_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
345 			      _M_message(__msg_bad_inc)
346 			      ._M_iterator(*this, "this"));
347 	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
348 	return _Safe_iterator(base()++, this->_M_sequence, _Attach_single());
349       }
350 
351       // ------ Bidirectional iterator requirements ------
352       /**
353        *  @brief Iterator predecrement
354        *  @pre iterator is decrementable
355        */
356       _Safe_iterator&
357       operator--() _GLIBCXX_NOEXCEPT
358       {
359 	_GLIBCXX_DEBUG_VERIFY(this->_M_decrementable(),
360 			      _M_message(__msg_bad_dec)
361 			      ._M_iterator(*this, "this"));
362 	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
363 	--base();
364 	return *this;
365       }
366 
367       /**
368        *  @brief Iterator postdecrement
369        *  @pre iterator is decrementable
370        */
371       _Safe_iterator
372       operator--(int) _GLIBCXX_NOEXCEPT
373       {
374 	_GLIBCXX_DEBUG_VERIFY(this->_M_decrementable(),
375 			      _M_message(__msg_bad_dec)
376 			      ._M_iterator(*this, "this"));
377 	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
378 	return _Safe_iterator(base()--, this->_M_sequence, _Attach_single());
379       }
380 
381       // ------ Random access iterator requirements ------
382       reference
383       operator[](const difference_type& __n) const _GLIBCXX_NOEXCEPT
384       {
385 	_GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(__n)
386 			      && this->_M_can_advance(__n+1),
387 			      _M_message(__msg_iter_subscript_oob)
388 			      ._M_iterator(*this)._M_integer(__n));
389 	return base()[__n];
390       }
391 
392       _Safe_iterator&
393       operator+=(const difference_type& __n) _GLIBCXX_NOEXCEPT
394       {
395 	_GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(__n),
396 			      _M_message(__msg_advance_oob)
397 			      ._M_iterator(*this)._M_integer(__n));
398 	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
399 	base() += __n;
400 	return *this;
401       }
402 
403       _Safe_iterator
404       operator+(const difference_type& __n) const _GLIBCXX_NOEXCEPT
405       {
406 	_GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(__n),
407 			      _M_message(__msg_advance_oob)
408 			      ._M_iterator(*this)._M_integer(__n));
409 	return _Safe_iterator(base() + __n, this->_M_sequence);
410       }
411 
412       _Safe_iterator&
413       operator-=(const difference_type& __n) _GLIBCXX_NOEXCEPT
414       {
415 	_GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(-__n),
416 			      _M_message(__msg_retreat_oob)
417 			      ._M_iterator(*this)._M_integer(__n));
418 	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
419 	base() -= __n;
420 	return *this;
421       }
422 
423       _Safe_iterator
424       operator-(const difference_type& __n) const _GLIBCXX_NOEXCEPT
425       {
426 	_GLIBCXX_DEBUG_VERIFY(this->_M_can_advance(-__n),
427 			      _M_message(__msg_retreat_oob)
428 			      ._M_iterator(*this)._M_integer(__n));
429 	return _Safe_iterator(base() - __n, this->_M_sequence);
430       }
431 
432       // ------ Utilities ------
433       /**
434        * @brief Return the underlying iterator
435        */
436       _Iterator&
437       base() _GLIBCXX_NOEXCEPT { return *this; }
438 
439       const _Iterator&
440       base() const _GLIBCXX_NOEXCEPT { return *this; }
441 
442       /**
443        * @brief Conversion to underlying non-debug iterator to allow
444        * better interaction with non-debug containers.
445        */
446       operator _Iterator() const _GLIBCXX_NOEXCEPT { return *this; }
447 
448       /** Attach iterator to the given sequence. */
449       void
450       _M_attach(_Safe_sequence_base* __seq)
451       { _Safe_base::_M_attach(__seq, _M_constant()); }
452 
453       /** Likewise, but not thread-safe. */
454       void
455       _M_attach_single(_Safe_sequence_base* __seq)
456       { _Safe_base::_M_attach_single(__seq, _M_constant()); }
457 
458       /// Is the iterator dereferenceable?
459       bool
460       _M_dereferenceable() const
461       { return !this->_M_singular() && !_M_is_end() && !_M_is_before_begin(); }
462 
463       /// Is the iterator before a dereferenceable one?
464       bool
465       _M_before_dereferenceable() const
466       {
467 	if (this->_M_incrementable())
468 	{
469 	  _Iterator __base = base();
470 	  return ++__base != _M_get_sequence()->_M_base().end();
471 	}
472 	return false;
473       }
474 
475       /// Is the iterator incrementable?
476       bool
477       _M_incrementable() const
478       { return !this->_M_singular() && !_M_is_end(); }
479 
480       // Is the iterator decrementable?
481       bool
482       _M_decrementable() const { return !_M_singular() && !_M_is_begin(); }
483 
484       // Can we advance the iterator @p __n steps (@p __n may be negative)
485       bool
486       _M_can_advance(const difference_type& __n) const;
487 
488       // Is the iterator range [*this, __rhs) valid?
489       bool
490       _M_valid_range(const _Safe_iterator& __rhs) const;
491 
492       // The sequence this iterator references.
493       typename
494       __gnu_cxx::__conditional_type<std::__are_same<_Const_iterator,
495 						    _Safe_iterator>::__value,
496 				    const _Sequence*,
497 				    _Sequence*>::__type
498       _M_get_sequence() const
499       { return static_cast<_Sequence*>(_M_sequence); }
500 
501       /// Is this iterator equal to the sequence's begin() iterator?
502       bool
503       _M_is_begin() const
504       { return base() == _M_get_sequence()->_M_base().begin(); }
505 
506       /// Is this iterator equal to the sequence's end() iterator?
507       bool
508       _M_is_end() const
509       { return base() == _M_get_sequence()->_M_base().end(); }
510 
511       /// Is this iterator equal to the sequence's before_begin() iterator if
512       /// any?
513       bool
514       _M_is_before_begin() const
515       { return _BeforeBeginHelper<_Sequence>::_S_Is(*this); }
516 
517       /// Is this iterator equal to the sequence's before_begin() iterator if
518       /// any or begin() otherwise?
519       bool
520       _M_is_beginnest() const
521       { return _BeforeBeginHelper<_Sequence>::_S_Is_Beginnest(*this); }
522     };
523 
524   template<typename _IteratorL, typename _IteratorR, typename _Sequence>
525     inline bool
526     operator==(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
527 	       const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
528     _GLIBCXX_NOEXCEPT
529     {
530       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
531 			    _M_message(__msg_iter_compare_bad)
532 			    ._M_iterator(__lhs, "lhs")
533 			    ._M_iterator(__rhs, "rhs"));
534       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
535 			    _M_message(__msg_compare_different)
536 			    ._M_iterator(__lhs, "lhs")
537 			    ._M_iterator(__rhs, "rhs"));
538       return __lhs.base() == __rhs.base();
539     }
540 
541   template<typename _Iterator, typename _Sequence>
542     inline bool
543     operator==(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
544 	       const _Safe_iterator<_Iterator, _Sequence>& __rhs)
545     _GLIBCXX_NOEXCEPT
546     {
547       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
548 			    _M_message(__msg_iter_compare_bad)
549 			    ._M_iterator(__lhs, "lhs")
550 			    ._M_iterator(__rhs, "rhs"));
551       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
552 			    _M_message(__msg_compare_different)
553 			    ._M_iterator(__lhs, "lhs")
554 			    ._M_iterator(__rhs, "rhs"));
555       return __lhs.base() == __rhs.base();
556     }
557 
558   template<typename _IteratorL, typename _IteratorR, typename _Sequence>
559     inline bool
560     operator!=(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
561 	       const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
562     _GLIBCXX_NOEXCEPT
563     {
564       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
565 			    _M_message(__msg_iter_compare_bad)
566 			    ._M_iterator(__lhs, "lhs")
567 			    ._M_iterator(__rhs, "rhs"));
568       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
569 			    _M_message(__msg_compare_different)
570 			    ._M_iterator(__lhs, "lhs")
571 			    ._M_iterator(__rhs, "rhs"));
572       return __lhs.base() != __rhs.base();
573     }
574 
575   template<typename _Iterator, typename _Sequence>
576     inline bool
577     operator!=(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
578 	       const _Safe_iterator<_Iterator, _Sequence>& __rhs)
579     _GLIBCXX_NOEXCEPT
580     {
581       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
582 			    _M_message(__msg_iter_compare_bad)
583 			    ._M_iterator(__lhs, "lhs")
584 			    ._M_iterator(__rhs, "rhs"));
585       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
586 			    _M_message(__msg_compare_different)
587 			    ._M_iterator(__lhs, "lhs")
588 			    ._M_iterator(__rhs, "rhs"));
589       return __lhs.base() != __rhs.base();
590     }
591 
592   template<typename _IteratorL, typename _IteratorR, typename _Sequence>
593     inline bool
594     operator<(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
595 	      const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
596     _GLIBCXX_NOEXCEPT
597     {
598       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
599 			    _M_message(__msg_iter_order_bad)
600 			    ._M_iterator(__lhs, "lhs")
601 			    ._M_iterator(__rhs, "rhs"));
602       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
603 			    _M_message(__msg_order_different)
604 			    ._M_iterator(__lhs, "lhs")
605 			    ._M_iterator(__rhs, "rhs"));
606       return __lhs.base() < __rhs.base();
607     }
608 
609   template<typename _Iterator, typename _Sequence>
610     inline bool
611     operator<(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
612 	      const _Safe_iterator<_Iterator, _Sequence>& __rhs)
613     _GLIBCXX_NOEXCEPT
614     {
615       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
616 			    _M_message(__msg_iter_order_bad)
617 			    ._M_iterator(__lhs, "lhs")
618 			    ._M_iterator(__rhs, "rhs"));
619       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
620 			    _M_message(__msg_order_different)
621 			    ._M_iterator(__lhs, "lhs")
622 			    ._M_iterator(__rhs, "rhs"));
623       return __lhs.base() < __rhs.base();
624     }
625 
626   template<typename _IteratorL, typename _IteratorR, typename _Sequence>
627     inline bool
628     operator<=(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
629 	       const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
630     _GLIBCXX_NOEXCEPT
631     {
632       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
633 			    _M_message(__msg_iter_order_bad)
634 			    ._M_iterator(__lhs, "lhs")
635 			    ._M_iterator(__rhs, "rhs"));
636       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
637 			    _M_message(__msg_order_different)
638 			    ._M_iterator(__lhs, "lhs")
639 			    ._M_iterator(__rhs, "rhs"));
640       return __lhs.base() <= __rhs.base();
641     }
642 
643   template<typename _Iterator, typename _Sequence>
644     inline bool
645     operator<=(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
646 	       const _Safe_iterator<_Iterator, _Sequence>& __rhs)
647     _GLIBCXX_NOEXCEPT
648     {
649       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
650 			    _M_message(__msg_iter_order_bad)
651 			    ._M_iterator(__lhs, "lhs")
652 			    ._M_iterator(__rhs, "rhs"));
653       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
654 			    _M_message(__msg_order_different)
655 			    ._M_iterator(__lhs, "lhs")
656 			    ._M_iterator(__rhs, "rhs"));
657       return __lhs.base() <= __rhs.base();
658     }
659 
660   template<typename _IteratorL, typename _IteratorR, typename _Sequence>
661     inline bool
662     operator>(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
663 	      const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
664     _GLIBCXX_NOEXCEPT
665     {
666       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
667 			    _M_message(__msg_iter_order_bad)
668 			    ._M_iterator(__lhs, "lhs")
669 			    ._M_iterator(__rhs, "rhs"));
670       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
671 			    _M_message(__msg_order_different)
672 			    ._M_iterator(__lhs, "lhs")
673 			    ._M_iterator(__rhs, "rhs"));
674       return __lhs.base() > __rhs.base();
675     }
676 
677   template<typename _Iterator, typename _Sequence>
678     inline bool
679     operator>(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
680 	      const _Safe_iterator<_Iterator, _Sequence>& __rhs)
681     _GLIBCXX_NOEXCEPT
682     {
683       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
684 			    _M_message(__msg_iter_order_bad)
685 			    ._M_iterator(__lhs, "lhs")
686 			    ._M_iterator(__rhs, "rhs"));
687       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
688 			    _M_message(__msg_order_different)
689 			    ._M_iterator(__lhs, "lhs")
690 			    ._M_iterator(__rhs, "rhs"));
691       return __lhs.base() > __rhs.base();
692     }
693 
694   template<typename _IteratorL, typename _IteratorR, typename _Sequence>
695     inline bool
696     operator>=(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
697 	       const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
698     _GLIBCXX_NOEXCEPT
699     {
700       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
701 			    _M_message(__msg_iter_order_bad)
702 			    ._M_iterator(__lhs, "lhs")
703 			    ._M_iterator(__rhs, "rhs"));
704       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
705 			    _M_message(__msg_order_different)
706 			    ._M_iterator(__lhs, "lhs")
707 			    ._M_iterator(__rhs, "rhs"));
708       return __lhs.base() >= __rhs.base();
709     }
710 
711   template<typename _Iterator, typename _Sequence>
712     inline bool
713     operator>=(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
714 	       const _Safe_iterator<_Iterator, _Sequence>& __rhs)
715     _GLIBCXX_NOEXCEPT
716     {
717       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
718 			    _M_message(__msg_iter_order_bad)
719 			    ._M_iterator(__lhs, "lhs")
720 			    ._M_iterator(__rhs, "rhs"));
721       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
722 			    _M_message(__msg_order_different)
723 			    ._M_iterator(__lhs, "lhs")
724 			    ._M_iterator(__rhs, "rhs"));
725       return __lhs.base() >= __rhs.base();
726     }
727 
728   // _GLIBCXX_RESOLVE_LIB_DEFECTS
729   // According to the resolution of DR179 not only the various comparison
730   // operators but also operator- must accept mixed iterator/const_iterator
731   // parameters.
732   template<typename _IteratorL, typename _IteratorR, typename _Sequence>
733     inline typename _Safe_iterator<_IteratorL, _Sequence>::difference_type
734     operator-(const _Safe_iterator<_IteratorL, _Sequence>& __lhs,
735 	      const _Safe_iterator<_IteratorR, _Sequence>& __rhs)
736     _GLIBCXX_NOEXCEPT
737     {
738       _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
739 			    _M_message(__msg_distance_bad)
740 			    ._M_iterator(__lhs, "lhs")
741 			    ._M_iterator(__rhs, "rhs"));
742       _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
743 			    _M_message(__msg_distance_different)
744 			    ._M_iterator(__lhs, "lhs")
745 			    ._M_iterator(__rhs, "rhs"));
746       return __lhs.base() - __rhs.base();
747     }
748 
749    template<typename _Iterator, typename _Sequence>
750      inline typename _Safe_iterator<_Iterator, _Sequence>::difference_type
751      operator-(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
752 	       const _Safe_iterator<_Iterator, _Sequence>& __rhs)
753     _GLIBCXX_NOEXCEPT
754      {
755        _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
756 			     _M_message(__msg_distance_bad)
757 			     ._M_iterator(__lhs, "lhs")
758 			     ._M_iterator(__rhs, "rhs"));
759        _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
760 			     _M_message(__msg_distance_different)
761 			     ._M_iterator(__lhs, "lhs")
762 			     ._M_iterator(__rhs, "rhs"));
763        return __lhs.base() - __rhs.base();
764      }
765 
766   template<typename _Iterator, typename _Sequence>
767     inline _Safe_iterator<_Iterator, _Sequence>
768     operator+(typename _Safe_iterator<_Iterator,_Sequence>::difference_type __n,
769 	      const _Safe_iterator<_Iterator, _Sequence>& __i) _GLIBCXX_NOEXCEPT
770     { return __i + __n; }
771 } // namespace __gnu_debug
772 
773 #include <debug/safe_iterator.tcc>
774 
775 #endif
776