libstdc++
functions.h
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1 // Debugging support implementation -*- C++ -*-
2 
3 // Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
4 // Free Software Foundation, Inc.
5 //
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 3, or (at your option)
10 // any later version.
11 
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14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
16 
17 // Under Section 7 of GPL version 3, you are granted additional
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19 // 3.1, as published by the Free Software Foundation.
20 
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25 
26 /** @file debug/functions.h
27  * This file is a GNU debug extension to the Standard C++ Library.
28  */
29 
30 #ifndef _GLIBCXX_DEBUG_FUNCTIONS_H
31 #define _GLIBCXX_DEBUG_FUNCTIONS_H 1
32 
33 #include <bits/c++config.h>
34 #include <bits/stl_iterator_base_types.h> // for iterator_traits, categories
35 #include <bits/cpp_type_traits.h> // for __is_integer
36 #include <debug/formatter.h>
37 
38 namespace __gnu_debug
39 {
40  template<typename _Iterator, typename _Sequence>
41  class _Safe_iterator;
42 
43  // An arbitrary iterator pointer is not singular.
44  inline bool
45  __check_singular_aux(const void*) { return false; }
46 
47  // We may have an iterator that derives from _Safe_iterator_base but isn't
48  // a _Safe_iterator.
49  template<typename _Iterator>
50  inline bool
51  __check_singular(_Iterator& __x)
52  { return __check_singular_aux(&__x); }
53 
54  /** Non-NULL pointers are nonsingular. */
55  template<typename _Tp>
56  inline bool
57  __check_singular(const _Tp* __ptr)
58  { return __ptr == 0; }
59 
60  /** Safe iterators know if they are singular. */
61  template<typename _Iterator, typename _Sequence>
62  inline bool
63  __check_singular(const _Safe_iterator<_Iterator, _Sequence>& __x)
64  { return __x._M_singular(); }
65 
66  /** Assume that some arbitrary iterator is dereferenceable, because we
67  can't prove that it isn't. */
68  template<typename _Iterator>
69  inline bool
71  { return true; }
72 
73  /** Non-NULL pointers are dereferenceable. */
74  template<typename _Tp>
75  inline bool
76  __check_dereferenceable(const _Tp* __ptr)
77  { return __ptr; }
78 
79  /** Safe iterators know if they are singular. */
80  template<typename _Iterator, typename _Sequence>
81  inline bool
83  { return __x._M_dereferenceable(); }
84 
85  /** If the distance between two random access iterators is
86  * nonnegative, assume the range is valid.
87  */
88  template<typename _RandomAccessIterator>
89  inline bool
90  __valid_range_aux2(const _RandomAccessIterator& __first,
91  const _RandomAccessIterator& __last,
93  { return __last - __first >= 0; }
94 
95  /** Can't test for a valid range with input iterators, because
96  * iteration may be destructive. So we just assume that the range
97  * is valid.
98  */
99  template<typename _InputIterator>
100  inline bool
101  __valid_range_aux2(const _InputIterator&, const _InputIterator&,
103  { return true; }
104 
105  /** We say that integral types for a valid range, and defer to other
106  * routines to realize what to do with integral types instead of
107  * iterators.
108  */
109  template<typename _Integral>
110  inline bool
111  __valid_range_aux(const _Integral&, const _Integral&, std::__true_type)
112  { return true; }
113 
114  /** We have iterators, so figure out what kind of iterators that are
115  * to see if we can check the range ahead of time.
116  */
117  template<typename _InputIterator>
118  inline bool
119  __valid_range_aux(const _InputIterator& __first,
120  const _InputIterator& __last, std::__false_type)
121  {
122  typedef typename std::iterator_traits<_InputIterator>::iterator_category
123  _Category;
124  return __valid_range_aux2(__first, __last, _Category());
125  }
126 
127  /** Don't know what these iterators are, or if they are even
128  * iterators (we may get an integral type for InputIterator), so
129  * see if they are integral and pass them on to the next phase
130  * otherwise.
131  */
132  template<typename _InputIterator>
133  inline bool
134  __valid_range(const _InputIterator& __first, const _InputIterator& __last)
135  {
136  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
137  return __valid_range_aux(__first, __last, _Integral());
138  }
139 
140  /** Safe iterators know how to check if they form a valid range. */
141  template<typename _Iterator, typename _Sequence>
142  inline bool
145  { return __first._M_valid_range(__last); }
146 
147  /** Safe local iterators know how to check if they form a valid range. */
148  template<typename _Iterator, typename _Sequence>
149  inline bool
152  { return __first._M_valid_range(__last); }
153 
154  /* Checks that [first, last) is a valid range, and then returns
155  * __first. This routine is useful when we can't use a separate
156  * assertion statement because, e.g., we are in a constructor.
157  */
158  template<typename _InputIterator>
159  inline _InputIterator
160  __check_valid_range(const _InputIterator& __first,
161  const _InputIterator& __last
162  __attribute__((__unused__)))
163  {
164  __glibcxx_check_valid_range(__first, __last);
165  return __first;
166  }
167 
168  /** Checks that __s is non-NULL or __n == 0, and then returns __s. */
169  template<typename _CharT, typename _Integer>
170  inline const _CharT*
171  __check_string(const _CharT* __s,
172  const _Integer& __n __attribute__((__unused__)))
173  {
174 #ifdef _GLIBCXX_DEBUG_PEDANTIC
175  __glibcxx_assert(__s != 0 || __n == 0);
176 #endif
177  return __s;
178  }
179 
180  /** Checks that __s is non-NULL and then returns __s. */
181  template<typename _CharT>
182  inline const _CharT*
183  __check_string(const _CharT* __s)
184  {
185 #ifdef _GLIBCXX_DEBUG_PEDANTIC
186  __glibcxx_assert(__s != 0);
187 #endif
188  return __s;
189  }
190 
191  // Can't check if an input iterator sequence is sorted, because we
192  // can't step through the sequence.
193  template<typename _InputIterator>
194  inline bool
195  __check_sorted_aux(const _InputIterator&, const _InputIterator&,
197  { return true; }
198 
199  // Can verify if a forward iterator sequence is in fact sorted using
200  // std::__is_sorted
201  template<typename _ForwardIterator>
202  inline bool
203  __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
205  {
206  if (__first == __last)
207  return true;
208 
209  _ForwardIterator __next = __first;
210  for (++__next; __next != __last; __first = __next, ++__next)
211  if (*__next < *__first)
212  return false;
213 
214  return true;
215  }
216 
217  // Can't check if an input iterator sequence is sorted, because we can't step
218  // through the sequence.
219  template<typename _InputIterator, typename _Predicate>
220  inline bool
221  __check_sorted_aux(const _InputIterator&, const _InputIterator&,
222  _Predicate, std::input_iterator_tag)
223  { return true; }
224 
225  // Can verify if a forward iterator sequence is in fact sorted using
226  // std::__is_sorted
227  template<typename _ForwardIterator, typename _Predicate>
228  inline bool
229  __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
230  _Predicate __pred, std::forward_iterator_tag)
231  {
232  if (__first == __last)
233  return true;
234 
235  _ForwardIterator __next = __first;
236  for (++__next; __next != __last; __first = __next, ++__next)
237  if (__pred(*__next, *__first))
238  return false;
239 
240  return true;
241  }
242 
243  // Determine if a sequence is sorted.
244  template<typename _InputIterator>
245  inline bool
246  __check_sorted(const _InputIterator& __first, const _InputIterator& __last)
247  {
248  typedef typename std::iterator_traits<_InputIterator>::iterator_category
249  _Category;
250 
251  // Verify that the < operator for elements in the sequence is a
252  // StrictWeakOrdering by checking that it is irreflexive.
253  __glibcxx_assert(__first == __last || !(*__first < *__first));
254 
255  return __check_sorted_aux(__first, __last, _Category());
256  }
257 
258  template<typename _InputIterator, typename _Predicate>
259  inline bool
260  __check_sorted(const _InputIterator& __first, const _InputIterator& __last,
261  _Predicate __pred)
262  {
263  typedef typename std::iterator_traits<_InputIterator>::iterator_category
264  _Category;
265 
266  // Verify that the predicate is StrictWeakOrdering by checking that it
267  // is irreflexive.
268  __glibcxx_assert(__first == __last || !__pred(*__first, *__first));
269 
270  return __check_sorted_aux(__first, __last, __pred, _Category());
271  }
272 
273  template<typename _InputIterator>
274  inline bool
275  __check_sorted_set_aux(const _InputIterator& __first,
276  const _InputIterator& __last,
277  std::__true_type)
278  { return __check_sorted(__first, __last); }
279 
280  template<typename _InputIterator>
281  inline bool
282  __check_sorted_set_aux(const _InputIterator&,
283  const _InputIterator&,
284  std::__false_type)
285  { return true; }
286 
287  template<typename _InputIterator, typename _Predicate>
288  inline bool
289  __check_sorted_set_aux(const _InputIterator& __first,
290  const _InputIterator& __last,
291  _Predicate __pred, std::__true_type)
292  { return __check_sorted(__first, __last, __pred); }
293 
294  template<typename _InputIterator, typename _Predicate>
295  inline bool
296  __check_sorted_set_aux(const _InputIterator&,
297  const _InputIterator&, _Predicate,
298  std::__false_type)
299  { return true; }
300 
301  // ... special variant used in std::merge, std::includes, std::set_*.
302  template<typename _InputIterator1, typename _InputIterator2>
303  inline bool
304  __check_sorted_set(const _InputIterator1& __first,
305  const _InputIterator1& __last,
306  const _InputIterator2&)
307  {
308  typedef typename std::iterator_traits<_InputIterator1>::value_type
309  _ValueType1;
310  typedef typename std::iterator_traits<_InputIterator2>::value_type
311  _ValueType2;
312 
313  typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
314  _SameType;
315  return __check_sorted_set_aux(__first, __last, _SameType());
316  }
317 
318  template<typename _InputIterator1, typename _InputIterator2,
319  typename _Predicate>
320  inline bool
321  __check_sorted_set(const _InputIterator1& __first,
322  const _InputIterator1& __last,
323  const _InputIterator2&, _Predicate __pred)
324  {
325  typedef typename std::iterator_traits<_InputIterator1>::value_type
326  _ValueType1;
327  typedef typename std::iterator_traits<_InputIterator2>::value_type
328  _ValueType2;
329 
330  typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
331  _SameType;
332  return __check_sorted_set_aux(__first, __last, __pred, _SameType());
333  }
334 
335  // _GLIBCXX_RESOLVE_LIB_DEFECTS
336  // 270. Binary search requirements overly strict
337  // Determine if a sequence is partitioned w.r.t. this element.
338  template<typename _ForwardIterator, typename _Tp>
339  inline bool
340  __check_partitioned_lower(_ForwardIterator __first,
341  _ForwardIterator __last, const _Tp& __value)
342  {
343  while (__first != __last && *__first < __value)
344  ++__first;
345  while (__first != __last && !(*__first < __value))
346  ++__first;
347  return __first == __last;
348  }
349 
350  template<typename _ForwardIterator, typename _Tp>
351  inline bool
352  __check_partitioned_upper(_ForwardIterator __first,
353  _ForwardIterator __last, const _Tp& __value)
354  {
355  while (__first != __last && !(__value < *__first))
356  ++__first;
357  while (__first != __last && __value < *__first)
358  ++__first;
359  return __first == __last;
360  }
361 
362  // Determine if a sequence is partitioned w.r.t. this element.
363  template<typename _ForwardIterator, typename _Tp, typename _Pred>
364  inline bool
365  __check_partitioned_lower(_ForwardIterator __first,
366  _ForwardIterator __last, const _Tp& __value,
367  _Pred __pred)
368  {
369  while (__first != __last && bool(__pred(*__first, __value)))
370  ++__first;
371  while (__first != __last && !bool(__pred(*__first, __value)))
372  ++__first;
373  return __first == __last;
374  }
375 
376  template<typename _ForwardIterator, typename _Tp, typename _Pred>
377  inline bool
378  __check_partitioned_upper(_ForwardIterator __first,
379  _ForwardIterator __last, const _Tp& __value,
380  _Pred __pred)
381  {
382  while (__first != __last && !bool(__pred(__value, *__first)))
383  ++__first;
384  while (__first != __last && bool(__pred(__value, *__first)))
385  ++__first;
386  return __first == __last;
387  }
388 } // namespace __gnu_debug
389 
390 #endif