libstdc++-v3/include/debug/functions.h

   1 // Debugging support implementation -*- C++ -*-
   2
   3 // Copyright (C) 2003, 2005
   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 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 #ifndef _GLIBCXX_DEBUG_FUNCTIONS_H
  32 #define _GLIBCXX_DEBUG_FUNCTIONS_H 1
  33
  34 #include <bits/c++config.h>
  35 #include <stddef.h>                       // for ptrdiff_t
  36 #include <bits/stl_iterator_base_types.h> // for iterator_traits, categories
  37 #include <bits/cpp_type_traits.h>         // for __is_integer
  38
  39 namespace std
  40 {
  41 namespace __gnu_debug
  42 {
  43   template<typename _Iterator, typename _Sequence>
  44     class _Safe_iterator;
  45
  46   // An arbitrary iterator pointer is not singular.
  47   inline bool
  48   __check_singular_aux(const void*) { return false; }
  49
  50   // We may have an iterator that derives from _Safe_iterator_base but isn't
  51   // a _Safe_iterator.
  52   template<typename _Iterator>
  53     inline bool
  54     __check_singular(_Iterator& __x)
  55     { return __check_singular_aux(&__x); }
  56
  57   /** Non-NULL pointers are nonsingular. */
  58   template<typename _Tp>
  59     inline bool
  60     __check_singular(const _Tp* __ptr)
  61     { return __ptr == 0; }
  62
  63   /** Safe iterators know if they are singular. */
  64   template<typename _Iterator, typename _Sequence>
  65     inline bool
  66     __check_singular(const _Safe_iterator<_Iterator, _Sequence>& __x)
  67     { return __x._M_singular(); }
  68
  69   /** Assume that some arbitrary iterator is dereferenceable, because we
  70       can't prove that it isn't. */
  71   template<typename _Iterator>
  72     inline bool
  73     __check_dereferenceable(_Iterator&)
  74     { return true; }
  75
  76   /** Non-NULL pointers are dereferenceable. */
  77   template<typename _Tp>
  78     inline bool
  79     __check_dereferenceable(const _Tp* __ptr)
  80     { return __ptr; }
  81
  82   /** Safe iterators know if they are singular. */
  83   template<typename _Iterator, typename _Sequence>
  84     inline bool
  85     __check_dereferenceable(const _Safe_iterator<_Iterator, _Sequence>& __x)
  86     { return __x._M_dereferenceable(); }
  87
  88   /** If the distance between two random access iterators is
  89    *  nonnegative, assume the range is valid.
  90   */
  91   template<typename _RandomAccessIterator>
  92     inline bool
  93     __valid_range_aux2(const _RandomAccessIterator& __first,
  94                        const _RandomAccessIterator& __last,
  95                        std::random_access_iterator_tag)
  96     { return __last - __first >= 0; }
  97
  98   /** Can't test for a valid range with input iterators, because
  99    *  iteration may be destructive. So we just assume that the range
 100    *  is valid.
 101   */
 102   template<typename _InputIterator>
 103     inline bool
 104     __valid_range_aux2(const _InputIterator&, const _InputIterator&,
 105                        std::input_iterator_tag)
 106     { return true; }
 107
 108   /** We say that integral types for a valid range, and defer to other
 109    *  routines to realize what to do with integral types instead of
 110    *  iterators.
 111   */
 112   template<typename _Integral>
 113     inline bool
 114     __valid_range_aux(const _Integral&, const _Integral&, __true_type)
 115     { return true; }
 116
 117   /** We have iterators, so figure out what kind of iterators that are
 118    *  to see if we can check the range ahead of time.
 119   */
 120   template<typename _InputIterator>
 121     inline bool
 122     __valid_range_aux(const _InputIterator& __first,
 123                       const _InputIterator& __last, __false_type)
 124   {
 125     typedef typename std::iterator_traits<_InputIterator>::iterator_category
 126       _Category;
 127     return __valid_range_aux2(__first, __last, _Category());
 128   }
 129
 130   /** Don't know what these iterators are, or if they are even
 131    *  iterators (we may get an integral type for InputIterator), so
 132    *  see if they are integral and pass them on to the next phase
 133    *  otherwise.
 134   */
 135   template<typename _InputIterator>
 136     inline bool
 137     __valid_range(const _InputIterator& __first, const _InputIterator& __last)
 138     {
 139       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
 140       return __valid_range_aux(__first, __last, _Integral());
 141     }
 142
 143   /** Safe iterators know how to check if they form a valid range. */
 144   template<typename _Iterator, typename _Sequence>
 145     inline bool
 146     __valid_range(const _Safe_iterator<_Iterator, _Sequence>& __first,
 147                   const _Safe_iterator<_Iterator, _Sequence>& __last)
 148     { return __first._M_valid_range(__last); }
 149
 150   /* Checks that [first, last) is a valid range, and then returns
 151    * __first. This routine is useful when we can't use a separate
 152    * assertion statement because, e.g., we are in a constructor.
 153   */
 154   template<typename _InputIterator>
 155     inline _InputIterator
 156     __check_valid_range(const _InputIterator& __first,
 157                         const _InputIterator& __last)
 158     {
 159       _GLIBCXX_DEBUG_ASSERT(__valid_range(__first, __last));
 160       return __first;
 161     }
 162
 163   /** Checks that __s is non-NULL or __n == 0, and then returns __s. */
 164   template<typename _CharT, typename _Integer>
 165     inline const _CharT*
 166     __check_string(const _CharT* __s, const _Integer& __n)
 167     {
 168 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 169       _GLIBCXX_DEBUG_ASSERT(__s != 0 || __n == 0);
 170 #endif
 171       return __s;
 172     }
 173
 174   /** Checks that __s is non-NULL and then returns __s. */
 175   template<typename _CharT>
 176     inline const _CharT*
 177     __check_string(const _CharT* __s)
 178     {
 179 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 180       _GLIBCXX_DEBUG_ASSERT(__s != 0);
 181 #endif
 182       return __s;
 183     }
 184
 185   // Can't check if an input iterator sequence is sorted, because we
 186   // can't step through the sequence.
 187   template<typename _InputIterator>
 188     inline bool
 189     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 190                        std::input_iterator_tag)
 191     { return true; }
 192
 193   // Can verify if a forward iterator sequence is in fact sorted using
 194   // std::__is_sorted
 195   template<typename _ForwardIterator>
 196     inline bool
 197     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 198                        std::forward_iterator_tag)
 199     {
 200       if (__first == __last)
 201         return true;
 202
 203       _ForwardIterator __next = __first;
 204       for (++__next; __next != __last; __first = __next, ++__next) {
 205         if (*__next < *__first)
 206           return false;
 207       }
 208
 209       return true;
 210     }
 211
 212   // Can't check if an input iterator sequence is sorted, because we can't step
 213   // through the sequence.
 214   template<typename _InputIterator, typename _Predicate>
 215     inline bool
 216     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 217                        _Predicate, std::input_iterator_tag)
 218     { return true; }
 219
 220   // Can verify if a forward iterator sequence is in fact sorted using
 221   // std::__is_sorted
 222   template<typename _ForwardIterator, typename _Predicate>
 223     inline bool
 224     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 225                        _Predicate __pred, std::forward_iterator_tag)
 226     {
 227       if (__first == __last)
 228         return true;
 229
 230       _ForwardIterator __next = __first;
 231       for (++__next; __next != __last; __first = __next, ++__next) {
 232         if (__pred(*__next, *__first))
 233           return false;
 234       }
 235
 236       return true;
 237     }
 238
 239   // Determine if a sequence is sorted.
 240   template<typename _InputIterator>
 241     inline bool
 242     __check_sorted(const _InputIterator& __first, const _InputIterator& __last)
 243     {
 244       typedef typename std::iterator_traits<_InputIterator>::iterator_category
 245         _Category;
 246       return __check_sorted_aux(__first, __last, _Category());
 247     }
 248
 249   template<typename _InputIterator, typename _Predicate>
 250     inline bool
 251     __check_sorted(const _InputIterator& __first, const _InputIterator& __last,
 252                    _Predicate __pred)
 253     {
 254       typedef typename std::iterator_traits<_InputIterator>::iterator_category
 255         _Category;
 256       return __check_sorted_aux(__first, __last, __pred,
 257                                              _Category());
 258     }
 259
 260   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 261   // 270. Binary search requirements overly strict
 262   // Determine if a sequence is partitioned w.r.t. this element.
 263   template<typename _ForwardIterator, typename _Tp>
 264     inline bool
 265     __check_partitioned(_ForwardIterator __first, _ForwardIterator __last,
 266                         const _Tp& __value)
 267     {
 268       while (__first != __last && *__first < __value)
 269         ++__first;
 270       while (__first != __last && !(*__first < __value))
 271         ++__first;
 272       return __first == __last;
 273     }
 274
 275   // Determine if a sequence is partitioned w.r.t. this element.
 276   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 277     inline bool
 278     __check_partitioned(_ForwardIterator __first, _ForwardIterator __last,
 279                         const _Tp& __value, _Pred __pred)
 280     {
 281       while (__first != __last && __pred(*__first, __value))
 282         ++__first;
 283       while (__first != __last && !__pred(*__first, __value))
 284         ++__first;
 285       return __first == __last;
 286     }
 287 } // namespace __gnu_debug
 288 } // namespace std
 289
 290 #endif