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

   1 // Debugging support implementation -*- C++ -*-
   2
   3 // Copyright (C) 2003, 2005, 2006
   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 /** @file debug/functions.h
  32  *  This file is a GNU debug extension to the Standard C++ Library.
  33  */
  34
  35 #ifndef _GLIBCXX_DEBUG_FUNCTIONS_H
  36 #define _GLIBCXX_DEBUG_FUNCTIONS_H 1
  37
  38 #include <bits/c++config.h>
  39 #include <cstddef>                       // for ptrdiff_t
  40 #include <bits/stl_iterator_base_types.h> // for iterator_traits, categories
  41 #include <bits/cpp_type_traits.h>         // for __is_integer
  42
  43 namespace __gnu_debug
  44 {
  45   template<typename _Iterator, typename _Sequence>
  46     class _Safe_iterator;
  47
  48   // An arbitrary iterator pointer is not singular.
  49   inline bool
  50   __check_singular_aux(const void*) { return false; }
  51
  52   // We may have an iterator that derives from _Safe_iterator_base but isn't
  53   // a _Safe_iterator.
  54   template<typename _Iterator>
  55     inline bool
  56     __check_singular(_Iterator& __x)
  57     { return __check_singular_aux(&__x); }
  58
  59   /** Non-NULL pointers are nonsingular. */
  60   template<typename _Tp>
  61     inline bool
  62     __check_singular(const _Tp* __ptr)
  63     { return __ptr == 0; }
  64
  65   /** Safe iterators know if they are singular. */
  66   template<typename _Iterator, typename _Sequence>
  67     inline bool
  68     __check_singular(const _Safe_iterator<_Iterator, _Sequence>& __x)
  69     { return __x._M_singular(); }
  70
  71   /** Assume that some arbitrary iterator is dereferenceable, because we
  72       can't prove that it isn't. */
  73   template<typename _Iterator>
  74     inline bool
  75     __check_dereferenceable(_Iterator&)
  76     { return true; }
  77
  78   /** Non-NULL pointers are dereferenceable. */
  79   template<typename _Tp>
  80     inline bool
  81     __check_dereferenceable(const _Tp* __ptr)
  82     { return __ptr; }
  83
  84   /** Safe iterators know if they are singular. */
  85   template<typename _Iterator, typename _Sequence>
  86     inline bool
  87     __check_dereferenceable(const _Safe_iterator<_Iterator, _Sequence>& __x)
  88     { return __x._M_dereferenceable(); }
  89
  90   /** If the distance between two random access iterators is
  91    *  nonnegative, assume the range is valid.
  92   */
  93   template<typename _RandomAccessIterator>
  94     inline bool
  95     __valid_range_aux2(const _RandomAccessIterator& __first,
  96                        const _RandomAccessIterator& __last,
  97                        std::random_access_iterator_tag)
  98     { return __last - __first >= 0; }
  99
 100   /** Can't test for a valid range with input iterators, because
 101    *  iteration may be destructive. So we just assume that the range
 102    *  is valid.
 103   */
 104   template<typename _InputIterator>
 105     inline bool
 106     __valid_range_aux2(const _InputIterator&, const _InputIterator&,
 107                        std::input_iterator_tag)
 108     { return true; }
 109
 110   /** We say that integral types for a valid range, and defer to other
 111    *  routines to realize what to do with integral types instead of
 112    *  iterators.
 113   */
 114   template<typename _Integral>
 115     inline bool
 116     __valid_range_aux(const _Integral&, const _Integral&, std::__true_type)
 117     { return true; }
 118
 119   /** We have iterators, so figure out what kind of iterators that are
 120    *  to see if we can check the range ahead of time.
 121   */
 122   template<typename _InputIterator>
 123     inline bool
 124     __valid_range_aux(const _InputIterator& __first,
 125                       const _InputIterator& __last, std::__false_type)
 126   {
 127     typedef typename std::iterator_traits<_InputIterator>::iterator_category
 128       _Category;
 129     return __valid_range_aux2(__first, __last, _Category());
 130   }
 131
 132   /** Don't know what these iterators are, or if they are even
 133    *  iterators (we may get an integral type for InputIterator), so
 134    *  see if they are integral and pass them on to the next phase
 135    *  otherwise.
 136   */
 137   template<typename _InputIterator>
 138     inline bool
 139     __valid_range(const _InputIterator& __first, const _InputIterator& __last)
 140     {
 141       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
 142       return __valid_range_aux(__first, __last, _Integral());
 143     }
 144
 145   /** Safe iterators know how to check if they form a valid range. */
 146   template<typename _Iterator, typename _Sequence>
 147     inline bool
 148     __valid_range(const _Safe_iterator<_Iterator, _Sequence>& __first,
 149                   const _Safe_iterator<_Iterator, _Sequence>& __last)
 150     { return __first._M_valid_range(__last); }
 151
 152   /* Checks that [first, last) is a valid range, and then returns
 153    * __first. This routine is useful when we can't use a separate
 154    * assertion statement because, e.g., we are in a constructor.
 155   */
 156   template<typename _InputIterator>
 157     inline _InputIterator
 158     __check_valid_range(const _InputIterator& __first,
 159                         const _InputIterator& __last
 160                         __attribute__((__unused__)))
 161     {
 162       _GLIBCXX_DEBUG_ASSERT(__valid_range(__first, __last));
 163       return __first;
 164     }
 165
 166   /** Checks that __s is non-NULL or __n == 0, and then returns __s. */
 167   template<typename _CharT, typename _Integer>
 168     inline const _CharT*
 169     __check_string(const _CharT* __s,
 170                    const _Integer& __n __attribute__((__unused__)))
 171     {
 172 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 173       _GLIBCXX_DEBUG_ASSERT(__s != 0 || __n == 0);
 174 #endif
 175       return __s;
 176     }
 177
 178   /** Checks that __s is non-NULL and then returns __s. */
 179   template<typename _CharT>
 180     inline const _CharT*
 181     __check_string(const _CharT* __s)
 182     {
 183 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 184       _GLIBCXX_DEBUG_ASSERT(__s != 0);
 185 #endif
 186       return __s;
 187     }
 188
 189   // Can't check if an input iterator sequence is sorted, because we
 190   // can't step through the sequence.
 191   template<typename _InputIterator>
 192     inline bool
 193     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 194                        std::input_iterator_tag)
 195     { return true; }
 196
 197   // Can verify if a forward iterator sequence is in fact sorted using
 198   // std::__is_sorted
 199   template<typename _ForwardIterator>
 200     inline bool
 201     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 202                        std::forward_iterator_tag)
 203     {
 204       if (__first == __last)
 205         return true;
 206
 207       _ForwardIterator __next = __first;
 208       for (++__next; __next != __last; __first = __next, ++__next) {
 209         if (*__next < *__first)
 210           return false;
 211       }
 212
 213       return true;
 214     }
 215
 216   // Can't check if an input iterator sequence is sorted, because we can't step
 217   // through the sequence.
 218   template<typename _InputIterator, typename _Predicate>
 219     inline bool
 220     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 221                        _Predicate, std::input_iterator_tag)
 222     { return true; }
 223
 224   // Can verify if a forward iterator sequence is in fact sorted using
 225   // std::__is_sorted
 226   template<typename _ForwardIterator, typename _Predicate>
 227     inline bool
 228     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 229                        _Predicate __pred, std::forward_iterator_tag)
 230     {
 231       if (__first == __last)
 232         return true;
 233
 234       _ForwardIterator __next = __first;
 235       for (++__next; __next != __last; __first = __next, ++__next) {
 236         if (__pred(*__next, *__first))
 237           return false;
 238       }
 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       return __check_sorted_aux(__first, __last, _Category());
 251     }
 252
 253   template<typename _InputIterator, typename _Predicate>
 254     inline bool
 255     __check_sorted(const _InputIterator& __first, const _InputIterator& __last,
 256                    _Predicate __pred)
 257     {
 258       typedef typename std::iterator_traits<_InputIterator>::iterator_category
 259         _Category;
 260       return __check_sorted_aux(__first, __last, __pred,
 261                                              _Category());
 262     }
 263
 264   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 265   // 270. Binary search requirements overly strict
 266   // Determine if a sequence is partitioned w.r.t. this element.
 267   template<typename _ForwardIterator, typename _Tp>
 268     inline bool
 269     __check_partitioned(_ForwardIterator __first, _ForwardIterator __last,
 270                         const _Tp& __value)
 271     {
 272       while (__first != __last && *__first < __value)
 273         ++__first;
 274       while (__first != __last && !(*__first < __value))
 275         ++__first;
 276       return __first == __last;
 277     }
 278
 279   // Determine if a sequence is partitioned w.r.t. this element.
 280   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 281     inline bool
 282     __check_partitioned(_ForwardIterator __first, _ForwardIterator __last,
 283                         const _Tp& __value, _Pred __pred)
 284     {
 285       while (__first != __last && __pred(*__first, __value))
 286         ++__first;
 287       while (__first != __last && !__pred(*__first, __value))
 288         ++__first;
 289       return __first == __last;
 290     }
 291 } // namespace __gnu_debug
 292
 293 #endif