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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  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 <stddef.h>                       // for ptrdiff_t
  35 #include <bits/stl_iterator_base_types.h> // for iterator_traits, categories
  36 #include <bits/cpp_type_traits.h>         // for __is_integer
  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 __gnu_debug::__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
  70     __check_dereferenceable(_Iterator&)
  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
  82     __check_dereferenceable(const _Safe_iterator<_Iterator, _Sequence>& __x)
  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,
  92                        std::random_access_iterator_tag)
  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&,
 102                        std::input_iterator_tag)
 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&, __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, __false_type)
 121   {
 122     typedef typename std::iterator_traits<_InputIterator>::iterator_category
 123       _Category;
 124     return __gnu_debug::__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 __gnu_debug::__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
 143     __valid_range(const _Safe_iterator<_Iterator, _Sequence>& __first,
 144                   const _Safe_iterator<_Iterator, _Sequence>& __last)
 145     { return __first._M_valid_range(__last); }
 146
 147   /* Checks that [first, last) is a valid range, and then returns
 148    * __first. This routine is useful when we can't use a separate
 149    * assertion statement because, e.g., we are in a constructor.
 150   */
 151   template<typename _InputIterator>
 152     inline _InputIterator
 153     __check_valid_range(const _InputIterator& __first,
 154                         const _InputIterator& __last)
 155     {
 156       _GLIBCXX_DEBUG_ASSERT(__gnu_debug::__valid_range(__first, __last));
 157       return __first;
 158     }
 159
 160   /** Checks that __s is non-NULL or __n == 0, and then returns __s. */
 161   template<typename _CharT, typename _Integer>
 162     inline const _CharT*
 163     __check_string(const _CharT* __s, const _Integer& __n)
 164     {
 165 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 166       _GLIBCXX_DEBUG_ASSERT(__s != 0 || __n == 0);
 167 #endif
 168       return __s;
 169     }
 170
 171   /** Checks that __s is non-NULL and then returns __s. */
 172   template<typename _CharT>
 173     inline const _CharT*
 174     __check_string(const _CharT* __s)
 175     {
 176 #ifdef _GLIBCXX_DEBUG_PEDANTIC
 177       _GLIBCXX_DEBUG_ASSERT(__s != 0);
 178 #endif
 179       return __s;
 180     }
 181
 182   // Can't check if an input iterator sequence is sorted, because we
 183   // can't step through the sequence.
 184   template<typename _InputIterator>
 185     inline bool
 186     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 187                        std::input_iterator_tag)
 188     { return true; }
 189
 190   // Can verify if a forward iterator sequence is in fact sorted using
 191   // std::__is_sorted
 192   template<typename _ForwardIterator>
 193     inline bool
 194     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 195                        std::forward_iterator_tag)
 196     {
 197       if (__first == __last)
 198         return true;
 199
 200       _ForwardIterator __next = __first;
 201       for (++__next; __next != __last; __first = __next, ++__next) {
 202         if (*__next < *__first)
 203           return false;
 204       }
 205
 206       return true;
 207     }
 208
 209   // Can't check if an input iterator sequence is sorted, because we can't step
 210   // through the sequence.
 211   template<typename _InputIterator, typename _Predicate>
 212     inline bool
 213     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
 214                        _Predicate, std::input_iterator_tag)
 215     { return true; }
 216
 217   // Can verify if a forward iterator sequence is in fact sorted using
 218   // std::__is_sorted
 219   template<typename _ForwardIterator, typename _Predicate>
 220     inline bool
 221     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
 222                        _Predicate __pred, std::forward_iterator_tag)
 223     {
 224       if (__first == __last)
 225         return true;
 226
 227       _ForwardIterator __next = __first;
 228       for (++__next; __next != __last; __first = __next, ++__next) {
 229         if (__pred(*__next, *__first))
 230           return false;
 231       }
 232
 233       return true;
 234     }
 235
 236   // Determine if a sequence is sorted.
 237   template<typename _InputIterator>
 238     inline bool
 239     __check_sorted(const _InputIterator& __first, const _InputIterator& __last)
 240     {
 241       typedef typename std::iterator_traits<_InputIterator>::iterator_category
 242         _Category;
 243       return __gnu_debug::__check_sorted_aux(__first, __last, _Category());
 244     }
 245
 246   template<typename _InputIterator, typename _Predicate>
 247     inline bool
 248     __check_sorted(const _InputIterator& __first, const _InputIterator& __last,
 249                    _Predicate __pred)
 250     {
 251       typedef typename std::iterator_traits<_InputIterator>::iterator_category
 252         _Category;
 253       return __gnu_debug::__check_sorted_aux(__first, __last, __pred,
 254                                              _Category());
 255     }
 256
 257   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 258   // 270. Binary search requirements overly strict
 259   // Determine if a sequence is partitioned w.r.t. this element.
 260   template<typename _ForwardIterator, typename _Tp>
 261     inline bool
 262     __check_partitioned(_ForwardIterator __first, _ForwardIterator __last,
 263                         const _Tp& __value)
 264     {
 265       while (__first != __last && *__first < __value)
 266         ++__first;
 267       while (__first != __last && !(*__first < __value))
 268         ++__first;
 269       return __first == __last;
 270     }
 271
 272   // Determine if a sequence is partitioned w.r.t. this element.
 273   template<typename _ForwardIterator, typename _Tp, typename _Pred>
 274     inline bool
 275     __check_partitioned(_ForwardIterator __first, _ForwardIterator __last,
 276                         const _Tp& __value, _Pred __pred)
 277     {
 278       while (__first != __last && __pred(*__first, __value))
 279         ++__first;
 280       while (__first != __last && !__pred(*__first, __value))
 281         ++__first;
 282       return __first == __last;
 283     }
 284 } // namespace __gnu_debug
 285
 286 #endif