functions.h

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00001 // Debugging support implementation -*- C++ -*-
00002 
00003 // Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
00004 // Free Software Foundation, Inc.
00005 //
00006 // This file is part of the GNU ISO C++ Library.  This library is free
00007 // software; you can redistribute it and/or modify it under the
00008 // terms of the GNU General Public License as published by the
00009 // Free Software Foundation; either version 3, or (at your option)
00010 // any later version.
00011 
00012 // This library is distributed in the hope that it will be useful,
00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015 // GNU General Public License for more details.
00016 
00017 // Under Section 7 of GPL version 3, you are granted additional
00018 // permissions described in the GCC Runtime Library Exception, version
00019 // 3.1, as published by the Free Software Foundation.
00020 
00021 // You should have received a copy of the GNU General Public License and
00022 // a copy of the GCC Runtime Library Exception along with this program;
00023 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00024 // <http://www.gnu.org/licenses/>.
00025 
00026 /** @file debug/functions.h
00027  *  This file is a GNU debug extension to the Standard C++ Library.
00028  */
00029 
00030 #ifndef _GLIBCXX_DEBUG_FUNCTIONS_H
00031 #define _GLIBCXX_DEBUG_FUNCTIONS_H 1
00032 
00033 #include <bits/c++config.h>
00034 #include <cstddef>                       // for ptrdiff_t
00035 #include <bits/stl_iterator_base_types.h> // for iterator_traits, categories
00036 #include <bits/cpp_type_traits.h>         // for __is_integer
00037 
00038 namespace __gnu_debug
00039 {
00040   template<typename _Iterator, typename _Sequence>
00041     class _Safe_iterator;
00042 
00043   // An arbitrary iterator pointer is not singular.
00044   inline bool
00045   __check_singular_aux(const void*) { return false; }
00046 
00047   // We may have an iterator that derives from _Safe_iterator_base but isn't
00048   // a _Safe_iterator.
00049   template<typename _Iterator>
00050     inline bool
00051     __check_singular(_Iterator& __x)
00052     { return __check_singular_aux(&__x); }
00053 
00054   /** Non-NULL pointers are nonsingular. */
00055   template<typename _Tp>
00056     inline bool
00057     __check_singular(const _Tp* __ptr)
00058     { return __ptr == 0; }
00059 
00060   /** Safe iterators know if they are singular. */
00061   template<typename _Iterator, typename _Sequence>
00062     inline bool
00063     __check_singular(const _Safe_iterator<_Iterator, _Sequence>& __x)
00064     { return __x._M_singular(); }
00065 
00066   /** Assume that some arbitrary iterator is dereferenceable, because we
00067       can't prove that it isn't. */
00068   template<typename _Iterator>
00069     inline bool
00070     __check_dereferenceable(_Iterator&)
00071     { return true; }
00072 
00073   /** Non-NULL pointers are dereferenceable. */
00074   template<typename _Tp>
00075     inline bool
00076     __check_dereferenceable(const _Tp* __ptr)
00077     { return __ptr; }
00078 
00079   /** Safe iterators know if they are singular. */
00080   template<typename _Iterator, typename _Sequence>
00081     inline bool
00082     __check_dereferenceable(const _Safe_iterator<_Iterator, _Sequence>& __x)
00083     { return __x._M_dereferenceable(); }
00084 
00085   /** If the distance between two random access iterators is
00086    *  nonnegative, assume the range is valid.
00087   */
00088   template<typename _RandomAccessIterator>
00089     inline bool
00090     __valid_range_aux2(const _RandomAccessIterator& __first,
00091                const _RandomAccessIterator& __last,
00092                std::random_access_iterator_tag)
00093     { return __last - __first >= 0; }
00094 
00095   /** Can't test for a valid range with input iterators, because
00096    *  iteration may be destructive. So we just assume that the range
00097    *  is valid.
00098   */
00099   template<typename _InputIterator>
00100     inline bool
00101     __valid_range_aux2(const _InputIterator&, const _InputIterator&,
00102                std::input_iterator_tag)
00103     { return true; }
00104 
00105   /** We say that integral types for a valid range, and defer to other
00106    *  routines to realize what to do with integral types instead of
00107    *  iterators.
00108   */
00109   template<typename _Integral>
00110     inline bool
00111     __valid_range_aux(const _Integral&, const _Integral&, std::__true_type)
00112     { return true; }
00113 
00114   /** We have iterators, so figure out what kind of iterators that are
00115    *  to see if we can check the range ahead of time.
00116   */
00117   template<typename _InputIterator>
00118     inline bool
00119     __valid_range_aux(const _InputIterator& __first,
00120               const _InputIterator& __last, std::__false_type)
00121   {
00122     typedef typename std::iterator_traits<_InputIterator>::iterator_category
00123       _Category;
00124     return __valid_range_aux2(__first, __last, _Category());
00125   }
00126 
00127   /** Don't know what these iterators are, or if they are even
00128    *  iterators (we may get an integral type for InputIterator), so
00129    *  see if they are integral and pass them on to the next phase
00130    *  otherwise.
00131   */
00132   template<typename _InputIterator>
00133     inline bool
00134     __valid_range(const _InputIterator& __first, const _InputIterator& __last)
00135     {
00136       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
00137       return __valid_range_aux(__first, __last, _Integral());
00138     }
00139 
00140   /** Safe iterators know how to check if they form a valid range. */
00141   template<typename _Iterator, typename _Sequence>
00142     inline bool
00143     __valid_range(const _Safe_iterator<_Iterator, _Sequence>& __first,
00144           const _Safe_iterator<_Iterator, _Sequence>& __last)
00145     { return __first._M_valid_range(__last); }
00146 
00147   /* Checks that [first, last) is a valid range, and then returns
00148    * __first. This routine is useful when we can't use a separate
00149    * assertion statement because, e.g., we are in a constructor.
00150   */
00151   template<typename _InputIterator>
00152     inline _InputIterator
00153     __check_valid_range(const _InputIterator& __first,
00154             const _InputIterator& __last
00155             __attribute__((__unused__)))
00156     {
00157       _GLIBCXX_DEBUG_ASSERT(__valid_range(__first, __last));
00158       return __first;
00159     }
00160 
00161   /** Checks that __s is non-NULL or __n == 0, and then returns __s. */
00162   template<typename _CharT, typename _Integer>
00163     inline const _CharT*
00164     __check_string(const _CharT* __s,
00165            const _Integer& __n __attribute__((__unused__)))
00166     {
00167 #ifdef _GLIBCXX_DEBUG_PEDANTIC
00168       _GLIBCXX_DEBUG_ASSERT(__s != 0 || __n == 0);
00169 #endif
00170       return __s;
00171     }
00172 
00173   /** Checks that __s is non-NULL and then returns __s. */
00174   template<typename _CharT>
00175     inline const _CharT*
00176     __check_string(const _CharT* __s)
00177     {
00178 #ifdef _GLIBCXX_DEBUG_PEDANTIC
00179       _GLIBCXX_DEBUG_ASSERT(__s != 0);
00180 #endif
00181       return __s;
00182     }
00183 
00184   // Can't check if an input iterator sequence is sorted, because we
00185   // can't step through the sequence.
00186   template<typename _InputIterator>
00187     inline bool
00188     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
00189                        std::input_iterator_tag)
00190     { return true; }
00191 
00192   // Can verify if a forward iterator sequence is in fact sorted using
00193   // std::__is_sorted
00194   template<typename _ForwardIterator>
00195     inline bool
00196     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
00197                        std::forward_iterator_tag)
00198     {
00199       if (__first == __last)
00200         return true;
00201 
00202       _ForwardIterator __next = __first;
00203       for (++__next; __next != __last; __first = __next, ++__next)
00204         if (*__next < *__first)
00205           return false;
00206 
00207       return true;
00208     }
00209 
00210   // Can't check if an input iterator sequence is sorted, because we can't step
00211   // through the sequence.
00212   template<typename _InputIterator, typename _Predicate>
00213     inline bool
00214     __check_sorted_aux(const _InputIterator&, const _InputIterator&,
00215                        _Predicate, std::input_iterator_tag)
00216     { return true; }
00217 
00218   // Can verify if a forward iterator sequence is in fact sorted using
00219   // std::__is_sorted
00220   template<typename _ForwardIterator, typename _Predicate>
00221     inline bool
00222     __check_sorted_aux(_ForwardIterator __first, _ForwardIterator __last,
00223                        _Predicate __pred, std::forward_iterator_tag)
00224     {
00225       if (__first == __last)
00226         return true;
00227 
00228       _ForwardIterator __next = __first;
00229       for (++__next; __next != __last; __first = __next, ++__next)
00230         if (__pred(*__next, *__first))
00231           return false;
00232 
00233       return true;
00234     }
00235 
00236   // Determine if a sequence is sorted.
00237   template<typename _InputIterator>
00238     inline bool
00239     __check_sorted(const _InputIterator& __first, const _InputIterator& __last)
00240     {
00241       typedef typename std::iterator_traits<_InputIterator>::iterator_category
00242         _Category;
00243 
00244       // Verify that the < operator for elements in the sequence is a
00245       // StrictWeakOrdering by checking that it is irreflexive.
00246       _GLIBCXX_DEBUG_ASSERT(__first == __last || !(*__first < *__first));
00247 
00248       return __check_sorted_aux(__first, __last, _Category());
00249     }
00250 
00251   template<typename _InputIterator, typename _Predicate>
00252     inline bool
00253     __check_sorted(const _InputIterator& __first, const _InputIterator& __last,
00254                    _Predicate __pred)
00255     {
00256       typedef typename std::iterator_traits<_InputIterator>::iterator_category
00257         _Category;
00258 
00259       // Verify that the predicate is StrictWeakOrdering by checking that it
00260       // is irreflexive.
00261       _GLIBCXX_DEBUG_ASSERT(__first == __last || !__pred(*__first, *__first));
00262 
00263       return __check_sorted_aux(__first, __last, __pred, _Category());
00264     }
00265 
00266   template<typename _InputIterator>
00267     inline bool
00268     __check_sorted_set_aux(const _InputIterator& __first,
00269                const _InputIterator& __last,
00270                std::__true_type)
00271     { return __check_sorted(__first, __last); }
00272 
00273   template<typename _InputIterator>
00274     inline bool
00275     __check_sorted_set_aux(const _InputIterator&,
00276                const _InputIterator&,
00277                std::__false_type)
00278     { return true; }
00279 
00280   template<typename _InputIterator, typename _Predicate>
00281     inline bool
00282     __check_sorted_set_aux(const _InputIterator& __first,
00283                const _InputIterator& __last,
00284                _Predicate __pred, std::__true_type)
00285     { return __check_sorted(__first, __last, __pred); }
00286 
00287   template<typename _InputIterator, typename _Predicate>
00288     inline bool
00289     __check_sorted_set_aux(const _InputIterator&,
00290                const _InputIterator&, _Predicate,
00291                std::__false_type)
00292     { return true; }
00293 
00294   // ... special variant used in std::merge, std::includes, std::set_*.
00295   template<typename _InputIterator1, typename _InputIterator2>
00296     inline bool
00297     __check_sorted_set(const _InputIterator1& __first,
00298                const _InputIterator1& __last,
00299                const _InputIterator2&)
00300     {
00301       typedef typename std::iterator_traits<_InputIterator1>::value_type
00302     _ValueType1;
00303       typedef typename std::iterator_traits<_InputIterator2>::value_type
00304     _ValueType2;
00305 
00306       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
00307     _SameType;
00308       return __check_sorted_set_aux(__first, __last, _SameType());
00309     }
00310 
00311   template<typename _InputIterator1, typename _InputIterator2,
00312        typename _Predicate>
00313     inline bool
00314     __check_sorted_set(const _InputIterator1& __first,
00315                const _InputIterator1& __last,
00316                const _InputIterator2&, _Predicate __pred)
00317     {
00318       typedef typename std::iterator_traits<_InputIterator1>::value_type
00319     _ValueType1;
00320       typedef typename std::iterator_traits<_InputIterator2>::value_type
00321     _ValueType2;
00322 
00323       typedef typename std::__are_same<_ValueType1, _ValueType2>::__type
00324     _SameType;
00325       return __check_sorted_set_aux(__first, __last, __pred, _SameType());
00326    }
00327 
00328   // _GLIBCXX_RESOLVE_LIB_DEFECTS
00329   // 270. Binary search requirements overly strict
00330   // Determine if a sequence is partitioned w.r.t. this element.
00331   template<typename _ForwardIterator, typename _Tp>
00332     inline bool
00333     __check_partitioned_lower(_ForwardIterator __first,
00334                   _ForwardIterator __last, const _Tp& __value)
00335     {
00336       while (__first != __last && *__first < __value)
00337     ++__first;
00338       while (__first != __last && !(*__first < __value))
00339     ++__first;
00340       return __first == __last;
00341     }
00342 
00343   template<typename _ForwardIterator, typename _Tp>
00344     inline bool
00345     __check_partitioned_upper(_ForwardIterator __first,
00346                   _ForwardIterator __last, const _Tp& __value)
00347     {
00348       while (__first != __last && !(__value < *__first))
00349     ++__first;
00350       while (__first != __last && __value < *__first)
00351     ++__first;
00352       return __first == __last;
00353     }
00354 
00355   // Determine if a sequence is partitioned w.r.t. this element.
00356   template<typename _ForwardIterator, typename _Tp, typename _Pred>
00357     inline bool
00358     __check_partitioned_lower(_ForwardIterator __first,
00359                   _ForwardIterator __last, const _Tp& __value,
00360                   _Pred __pred)
00361     {
00362       while (__first != __last && bool(__pred(*__first, __value)))
00363     ++__first;
00364       while (__first != __last && !bool(__pred(*__first, __value)))
00365     ++__first;
00366       return __first == __last;
00367     }
00368 
00369   template<typename _ForwardIterator, typename _Tp, typename _Pred>
00370     inline bool
00371     __check_partitioned_upper(_ForwardIterator __first,
00372                   _ForwardIterator __last, const _Tp& __value,
00373                   _Pred __pred)
00374     {
00375       while (__first != __last && !bool(__pred(__value, *__first)))
00376     ++__first;
00377       while (__first != __last && bool(__pred(__value, *__first)))
00378     ++__first;
00379       return __first == __last;
00380     }
00381 } // namespace __gnu_debug
00382 
00383 #endif

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