# functions.h

Go to the documentation of this file.

    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