[STDCXX-972] std::vector<bool>::iterator doesn't meet random iterator requirements

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.1.2, 4.1.3, 4.1.4, 4.2.0, 4.2.1
• Fix Version/s: 4.2.2
• Component/s: 23. Containers

Environment

All

• Patch Info: Patch Available
• Severity: Compiler Error
• Assignee: Farid Zaripov
• Reporter: Farid Zaripov
• Created: 21/Jun/08 07:45
• Updated: 03/Jul/08 10:41
• Resolved: 23/Jun/08 13:49

Description

The test below fails to compile.

test.cpp

#include <vector>

typedef std::vector<bool> VecBool;
typedef VecBool::iterator VecBoolIter;
typedef VecBool::const_iterator VecBoolCIter;

int main ()
{
    VecBool vb;
    VecBoolIter it = vb.begin ();
    VecBoolCIter cit = vb.begin ();

    5 + it;
    5 + cit;

    return 0;
}

test.cpp(13) : error C2784: 'std::reverse_iterator<_Iterator> std::operator +(iterator_traits<_Iterator>::difference_type,const std::reverse_iterator<_Iterator> &)' : could not deduce template argument for 'const std::reverse_iterator<_Iterator> &' from 'VecBoolCIter'
        include/rw/_iterator.h(274) : see declaration of 'std::operator +'
test.cpp(13) : error C2784: 'std::reverse_iterator<_Iterator> std::operator +(iterator_traits<_Iterator>::difference_type,const std::reverse_iterator<_Iterator> &)' : could not deduce template argument for 'const std::reverse_iterator<_Iterator> &' from 'VecBoolCIter'
        include/rw/_iterator.h(274) : see declaration of 'std::operator +'
test.cpp(13) : error C2784: 'std::reverse_iterator<_Iterator> std::operator +(iterator_traits<_Iterator>::difference_type,const std::reverse_iterator<_Iterator> &)' : could not deduce template argument for 'const std::reverse_iterator<_Iterator> &' from 'VecBoolCIter'
        include/rw/_iterator.h(274) : see declaration of 'std::operator +'
test.cpp(13) : error C2784: '__rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> std::operator +(_Cont::difference_type,const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &)' : could not deduce template argument for 'const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &' from 'VecBoolCIter'
        include/rw/_iterbase.h(594) : see declaration of 'std::operator +'
test.cpp(13) : error C2784: '__rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> std::operator +(_Cont::difference_type,const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &)' : could not deduce template argument for 'const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &' from 'VecBoolCIter'
        include/rw/_iterbase.h(594) : see declaration of 'std::operator +'
test.cpp(13) : error C2784: '__rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> std::operator +(_Cont::difference_type,const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &)' : could not deduce template argument for 'const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &' from 'VecBoolCIter'
        include/rw/_iterbase.h(594) : see declaration of 'std::operator +'
test.cpp(13) : error C2677: binary '+' : no global operator found which takes type 'VecBoolCIter' (or there is no acceptable conversion)
test.cpp(14) : error C2784: 'std::reverse_iterator<_Iterator> std::operator +(iterator_traits<_Iterator>::difference_type,const std::reverse_iterator<_Iterator> &)' : could not deduce template argument for 'const std::reverse_iterator<_Iterator> &' from 'VecBoolIter'
        include/rw/_iterator.h(274) : see declaration of 'std::operator +'
test.cpp(14) : error C2784: 'std::reverse_iterator<_Iterator> std::operator +(iterator_traits<_Iterator>::difference_type,const std::reverse_iterator<_Iterator> &)' : could not deduce template argument for 'const std::reverse_iterator<_Iterator> &' from 'VecBoolIter'
        include/rw/_iterator.h(274) : see declaration of 'std::operator +'
test.cpp(14) : error C2784: 'std::reverse_iterator<_Iterator> std::operator +(iterator_traits<_Iterator>::difference_type,const std::reverse_iterator<_Iterator> &)' : could not deduce template argument for 'const std::reverse_iterator<_Iterator> &' from 'VecBoolIter'
        include/rw/_iterator.h(274) : see declaration of 'std::operator +'
test.cpp(14) : error C2784: '__rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> std::operator +(_Cont::difference_type,const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &)' : could not deduce template argument for 'const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &' from 'VecBoolIter'
        include/rw/_iterbase.h(594) : see declaration of 'std::operator +'
test.cpp(14) : error C2784: '__rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> std::operator +(_Cont::difference_type,const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &)' : could not deduce template argument for 'const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &' from 'VecBoolIter'
        include/rw/_iterbase.h(594) : see declaration of 'std::operator +'
test.cpp(14) : error C2784: '__rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> std::operator +(_Cont::difference_type,const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &)' : could not deduce template argument for 'const __rw::__rw_debug_iter<_Container,_Iterator,_MutableIterator> &' from 'VecBoolIter'
        include/rw/_iterbase.h(594) : see declaration of 'std::operator +'
test.cpp(14) : error C2677: binary '+' : no global operator found which takes type 'VecBoolIter' (or there is no acceptable conversion)

The proposed fix:

Index: include/vector
===================================================================
--- include/vector	(revision 670160)
+++ include/vector	(working copy)
@@ -956,6 +956,11 @@
         reference operator[] (difference_type __i) {
             return *(*this + __i);
         }
+
+        friend iterator operator+ (difference_type __n,
+                                   const iterator &__x) {
+            return __x + __n;
+        }
     };
 
     class const_iterator
@@ -1025,6 +1030,11 @@
         const_reference operator[] (difference_type __i) { 
             return *(*this + __i); 
         }
+
+        friend const_iterator operator+ (difference_type __n,
+                                         const const_iterator &__x) {
+            return __x + __n;
+        }
     };
 
 #ifndef _RWSTD_NO_CLASS_PARTIAL_SPEC