[Bug c++/24061] New: Documentation in /tr1/hashtable proposes possibly misleading change

[atavory at gmail dot com]

/tr1/hashtable lines 1318-132 documents hashtable::erase(const_iterator i)

It states: 

"The return type should be const_iterator,
and it should return the iterator following the one we've erased.
That would simplify range erase."

However, if erase would return an iterator, range-erase would not work the way
the comment suggests. The comment (probably) refers to code like the following
(attempting to erase values whose key is larger than 20):

for(typename T::iterator i = t.begin(); i != t.end();)
  if(i->first > 20)
    i = t.erase(i); // (*)
  else
    ++i;

This looks simple, but it probably won't work. The line marked by (*) might
resize the container, which will rehash/reposition all values. The iterator i
might point to values already accessed, or might have skipped passt values not
yet accessed, or both. tr1 is correct: t.erase(i) cannot return any meaningful
iterator.

-- 
           Summary: Documentation in /tr1/hashtable proposes possibly
                    misleading change
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: atavory at gmail dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24061