How to call erase with a reverse iterator

After some more research and testing I found the solution. Apparently according to the standard [24.4.1/1] the relationship between i.base() and i is:

&*(reverse_iterator(i)) == &*(i - 1)

(from a Dr. Dobbs article):

alt text

So you need to apply an offset when getting the base(). Therefore the solution is:

m_CursorStack.erase( --(i.base()) );

EDIT

Updating for C++11.

reverse_iterator i is unchanged:

m_CursorStack.erase( std::next(i).base() );

reverse_iterator i is advanced:

std::advance(i, 1);
m_CursorStack.erase( i.base() );

I find this much clearer than my previous solution. Use whichever you require.


Please note that m_CursorStack.erase( (++i).base()) may be a problem if used in a for loop (see original question) because it changes the value of i. Correct expression is m_CursorStack.erase((i+1).base())


... or another way to remove this element from the list?

This requires the -std=c++11 flag (for auto):

auto it=vt.end();
while (it>vt.begin())
{
    it--;
    if (*it == pCursor) //{ delete *it;
        it = vt.erase(it); //}
}

Tags:

C++