C++: Using erase in a vector of iterators

Question

I'm experiencing a problem using the erase function in C++.

I have the following structure:

typedef std::map<std::string,TreeElement> ObjMap;
class TreeElement {
    public:
        ObjMap::const_iterator parent;
        std::vector<ObjMap::const_iterator > children;
}

Now I'm trying to remove a TreeElement from the list of children of its parent using the erase function.

//Remove from parent
SegmentMap::const_iterator parent = segment->second.parent;
std::vector<SegmentMap::const_iterator >::const_iterator it = parent->second.children.begin();
for(;((*it)->first != segment->first) && (it != parent->second.children.end()); it++);
parent->second.children.erase(it); //Compilation fails

This gives an error during compilation indicating it can't convert

__gnu_cxx::__normal_iterator<const std::_Rb_tree_const_iterator<std::pair<const std::basic_string<char>, TreeElement> >*, std::vector<std::_Rb_tree_const_iterator<std::pair<const std::basic_string<char>, TreeElement> > > >

to

__gnu_cxx::__normal_iterator<std::_Rb_tree_const_iterator<std::pair<const std::basic_string<char>, TreeElement> >*, std::vector<std::_Rb_tree_const_iterator<std::pair<const std::basic_string<char>, TreeElement> > > >

Is there any way to fix this? I tried using an iterator instead of a const_iterator but this just moved the compilation error to

std::vector<SegmentMap::const_iterator >::iterator it = parent->second.children.begin();

Clarification: I know the erase function expects a non-const iterator. I'm looking for a way to create this non-const iterator without changing the declaration of parent and children in the TreeElement class.

Answer 1

Parent is const iterator, therefore parent->second is const, therefore parent->second.children is const, therefore parent->second.children.begin() returns const iterator.

erase expects a non-const iterator.