Iterator : CLAN Warning - "Invalidated Interator accessed"

I'm using const_iterator in a for loop for a map that has been defined. While accessing the iterator->first, i encountered CLANG Warning as "Invalidated iterator accessed". Can someone help on this.

Code reference below:

    for (MAP::iterator iter = local_map.begin(); iter != local_map.end(); )
    {
        local_variable XXX = iter->first;