Question

When I execute the following code, I am getting map/set iterators not incrementable error.

typedef std::multimap<int, int> MapType;

assgnt::MapType my_map;
assgnt::MapType::iterator it;
for(it = my_map.begin(); it != my_map.end(); )
{
    my_map = obj1.addGoodNeighbours(it->first, it->second, my_map); 
    ++it;
}

Please help

Answer 1

I don’t know what a assgnt::MapType is, but assigning another assgnt::MapType to my_map inside the for loop, can’t be a good thing:

my_map = obj1.addGoodNeighbours(it->first, it->second, my_map); 

You should at least reassign the iterator:

for(it = my_map.begin(); it != my_map.end(); ++it;) {
    my_map = obj1.addGoodNeighbours(it->first, it->second, my_map); 
    it = my_map.begin();
}

But i believe that code is far from correct. You are basically destroying the structure that you’re iterating while iterating it.

EDIT: Well we do know what a MapType is now. All of the above is still correct. You can’t just re-assign your maps while iterating them.