CODEWITHSUNDEEP
c++dictionaryiterator
Michał Iwanicki
Michał Iwanicki

Reputation: 103

map iterator not incrementable

When I try to run my program I get 'map/set iterator not incrementable' error. I read that it happens when you invalidate iterator, but I'm only editing objects pointed by iterator. Is this normal behaviour? What can I do about it? If I delete this line then there is no error:

iterator->second.neighbour[direction] = &(find_iter->second);

Full code:

void Gomoku::addUniqueMap( const map_Map& map_to_add )
{
    this->unique_maps.push_front( map_to_add );

    std::list<map_Map>::iterator map_iter = this->unique_maps.begin();
    map_Iterator iterator = map_iter->begin();

    for( ; iterator != map_iter->end(); ++iterator )
    {
        for( int i = 1, direction = 0; i > -2; --i )
        {
            for( int j = -1; j < 2; ++j )
            {
                if( iterator->second.neighbour[direction] == nullptr )
                {
                    ++direction;
                    continue;
                }
                if( i == 0 && j == 0 )
                    continue;

                COORD pos( iterator->first.x + j, iterator->first.y + i );
                wrap( pos, this->map_size );

                map_Iterator find_iter = map_iter->find( pos );
                if( find_iter != map_iter->end() )
                {
                    iterator->second.neighbour[direction] = &(find_iter->second);
                }

                ++direction;
            }
        }
    }
}

'map_Map' - std::map<COORD, Pawn>
'map_Iterator' - std::map<COORD, Pawn>::iterator
'Pawn' - 

struct Pawn
{
    Pawn( Player player );
    Player      player;
    const Pawn* neighbour[8];
};

Upvotes: 0

Views: 1112

Answers (1)

Michał Iwanicki
Michał Iwanicki

Reputation: 103

The cause of the error was that I was accessing and modifying neighbour[8], so I was modifying element of out array range and possibly it has done something to the iterator.
In Debug version I got map/set iterator not incrementable error while in Release version iterator couldn't be incremented and it caused program to loop infinitely.

Upvotes: 0

Related Questions