Question

I’d like to create a std::map that contains a std::vector of iterators into itself, to implement a simple adjacency list-based graph structure.

However, the type declaration has me stumped: it would seem you need the entire map type definition to get the iterator type of said map, like so:

map< int, Something >::iterator MyMap_it;  // what should Something be?
map< int, vector<MyMap_it> > MyMap_t;

Is there some sort of partial map iterator type I can get with just the key type, so I can declare the full map?

Answer 1

You could use forward declaration of a new type.

class MapItContainers;
typedef map<int, MapItContainers>::iterator MyMap_it;

class MapItContainers
{
public:
 vector<MyMap_it> vec;
};

With this indirection the compiler should let you get away with it.
It is not so very pretty but honestly I don’t think you can break the self referencing easily.