C++ :: Two Dimensional Map - Data Structure

I'm currently having the following data structure:

typedef struct {
int a;
int b;
} S;
<vector <vector<S> > v;

Now I also have different pointers that can be set in connection with one instance of the above shown vector. Therefore I was attempting to work with a map:

map<p*, <vector<vector <S> >, vector<sI> > m;

However, it seems like it doesn't work that way. Therefore I tried the following:

map<p*, map<<vector<vector <S> >, vector<S> > > m2;

With this attempt I do now, however, get another mistake here, that [] cannot be used here:

S s;
m2[p][0].push_back(s);