Dynamics...

I have a variable **foo which I let user to initialize to foo[x][y]. Now, the problem is that how to change that size in the fly so, in example, when I first have foo[10][10] I would later have foo[100][100]. I could of course use another variable for swapping but I'm thinking of sizes like foo[10000][10000] so that would be a real memory eater (though, even without the temporary variable).

I've been thinking of linked lists, but that would be slow and still eats lots of memory. Any ideas?

How about using a vector container class that allows resizing and create another class that is a vector of a vector.

template <class T>
class CMatrix
{
.
.
.
private:
vector<vector<T> > myVector;
};