C++ boost::mpl::type forward declaration

Question

I have the following type:

typedef boost::mpl::fold<hostObjectTypes, void, base>::type caClientObject;

and i need a forward decleration of this caClientObject. Does anyone know how to achieve it?

Answer 1

I'd do

struct caClientObject; /* forward */

and later

struct caClientObject : boost::mpl::fold<hostObjectTypes, void, base> {
};