Generalized abstarct factory

In Modern C++ Design, Alexandrescu describes disadvateages of an object factory, designed as follows:

class WidgetFactory
{
public:
    virtual Window* CreateWindow() = 0;
    virtual Button* CreateButton() = 0;
    virtual ScrollBar* CreateScrollBar() = 0;
};

One of those disadvanteges is unable to create a widget in a Generic way:

template <class T>
T* MakeRedWidget(WidgetFactory& factory)
{
    T* pW = factory.CreateT(); // huh???
    pW->SetColor(RED);
    return pW;
}

or

template <class T>
T* MakeRedWidget(WidgetFactory& factory)
{
    T* pW = factory.Create<T>(); // aha!
    pW->SetColor(RED);
    return pW;
}

if a creation function were a function template. So, the solution he proposed was a TypeList. OK, we have typlists concept now, but it's still not clear how we can create a generic object factory solving the problem about generic widget creation.

template <class TList>
class WidgetFactory
{
    //What??
}