Not sure about the diagnostic of this, could be the return object construction, or the specification of the function return type (I'm betting on the latter):

class Type { };

struct Holder {
template <class T1> struct B {
typedef int type1;
typedef int type2;
};
};

template <class T1, class T2> struct A { };

template <class T>
A<typename T:: B<Type>::type1,
typename T:: B<Type>::type2> fn() { return A<int,int>(); }
// Error: 2 actual arguments expected for A, had 1
// Internal error: template 1656

int main() {
fn<Holder>();
}

I fixed up the FC++ lib for DM intending to give result to Christof, but a section of the lib with this form fails and I can't think of a useful workaround.

Richard