SFINAE - recursive template - c++

Question

I'm trying to do this:
struct A
{
typedef void NoHalf;
};
struct B : A
{
typedef A Half;
};
struct C : B
{
typedef B Half;
};
template<class T, typename = T::NoHalf> void TEST() { };
template<class T, typename = T::Half> void TEST()
{
TEST<T::Half>();
};
int main()
{
TEST<A>();
TEST<B>();
TEST<C>();
};
So the TEST<C> function should do something with class C, then recurse TEST<B>, then to TEST<A> and stop there. Unfortunately I get bunch of errors like TEST has already been defined and funny enough also TEST identifier not found. What am I doing wrong and how to fix that?

Answer 1

Ok, so here's a solution, quite uglier, but seems working:
struct A
{
typedef void Half;
static const int I = 0;
};
struct B : A
{
typedef A Half;
static const int I = 1;
};
struct C : B
{
typedef B Half;
static const int I = 2;
};
template<class T> std::enable_if_t<std::is_void_v<T> > TEST() { };
template<class T> std::enable_if_t<!std::is_void_v<T> > TEST()
{
printf("%i", T::I);
TEST<T::Half>();
};
int main()
{
TEST<A>();
TEST<B>();
TEST<C>();
};