Function Template Overloading

[Q. Schroll via Digitalmars-d-learn]

void test(T)(T* arg);
void test(T)(ref T arg);

Let p be any pointer. Why is test(p) not an ambiguity error? Why 
is the second overload chosen?
Making the first one take auto ref T* lets the compiler choose 
the first.
Making the second one non-ref lets the compiler give me an 
ambiguity error.

Template Functions are not mentioned in the spec, at least not on 
https://dlang.org/spec/function.html#function-overloading, but it 
suggests that ref should not make the decision if it can be bound 
to.