How do I the temlate parameter name as string?

[PacMan]

ParameterIdentifierTuple from std.traits did work fine for 
regular functions but not for template functions:

> Error: template instance 
> `std.traits.ParameterIdentifierTuple!(f)` does not match 
> template declaration `ParameterIdentifierTuple(func...) if 
> (func.length == 1 && isCallable!func)` (foo)

f is defined as:

> void f(T)(T t, string p)
> if(is(T == A) || is(T == B))
>{
>	// ...
>}

my goal is get "p" as string.