How to overload with enum type?

[Domain]

On Sunday, 15 October 2017 at 08:47:42 UTC, Domain wrote:
> void f(int i)
> {
>     writeln("i");
> }
>
> void f(E)(E e) if (is(E == enum))
> {
>     writeln("e");
> }
>
> enum E { A }
> E e = E.A;
> f(e);    // output i
>
> How can I overload with enum type?

I know I can do that with this:

void f(T)(T i) if (is(T == int))
{
     writeln("i");
}

But that looks strange.