Get the type of 'alias this ='

[Vladimirs Nordholm via Digitalmars-d-learn]

Hello people from D-land.

Short question: Can get the type of a struct that has `alias this 
= <type>` ?

See this example, where a struct is aliased to an enum:


    enum Enum { one, two, three, fourtytwo }

    private template Mix()
    {
        this(Enum ee) { e = ee; }
        Enum e;
        alias this = e;
    }
    struct A { mixin Mix }
    struct B { mixin Mix }

    T foo(T) (T f) if (is(T == A) || is(T == B) || is(T == Enum))
    //               |------------------------------------------|
    //                         ^ I want to change this into 
something more nice looking
    {
        // ...
    }


I want to check the type in a more 'cleaner' way.

Best regards,
Vladimirs Nordholm