Constructing an enum using the members of an AliasSeq as enumerator names

[Nordlöw via Digitalmars-d-learn]

What's the easiest way to create an `enum` using the symbol names 
of an `AliasSeq` as enumerator names?

That is, given

     alias Types = AliasSeq!(byte, short, int);

we need some compile-time type-constructor `makeEnum` called as

     alias E = makeEnum!Types;

that should be equivalent to

     enum E { _byte, _short, _int }

I guess a `mixin` is the way to go here, right?