Get type of a "singleton type"

We can create a literal types via shapeless:

import shapeless.syntax.singleton._
var x = 42.narrow
// x: Int(42) = 42

But how can I operate with Int(42) as a type if it's even impossible to create type alias

type Answ = Int(42) // won't compile
// or
def doSmth(value: Int(42)) = ... // won't compile