F# Discriminated Union as Option Type

type Options<'a> =
    | Some of 'a
    | None

let op1 = Some(10.0)
let op2 = None
let op3 = Options.Some("adf")

let ShowOption x =
    match x with 
    | None ->printfn "%A" "Nothing"
    | Some t ->printfn "%A" t

ShowOption op1
ShowOption op2
ShowOption op3