Haskell's "deriving Show" in F#?

In Haskell it is easy to make an algebraic type/discriminated union "displayable" as a string by simply adding deriving Show to the type definition.

In F# I end up writing things like:

type Pos = 
    | Pos of int * int
    override this.ToString() = 
        match this with
        Pos(startp, endp) -> sprintf "Pos(%d, %d)" startp endp

and obviously it gets much worse with more complicated types.

Any way to get something like deriving Show in F#?