Stefan Monnier wrote:

> 
> Is there a void type in OCaml (i.e. a type which has no values), or a way to
> simulate it?

Yes, the unit type which is written "()".

    Objective Caml version 3.09.2
    # let x = () ;;
    val x : unit = ()

Unit can also be returned from a function, and a function
can have its input of type unit:

    # let f () = 3.141 ;;
    val f : unit -> float = <fun>

Erik
-- 
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Erik de Castro Lopo
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"Unix and C are the ultimate computer viruses." -- Richard P Gabriel