You can search for identifiers within the package.
in-package search v0.2.0
include Cstubs.FOREIGN with type 'a return = 'a and type 'a result = 'a
type 'a fn
type !'a return = 'a
val (@->) : 'a Ctypes.typ -> 'b fn -> ('a -> 'b) fn
val returning : 'a Ctypes.typ -> 'a return fn
type !'a result = 'a
val foreign : string -> ('a -> 'b) fn -> ('a -> 'b) result
val foreign_value : string -> 'a Ctypes.typ -> 'a Ctypes.ptr result