chickadee » srfi-209 » enum-set-union!

Returns an enum set containing all the elements of either enum-set-1 or enum-set-2. It is an error if all the elements of the result do not belong to the same enum type.

(enum-set-map->list enum-name
                    (enum-set-union (enum-set color color-orange)
                                    (enum-set color color-blue)))
 ⇒ (orange blue)

(enum-set=? color-set (enum-set-union! reddish ~reddish)) ⇒ #t