I'm working on a weight lifting app and I want to strictly define the way that weights can be added to a set. there can be dumbbell exercises, barbell exercises, or bodyweight exercises, but I'm not lifting dumbbells and barbells a the same time.
export type BodyWeight = {
/* `weightInLbsBody` is required for all types. I always weigh something. */
readonly weightInLbsBody: number
readonly weightInLbsLeft?: null