A container type for 3 singleton types.
init : a1 -> a2 -> a3 -> Singletons3 a1 a2 a3
Initialize a container type for 3 singleton types.
specs : (Ecs.Internal.SingletonSpec a1 (Singletons3 a1 a2 a3) -> Ecs.Internal.SingletonSpec a2 (Singletons3 a1 a2 a3) -> Ecs.Internal.SingletonSpec a3 (Singletons3 a1 a2 a3) -> specs) -> specs
Create all singleton specifications for 3 singleton types.