Rafael Machado: The documentation, which is only founded in header files says: A Swift Array or Dictionary of types conforming to ObjectiveCBridgeable can be passed to Objective-C as an NSArray or NSDictionary, respectively. The elements of the resulting NSArray or NSDictionary will be the result of calling bridgeToObjectiveC on each element of the source container. … Continue reading Swift Casting With _ObjectiveCBridgeable