I am changing the class of some objects using object_setClass(id object, Class cls). I am changing the class to a subclass of the original class. T
object_setClass(id object, Class cls)
Instead of using a larger subclass, use objc_setAssociatedObject and objc_getAssociatedObject to attach dynamically additional objects to your existing fixed-size object.
objc_setAssociatedObject
objc_getAssociatedObject