abstract:In category theory, a branch of mathematics, a subobject is, roughly speaking, an object which sits inside another object in the same category. The notion is a generalization of the older concepts of subset from set theory and subgroup from group theory.
Twoobjects that are notbit-fieldsmayhave the sameaddressifoneisasubobjectof the other, or if at leastone is a base classsubobjectof zero size andtheyareof different types;