!! With MI, the “this” pointer field is not always identical between the Base object and the Derived object.
** Remember a primitive technique of a home-made “class” is a C struct + a self-pointer field [2]. Similarly, In Python methods, “self” must be the first argument…
[2] I don’t think we should add a 32-bit field to each instance! I guess compiler can help make do without it.
!! In a Derived instance, there’s not always a single Base1 instance.
** Basic example — D extends C1 and C2, which both extend B.
** Even if C1 and C2 both virtually extend B, if C3 extends B without “virtual”, D instance still embeds 2 B instances.
!! Casting within inheritance hierarchy doesn’t always maintain the address held inside a Derived pointer or Base pointer. SI — always. ARM P 221 says “with MI, casting changes the value of a pointer”. See my experiment https://github.com/tiger40490/repo1/blob/cpp1/cpp/88miscLang/ptrArithmeticMI.cpp
!! Each Derived instance uses more than one vtbl. If D inherits from B1 and B2, then that instance uses two vtbl’s. See ARM P230.
!! AOB (see other posts) assumes a 0 “delta” but in MI, delta is introduced because it’s not 0! ARM P222
— Below rules still holds, in SI and MI —
dtor sequence is the exact reverse of ctor sequence which is BCDC (see other posts)
keep learning 活到老学到老 