Earlier quoted context omitted.
> while OP use void pointers OP doesn't use void pointers, he uses void. He writes about functions having no arguments and returning nothing for the same reason other blog posts name functions foo and bar. > OP uses this vtable as a form of indirection to implement runtime method swapping and polymorphism The kernel uses vtables to implement polymorphism, it doesn't store the vtable in the object to save space. If th…
> If there is no polymorphism, you don't use a vtable at all, that's saving even more space. Not true. You use a vtable even if there is no polymorphism, in cases where you want to have objects store pointers to their methods (OO interface), but don't want each instance to have pointers to all methods. I was referring to this article, which the OP links in his post https://lwn.net/Articles/444910/
Re: Object-oriented design patterns in C and kernel development
#221When do objects need to have function pointers? If the function never changes per object, then you would just directly call the function. When do you use function pointers? When the caller only knows the type of struct foo_ops, but not the actual called function. That's polymorphism.