Virtual dispatch implementation details

Question

First of all, I want to make myself clear that I do understand that there is no notion of vtables and vptrs in the C++ standard. However I think that virtually all

Answer 1

1. Looks good to me

2. Implementation specific, but most are just in source code order -- meaning the order they appear in the class -- starting with the base class, then adding on new virtual functions from the derived. As long as the compiler has a deterministic way of doing this, then anything it wants to do is fine. However, on Windows, to create COM compatible V-Tables, it has to be in source order

3. (not sure)

4. (guess) A diamond just means that you could have two copies of a base class B. Virtual inheritance will merge them into one instance. So if you set a member via D1, you can read it via D2. (with C derived from D1, D2, each of them derived from B). I believe that in both cases, the vtables would be identical, as the function pointers are the same -- the memory for data members is what is merged.