[cfe-dev] COM ABI support?

[Stephen Lin]

> Some don't. IBM's C/Set++ or the VisualAge C++ compiler for OS/2
> didn't (the pointers in the vtable were 8 bytes apart, despite it
> being a 32-bit compiler). Our (cross-platform: Windoes, OS/2, Mac,
> Unix, NetWare, ...) product had a library with a COM wrapper on it.
> All platforms implemented COM in C++, except OS/2, where we had to use
> plain C to get the correct layout.

Out of curiosity, what were the extra 4 bytes in each vtable entry
for? Was this part of some implementation strategy to support
pointers-to-member-functions, or something like that?

Stephen