IIRC COM relies on vftables being ABI stable so you can pass interface pointers. As long as the interfaces don't pass any non-primitives by value. It is how I

IIRC COM relies on vftables being ABI stable so you can pass interface pointers. As long as the interfaces don't pass any non-primitives by value. It is how I often provide APIs that need to work across (many) compiler boundaries. It is not standardized or anything, but de facto reliable on Windows.