widl: Do not generate empty Vtbl structure for empty interfaces.

[Alexandre Julliard]

Thomas Faber <thfabba at gmx.de> writes:

> An alternative solution would be not to generate a vtable structure at all,
> and instead add a dummy member to the class directly. That would be in line
> with what the defined(__cplusplus) && !defined(CINTERFACE) case results in,
> but require a slightly larger change to widl.

I'm not sure it makes sense to even define a C structure at all, since
there's nothing you can do with it.

-- 
Alexandre Julliard
julliard at winehq.org