You might find this useful - http://github.com/rpeev/Fzeet/blob/cleanup/lib/fzeet/windows/oleaut/Variant.ffi.rb
It is part of a larger lib, but except for a small module called
AnonymousSupport is self-contained
Either comment-out the include AnonymousSupport line (but field access
will be more verbose)
or fish out the definition from here -
http://github.com/rpeev/Fzeet/blob/cleanup/lib/fzeet/windows/core/Common.rb