Sizeof class instance

[Justin Johansson]

How does one determine the sizeof (in bytes) of an instance of a class in D?

.sizeof works as advertised for structs, but for reference types,
.sizeof yields the sizeof the referencing variable (effectively same as size of a pointer)
and not the size of the underlying instance.

I did try scanning the NG and read spec_D1.00.pdf.  Perhaps I missed it in the latter.

btw. I was poking under the hood of std.xml and though, wow, instances of Element
class look humongous, and so I'm interested to how exactly how humongous.

Thanks for all help.
Justin