CPP13 — Supporting typedefs for _var types?

quite some time ago, we added the _var_type and _ptr_type definitions
to proxies to make it easier to write templates. Similarly, we have
the _whatever_seq typedefs for recursive structs and unions, to avoid
problems with anonymous types.

What's missing at the moment is a similar feature for _var types.
When I'm writing a template that does it's job in terms of _var types,
I also quite often want to do something to the underlying target type
of the _var. However, I can't do that unless I pass in an extra template
parameter (which, in turn, doesn't always work if I also want to use
STL standard binders and such...)

So, why not add a typedef for the target type to every _var type?