Hi,

> This is not really a bug; I'd qualify this as an "undesirable"
> feature: sexplib erases type information; for instance the
> representation of None* will always be the same and therefore
> will be desexpable to any other option type. You may also note
> that some other type have compatible representations. In
> practice it would be really hard for a camlp4 extension to keep
> track of types. In you case you could use custom converters and
> save the phantom type in the sexp.

Yes, I figured as much (see the last paragraph of my original
message).  I was just wondering if there was already a canned
solution to this sort of problem (or one in the works), before
I wrote a custom converter.

Cheers,
Dario Teixeira