"Robert Ramey" <ramey@rrsd.com> wrote in message news:cnt6jr$m32$1@sea.gmane.org...
Basically, this looks OK to me as well. I would like to see it made more automatic and more inline with what other serializations uses. On one level, this is merely a cosmetic issue. On the other level, its about leverage of user interface patterns. Ideally, I would like to see usage something as simple as:
Struct X { variant<int, char, unsigned long> x template<class Archive, class T> void serialize(Archive &ar, T& t, unsigned int version){ ar & x; } };
A couple of questions though
a) would it not be interesting for variant to return an integer corresponding to is current type? unsigned variant::get_type_index();
What about "int variant::which()" ?
b) and the reverse variant::set_type_index(unsigned int ti); // of course this destroys any variable stored therein
I would hope this might be implementable. My experience with mpl suggests that it might be. In this case the serialization would be a dream come true.
so we could something like: template<class Archive, class T> void save(Archive &ar, const T & v){ usigned int ti = x.get_type_index(); ar << ti apply_visitor( bind( variant_saver(), ref(ar), _1 ), v ); }
template<class Archive, class T> void load(Archive &ar, T & v, unsigned int version){ unsigned int ti; ar >> ti; v.set_type_index(ti); apply_visitor( bind( variant_loader(), ref(ar), _1 ), v ); }
The above would be nice indeed. I've also been deserializing variants and wondered if there was any another way to do it - this would definitely make things easier. // Johan