"Vladimir Prus" <ghost@cs.msu.su> wrote in message news:200409281058.35304.ghost@cs.msu.su...
Hi Jonathan,
II. A system for allowing user-defined type to advertise their internal
structure, ......
Isn't this close to using 'serialize' for extracting members, that I advocate?
Could you repeat how this would work? I considered allowing user defined types to provide a function (member or non-member) which returns a list of members for use in serialization; unfortunately this was very wastefull in the (common) case that you don;t need to use all the information
I though the system will just work by providing an object with overloaded operator&:
class outputter { public: template<class T> outputter& operator&(const boost::nvp<T>& nvp) { cout << nvp.name() << ":" << nvp.value() << "\n"; } };
class my { template<.....> void serialize(Archive& ar......) { ar & BOOST_SERIALIZATION_NVP(i); } int i; };
Why do you think it's common to don't need all the information? Yes, you probably don't need names for many formatters, but then the operator& will be inline and compiler can optimize passing of the name.
I can imagine wanting to generate a report in xml which involves enumerating the employees working on a project. The employees may be represented by complex objects containing extraneous information such as work history, and only the employee name may be needed. In that case, using a serialize method would be wasteful. I don't see why a framework can't provide several options. Jonathan