Topic: Friendly text format.
There is some data structure, with vectors, map, and optional variables (boost:: optional). It is required to make a user-friendly format of filling of this structure. It should be easily transparent for the user a text format. It is desirable, JSON-like, but approaches and xml (if not too overloaded). Tried Boost. Serialize in xml : boost:: optional <std:: string> comment; in xml turns in <comment class_id = "0" tracking_level = "0" version = "0"> <initialized> 1 </initialized> <item_version> 0 </item_version> <value> comment text </value> </comment> that is absolutely unacceptable. It was possible after all to be restricted to one attribute missing if the field is not set! Whether there are ready implementations of archives, a similar case? Or usage boost.serialize, basically the bad idea other approach also is necessary?