"Robert Ramey" <ramey@rrsd.com> writes:
Thinking about this while I was trying to sleep my thoughts on this clarified a little
There are really two things going on here.
a) There is a use using an archive.
?? sorry, can't parse that.
This is very similar to a user using a collection. He needs a description of the user interface for the collection class. This is essentially a list of requirements on the collection class template arguments and a list of member functions. The achive classes have no template arguments so the archive concept description fills the role. It is also very analogous to the standard class header.
b) There are facilities for creating a new archive class. These would be most analogus to the boost iterator. The archive classes use CRTP. Actually this part has been considered an implementation detail given the common interface to all archives described in the archive concept. Hence its not really described in the documentation at all.
I suspect that part of any confusion is that one is expecting to find b) but finds only a).
If one is looking for a) then he never notices that b) isn't there.
We don't care about any of that. All I -- and the people I'm working with, who can't figure this out either -- care about are the minimal requirements on a type in order for the serialization library to use it as an archive. *That* is the proper definition of the Archive concept. Let me add, if you haven't already got a lot of experience defining concepts rigorously, this is a bad time to try to innovate by using a pseudosignature approach. Write requirements tables using the standard columns, as applicable: valid expression result type requirements semantics preconditions/postconditions invariants notes One of the best ways to make sure you have the right concept specification is to use the Boost Concept Checking Library and define a concept archetype, then throw it at your code. That will at least check that you've got all the syntactic requirements right. Semantic requirements, you need to think through on your own. -- Dave Abrahams Boost Consulting www.boost-consulting.com