David Abrahams wrote:
As I said, I understand the general intent. It's the specific meaning that's unclear. It's especally unclear because you say "must implement the following interface..." and then show one member function with an implementation. You could provide that implementation by using a CRTP base class.
OK - I see this now. In fact, in the archives provided, it is implemented using the CRTP model. I concidered that as a feature of the implementation. I think I can adjust this to remove the implementations. I see now that they don't belong here and that it is confusing.
Note that his concept is different than others in the standard library in that one of the requirements is that it be a class with certain required member functions.
Most or all other concept definitions only specify operations for which the type is valid. As far as I know this doesn't include supporting specific member functions.
Actually, no. All of the concepts in the Container hierarchy share that property.
Of course. And I did study the SGI documentation in that regard. Now that I think about, I'm sure this is where I got the idea to do it this way.
Well, CRTP might be a good option for you, especially considering that function implementation I mentioned in the first paragraph above.
As I said, Ive used CRTP in the implementation. But I could imagine someone making an archive class that didn't use CRTP and still have the archive function. So I see it as an implementation detail rather than part of the concept.
So the question is, does the user actually need to use default arguments where your interface description does, or would overloads work just as well? Since you don't have a description of how to interpret your prototype, the answer is unclear.
The only default argument is register_type(T * t = NULL); and its only there because many compilers don't accept the syntax: ar.template register_type<T>() Its optional to support compilers that do support the above syntax. So I guess that should be explained. Robert Ramey