When comparing your code and the proposed library, I have two points.
First, the proposed one has a lot of code to detect what kind of object is output, for getting its elements, and so on. This adds a lot of complexity and should be avoided -- by using serialization library to do the task.
Ok. But I am not sure serialization library as it is now could be used for this purpose.
Your implementation is indeed simple. But: it contains code which iterators over elements of a vector. Should I define my_cool_vector, I'd have to define an overload that your code can use. I'd prefer to defining only overload for serialization library, and have the output library use that automatically.
Actually it's not exactly true. If you notice in a comment before void decorate_elements( std::ostream& ostr, std::vector<T> const& c, Decorator const& d ) I mention that it's actually supposed to be generic version that used for any class that match Collection concept, something like: enable_if<is_collection<T> > void decorate_elements( std::ostream& ostr, T const& c, Decorator const& d )
Another point about your implementation is that it does not distinguish between sequences/maps -- which might be desirable.
If you do want to distinguish you could do this with overloading like this enable_if<is_assoc_collection<T> > void decorate_elements( std::ostream& ostr, T const& c, Decorator const& d ) though I do not see an immediate need for this
Would you want something like string format ("% | %") it could be easily added, though I question its usability. It assumes a lot of things when applied to multivalue container. As for reflection framework, I would be interested in generic solution, but again not in a context of output formatting specifically (I may use it for this purpose, but not design it for this purpose).
What I'm proposing is that output library use the *existing* mechanism, provided by the serialization library.
I supposed you want to reuse namely reflection abilities of it. I am not quite sure existing mechanisms will allow you to supply convenient interfaces for most basic (but mostly used) cased.
- Volodya
Gennadiy. P.S. I did not have a chance yet to look on latest serialization library implementation, but here: http://article.gmane.org/gmane.comp.lib.boost.devel/78978 is my post dated somewhere in between two reviews, that describe traversing framework that could be used by serialization lib implementation and by ant other reflection need. I hope serialization library provide something like that. In this case We may use it for generic output formatting.