It doesn't even come close to fully improving template error messages in the way the C++0x concepts could
In what areas is Concepts Lite lacking in error reporting? Are you referring to the lack of multi-phase checking in Concepts Lite? Because it is possible to have multi-phase checking in the future, and I believe it is on the roadmap to be added.
The entire taxonomy of standard concepts for C++0x was done and the entire standard library was updated for it in N2914. It STILL got cut.
Well, I think one issue that always gets brought up is the number of concepts necessary in C++0x. Concepts Lite is taking the approach of having larger defined concepts, rather than defining smaller more modular based concepts. Either approach could be taken with C++0x concepts, and I don't think it points to an inherit design flaw with C++0x concepts.
It's a flawed design
The core part of its design is built around propositional logic and subsuming. While its an interesting idea, taking this design approach prevents future features such as specialization and concept mapping, which are vital for generic programming. The idea of creating a fork for concept-based libraries would just lead to similar problems with the python 3 fork. Plus, it comes with other surprises(like not being able to use type traits in the requires clause).
it would be a mistake for it to be in the standard.
Especially, since the current tools are improving in regards to error reporting(even when using the current template constraints) that the need for Concepts Lite becomes less. This would further hinder adoption even if it were in the standard. Paul -- View this message in context: http://boost.2283326.n4.nabble.com/Another-variant-type-was-peer-review-queu... Sent from the Boost - Dev mailing list archive at Nabble.com.