I would love to know what "concepts" are. It appears that they would complicate C++ for some gain in type safety. I found this <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2906.pdf" rel="nofollow">http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n290...</a>, but I fear that understanding will take more time than I have this morning. (I've been away from C++ for most of this century. :-)