Couple o' things:
On Sun, Feb 6, 2011 at 12:39 PM, Edward Diener
Features of the update include support for the older gcc 3.4.2 and 3.4.5, finer-grained introspection for the basic macro metafunctions, documentation examples, better and tighter design, and better use of Boost MPL methodology ( metafunctions are now passed as lambda expressions and metafunction globbing has been removed from the two metafunctions where it previously existed ). You can view the changes in the History section of the documentation.
FWIW, passing lambda expressions instead of metafunction classes is a trade-off: it's more expressive, but will lengthen compile times. For the implementation of a boost library, it's probably better to err on the side of speed.
The TTI library is based on the type_traits_ext portion of the Concept Traits Library, with improvements and additions, and also lifts functionality, for the purposes of orthogonality, from Boost.MPL regarding introspection of types and templates.
Orthogonality in what sense? Duplicating functionality seems like the opposite of orthogonality. -- Dave Abrahams BoostPro Computing http://www.boostpro.com