Is there a Boost policy on resolving conflicts between Boost behavior and the TR1 spec? As an example, std::tr1::is_base_of returns true, but boost::is_base_of returns false. Changing Boost behavior would presumably break existing code, but failing to implement TR1 semantics is likely to be confusing/surprising to many.

That particular trait was changed to TR1 conformance last November: http://cvs.sourceforge.net/viewcvs.py/boost/boost/boost/type_traits/is_base_... I don't think that change has seen a release yet though.

My understanding is that Boost is committed to bringing its TR1-like libraries into conformance with TR1, but it'd be helpful if people who follow Boost more closely than I could confirm that.

Yes, generally libraries have been tracking TR1. The Boost.TR1 docs document any incompatibilies that are currently known about (see http://www.boost.org/regression-logs/cs-win32_metacomm/doc/html/boost_tr1.ht...), no doubt wider use of TR1 components will detect others, but that's life. John.