I recently started looking at what changes in my libraries may not have made it into the trunk from 1.34.1. The easiest way was to go to my boost-trunk working copy and svn merge https://svn.boost.org/svn/boost/tags/merged_to_1_34_0/boost https://svn.boost.org/svn/boost/tags/Version_1_34_1/boost What I saw in libraries that weren't my own gave me pause for concern. There are a large number of files with a 'C' or an 'M' next to them. Neither is *necessarily* an indication of a problem, but 'M' (meaning "merged") especially is *likely* to indicate unmerged changes, and 'C' (meaning "conflict") may also indicate unmerged changes. I went and inspected a few of those files and the ones I looked at all seemed suspicious to me. I strongly suggest that all other Boost authors do the command above and inspect "merged (M)," "conflict (C)," and "added (A)" files that they may have touched during the 1.34.x release cycle, or we may find that we've dropped important improvements. One place you should especially check is in your test/ directories, to make sure that you haven't unintentionally dropped any tests between then and now. If your testing is complete and you make sure nothing is dropped, in theory, dropped features and bugfixes won't be able to hide. But there are also documentation changes, so I wouldn't take anything for granted ;-) -- Dave Abrahams Boost Consulting http://www.boost-consulting.com