At my request, Tom Kent has kindly added VC++ 14.0 (toolset msvc-14.0) to his develop branch tests. See http://www.boost.org/development/tests/develop/developer/summary.html rightmost column. This compiler is available as part of the Visual Studio 2015 Preview. See http://www.visualstudio.com/en-us/downloads/visual-studio-2015-downloads-vs.... Several libraries are showing new test failures. Please check out the test results to see if your library has started to fail. If it is your problem, fix it or at least create a ticket for yourself:-) If it is a Microsoft problem, consider submitting a bug report and posting a notice on the Boost list so that other developers are aware of the problem. Also post a link to the bug report on https://connect.microsoft.com Knowing the Microsoft Connect URL for the bug report lets other boosters up vote the importance of the issue. This is known to have at least some influence on the priority given the bug report, and that means faster fixes for the bugs boosters care about. Thanks, --Beman