I just came across this article on feature updates for their compiler during the VS2017 lifetime, I thought the section talking about version numbers might be of interest to the boost build maintainers and boost config maintainers. The blog post can be found here: https://blogs.msdn.microsoft.com/vcblog/2017/11/15/msvc-conformance-improvem... The interesting part about version numbers is three-quarters of the way down the post, under the "MSVC toolset version number increases to 14.12". The table that they have there is also illuminating: Visual Studio Version | MSVC Toolset Version | _MSC_VER --------------------------------------------------------------- VS2015 and updates 1, 2, & 3 | v140 in VS; version 14.00 | 1900 VS2017, Version 15.1 & 15.2 | v141 in VS; version 14.10 | 1910 VS2017, Version 15.3 & 15.4 | v141 in VS; version 14.11 | 1911 VS2017, Version 15.5 | v141 in VS; version 14.12 | 1912 --------------------------------------------------------------- Just wanted to give people a heads-up that this is something that may be encountered in the wild soon. Tom