The VS 2015 Update 3 release candidate has been announced. See https://blogs.msdn.microsoft.com/vcblog/2016/06/07/compiler-improvements-in-... (The following is partially for Boost developers who care about msvc, and partially to remind myself of what may need to be done to support update 3. It will be several weeks before I can work on this, so if any of the other config maintainers want to step in, please do so.) Update 3 supports standards versioning switches similarly to gcc, clang, and other compilers. We probably want to update Boost.Config accordingly. See https://blogs.msdn.microsoft.com/vcblog/2016/06/07/standards-version-switche... Update 3 fixes lots of constexpr bugs, so we need to review whether or not BOOST_NO_CXX11_CONSTEXPR is still required. Note that in develop there is an undocumented config macro BOOST_MSVC_CXX11_CONSTEXPR that turns off BOOST_NO_CXX11_CONSTEXPR to facilitate testing. Update 3 fixes the expression SFINAE issues that were causing most of the Boost develop test failures. https://blogs.msdn.microsoft.com/vcblog/2016/06/07/expression-sfinae-improve... Quoting from that: There are still three failing tests in the Boost [develop] test suite when compiling with MSVC. Two test failures relate to using the noexcept operator in a template type argument. We currently parse it immediately, even in a dependent context. One test failure is a Boost library issue that we’ve reported to the [library's] maintainers. There are still known update 3 expression SFINAE issues (see "What remains to be done?" in the blog article) so do we continue to define BOOST_NO_SFINAE_EXPR? There is an undocumented BOOST_MSVC_SFINAE_EXPR macro in develop that turns off BOOST_NO_SFINAE_EXPR, so it is easy for developers to use msvc expression SFINAE if the want to. But our usual criteria for a _NO_ macro is not full compliance, but whether or not Boost code works with a feature. So using that criteria for update 3 we would remove BOOST_NO_SFINAE_EXPR. Opinions? --Beman <aside> We always urged Microsoft to test their releases against Boost. For update 3 expression SFINAE, they did exactly that. Thanks to Microsoft's Andrew Pardoe for coordinated the effort and to Xiang Fan for running the tests and tracking down the reason for each test failure. An undocumented Boost.Config macro BOOST_MSVC_SFINAE_EXPR to support their testing. The approach was to run tests for all libraries with the normal test setup, and then run again with BOOST_MSVC_SFINAE_EXPR defined. If the problem was with the Boost library, Xiang then reported it to me. I need to review a long series of email exchanges with him to make sure I alerted library maintainers to any Boost problems. </aside>