In my effort to set the meta information of 'cxxstd' for the appropriate C++11 on up libraries, my PRs for these libraries have been kindly merged to 'develop' by the library maintainers: beast callable_traits context convert coroutine2 fiber geometry gil hana histogram hof json leaf mp11 nowide outcome pfr process safe_numerics static_string stl_interfaces variant2 yap If anyone knows of any other current library which is a C++11 on up library, please tell me. My testing showed that all other Boost libraries will work in C++03 mode, but maybe I missed some other library which is a C++11 on up library. Needless to say other libraries have noted their attention to move from C++03 to C++11 in the near future. If any library does change the C++ mode necessary to use that library, I hope the maintainer(s) of that library will update the 'cxxstd' meta information appropriately. If we can get the website to work properly using the 'cxxstd' meta information, end-users should be able to know immediately whether a Boost library is usable depending on the C++ standard mode their are using.