Hi, I'm planning to apply an ABI breaking change to the Boost.Any https://github.com/boostorg/any/pull/11 That PR makes the binaries that use boost::any smaller. For example libboost_program_options.so looses 4KB in size. Boost libraries were not guaranteeing ABI stability, but boost::any is quite often used across library boundaries. Double checking that there's no objections.