I think it is a huge waste of time for anyone to discuss or implement a CMake solution for Boost until the Boost Steering Committee actually gets involves and defines what "Boost using CMake" actually means and gives the specifics as to what this actually entails. Otherwise nearly everything said about Boost and CMake, although well-intentioned, is just a lot of hot air and we are going absolutely nowhere trying to make any progress in this so-called direction. The Boost Steering Committee is largely at fault for saying that Boost would be using CMake, without defining what this actually means. Once again, as in our discussion about Boost dropping support for C++03, we are all wasting our time because the meaning of some language having been used is not clear and way too general to reach any meaningful conclusions. But in this case the only people who can really define what Boost using CMake actually means is the Boost Steering Committee, or someone representing the Boost Steering Committee on this mailing list, who can clarify what Boost using CMake is actually about, since it was the Boost Steering Committee who made the decision in the first place. If it is not the case that the Boost Steering Committee defines what Boost using CMake actually is supposed to mean but rather it is up to those on this mailing list to decide the issue, I would argue that Boost should focus on the simplest solution first, making Boost libraries, whether header-only or not, available for use in end-user CMake scripts in such a way that it will be easy to add this functionality for the 130 or so individual Boost libraries with the least amount of effort or work involved for each library, without arguing unduly about more complicated or more purist solutions. In other words lets start with the easiest, most practical solution, because I assure you when the smoke has cleared, 99% of those people involved in the discussion will not want to do the practical work of actual adding necessary CMake scripts to any of the 130 or so libraries involved, and even the maintainers of those libraries will not want to spend much time implementing some complicated CMake solution for their library. But I still think that without a specific definition of what Boost using CMake actually entails from the steering committee we are just wasting time and breath and to no good purpose.