On 12/01/2025 20:51, Ruben Perez via Boost wrote:
Hi all,
I finally have something workable regarding Boost and C++20 modules. I've described it in detail in this article [1], but here's a rough summary:
Wow, thank you for this, that's a brilliant first step and proof of principle. I have a few comments, many of which are about things over which we/you have no control! 1) Are the CMake files usable with older CMake versions? 2) The lack of Visual Studio generators for CMake is annoying: by far the best user experience is likely to come from Visual Studio integration as that handles module dependencies very well. 3) The need for a separate object file even for header only libraries is annoying, it leads to all kind of issues: 3a) We're going to end up generating an awful lot of module import initializer libraries. 3b) Using Boost with modules may be untenable, without using CMake to handle the dependencies: given that Boost.Whatever may have no end of dependencies all of which will need to be manually specified on the command like otherwise. For a large project with multiple Boost dependencies things explode even further. We're between a rock and hard place here, as I don't see a single monolithic Boost module as a good solution either. But as things stand, building a trivial hello-world using-boost-as-module app from the command line could well be a no-no. 3c) I wonder what impact a dependency on lots of small modules will have on build times: both pre-compile module dependency-scanning phase, and linking to all those micro-libraries. Best, John.