I have several small C++ projects that now use C++23 with modules, using clang++ 19.1.7 and cmake 3.31.6. Since this discussion is six months old and the GH issues (#15496 linked above and the newer #25110) end about three months ago, I’m quite interested in finding out the current thinking on enabling support for C++ modules. I have zero knowledge of the Zig C++ compiler implementation, but it seems to me that in order to support C++ modules, Zig would have to do something akin to what CMake implemented, i.e., scan the source files to determine inter-module dependencies (which are saved to “.ddi” files) so that it can figure out the correct compilation order.