C++ modules

[friendlyanon]

This issue is just for tracking the progress of modules.

At the moment, no generally available compiler seems to properly support modules.

CMake is also designing its API to properly integrate C++ modules: https://discourse.cmake.org/t/api-design-c-modules-source-listings-and-interface-properties/5389

[ClausKlein]

Starting with CMake v3.28 the Module support in stable.

MS VC 2022 und clang-17 are fully working.

[friendlyanon]

Based on comments in https://old.reddit.com/r/cpp/comments/1b0zem7/what_is_the_state_of_modules_in_2024/ things aren't quite there yet. I have to also take care that things can be run in CI, so GitHub Actions also needs the necessary infra to enable that. Best I can do once compilers are better with modules is put up an example repository with custom tooling on the wiki page.

[ClausKlein]

see too https://discourse.cmake.org/t/installed-module-library-cant-find-imported-headers-ubuntu-22-04-lts-cmake-3-28-1-ninja-1-11-1-and-clang-17-0-6/9819/23
and my example https://github.com/ClausKlein/cmake-module-error

[ClausKlein]

How can I help to go forward to implement this issue?

see too https://discourse.cmake.org/t/building-installing-and-consuming-shared-libraries-with-c-20-modules/10576

[friendlyanon]

I'll only add modules stuff to the templates once import std; works in GitHub Actions with the pre-installed toolchains. AFAIK, libstdc++ hasn't even been modularized yet.

[ConorWilliams]

Looking forward to this

[ClausKlein]

I got the CXX_MODULE work for the fmt and partly for asio library:

https://github.com/ClausKlein/fmt-module