C++20 Modules with MSVC and Clang, Using CMake
This repository provides a guide on how to use C++20 modules with both the MSVC and Clang compilers in CMake projects. C++20 modules with CMake is an experimental feature that allows for improved code organization, faster builds, and better encapsulation compared to traditional header files and preprocessor-based inclusion.
Above all, modularisation is a modern feature in many newer programming languages. This git repo wil help you practice using this new C++ feature.
Prerequisites
Before proceeding, ensure that the following tools and versions are installed on your system:
- CMake (version 3.25 or later)
- A recent version of MSVC
- Clang compiler (16 or above)
Building with MSVC Compiler
TODO : See what flags are needed for CMake, as well as extra compiler flags - Create the right preset
Building with Clang Compiler
TODO : Create the right preset and add it to here
Notes
C++20 modules are still an experimental feature in both MSVC and Clang compilers. In addition, it is also an experimental feature in CMake.
Therefore, some features may not be fully supported or might behave differently compared to traditional header files. Always check the compiler documentation and release notes for updates on the status and stability of C++20 modules. For your convenience, the list in the folllowing section provides useful resources regarding the support of modules in CMake and the main compilers.
- CMake's modules support article (a must read)
- Compiler feature support for checking which compiler versions support modules. As a quick check, look out for "Standard Library Modules", as when this is supported by your compiler, modules will probably be somewhat stable in that version.
REMOVE-ME: Notes for the video
General comment
Important GUID selection for the right CMake: https://github.com/Kitware/CMake/blob/v3.26.0-rc2/Help/dev/experimental.rst
GCC Modules
Really hard to get a version that supports the features needed for modules. There seems to be a patched version, which is now quite out of date compared to the current trunk.
You will get the "unsupported flag...." pointing to the dependency scanning files if yout GCC version does not support modules.
CMake hacks required seem to be a lot more cumbersome compared to the Clang & MSVC versions.
Clang Modules
The earliest version supporting modules fully seems to be 16. Need to go through hoops if you want to install in Ubuntu 18/22
Integration seems pretty good, however no standard library import modules, so you still need the include.
No hard CMake hacks are needed for module support with Clang, apart from setting the experimental features and the correct GUID thing.
MSVC
TODO
Contributing
If you would like to contribute to this repository, please follow the standard GitHub fork and pull request workflow.
License
This project is licensed under the MIT License.