C++20 Modules, 5 Years Later

on YouTube ↗01h 08m

" summary

C++20 modules cut compilation work by prebuilding interfaces so repeated preprocessing and parsing are avoided, showing 20–70% faster results in the presenter’s microbenchmarks (50 files: 2.6s→2.1s; 100 files: 10s→3s) and a Boost test rebuild case (200 TUs: headers rebuild 2m10s → modules 39s). Compilers advertise support (GCC 14 / Clang 16 / MSVC), but Apple Clang lags, module artifacts are not portable between compilers or versions, CMake has partial support (3.28+), and package managers remain immature though fetchcontent can work.

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" chapters (15)

1. 0:00C++20 modules intro
2. 1:13What C++20 modules are
3. 3:01Why modules replace headers
4. 8:19Modules speed compilation
5. 16:33Fragile dependencies leak
6. 21:53Writing a simple module
7. 27:15Splitting modules into partitions
8. 31:58Compiler and build support
9. 35:47Library package challenges
10. 41:05Tooling limits and UX
11. 45:18Build system experience
12. 50:20Scanning module deps
13. 52:52Live demo: dep scanning
14. 57:06Conclusion and future
15. 1:00:19Q&A on modules

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