Bill Hoffman, CTO @ Kitware creator of CMake 1 import CMake; // Mastering C++ Modules2 _____________________ GUY CMake / Sandal / Kitware Bill Hoffman3 About Me • 1990-1999 GE research in a Computer // Mastering C++ ModulesEnough with the Background Let's Talk Modules! 7C++ Named Modules Only 8 See Daniel Ruoso talk: "C++ Modules: The Challenges of Implementing Header Units" From C++ Now 20239 -std:c++20 -interface -c A.cpp A.cpp $ ls A.cpp A.ifc A.obj B.cpp B.ifc B.objChicken and the Egg • Modules require the build system to know which files produce which BMI files and which files consume them

1Daniela Engert - CppCon 2021 Modules demystified and applied A (SHORT) TOUR OF C++ MODULES 2ABOUT ME Electrical engineer Build computers and create software for 40 years Develop hardware and 30 years Member of the C++ committee (learning novice) employed by 3OVERVIEW Modules Foundations C++20 Modules, a short recap Module unit types and Module composition Visibility of Identifiers linkage and linker symbols Modules in practice Moving towards modules (by example) Imports are different! Is it worth it? (a case study) The state of the ecosystem 4C++20 MODULES a short recap 5source

1/50 C++ Modules - Getting Started Today Andreas Weis Woven by Toyota CppCon 20232/50 Introduction3/50 About me - Andreas Weis (he/him) ComicSansMS Co-organizer of the Munich C++ User Group Currently // [...]10/50 Hello Modules! — File: module.cpp export module my_module; export char const* my_function () { return "Hello Modules!"; } — File: main.cpp #include import S{}; }16/50 Daniela Engert - The three secret spices of C++ Modules - Visibility, Reachability, Linkage17/50 Different shapes of modules18/50 Primary Module Interface Unit — File: my module.cpp export

C++20 Modules: The Packaging and Binary Redistribution StoryScope ● Brief introduction on C++ modules and their advantages ● Focus on named modules ● Using modules today ○ Can we package module-ready world!\n"); }Why use modules In short: better isolation - some advantages to headers: ● Importers cannot affect the contents of the module being imported ● Imported modules cannot affect the state Ordering of imports does not matter ● Potential for improved build times (more on this later)Why use modules (cont’d) wirepair.org C:\path\to\include\fb/verifier.h(38,23): warning C4003: not enough arguments

Implementing C++ Modules: Lessons Learned, Lessons Abandoned Gabriel Dos Reis & Cameron DaCamara MicrosoftOverview 2 (C) Dos Reis & DaCamara; CppCon 2021C++ Modules Design Goals 1. Componentization Named modules provide ODR guarantees, by design – Header files and header units require (expensive) incomplete ODR checks, and demand complete trust 4 (C) Dos Reis & DaCamara; CppCon 2021Modules and ODR hunt” (C) Dos Reis & DaCamara; CppCon 2021 6The Global Module ▪ Everything we used to do before Modules – Merry mess ▪ Provide no ODR guarantees – Responsibility of the programmer ▪ Complete ODR check

systems which use CMake ○ C++ modules support ● Working with the community to improve building software ○ ISO standards ■ Dependency format ○ Pushing forward modules support in other build systems systems ■ xmake ■ bazel 2Outline 1. What are compilation databases? 2. How do modules change the status quo? 3. Build databases 3Compilation Databases: Overview ● JSON document ● Array of JSON objects files) ● C++ modules… Compilation Databases: Limitations 2 9C++ Modules on the Scene ● Modules complicate C++ compilation ○ Surprise! 🎉 ○ Basically inherit the Fortran 90 modules compilation model

Why do I care about reflection even more?• Implement reflection • Go over current techniques • Modules • Patterns and Tricks for runtime reflection 9 How do we get there?• Go from client API 1 0 put in source C++ compilation process• “Modules are a tooling opportunity” - Gabriel dos Reis • Fast! Work already happened 2 4 What happens with modules?2 5 • No further context needed • In theory add_executable(TheExe) target_link_libraries(TheExe PUBLIC MyProject MyProject_ReflectionData )• Only modules • No user attributes • BMI filename query 3 1 Trivial Ifc limitations• Templates not instantiated

complete • C++23 • Standard library modules • std::print • Ranges: • to • zip and enumerate • cartesian_product 🕙 Coming next for C++23 • Deducing this (modules support) • 9 remaining C++ STL features 915 505 272 878 1059 2886 0 500 1000 1500 2000 2500 3000 3500 Unreal Engine 5 TensorFlow Blender AAA Game 3 AAA Game 2 AAA Game 1 Time in Seconds (Lower is better) VS 17.5 VS 17.7In Visual individual solutions for better collaboration Coming Soon: View Instruction Pointers for functions in modules view. Breakpoint Groups Visit https://aka.ms/BreakpointGroups for more details Dependent Breakpoint

CUDA 编译器，链接 OpenVDB 在 Blender 中查看导出的结果 边界条件 边界条件：初始化 边界条件：添加判断边界的版本 边界条件：仅在第一层额外判断边界条件 进一步改进 VDB 导出：支持导出多个网格，并指定名称 进一步改进 VDB 导出： P-IMPL 模式 进一步改进 VDB 导出： F-IMPL 模式 Blender 渲染结果 改进 改进边界条件：外部边界流出而不是反弹，内部边界可以流出速度 改进边界条件：外部边界流出而不是反弹，内部边界可以流出速度 Blender 中调整一下材质 Blender 中调整一下材质 改进对流：让烟雾随时间逐渐褪色 改进对流：让烟雾随时间逐渐褪色 改进褪色：不是褪色 density ，而是褪色 temperature 改进褪色：不是褪色 density ，而是褪色 temperature 改进褪色：不是单纯地乘以 decayRate ，还和周围环境温度求平均值

pattern is actually used ○ grep -irn “factory” . ● The answer is yes! ● https://github.com/blender/blender ● ● ●Factory Method/Pattern Usage (5/6) 81 ● I dug around a few open source projects to see