Re:My Favorite C++ Pattern: X Macros (2023)
by rogual on Tuesday March 25, 2025 @10:56PM
(#43478405)
This is what I do, these days. Whenever I would previously have reached for X-macros or some other macro hack, I tend to use Cog [1] now instead.
It's quite a clever design; you write Python to generate your C++ code and put it inside a comment. Then when you run the Cog tool on your source file, it writes the generated code directly into your C++ file right after your comment (and before a matching "end" comment).
This is great because you don't need Cog itself to build your project, and your IDE still understands your C++ code. I've also got used to being able to see the results of my code generation, and going back to normal macros feels a bit like fiddling around in the dark now.
It's quite a clever design; you write Python to generate your C++ code and put it inside a comment. Then when you run the Cog tool on your source file, it writes the generated code directly into your C++ file right after your comment (and before a matching "end" comment).
This is great because you don't need Cog itself to build your project, and your IDE still understands your C++ code. I've also got used to being able to see the results of my code generation, and going back to normal macros feels a bit like fiddling around in the dark now.
[1] https://nedbatchelder.com/code/cog/