But then your code can't be used by anyone without your preprocessor. There is a lot of value in plain C metaprogramming because it can be compiled with an ordinary C compiler.

You can, however, use a script to generate some of the preprocessor boilerplate while still having the templates configurable and instantiable with an ordinary C compiler. This is how my metaprogramming library Pottery works:

https://github.com/ludocode/pottery

It uses #include for templates rather than code block macros, something the article doesn't really go into. It's more powerful this way and the templates are far more readable; aside from the generated metaprogramming boilerplate, the templated code looks like (and preprocesses to) ordinary C.

Let me preface this with: I’m not a Rust fanatic (I still like C#). But Rust’s “procedural macros” are pretty interesting. They’re not just regular typed macros (which Rust has), but a function that takes a token stream and outputs a new token stream. This allows pretty cool macros like hex! for example: https://docs.rs/hex/0.4.2/hex/

So basically create your own language + compiler that compiles to C?

Or use Nim, which compiles to C :)

To each their own :)

Yes, its less work