Incremental compilation is something that no major compiler for any ahead-of-time compiled language anywhere does. It's one of the most advanced features in any compiler, and as such it's taking time to implement. No C++ compiler I know of is even thinking of it.
As the first post here in this thread mentions, going down the C++ road of header files might have gotten us some short term wins, but ultimately it hits a brick wall. Incremental compilation is inescapable.
A lot of things did happen. One of them is having the option to check the source which is much faster than compiling. 99% of the time you're compiling code in rust is to run the borrow checker and fix those errors.
That's indeed something where Rust is a lot better than C++. But for many projects (like games or GUI apps) you'll need to iterate with changes which can only be seen in the final product. So you'll need a complete build to run the binary.
Fair enough. However games and GUI apps are still a small percentage of applications developed in rust. I want that to change, of course. I just wanted to point that out.
I'm personally writing a game in Rust but the main logic is written in a compile-to-JS language and uses V8, so the issue doesn't affect me.
Yeah, last time I've tried it (a few months ago) incremental build times where a lot slower for a full rebuild and only about 10 % faster when touching a single rs file. I've already found a few issues and it seems you guys are working on it :)
But as of now: C++ incremental build times (with the right build system) are a lot better than Rust's.