A coworker found a stack use after free in production that no amount of linters or tidyers caught. It only actually happened in the release build, and asan caught it, but only when we pushed to 100% branch coverage instead of just line coverage. Rust makes coverage much easier to get with fewer tests due to it's type system. It seems really clear to me that rust will be the c++ successor. If you need that extra flexibility, you use unsafe. That still feels less foot gun ridden than c++. The slow adoption of rust is because c++ interoperability is bad and people are stuck maintaining c++ behemoths. Green field rust adoption in c++ domains is much higher. Zig is more of a c replacement, but as much as I like it, I don't think that will happen. C is like a standardized ir. But when sonos wanted to make an arm cpu only onnx inference engine for instance, they made it in rust (tract). When c++ developers get to choose rust, we often do. I can throw earlier career c++ devs with modern c++ experience directly into a rust codebase and have them be immediately productive, but also not worry about them doing horrible things.
Yeah, you and I are both entitled to our guesses about Rust and Zig respectively in the future. Both have serious production projects (bun and TigerBeetle are best-in-class to head off any "hobby project" stuff), neither is making serious inroads to the domains I'm talking about: it doesn't get any hotter than the new CUTLASS stuff, and that's greenfield modern C++ with a standardization regime (mdarray) with 100% industry voting as a bloc for "it's still modern C++ at the frontier". HFT shops have at least some Rust at least auditioning, but the reqs are still C++, and they rewrite anything that alpha decays out.
When it's for all the marbles today? It's C++. The future is an open question, but a lot of us are pushing hard for C++.
