Rust is used in production by hundreds of companies, from ones as large as Facebook, Amazon, and Microsoft, down to tiny new startups.

The visual tooling is still very meh though. Just compare the kind of code completion you get for C++ (even something as gnarly as Boost) in modern IDEs, to what RLS can do in VSCode.

IntelliJ is heavily investing, and it’s already showing. We are too: https://ferrous-systems.com/blog/rust-analyzer-2019/

But yeah, if that matters to you, it’s less mature. We’ll get there!

As is C++ at all of those companies.

Sure. The question was if Rust was production ready, it has nothing directy to do with C++. Everyone knows C++ is production ready.

What is the state of UI bindings?

GTK is coming along really well. There’s two different native-to-Rust ones in progress I’m excited about. It’s not my area of specialty though.

I wouldn't say that d "doesn't have a straight story on garbage collection." It's solidly a garbage-collected language, and although there is interest in changing it, it's not there yet. D isn't entirely stable (features regularly get deprecated and then removed over the course of 5-10 versions), but why do you say it isn't reliable?

D's creator said himself (in the link I posted) that its garbage collection implementation is lackluster.

To clarify, I didn't necessarily mean that D is not reliable, just that it doesn't have the combination of stable+reliable+supported that C++ enjoys.