I have only briefly dabbled in Rust so I might be mistaken here - it seems hard to replace the major languages when there is so much tooling (ides, profiling tools) and such a developed ecosystem with the incumbent languages. C#, Java and Node are also a lot easier to write than Rust in my opinion. C++ is what it should replace, except it’s not clear that Rust is as fast for performance-oriented applications, and if that’s what you care about and c++ has a greater ecosystem… maybe it’s a hard sell.
Though I would say it’s easier that C++ to deal with and would expect this would help it win a larger share in systems programming. Eventually
> C++ is what it should replace, except it’s not clear that Rust is as fast for performance-oriented applications
I don't think that's true, at least not in a way that matters in practice. Sure, from time to time there's an article about a micro-benchmark in which carefully optimized C++ is 10% faster than carefully optimized Rust. Well, my users don't run micro-benchmarks, they run applications, and with Rust it's much easier and faster to experiment with macro-scale optimizations, which have a real impact on performance.
Case in point, recently I took a single-threaded CLI program and made it multi-threaded by spawning some threads and adding a work queue. There, instant 300% speedup, just add water. Yes, I could have done the same with C++, but it would have taken much longer to make sure I didn't introduce some concurrency bug in my code – and only on the condition that the libraries I was using could be used from multiple threads simultaneously, which is far from certain in the C and C++ ecosystems.
Though I would say it’s easier that C++ to deal with and would expect this would help it win a larger share in systems programming. Eventually