Graydon Hoare, a former C++ programmer on Mozilla Firefox and the original creator of Rust, acknowledges that for many people, Rust has become a viable alternative to C++ :

https://graydon2.dreamwidth.org/307291.html

And on slide #4, he mentions that "C++ is well past expiration date" :

https://venge.net/graydon/talks/intro-talk-2.pdf

It's possible that Graydon's earliest private versions of Rust the 4 years prior to that pdf were an OCaml-inspired language but it's clear that once the team of C++ programmers at Mozilla started adding their influences, they wanted it to be a cleaner version of C++. That's also how the rest of the industry views it.

> Rust has become a viable alternative to C++

Alternative yes, derivative no. Rust doesn't approach C++'s metaprogramming features, and it probably shouldn't given how it seems to be used. It's slightly self-serving for browser devs to claim Rust solves all relevant problems in their domain and therefore eclipses C++, but to me in the scientific and financial space it's a better C, making tradeoffs I don't see as particularly relevant.

I say this as a past contributor to the Rust std lib.