Well, rust is beating g++ in the benchmark game now. [1] (please don't take microbenchmarks seriously) Performance is complicated, rust has a couple of things going for it that will help out a lot. First, there's a pretty strong bias to use the stack. As opposed to java or scheme where stuff is heap allocated by default. Second, rust avoids the pointer aliasing problems of c and c++. When someone gets around to making a fast matrix library, it'll likely take much much less time to catch fortran than c++ took.

But again, performance is complicated. People have put tens of thousands of hours into c/c++ optimization. rust is young, so not so much time there. On the upside, rust has room to grow.

https://benchmarksgame.alioth.debian.org/u64q/which-programs...