Not just any c++, I'd recommend performance aware modern c++. It leads towards the functional-ish zero-copy lock-free thinking rust rewards. I've been told ocaml or f# programmers also find rust easy.
I think there are definitely aspects of Rust that OCaml/F# developers would find easy because it borrows a lot of syntax and concepts from ML. But to be honest those bits are the easy parts or Rust. Knowing OCaml or F# won't help with the borrow checker.
I think C++ programmers are probably the ones that are likely to find Rust easiest because they should be familiar with lifetimes even if they never really had to write them down.
I think C++ programmers are probably the ones that are likely to find Rust easiest because they should be familiar with lifetimes even if they never really had to write them down.