[jeremyjh]

When I first learned Rust I'd been writing Haskell in serious side projects for four years, and had used C++ at work as well as a game project and was quite familiar with it (I'm not sure C++ is ever comfortable). Practically every feature in Rust other than the borrow checker was thus already known to me, and I still found Rust a quite significant learning curve, though to be fair I probably also learned about some things in C++ that looked safe but weren't.