I read through the Rust book, and the problem I was having with it and the other docs is that it was hard to map the Rust concepts with what actually runs when it is compiled. For a language that touts "uncompromising performance", it was difficult for me to find performance characteristics of the underlying abstractions and std library (for example, are algebraic data structures just tagged unions or does the compiler do more fancy things with them? What about iterators?). I'd really like to see a "Rust for C/C++ devs" guide that helps you figure out if you were using [some C++ feature] the way to get that behavior/performance with idiomatic Rust.

Another thing that is still tricky for me is figuring out when I should use 'unsafe' blocks in my code. Is it to be avoided if at all possible, or should I go there any time the 'safe' part of the language is making it difficult to express what I want? The meme that Rust is C++ without SegFaults and or race conditions is a bit misleading since the actual guarantee is that you don't get SegFaults or Race conditions outside of Unsafe blocks, and any nontrivial project will make use of unsafe blocks.

I haven't had to resort to "unsafe" blocks in the Rust I have written so far but "ffi" is one use case for unsafe blocks. Another resource that I have yet to read is "https://doc.rust-lang.org/nomicon/" which seems to explain how to write unsafe Rust code.