Hey hey! So, this specific example has nothing to do with auto dereferencing in the language. It's that Display, implemented for &T, displays the value instead of the reference. This is what you want 99% of the time, so Rust is trying to Do The Right Thing here. If you want to print out the numeric version of the pointer, {:p} will do it. It's a bit tough to document specific implementations at the moment, so it's certainly not as clear as it could be. you're right.

( For reference, this implementation is here: https://github.com/rust-lang/rust/blob/master/src/libcore/fm... note that this is in a macro to do this for all of the traits at once...)

I'm actually re-writing the book right now, and one of the things I'm focusing hard on is the stuff around ownership and borrowing. The current chapters are too abstract, the new ones are focused on String/&str. You can find that here: http://rust-lang.github.io/book/ch04-00-understanding-owners...

  > "You almost never want to pass a variable by value".

So, the issue with advice like this is that it's not always true: you almost never want to pass some things by value, but Copy types, for example, you almost always want to pass by value. It's tricky!

That said, it's true that learning Rust can be tricky; we're trying to focus on improving that in the coming year. So keep it coming! This kind of feedback is very helpful, thank you.