The first paragraph of the chapter on unsafe rust in TRPL reads:
> However, Rust has a second language hidden inside it that doesn’t enforce these memory safety guarantees: it’s called unsafe Rust and works just like regular Rust, but gives us extra superpowers.
I disagree that “{ X }” and “unsafe { X }” are the same. The former is provably safe if a bug free rust compiler accepts it. The latter leaves the burden of proof on the programmer.