Great article.

I've never used Rust before so I'm exactly the target audience. I first got tripped up around

> Trait methods can also take self by reference or mutable reference:

  impl std::clone::Clone for Number {
    fn clone(&self) -> Self {
        Self { ..*self }
    }
  }

What's the asterisk doing in this code? I guess it's destructuring the struct somehow, but I don't see that syntax elsewhere: destructuring was introduced but looked like it worked without the star. Alternatively, it's dereferencing the reference, but that seems less likely.