[richardwhiuk]

The former code is more equivalent to:

  let file = match file {
    Some(file) => file,
    None => panic!("file was null");
  };

[timidger]

Which you'd never write in practice since `expect` exists

[vikiomega9]

Can you say more here, I don't have the context.

[steveklabnik]

This code is identical to

  let file = file.expect("file was null");

That is, the "expect" method does exactly this.

[jeswin]

I like Rust from what I've tried. But I'd have preferred something like this:

  let file = file.unwrapOrPanicWith("file was null");

option.expect(message) doesn't semantically make sense.

[steveklabnik]

There was some discussion about this when the method was named; you're not alone. In the end, it is what it is. You could define your own method like that if you really wanted to.

[jack1243star]

I read it as expect (prepare) for the worst!