[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!