Is there a more concise way to format .expect() message?

I currently have to use this to format a .expect() message:

fn main() {
let x: Option = None;
x.expect(&format!("the world is ending: {}", "foo")[..]);
}


Is there a less verbose way?

First you don't need to write [..]

If you really want to panic but also want to format the error message, I think I would use assert!():

fn main() {
let x: Option = None;
assert!(x.is_some(), "the world is ending: {}", "foo");
let _x = x.unwrap();
}


If you want you could also use the unwrap crate:

use unwrap::unwrap;

fn main() {
let x: Option = None;
let _x = unwrap!(x, "the world is ending: {}", "foo");
}


Also, both these methods avoid the construction of the error String every time, unlike calling expect() with format!().

Stack Overflow Q#55513198, score: 13