#![allow(unreachable_code)]


fn main() {
    println!("{:?}", {
        use std::mem::replace; pub fn fibonacci() -> impl Iterator<Item=u128> { let mut (a, b) = (0, 1); std::iter::from_fn(|| replace(&mut a, replace(&mut b, a + b))) }
    });
}


/* ~~~~=== stderr ===~~~~
   Compiling playground v0.0.1 (/playground)
error: expected identifier, found `(`
 --> src/main.rs:6:89
  |
6 |         use std::mem::replace; pub fn fibonacci() -> impl Iterator<Item=u128> { let mut (a, b) = (0, 1); std::iter::from_fn(|| replace(&mut a, replace(&mut b, a + b))) }
  |                                                                                         ^ expected identifier

warning: unused import: `std::mem::replace`
 --> src/main.rs:6:13
  |
6 |         use std::mem::replace; pub fn fibonacci() -> impl Iterator<Item=u128> { let mut (a, b) = (0, 1); std::iter::from_fn(|| replace(&mut a, replace(&mut b, a + b))) }
  |             ^^^^^^^^^^^^^^^^^
  |
  = note: #[warn(unused_imports)] on by default

error: aborting due to previous error

error: Could not compile `playground`.

To learn more, run the command again with --verbose.

*/

/* ~~~~=== stdout ===~~~~

*/