gistfile1.txt

$ rustc main.rs 
main.rs:22:7: 22:16 warning: unused variable: `prev_fib`
main.rs:22 		let (prev_fib, curr_fib) = (curr_fib, curr_fib+prev_fib);
                  ^~~~~~~~~
main.rs:22:17: 22:26 warning: unused variable: `curr_fib`
main.rs:22 		let (prev_fib, curr_fib) = (curr_fib, curr_fib+prev_fib);
                            ^~~~~~~~~

main.rs

let mut prev_fib = 0;
let mut curr_fib = 1;

while curr_fib < 1000 {
    io::println(#fmt("%u", curr_fib));
    let (prev_fib, curr_fib) = (curr_fib, curr_fib+prev_fib);
}