1use trace_var::trace_var; 2 3fn main() { 4 println!("{}", factorial(8)); 5} 6 7#[trace_var(p, n)] 8fn factorial(mut n: u64) -> u64 { 9 let mut p = 1; 10 while n > 1 { 11 p *= n; 12 n -= 1; 13 } 14 p 15} 16