1use my_stack::Stack; 2 3fn main() { 4 let mut stack = Stack::new(); 5 6 stack.push(1); 7 stack.push(2); 8 stack.push(3); 9 10 println!("{:?}", stack); 11 let sum = stack.iter().sum::<i32>(); 12 println!("sum: {}", sum); 13}