fn main() {↵
let mut nums = vec![3, 1, 4, 1, 5, 9, 2, 6];↵
↵
println!("len: {}", nums.len());↵
println!("is_empty: {}", nums.is_empty());↵
println!("first: {:?}", nums.first());↵
println!("last: {:?}", nums.last());↵
println!("get(2): {:?}", nums.get(2));↵
↵
nums.reverse();↵
println!("reversed: {:?}", nums);↵
↵
nums.retain(|&x| x > 3);↵
println!("retain > 3: {:?}", nums);↵
↵
let mut other = vec![10, 20];↵
nums.append(&mut other);↵
println!("after append: {:?}", nums);↵
}