[Rust] Vector manipulation demo.

fn main() {
    // Declare an empty vector
    let mut vec = Vec::new();

    // Append data to the tail of the vector
    vec.push(1);
    vec.push(2);
    vec.push(3);

    // Get the length of the vector
    assert_eq!(vec.len(), 3);

    // Pop data from the tail of the vector
    let popped = vec.pop().unwrap();
    assert_eq!(popped, 3);
    assert_eq!(vec, vec![1, 2]);

    // Insert data into the middle of the vector
    vec.insert(1, 99);
    assert_eq!(vec, vec![1, 99, 2]);

    // Remove data from the middle of the vector
    let removed = vec.remove(1);
    assert_eq!(removed, 99);
}