#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn main() {
    let a = [1, 4, 2, 3];
    let sum = a.iter().cloned().filter(|x| x % 2 == 0).fold(0, |sum, i| sum + i);
    println!("{sum}");
    let sum = a
        .iter()
        .cloned()
        .inspect(|x| println!("about to filter: {x}"))
        .filter(|x| x % 2 == 0)
        .inspect(|x| println!("made it through filter: {x}"))
        .fold(0, |sum, i| sum + i);
    println!("{sum}");
}