#[derive(Debug)]
struct Foo {
    val: u8,
}

fn main() {
    let mut f = Foo { val: 0 };
    let mut funcs: [Box<dyn FnMut()>; 3] = [
        Box::new(|| { f.val = 3; }),
        Box::new(|| { f.val = 10; }),
        Box::new(|| { f.val = 1; }),
    ];

    for fun in &mut funcs {
        fun();
    }

    println!("{:?}", f);
}