use std::mem::MaybeUninit;
use std::sync::Once;

static mut VAL: MaybeUninit<usize> = MaybeUninit::uninit();
static INIT: Once = Once::new();

pub fn init() {
    INIT.call_once(|| {
        unsafe {
            VAL = MaybeUninit::new(5);
        }
    });
}

fn main() {
    init(); // init is always called before access, I just care for the safety of using MaybeUninit here

    let a = unsafe {
        VAL.assume_init()
    };

    println!("Value: {}", a);
}