#![allow(dead_code, deprecated, unused_variables, unused_mut)]
use std::{ptr, mem::MaybeUninit};
struct Demo {
    field: bool,
}
fn main() {
    let mut uninit = MaybeUninit::<Demo>::uninit();
    let f1_ptr = unsafe { ptr::addr_of_mut!((* uninit.as_mut_ptr()).field) };
    unsafe {
        f1_ptr.write(true);
    }
    let init = unsafe { uninit.assume_init() };
}