#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#![feature(set_ptr_value)]
use core::fmt::Debug;
fn main() {
    let mut arr: [i32; 3] = [1, 2, 3];
    let mut ptr = arr.as_mut_ptr() as *mut dyn Debug;
    let thin = ptr as *mut u8;
    unsafe {
        ptr = thin.add(8).with_metadata_of(ptr);
        assert_eq!(* (ptr as * mut i32), 3);
        println!("{:?}", &* ptr);
    }
}