src/tools/miri/tests/pass/static_mut.rs

// FIXME(static_mut_refs): Do not allow `static_mut_refs` lint
#![allow(static_mut_refs)]

use std::ptr::addr_of;

static mut FOO: i32 = 42;

static BAR: Foo = Foo(addr_of!(FOO));

#[allow(dead_code)]
struct Foo(*const i32);

unsafe impl Sync for Foo {}

fn main() {
    unsafe {
        assert_eq!(*BAR.0, 42);
        FOO = 5;
        assert_eq!(FOO, 5);
        assert_eq!(*BAR.0, 5);
    }
}