#![allow(unused_variables)]
#![feature(allocator_api)]
#![feature(get_mut_unchecked)]
fn main() {
    fn _inner() -> core::result::Result<(), impl core::fmt::Debug> {
        use std::rc::Rc;
        let mut five = Rc::<u32>::try_new_uninit()?;
        Rc::get_mut(&mut five).unwrap().write(5);
        let five = unsafe { five.assume_init() };
        assert_eq!(* five, 5);
        Ok::<(), std::alloc::AllocError>(())
    }
    _inner().unwrap()
}