#![allow(unused_variables)]
#![feature(allocator_api)]
fn main() {
    use std::rc::Rc;
    use std::alloc::System;
    let five = Rc::new_in(5, System);
    unsafe {
        let (ptr, _alloc) = Rc::into_raw_with_allocator(five);
        Rc::increment_strong_count_in(ptr, System);
        let five = Rc::from_raw_in(ptr, System);
        assert_eq!(2, Rc::strong_count(& five));
        Rc::decrement_strong_count_in(ptr, System);
    }
}