#![allow(unused_variables)]
#![feature(binary_heap_peek_mut_refresh)]
fn main() {
    use std::collections::BinaryHeap;
    let mut heap: BinaryHeap<u32> = (0..128).collect();
    let mut peek = heap.peek_mut().unwrap();
    loop {
        *peek = 99;
        if !peek.refresh() {
            break;
        }
    }
    assert!(* peek < 100);
}