Description
hello,
Thank you for your work on this library!
Based on the documentation, I had thought that changing the priorities of items in the course of iterating over them via iter_mut would update their priority rankings in the queue. However, unless I am missing something, that does not seem to be the case.
Here is a simple example of what I mean in the form of a test:
#[cfg(test)]
mod tests {
use std::time::*;
#[test]
fn verify_how_priority_queue_works() {
let mut queue: priority_queue::PriorityQueue<&'static str, Duration> = Default::default();
queue.push("a", Duration::new(0, 0));
queue.push("b", Duration::new(0, 1));
assert_eq!(queue.peek().unwrap().0, &"b");
for (k, v) in queue.iter_mut() {
if k == &"a" {
*v = Duration::new(0, 2);
}
}
assert_eq!(queue.peek().unwrap().0, &"a"); // this assertion fails
}
}the peek call instead returns the "b" item.
if this test is modified to use queue.change_priority("a", Duration::new(0, 2)) rather than assigning to the priority as it is above, the return value of peek is "a" as expected.
The docs say:
It's not an error, instead, to modify the priorities, because the heap will be rebuilt once the IterMut goes out of scope.
Based on this, I had thought that changing the value of the priority when iterating over the queue via iter_mut would work the same as change_priority.
Could you tell me if this a bug, or a misunderstanding of how `PriorityQueue works?
what would be a good way to update all of the priorities at once?
thank you for your help on this!