An implemenation of a CLOCK cache as first described in A Paging Experiment with the Multics System.
Below is a simple example of how to instantiate a CLOCK cache.
extern crate clock_cache;
use clock_cache::ClockCache;
fn main() {
let mut cache = ClockCache::new(2);
cache.put("apple", "red");
cache.put("banana", "yellow");
assert_eq!(*cache.get(&"apple").unwrap(), "red");
assert_eq!(*cache.get(&"banana").unwrap(), "yellow");
assert!(cache.get(&"pear").is_none());
cache.put("pear", "green");
assert_eq!(*cache.get(&"pear").unwrap(), "green");
assert_eq!(*cache.get(&"banana").unwrap(), "yellow");
assert!(cache.get(&"apple").is_none());
}