IdMap is a container that gives each item a unique id. Adding and removing by index is O(1).

Examples

#
let mut map = IdMap::new();
let blue_id = map.insert("blue");
let red_id = map.insert("red");

map.retain(|_, &color| color != "red");

assert!(!map.contains(red_id));
assert_eq!(map[blue_id], "blue");

id-map

See also slab or slotmap for a better optimized version of this crate.