Deprecated: use slotmap.
Slot map: array storage with persistent indices
Vec<T>-like collection with stable indices.
The underlying array's indices are re-used by incrementing a
versioning tag in the index type.
The SlotMapIndex type consists of a u32 for storing the
index into the underlying array, and a u32 for storing
the version. Deleting and inserting more times than the maximum
value of u32 will cause overflow and index conflict bugs.
Example
# use *;
let mut map = new;
map.insert;
let idx = map.insert;
map.insert;
map.remove;
let idx2 = map.insert;
assert_eq!;
assert_eq!;