Yet another index-based arena.
- Yet another index-based arena.
- A map from arena indexes to some other type. Space requirement is O(highest index).
- The index of a value allocated in an arena that holds
- A range of densely allocated arena values.
- An iterator over the arena’s elements.
- The raw index of a value in an arena.
- A view into a single entry in a map, which may either be vacant or occupied.