Fields
- count: int
- Entries in the map. Read only.
- capacity: int
- Slots in the map: zero before the first insert, then a power of two, at least GROUP_SIZE. Read only.
- growth_left: int
- Empty slots that may still be filled before the map has to be rebuilt.
- allocator: Allocator
- control: *u8
- One byte per slot, followed in the same allocation by the entries.
- entries: *Entry