Module hash 

Specialized hash containers.

Two keys in this crate already carry enough entropy to skip the default hasher:

• Entity is a pair of integers packed into one u64. EntityHash spreads that value upward with a Fibonacci multiply, which is where the SwissTable needs the bits, while leaving the low bits so that entities spawned together land together.
• TypeId is itself a high-quality hash, so TypeIdHashMap uses NoOpHash and NoOpHasher forwards the u64 the Hash impl writes.

EntityHasher panics on a key that is not u64-shaped, which is a programming error in this crate’s own use of it. NoOpHasher does not: it folds byte-wise writes rather than panicking, so a container that hashes a non-u64 key still works, if with a worse hash.

Re-exports

use core::any::TypeId; 🔒

use core::hash::BuildHasher; 🔒

use core::hash::Hash; 🔒

use core::hash::Hash; 🔒

use core::hash::Hasher; 🔒

use hashbrown::HashMap; 🔒

use hashbrown::HashSet; 🔒

use crate::entity::Entity; 🔒

Structs

EntityHash

A BuildHasher for generational indices.

EntityHasher

The hasher of EntityHash.

NoOpHash

A BuildHasher that passes u64 keys through unchanged.

NoOpHasher

The hasher of NoOpHash.

Type Aliases

EntityHashMap

A hash map keyed by Entity.

EntityHashSet

A hash set of Entitys.

TypeIdHashMap

A hash map keyed by TypeId.

TypeIdHashSet

A hash set of TypeIds.