shared_slab

This crate provides a single data type, Slab, which is very similar in concept to that provided by the slab or sharded-slab crates.

The key difference of this crate as compared to the others can be summed up in the function signatures:

pub fn get(&self, key: usize) -> Option<&T>
pub fn insert(&self, value: T) -> usize
pub fn insert_and_get(&self, value: T) -> (usize, &T)
pub fn remove(&mut self, key: usize) -> T

Or, in words, shared insertion while allowing shared access to the values contained within. (slab requires mutable access for insertion, and sharded-slab doesn't provide direct &T references to contained data)

As for use-cases, this structure is mainly useful for memoizing and reusing resources, in a pattern of:

pub fn add_resource(&self, resource_descriptor: Descriptor) -> &Resource