1. Open the Cargo.toml file that has been generated earlier for you.

2. Under [dependencies], add the following line:

slab = "0.4.0"

3. If you want, you can go to slab's crates.io page (https://crates.io/crates/slab) to check for the newest version, and use that one instead.

4. In the folder bin, create a file called slab.rs.

5. Add the following code, and run it with cargo run --bin slab:

1   extern crate slab;
2   use slab::{Slab, VacantEntry};
3 
4   fn main() {
5     // A slab is meant to be used as a limited buffer
6     // As such, you should initialize it with a pre-
7     // defined capacity
8     const CAPACITY: usize = 1024;
9     let mut slab = Slab::with_capacity(CAPACITY);
10 
11    // You cannot simply access a slab's entry by
12    // index or by searching it. Instead, every
13    // insert gives you a key that you can use to
14    // access its entry
15    let hello_key = slab.insert("hello");
16    let world_key = slab.insert("world");
17 
18    println!("hello_key -> '{}'", slab[hello_key],);
19    println!("world_key -> '{}'", slab[world_key],);
20 
21 
22    // You can pass an "empty spot" around
23    // in order to be filled
24    let data_key = {
25    let entry = slab.vacant_entry();
26      fill_some_data(entry)
27    };
28    println!("data_key -> '{}'", slab[data_key],);
29 
30    // When iterating, you get a key-value pair
31    for (key, val) in &slab {
32      println!("{} -> {}", key, val);
33    }
34 
35    // If you want to keep your slab at a constant
36    // capacity, you have to manually check its
37    // length before inserting data
38    if slab.len() != slab.capacity() {
39      slab.insert("the slab is not at capacity yet");
40    }
41  }
42 
43 
44  fn fill_some_data(entry: VacantEntry<&str>) -> usize {
45    let data = "Some data";
46    // insert() consumes the entry
47    // so we need to get the key before
48    let key = entry.key();
49    entry.insert(data);
50    key
51  }