# map_vec

## The Map and Set APIs backed by Vecs

[`map_vec::Map`](https://docs.rs/map_vec/latest/map_vec/map/struct.Map.html) is a data structure with the interface of [`HashMap`](https://doc.rust-lang.org/std/collections/hash_map/struct.HashMap.html).
Similarly [`map_vec::Set`](https://docs.rs/map_vec/latest/map_vec/set/struct.Set.html) is a data structure with the interface of [`HashSet`](https://doc.rust-lang.org/std/collections/hash_set/struct.HashSet.html).

Vector-backed maps and sets are primarily useful when you care about constant factors or prefer determinism to speed.
Please refer to the docs for [`HashMap`](https://doc.rust-lang.org/std/collections/hash_map/struct.HashMap.html) and [`HashSet`](https://doc.rust-lang.org/std/collections/hash_set/struct.HashSet.html) for details on and examples of using the `Map`/`Set` API.

## Optional features

Declare the `map_vec` dependency with `serde` support to get `Serialize` and `Deserialize` on `Map` and `Set`.

```toml
map_vec = { version = "0.6", features = ["serde"] }
```

## Map Example

```rust
let mut map = map_vec::Map::new();
map.insert("hello".to_string(), "world".to_string());
map.entry("hello".to_string()).and_modify(|mut v| v.push_str("!"));
assert_eq!(map.get("hello").map(String::as_str), Some("world!"))
```

## Set Example

```rust
let mut set1 = map_vec::Set::new();
let mut set2 = map_vec::Set::new();
set1.insert(1);
set1.insert(2);
set2.insert(2);
set2.insert(3);
let mut set3 = map_vec::Set::with_capacity(1);
assert!(set3.insert(3));
assert_eq!(&set2 - &set1, set3);
```