# contain-rs

A crate for defining/extending lifetimes.

## Examples

### Simple Container

A basic fast implementation of `Container` backed by `Vec`.

```rust
use contain::{Container, SimpleContainer};

fn append_thing<'a>(container: &'a impl Container<String>, s: &str) -> &'a str {
    container.put(format!("{}thing", s))
}

let container = SimpleContainer::new();
let a = append_thing(&container, "some");
let b = append_thing(&container, "a ");
let c = append_thing(&container, "that ");
assert_eq!(a, "something");
assert_eq!(b, "a thing");
assert_eq!(c, "that thing");
assert_eq!(container.len(), 3)
```

## Deduplicating Container

A deduplicating `Container` backed by a `std::collections::HashSet`.
If two equal items are stored, the second is dropped
and a reference to the first is returned.
Whilst more resource-intensive than `SimpleContainer`, it can be more memory efficient in scenarios where many
items are equal and equivalent since the duplicates will be dropped.

```rust
use contain::{Container, DeduplicatingContainer};

fn append_thing<'a>(container: &'a impl Container<String>, s: &str) -> &'a str {
    container.put(format!("{}thing", s))
}

let container = DeduplicatingContainer::new();
let a = append_thing(&container, "some");
let b = append_thing(&container, "a ");
let c = append_thing(&container, "some");
assert_eq!(a, "something");
assert_eq!(b, "a thing");
assert_eq!(c, "something");
assert_eq!(container.len(), 2);
 ```