# task-local-extensions

Provides a type-safe task-local container for arbitrary data keyed by types.

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## How to install

Add `task-local-extensions` to your dependencies

```toml
[dependencies]
# ...
task-local-extensions = "0.1.0"
```

## Usage

[`Extensions`](https://docs.rs/task-local-extensions/latest/task_local_extensions/struct.Extensions.html)
is a container that can store up to one value of each type, so you can insert and retrive values by
their type:

```rust
use task_local_extensions::Extensions;

let a: i64 = 3;
let mut ext = Extensions::new();
ext.insert(a);
assert_eq!(ext.get::<i64>(), Some(&3));
```

The crate also provides [`with_extensions`](https://docs.rs/task-local-extensions/latest/task_local_extensions/fn.with_extensions.html)
so you set an `Extensions` instance while running a given task:

```rust
use task_local_extensions::{get_local_item, set_local_item, with_extensions, Extensions};

async fn my_task() {
  let a: i64 = get_local_item().await.unwrap(0);
  let msg = format!("The value of a is: {}", a);
  set_local_item(msg).await;
}

let a: i64 = 3;
let (out_ext, _) = with_extensions(Extensions::new().with(a), my_task()).await;
let msg = out_ext.get::<String>().unwrap();
assert_eq!(msg.as_str(), "The value of a is: 3");
```

#### License

Licensed under either of Apache License, Version
2.0 or MIT license at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
dual licensed as above, without any additional terms or conditions.

