Type Alias BoxedAnySend

pub type BoxedAnySend = Box<dyn Any + Send + 'static>;

A Box that can hold any value that is Send.

Values sent through pipes are trait objects of this type.

This type is publicly exposed as it’s needed when building a pipeline stage with multiple outputs. Since each output could have a different type, it’s more feasible to define the outputs to use dynamic dispatching rather that static dispatching.

Examples

Here’s an example of a closure representing the task function given to the pipeline builder when creating a “branching” stage. Three outputs are returned, each of a different type.

use async_pipes::branch;

#[tokio::main]
async fn main() {
    let task = |value: String| async move {
        let length: usize = value.len();
        let excited: String = format!("{}!", value);
        let odd_length: bool = length % 2 == 1;

        Some(branch![length, excited, odd_length])
    };

    // E.g.:
    // ...
    // .with_branching_stage("pipe_in", vec!["pipe_len", "pipe_excited", "pipe_odd"], <task>)
    // ...

    let mut results = task("hello".to_string()).await.unwrap();

    let length = results.remove(0).unwrap().downcast::<usize>().unwrap();
    let excited = results.remove(0).unwrap().downcast::<String>().unwrap();
    let odd_length = results.remove(0).unwrap().downcast::<bool>().unwrap();

    assert_eq!(*length, 5usize);
    assert_eq!(*excited, "hello!".to_string());
    assert_eq!(*odd_length, true);
}

Aliased Type

struct BoxedAnySend(/* private fields */);