Extend in async_std::stream - Rust (original) (raw)

pub trait Extend<A> {
    // Required method
    fn extend<'a, T: IntoStream<Item = A> + 'a>(
        &'a mut self,
        stream: T,
    ) -> Pin<Box<dyn Future<Output = ()> + Send + 'a>>
       where <T as IntoStream>::IntoStream: Send;
}

Available on unstable only.

Expand description

Extends a collection with the contents of a stream.

Streams produce a series of values asynchronously, and collections can also be thought of as a series of values. The Extend trait bridges this gap, allowing you to extend a collection asynchronously by including the contents of that stream. When extending a collection with an already existing key, that entry is updated or, in the case of collections that permit multiple entries with equal keys, that entry is inserted.

§Examples

use async_std::prelude::*;
use async_std::stream;

let mut v: Vec<usize> = vec![1, 2];
let s = stream::repeat(3usize).take(3);
stream::Extend::extend(&mut v, s).await;

assert_eq!(v, vec![1, 2, 3, 3, 3]);

Source

Extends a collection with the contents of a stream.

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Source §