Attribute Macro completion 

#[completion]

Available on crate features macro and std only.

An attribute macro to generate completion async fns. These async functions evaluate to a CompletionFuture, and you can .await other CompletionFutures inside of them.

See also [completion_async!] for more details.

Examples

use completion::{completion, completion_async};

#[completion]
async fn async_completion() -> i32 {
    let fut = async { 3 };
    let completion_fut = completion_async! { 5 };
    fut.await + completion_fut.await
}

This macro needs to know a path to this crate in order to work. By default it uses ::completion, but you can change it using the crate option:

mod path {
    pub mod to {
        pub extern crate completion as completion_crate;
    }
}
use path::to::completion_crate::completion;

#[completion(crate = path::to::completion_crate)]
async fn async_completion(x: &i32) -> i32 {
    *x
}

You can return a boxed completion future from the function by using the box option. For example this can be used to implement async traits:

use completion::completion;

trait MyTrait {
    #[completion(box)]
    async fn run(&self);
}

struct Item;
impl MyTrait for Item {
    #[completion(box)]
    async fn run(&self) {
        println!("Hello!");
    }
}

By default the box option will require the futures to implement Send. If you don’t want this, you can pass in the ?Send option:

use completion::completion;

trait MyTrait {
    #[completion(box(?Send))]
    async fn run(&self);
}

That will allow you to hold !Send types across await points in the future, but will only allow it to be executed on a single-threaded executor.