Macro smol::pin

macro_rules! pin {
    ($($x:ident),* $(,)?) => { ... };
}

Pins a variable of type T on the stack and rebinds it as Pin<&mut T>.

use futures_lite::{future, pin};
use std::fmt::Debug;
use std::future::Future;
use std::pin::Pin;
use std::time::Instant;

// Inspects each invocation of `Future::poll()`.
async fn inspect<T: Debug>(f: impl Future<Output = T>) -> T {
    pin!(f);
    future::poll_fn(|cx| dbg!(f.as_mut().poll(cx))).await
}

let f = async { 1 + 2 };
inspect(f).await;