# Function futures_util::future::lazy [−] [src]

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    pub fn lazy<F, R>(f: F) -> Lazy<F>ⓘNotable traits for Lazy<F>impl<F, R> Future for Lazy<F> where
        F: FnOnce(&mut Context<'_>) -> R,     type Output = R; where
        F: FnOnce(&mut Context<'_>) -> R,

Creates a new future that allows delayed execution of a closure.

The provided closure is only run once the future is polled.

# Examples

    use futures::future;

    let a = future::lazy(|_| 1);
    assert_eq!(a.await, 1);

    let b = future::lazy(|_| -> i32 {
        panic!("oh no!")
    });
    drop(b); // closure is never run