async_static 0.1.3

A macro for declaring async lazily evaluated statics in Rust.
Documentation 
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use std::time::Duration;

use async_static::async_static;
use tokio::time::sleep;

async fn get_num() -> i32 {
    println!("hello world");
    sleep(Duration::from_millis(100)).await;
    123
}

async_static! {
    static ref FOO:i32 = get_num().await;
}

/// run print
/// ```
/// hello world
/// The result of the first call: 123
/// The result of the second call: 123
/// ```
#[tokio::test]
async fn test() {
    // The first call, print hello world
    let n = FOO.await;
    println!("The result of the first call: {}", n);

    // The second call, nothing print
    let n = FOO.await;
    println!("The result of the second call: {}", n);
}