futures_concurrency/future/join/
mod.rs

1use core::future::Future;
2
3pub(crate) mod array;
4pub(crate) mod tuple;
5#[cfg(feature = "alloc")]
6pub(crate) mod vec;
7
8/// Wait for all futures to complete.
9///
10/// Awaits multiple futures simultaneously, returning the output of the futures
11/// in the same container type they were created once all complete.
12pub trait Join {
13    /// The resulting output type.
14    type Output;
15
16    /// The [`Future`] implementation returned by this method.
17    type Future: Future<Output = Self::Output>;
18
19    /// Waits for multiple futures to complete.
20    ///
21    /// Awaits multiple futures simultaneously, returning the output of the futures
22    /// in the same container type they we're created once all complete.
23    ///
24    /// # Examples
25    ///
26    /// Awaiting multiple futures of the same type can be done using either a vector
27    /// or an array.
28    /// ```rust
29    /// #  futures::executor::block_on(async {
30    /// use futures_concurrency::prelude::*;
31    ///
32    /// // all futures passed here are of the same type
33    /// let fut1 = core::future::ready(1);
34    /// let fut2 = core::future::ready(2);
35    /// let fut3 = core::future::ready(3);
36    ///
37    /// let outputs = [fut1, fut2, fut3].join().await;
38    /// assert_eq!(outputs, [1, 2, 3]);
39    /// # })
40    /// ```
41    ///
42    /// In practice however, it's common to want to await multiple futures of
43    /// different types. For example if you have two different `async {}` blocks,
44    /// you want to `.await`. To do that, you can call `.join` on tuples of futures.
45    /// ```rust
46    /// #  futures::executor::block_on(async {
47    /// use futures_concurrency::prelude::*;
48    ///
49    /// async fn some_async_fn() -> usize { 3 }
50    ///
51    /// // the futures passed here are of different types
52    /// let fut1 = core::future::ready(1);
53    /// let fut2 = async { 2 };
54    /// let fut3 = some_async_fn();
55    /// //                       ^ NOTE: no `.await` here!
56    ///
57    /// let outputs = (fut1, fut2, fut3).join().await;
58    /// assert_eq!(outputs, (1, 2, 3));
59    /// # })
60    /// ```
61    ///
62    /// <br><br>
63    /// This function returns a new future which polls all futures concurrently.
64    fn join(self) -> Self::Future;
65}
futures_concurrency/future/join/mod.rs

futures_concurrency/future/join/
mod.rs
