1 | //! The `stream_select` macro. |
2 | |
3 | #[allow (unreachable_pub)] |
4 | #[doc (hidden)] |
5 | pub use futures_macro::stream_select_internal; |
6 | |
7 | /// Combines several streams, all producing the same `Item` type, into one stream. |
8 | /// This is similar to `select_all` but does not require the streams to all be the same type. |
9 | /// It also keeps the streams inline, and does not require `Box<dyn Stream>`s to be allocated. |
10 | /// Streams passed to this macro must be `Unpin`. |
11 | /// |
12 | /// If multiple streams are ready, one will be pseudo randomly selected at runtime. |
13 | /// |
14 | /// # Examples |
15 | /// |
16 | /// ``` |
17 | /// # futures::executor::block_on(async { |
18 | /// use futures::{stream, StreamExt, stream_select}; |
19 | /// let endless_ints = |i| stream::iter(vec![i].into_iter().cycle()).fuse(); |
20 | /// |
21 | /// let mut endless_numbers = stream_select!(endless_ints(1i32), endless_ints(2), endless_ints(3)); |
22 | /// match endless_numbers.next().await { |
23 | /// Some(1) => println!("Got a 1" ), |
24 | /// Some(2) => println!("Got a 2" ), |
25 | /// Some(3) => println!("Got a 3" ), |
26 | /// _ => unreachable!(), |
27 | /// } |
28 | /// # }); |
29 | /// ``` |
30 | #[macro_export ] |
31 | macro_rules! stream_select { |
32 | ($($tokens:tt)*) => {{ |
33 | use $crate::__private as __futures_crate; |
34 | $crate::stream_select_internal! { |
35 | $( $tokens )* |
36 | } |
37 | }} |
38 | } |
39 | |