//! The `stream_select` macro. #[cfg(feature = "std")] #[allow(unreachable_pub)] #[doc(hidden)] pub use futures_macro::stream_select_internal; /// Combines several streams, all producing the same `Item` type, into one stream. /// This is similar to `select_all` but does not require the streams to all be the same type. /// It also keeps the streams inline, and does not require `Box`s to be allocated. /// Streams passed to this macro must be `Unpin`. /// /// If multiple streams are ready, one will be pseudo randomly selected at runtime. /// /// # Examples /// /// ``` /// # futures::executor::block_on(async { /// use futures::{stream, StreamExt, stream_select}; /// let endless_ints = |i| stream::iter(vec![i].into_iter().cycle()).fuse(); /// /// let mut endless_numbers = stream_select!(endless_ints(1i32), endless_ints(2), endless_ints(3)); /// match endless_numbers.next().await { /// Some(1) => println!("Got a 1"), /// Some(2) => println!("Got a 2"), /// Some(3) => println!("Got a 3"), /// _ => unreachable!(), /// } /// # }); /// ``` #[cfg(feature = "std")] #[macro_export] macro_rules! stream_select { ($($tokens:tt)*) => {{ use $crate::__private as __futures_crate; $crate::stream_select_internal! { $( $tokens )* } }} }