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use core::marker; use stream::Stream; use {Async, Poll}; /// Stream that produces the same element repeatedly. /// /// This structure is created by the `stream::repeat` function. #[derive(Debug)] #[must_use = "streams do nothing unless polled"] pub struct Repeat<T, E> where T: Clone { item: T, error: marker::PhantomData<E>, } /// Create a stream which produces the same item repeatedly. /// /// Stream never produces an error or EOF. Note that you likely want to avoid /// usage of `collect` or such on the returned stream as it will exhaust /// available memory as it tries to just fill up all RAM. /// /// ```rust /// use futures::*; /// /// let mut stream = stream::repeat::<_, bool>(10); /// assert_eq!(Ok(Async::Ready(Some(10))), stream.poll()); /// assert_eq!(Ok(Async::Ready(Some(10))), stream.poll()); /// assert_eq!(Ok(Async::Ready(Some(10))), stream.poll()); /// ``` pub fn repeat<T, E>(item: T) -> Repeat<T, E> where T: Clone { Repeat { item: item, error: marker::PhantomData, } } impl<T, E> Stream for Repeat<T, E> where T: Clone { type Item = T; type Error = E; fn poll(&mut self) -> Poll<Option<Self::Item>, Self::Error> { Ok(Async::Ready(Some(self.item.clone()))) } }