summaryrefslogtreecommitdiffstats
path: root/vendor/futures-util/src/stream/iter.rs
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/futures-util/src/stream/iter.rs')
-rw-r--r--vendor/futures-util/src/stream/iter.rs49
1 files changed, 49 insertions, 0 deletions
diff --git a/vendor/futures-util/src/stream/iter.rs b/vendor/futures-util/src/stream/iter.rs
new file mode 100644
index 000000000..20471c2ed
--- /dev/null
+++ b/vendor/futures-util/src/stream/iter.rs
@@ -0,0 +1,49 @@
+use super::assert_stream;
+use core::pin::Pin;
+use futures_core::stream::Stream;
+use futures_core::task::{Context, Poll};
+
+/// Stream for the [`iter`] function.
+#[derive(Debug, Clone)]
+#[must_use = "streams do nothing unless polled"]
+pub struct Iter<I> {
+ iter: I,
+}
+
+impl<I> Unpin for Iter<I> {}
+
+/// Converts an `Iterator` into a `Stream` which is always ready
+/// to yield the next value.
+///
+/// Iterators in Rust don't express the ability to block, so this adapter
+/// simply always calls `iter.next()` and returns that.
+///
+/// ```
+/// # futures::executor::block_on(async {
+/// use futures::stream::{self, StreamExt};
+///
+/// let stream = stream::iter(vec![17, 19]);
+/// assert_eq!(vec![17, 19], stream.collect::<Vec<i32>>().await);
+/// # });
+/// ```
+pub fn iter<I>(i: I) -> Iter<I::IntoIter>
+where
+ I: IntoIterator,
+{
+ assert_stream::<I::Item, _>(Iter { iter: i.into_iter() })
+}
+
+impl<I> Stream for Iter<I>
+where
+ I: Iterator,
+{
+ type Item = I::Item;
+
+ fn poll_next(mut self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Option<I::Item>> {
+ Poll::Ready(self.iter.next())
+ }
+
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.iter.size_hint()
+ }
+}