worst error message ever

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "futures-rs"]
+	path = futures-rs
+	url = git@github.com:rust-lang/futures-rs.git

futures-rs

@@ -0,0 +1 @@
+Subproject commit 86f0626e8b4d4484c381a37a492b2fff28dfaa92

src/main.rs

@@ -1,14 +1,17 @@
-use futures::{stream, Future, StreamExt};
+use std::{
+    future::Future,
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use futures::{stream, StreamExt};
 
 pub struct JoinHandle<T>(T);
 
 impl<T> Future for JoinHandle<T> {
     type Output = Result<T, ()>;
 
-    fn poll(
-        self: std::pin::Pin<&mut Self>,
-        cx: &mut std::task::Context<'_>,
-    ) -> std::task::Poll<Self::Output> {
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         loop {}
     }
 }
@@ -17,8 +20,128 @@ pub fn spawn<T: Future>(future: T) -> JoinHandle<T::Output> {
     loop {}
 }
 
+pub trait Stream {
+    /// Values yielded by the stream.
+    type Item;
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>>;
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, None)
+    }
+}
+
+pub struct Iter<I> {
+    iter: I,
+}
+
+impl<I> Unpin for Iter<I> {}
+
+pub(crate) fn assert_stream<T, S>(stream: S) -> S
+where
+    S: Stream<Item = T>,
+{
+    stream
+}
+
+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()
+    }
+}
+
+impl<S: Stream> Stream for &S {
+    type Item = S::Item;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        todo!()
+    }
+}
+impl<S: Stream> Stream for &mut S {
+    type Item = S::Item;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        todo!()
+    }
+}
+trait UwuStream: Stream {
+    fn map<T, F>(self, f: F) -> Map<Self, F>
+    where
+        F: FnMut(Self::Item) -> T,
+        Self: Sized,
+    {
+        loop {}
+    }
+    fn buffer_unordered(self, n: impl Into<Option<usize>>) -> BufferUnordered<Self>
+    where
+        Self::Item: Future,
+        Self: Sized,
+    {
+        loop {}
+    }
+}
+
+impl<S: Stream> UwuStream for S {}
+pub struct Map<St, F> {
+    stream: St,
+    f: F,
+}
+impl<St, F> Stream for Map<St, F>
+where
+    St: Stream,
+    F: FnMut(St::Item),
+{
+    type Item = F::Output;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        loop {}
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.stream.size_hint()
+    }
+}
+pub struct BufferUnordered<St>
+where
+    St: Stream,
+{
+    uwu: St,
+}
+
+impl<St> Stream for BufferUnordered<St>
+where
+    St: Stream,
+    St::Item: Future,
+{
+    type Item = <St::Item as Future>::Output;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        loop {}
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        loop {}
+    }
+}
 fn main() {
-    let bodies = stream::iter([])
+    let bodies = iter([])
         .map(|url: String| spawn(async { Result::Ok(url) }))
         .buffer_unordered(0);