use std::collections::BTreeSet;
use std::pin::Pin;
use crate::prelude::*;
use crate::stream::{self, IntoStream};
impl<T: Ord + Send> stream::Extend<T> for BTreeSet<T> {
fn extend<'a, S: IntoStream<Item = T> + 'a>(
&'a mut self,
stream: S,
) -> Pin<Box<dyn Future<Output = ()> + 'a + Send>>
where
<S as IntoStream>::IntoStream: Send,
{
Box::pin(stream.into_stream().for_each(move |item| {
self.insert(item);
}))
}
}