use futures::Stream;
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use std::{
convert::Infallible, iter, pin::Pin, slice, task::{Context, Poll}
};
use super::{
DistributedStream, IntoDistributedStream, IntoParallelStream, IterDistStream, IterParStream, ParallelStream, StreamTask
};
use crate::pool::ProcessSend;
impl_par_dist_rename! {
impl<T> IntoParallelStream for [T]
where
T: Send + 'static,
{
type ParStream = Never;
type Item = Never;
fn into_par_stream(self) -> Self::ParStream
where
Self: Sized,
{
unreachable!()
}
}
impl<'a, T: Clone> IntoParallelStream for &'a [T]
where
T: Send + 'static,
{
type ParStream = IterParStream<iter::Cloned<slice::Iter<'a, T>>>;
type Item = T;
#[inline]
fn into_par_stream(self) -> Self::ParStream
where
Self: Sized,
{
IterParStream(self.iter().cloned())
}
}
impl ParallelStream for Never {
type Item = Self;
type Task = Self;
fn size_hint(&self) -> (usize, Option<usize>) {
unreachable!()
}
fn next_task(self: Pin<&mut Self>, _cx: &mut Context) -> Poll<Option<Self::Task>> {
unreachable!()
}
}
}
pub struct Never(Infallible);
impl StreamTask for Never {
type Item = Self;
type Async = Self;
fn into_async(self) -> Self::Async {
self
}
}
impl Stream for Never {
type Item = Self;
fn poll_next(self: Pin<&mut Self>, _cx: &mut Context) -> Poll<Option<Self::Item>> {
unreachable!()
}
}
impl Serialize for Never {
fn serialize<S>(&self, _serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
unreachable!()
}
}
impl<'de> Deserialize<'de> for Never {
fn deserialize<D>(_deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
unreachable!()
}
}