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|
// run-pass
use std::marker;
use std::mem;
fn main() {
let workers = (0..0).map(|_| result::<u32, ()>());
drop(join_all(workers).poll());
}
trait Future {
type Item;
type Error;
fn poll(&mut self) -> Result<Self::Item, Self::Error>;
}
trait IntoFuture {
type Future: Future<Item=Self::Item, Error=Self::Error>;
type Item;
type Error;
fn into_future(self) -> Self::Future;
}
impl<F: Future> IntoFuture for F {
type Future = F;
type Item = F::Item;
type Error = F::Error;
fn into_future(self) -> F {
self
}
}
struct FutureResult<T, E> {
_inner: marker::PhantomData<(T, E)>,
}
fn result<T, E>() -> FutureResult<T, E> {
loop {}
}
impl<T, E> Future for FutureResult<T, E> {
type Item = T;
type Error = E;
fn poll(&mut self) -> Result<T, E> {
loop {}
}
}
struct JoinAll<I>
where I: IntoIterator,
I::Item: IntoFuture,
{
elems: Vec<<I::Item as IntoFuture>::Item>,
}
fn join_all<I>(_: I) -> JoinAll<I>
where I: IntoIterator,
I::Item: IntoFuture,
{
JoinAll { elems: vec![] }
}
impl<I> Future for JoinAll<I>
where I: IntoIterator,
I::Item: IntoFuture,
{
type Item = Vec<<I::Item as IntoFuture>::Item>;
type Error = <I::Item as IntoFuture>::Error;
fn poll(&mut self) -> Result<Self::Item, Self::Error> {
let elems = mem::replace(&mut self.elems, Vec::new());
Ok(elems.into_iter().map(|e| {
e
}).collect::<Vec<_>>())
}
}
|
