2 // compile-flags:-Zpolymorphize=on
4 pub trait ParallelIterator: Sized {
5 fn drive<C: Consumer<()>>(_: C) {
10 pub trait Consumer<T>: Sized {
12 fn into_folder() -> Self::Result;
15 impl ParallelIterator for () {}
17 impl<F: Fn(), T> Consumer<T> for F {
19 fn into_folder() -> Self::Result {