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//@ check-fail
//@ known-bug: unknown
// This gives us problems because `for<'a> I::Item<'a>: Debug` should mean "for
// all 'a where I::Item<'a> is WF", but really means "for all 'a possible"
trait LendingIterator: Sized {
type Item<'a>
where
Self: 'a;
fn next(&mut self) -> Self::Item<'_>;
}
fn fails<I: LendingIterator, F>(iter: &mut I, f: F) -> bool
where
F: FnMut(I::Item<'_>),
{
let mut iter2 = Eat(iter, f);
let _next = iter2.next();
true
}
impl<I: LendingIterator> LendingIterator for &mut I {
type Item<'a> = I::Item<'a> where Self:'a;
fn next(&mut self) -> Self::Item<'_> {
(**self).next()
}
}
struct Eat<I, F>(I, F);
impl<I: LendingIterator, F> Iterator for Eat<I, F>
where
F: FnMut(I::Item<'_>),
{
type Item = ();
fn next(&mut self) -> Option<Self::Item> {
None
}
}
fn main() {}
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