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//@ check-pass
//@ compile-flags: -Znext-solver
use std::ops::Deref;
pub struct List<T> {
skel: [T],
}
impl<'a, T: Copy> IntoIterator for &'a List<T> {
type Item = T;
type IntoIter = std::iter::Copied<<&'a [T] as IntoIterator>::IntoIter>;
fn into_iter(self) -> Self::IntoIter {
todo!()
}
}
impl<T> Deref for List<T> {
type Target = [T];
fn deref(&self) -> &[T] {
todo!()
}
}
impl<T> List<T> {
fn iter(&self) -> <&Self as IntoIterator>::IntoIter
where
T: Copy,
{
todo!()
}
}
fn test<Q>(t: &List<Q>) {
// Checking that `<&List<Q> as IntoIterator>::IntoIter` is WF
// will disqualify the inherent method, since normalizing it
// requires `Q: Copy` which does not hold. and allow us to fall
// through to the deref'd `<[Q]>::iter` method which works.
//
// In the old solver, the same behavior is achieved by just
// eagerly normalizing the return type.
t.iter();
}
fn main() {}
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