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|
trait Foo {}
impl<'a, T: Foo> Foo for &'a T {}
impl<T: Foo + ?Sized> Foo for Box<T> {}
struct Iter<'a, T> {
current: Option<Box<dyn Foo + 'a>>,
remaining: T,
}
impl<'a, T> Iterator for Iter<'a, T>
where
T: Iterator,
T::Item: Foo + 'a,
{
type Item = Box<dyn Foo + 'a>;
fn next(&mut self) -> Option<Self::Item> {
let result = self.current.take();
self.current = Box::new(self.remaining.next()).map(|f| Box::new(f) as _);
result
}
}
struct Bar(Vec<Box<dyn Foo>>);
impl Bar {
fn iter(&self) -> impl Iterator<Item = Box<dyn Foo>> {
Iter {
//~^ ERROR lifetime may not live long enough
current: None,
remaining: self.0.iter(),
}
}
}
struct Baz(Vec<Box<dyn Foo>>);
impl Baz {
fn iter(&self) -> impl Iterator<Item = Box<dyn Foo>> + '_ {
Iter {
//~^ ERROR lifetime may not live long enough
current: None,
remaining: self.0.iter(),
}
}
}
struct Bat(Vec<Box<dyn Foo>>);
impl Bat {
fn iter<'a>(&'a self) -> impl Iterator<Item = Box<dyn Foo>> + 'a {
Iter {
//~^ ERROR lifetime may not live long enough
current: None,
remaining: self.0.iter(),
}
}
}
struct Ban(Vec<Box<dyn Foo>>);
impl Ban {
fn iter<'a>(&'a self) -> impl Iterator<Item = Box<dyn Foo>> {
Iter {
//~^ ERROR lifetime may not live long enough
current: None,
remaining: self.0.iter(),
}
}
}
fn main() {}
|
