rust/tests/ui/object-lifetime/object-lifetime-default-dyn-binding-static.rs
2023-01-11 09:32:08 +00:00

29 lines
555 B
Rust

// Test that `dyn Bar<Item = XX>` uses `'static` as the default object
// lifetime bound for the type `XX`.
//
// check-pass
trait Foo {
type Item: ?Sized;
fn item(&self) -> Box<Self::Item> { panic!() }
}
trait Bar { }
impl<T> Foo for T {
type Item = dyn Bar;
}
fn is_static<T>(_: T) where T: 'static { }
// Here, we default to `dyn Bar + 'static`, and not `&'x dyn Foo<Item
// = dyn Bar + 'x>`.
fn bar(x: &str) -> &dyn Foo<Item = dyn Bar> { &() }
fn main() {
let s = format!("foo");
let r = bar(&s);
is_static(r.item());
}