1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
// Regression test for #53548. The `Box<dyn Trait>` type below is
// expanded to `Box<dyn Trait + 'static>`, but the generator "witness"
// that results is `for<'r> { Box<dyn Trait + 'r> }`. The WF code was
// encountering an ICE (when debug-assertions were enabled) and an
// unexpected compilation error (without debug-asserions) when trying
// to process this `'r` region bound. In particular, to be WF, the
// region bound must meet the requirements of the trait, and hence we
// got `for<'r> { 'r: 'static }`. This would ICE because the `Binder`
// constructor we were using was assering that no higher-ranked
// regions were involved (because the WF code is supposed to skip
// those). The error (if debug-asserions were disabled) came because
// we obviously cannot prove that `'r: 'static` for any region `'r`.
// Pursuant with our "lazy WF" strategy for higher-ranked regions, the
// fix is not to require that `for<'r> { 'r: 'static }` holds (this is
// also analogous to what we would do for higher-ranked regions
// appearing within the trait in other positions).
//
// check-pass
#![feature(generators)]
use std::cell::RefCell;
use std::rc::Rc;
trait Trait: 'static {}
struct Store<C> {
inner: Rc<RefCell<Option<C>>>,
}
fn main() {
Box::new(static move || {
let store = Store::<Box<dyn Trait>> {
inner: Default::default(),
};
yield ();
});
}
|
