35 lines
612 B
Rust
35 lines
612 B
Rust
//@ run-pass
|
|
// Uncovered during work on new scoping rules for safe destructors
|
|
// as an important use case to support properly.
|
|
|
|
|
|
pub struct E<'a> {
|
|
pub f: &'a u8,
|
|
}
|
|
impl<'b> E<'b> {
|
|
pub fn m(&self) -> &'b u8 { self.f }
|
|
}
|
|
|
|
pub struct P<'c> {
|
|
pub g: &'c u8,
|
|
}
|
|
pub trait M {
|
|
fn n(&self) -> u8;
|
|
}
|
|
impl<'d> M for P<'d> {
|
|
fn n(&self) -> u8 { *self.g }
|
|
}
|
|
|
|
fn extension<'e>(x: &'e E<'e>) -> Box<dyn M+'e> {
|
|
loop {
|
|
let p = P { g: x.m() };
|
|
return Box::new(p) as Box<dyn M+'e>;
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
let w = E { f: &10 };
|
|
let o = extension(&w);
|
|
assert_eq!(o.n(), 10);
|
|
}
|