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
|
#![feature(type_alias_impl_trait)]
#[derive(Clone)]
struct CopyIfEq<T, U>(T, U);
impl<T: Copy> Copy for CopyIfEq<T, T> {}
type E<'a, 'b> = impl Sized;
fn foo<'a, 'b, 'c>(x: &'static i32, mut y: &'a i32) -> E<'b, 'c> {
let v = CopyIfEq::<*mut _, *mut _>(&mut { x }, &mut y);
// This assignment requires that `x` and `y` have the same type due to the
// `Copy` impl. The reason why we are using a copy to create a constraint
// is that only borrow checking (not regionck in type checking) enforces
// this bound.
let u = v;
let _: *mut &'a i32 = u.1;
unsafe {
let _: &'b i32 = *u.0;
//~^ ERROR lifetime may not live long enough
}
u.0
}
fn main() {}
|
