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
|
fn prove_static<T: 'static + ?Sized>(_: &'static T) {}
fn lifetime_transmute_slice<'a, T: ?Sized>(x: &'a T, y: &T) -> &'a T {
let mut out = [x];
{
let slice: &mut [_] = &mut out;
slice[0] = y;
}
out[0]
//~^ ERROR explicit lifetime required in the type of `y` [E0621]
}
struct Struct<T, U: ?Sized> {
head: T,
_tail: U
}
fn lifetime_transmute_struct<'a, T: ?Sized>(x: &'a T, y: &T) -> &'a T {
let mut out = Struct { head: x, _tail: [()] };
{
let dst: &mut Struct<_, [()]> = &mut out;
dst.head = y;
}
out.head
//~^ ERROR explicit lifetime required in the type of `y` [E0621]
}
fn main() {
prove_static(lifetime_transmute_slice("", &String::from("foo")));
prove_static(lifetime_transmute_struct("", &String::from("bar")));
}
|
