blob: 558303c2e40bc90e2585dcdc79abd882cfc90dd2 (
plain)
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
39
40
41
|
// run-pass
#![allow(dead_code)]
#![allow(drop_copy)]
// "guessing" in trait selection can affect `copy_or_move`. Check that this
// is correctly handled. I am not sure what is the "correct" behaviour,
// but we should at least not ICE.
use std::mem;
struct U([u8; 1337]);
struct S<'a,T:'a>(&'a T);
impl<'a, T> Clone for S<'a, T> { fn clone(&self) -> Self { S(self.0) } }
/// This impl triggers inference "guessing" - S<_>: Copy => _ = U
impl<'a> Copy for S<'a, Option<U>> {}
fn assert_impls_fn<R,T: Fn()->R>(_: &T){}
fn main() {
let n = None;
let e = S(&n);
let f = || {
// S being copy is critical for this to work
drop(e);
mem::size_of_val(e.0)
};
assert_impls_fn(&f);
assert_eq!(f(), 1337+1);
assert_eq!((|| {
// S being Copy is not critical here, but
// we check it anyway.
let n = None;
let e = S(&n);
let ret = mem::size_of_val(e.0);
drop(e);
ret
})(), 1337+1);
}
|
