39 lines
968 B
Rust
39 lines
968 B
Rust
// run-pass
|
|
#![allow(dead_code)]
|
|
// "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);
|
|
}
|