blob: e556959204590a40d62f3b0eb58fd727920578ff (
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
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
//@ revisions: nofallback fallback
//@[fallback] check-pass
#![feature(never_type)]
#![cfg_attr(fallback, feature(never_type_fallback))]
#![allow(unreachable_code)]
use std::error::Error;
use std::mem;
fn raw_ptr_box<T>(t: T) -> *mut T {
panic!()
}
fn foo(x: !) -> Box<dyn Error> {
// Method resolution will generate new inference vars and relate them.
// Thus fallback will not fall back to `!`, but `()` instead.
Box::<_ /* ! */>::new(x)
//[nofallback]~^ ERROR trait bound `(): std::error::Error` is not satisfied
}
fn foo_raw_ptr(x: !) -> *mut dyn Error {
/* *mut $0 is coerced to *mut Error here */
raw_ptr_box::<_ /* ! */>(x)
//[nofallback]~^ ERROR trait bound `(): std::error::Error` is not satisfied
}
fn no_coercion(d: *mut dyn Error) -> *mut dyn Error {
/* an unsize coercion won't compile here, and it is indeed not used
because there is nothing requiring the _ to be Sized */
d as *mut _
}
trait Xyz {}
struct S;
struct T;
impl Xyz for S {}
impl Xyz for T {}
fn foo_no_never() {
let mut x /* : Option<S> */ = None;
let mut first_iter = false;
loop {
if !first_iter {
let y: Box<dyn Xyz>
= /* Box<$0> is coerced to Box<Xyz> here */ Box::new(x.unwrap());
}
x = Some(S);
first_iter = true;
}
let mut y: Option<S> = None;
// assert types are equal
mem::swap(&mut x, &mut y);
}
fn main() {}
|
