mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-23 07:14:28 +00:00
22 lines
487 B
Rust
22 lines
487 B
Rust
//! This test checks that opaque types get unsized instead of
|
|
//! constraining their hidden type to a trait object.
|
|
|
|
//@ revisions: next old
|
|
//@[next] compile-flags: -Znext-solver
|
|
//@[next] check-pass
|
|
|
|
trait Trait {}
|
|
|
|
impl Trait for u32 {}
|
|
|
|
fn hello() -> Box<impl Trait + ?Sized> {
|
|
if true {
|
|
let x = hello();
|
|
let y: Box<dyn Trait> = x;
|
|
//[old]~^ ERROR: the size for values of type `impl Trait + ?Sized` cannot be know
|
|
}
|
|
Box::new(1u32)
|
|
}
|
|
|
|
fn main() {}
|