rust/tests/ui/impl-trait/unsized_coercion3.rs
2024-10-15 20:42:17 -04:00

24 lines
654 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
trait Trait {}
impl Trait for u32 {}
fn hello() -> Box<impl Trait + ?Sized> {
//[next]~^ ERROR: the trait bound `dyn Send: Trait` is not satisfied
if true {
let x = hello();
//[next]~^ ERROR: the trait bound `dyn Send: Trait` is not satisfied
let y: Box<dyn Send> = x;
//[old]~^ ERROR: the size for values of type `impl Trait + ?Sized` cannot be know
}
Box::new(1u32)
//[next]~^ ERROR: mismatched types
}
fn main() {}