23 lines
503 B
Rust
23 lines
503 B
Rust
// revisions: current next
|
|
//[next] compile-flags: -Ztrait-solver=next
|
|
//[next] check-pass
|
|
#![feature(type_alias_impl_trait)]
|
|
|
|
type A = impl Foo;
|
|
type B = impl Foo;
|
|
|
|
trait Foo {}
|
|
|
|
fn muh(x: A) -> B {
|
|
if false {
|
|
return x; // B's hidden type is A (opaquely)
|
|
//[current]~^ ERROR opaque type's hidden type cannot be another opaque type
|
|
}
|
|
Bar // A's hidden type is `Bar`, because all the return types are compared with each other
|
|
}
|
|
|
|
struct Bar;
|
|
impl Foo for Bar {}
|
|
|
|
fn main() {}
|