| //@ build-pass | |
| // Regression test for <https://github.com/rust-lang/rust/issues/139812>. | |
| // Make sure that the unsize coercion we collect in mono for `Signal<i32> -> Signal<dyn Any>` | |
| // doesn't choke on the fact that the inner unsized field of `Signal<T>` is a (trivial) alias. | |
| // This exercises a normalize call that is necessary since we're getting a type from the type | |
| // system, which isn't guaranteed to be normalized after substitution. | |
| #![feature(coerce_unsized)] | |
| use std::ops::CoerceUnsized; | |
| trait Mirror { | |
| type Assoc: ?Sized; | |
| } | |
| impl<T: ?Sized> Mirror for T { | |
| type Assoc = T; | |
| } | |
| trait Any {} | |
| impl<T> Any for T {} | |
| struct Signal<'a, T: ?Sized>(<&'a T as Mirror>::Assoc); | |
| // This `CoerceUnsized` impl isn't special; it's a bit more restricted than we'd see in the wild, | |
| // but this ICE also reproduces if we were to make it general over `Signal<T> -> Signal<U>`. | |
| impl<'a> CoerceUnsized<Signal<'a, dyn Any>> for Signal<'a, i32> {} | |
| fn main() { | |
| Signal(&1i32) as Signal<dyn Any>; | |
| } |