rust/tests/ui/traits/next-solver/object-soundness-requires-generalization.rs
2024-02-16 20:02:50 +00:00

21 lines
691 B
Rust

//@ compile-flags: -Znext-solver
//@ ignore-test
trait Trait {
type Gat<'lt>;
}
impl Trait for u8 {
type Gat<'lt> = u8;
}
fn test<T: Trait, F: FnOnce(<T as Trait>::Gat<'_>) -> S + ?Sized, S>() {}
fn main() {
// Proving `dyn FnOnce: FnOnce` requires making sure that all of the supertraits
// of the trait and associated type bounds hold. We check this in
// `predicates_for_object_candidate`, and eagerly replace projections using equality
// which may generalize a type and emit a nested AliasRelate goal. Make sure that
// we don't ICE in that case, and bubble that goal up to the caller.
test::<u8, dyn FnOnce(<u8 as Trait>::Gat<'_>) + 'static, _>();
}