rust/tests/ui/traits/normalize-supertrait.rs

41 lines
812 B
Rust

// Regression test for #77653
// When monomorphizing `f` we need to prove `dyn Derived<()>: Base<()>`. This
// requires us to normalize the `Base<<() as Proj>::S>` to `Base<()>` when
// comparing the supertrait `Derived<()>` to the expected trait.
//@ build-pass
//@ revisions: current next
//@ ignore-compare-mode-next-solver (explicit revisions)
//@[next] compile-flags: -Znext-solver
trait Proj {
type S;
}
impl Proj for () {
type S = ();
}
impl Proj for i32 {
type S = i32;
}
trait Base<T> {
fn is_base(&self);
}
trait Derived<B: Proj>: Base<B::S> + Base<()> {
fn is_derived(&self);
}
fn f<P: Proj>(obj: &dyn Derived<P>) {
obj.is_derived();
Base::<P::S>::is_base(obj);
Base::<()>::is_base(obj);
}
fn main() {
let x: fn(_) = f::<()>;
let x: fn(_) = f::<i32>;
}