rust/tests/ui/unsized/unsize-coerce-multiple-adt-params.rs

30 lines
459 B
Rust

// check-pass
struct Foo<T, U>
where
(T, U): Trait,
{
f: <(T, U) as Trait>::Assoc,
}
trait Trait {
type Assoc: ?Sized;
}
struct Count<const N: usize>;
impl<const N: usize> Trait for (i32, Count<N>) {
type Assoc = [(); N];
}
impl<'a> Trait for (u32, ()) {
type Assoc = [()];
}
// Test that we can unsize several trait params in creative ways.
fn unsize<const N: usize>(x: &Foo<i32, Count<N>>) -> &Foo<u32, ()> {
x
}
fn main() {}