rust/tests/ui/traits/issue-52893.rs

58 lines
1.1 KiB
Rust

//@ check-fail
//
// regression test for issue 52893
trait At<Name> {
type AtRes;
fn at(self) -> Self::AtRes;
}
trait Push<T> {
type PushRes;
fn push(self, other: T) -> Self::PushRes;
}
trait AddClass<Name, F> {
type AddRes;
fn init(self, func: F);
}
trait ToRef {
type RefRes;
fn to_ref(&self) -> Self::RefRes;
}
struct Class<P>(P);
impl<P> Class<P> {
fn with<Name, F>(self) -> <Self as AddClass<Name, F>>::AddRes
where
Self: AddClass<Name, F>,
{
todo!()
}
fn from<F>(self) -> <Self as AddClass<P, F>>::AddRes
where
Self: AddClass<P, F>,
{
todo!()
}
}
impl<F, Name, P> AddClass<Name, F> for Class<P>
where
Self: At<Name>,
<Self as At<Name>>::AtRes: Push<F>,
<<Self as At<Name>>::AtRes as Push<F>>::PushRes: ToRef<RefRes = Self> + Push<F>,
{
type AddRes = ();
fn init(self, func: F) {
let builder = self.at().push(func);
let output = builder.to_ref();
builder.push(output); //~ ERROR mismatched types [E0308]
}
}
fn main() {}