rust/tests/ui/trait-bounds/super-assoc-mismatch.rs
2024-03-04 21:06:52 +01:00

61 lines
1.5 KiB
Rust

trait Super {
type Assoc;
}
impl Super for () {
type Assoc = u8;
}
trait Sub: Super<Assoc = u16> {}
trait BoundOnSelf: Sub {}
impl BoundOnSelf for () {}
//~^ ERROR the trait bound `(): Sub` is not satisfied
trait BoundOnParam<T: Sub> {}
impl BoundOnParam<()> for () {}
//~^ ERROR the trait bound `(): Sub` is not satisfied
trait BoundOnAssoc {
type Assoc: Sub;
}
impl BoundOnAssoc for () {
type Assoc = ();
//~^ ERROR the trait bound `(): Sub` is not satisfied
}
trait BoundOnGat where Self::Assoc<u8>: Sub {
type Assoc<T>;
}
impl BoundOnGat for u8 {
type Assoc<T> = ();
//~^ ERROR the trait bound `(): Sub` is not satisfied
}
fn trivial_bound() where (): Sub {}
//~^ ERROR the trait bound `(): Sub` is not satisfied
// The following is an edge case where the unsatisfied projection predicate
// `<<u8 as MultiAssoc>::Assoc1<()> as SuperGeneric<u16>>::Assoc == <u8 as MultiAssoc>::Assoc2`
// contains both associated types of `MultiAssoc`. To suppress the error about the unsatisfied
// super projection, the error's span must be equal to the span of the unsatisfied trait error.
trait SuperGeneric<T> {
type Assoc;
}
trait SubGeneric<T>: SuperGeneric<T, Assoc = T> {}
trait MultiAssoc
where
Self::Assoc1<()>: SubGeneric<Self::Assoc2>
{
type Assoc1<T>;
type Assoc2;
}
impl SuperGeneric<u16> for () {
type Assoc = u8;
}
impl MultiAssoc for u8 {
type Assoc1<T> = ();
//~^ ERROR the trait bound `(): SubGeneric<u16>` is not satisfied
type Assoc2 = u16;
}
fn main() {}