rust/tests/ui/coherence/normalize-for-errors.rs
lcnr fe0bd76a8b elaborate unknowable goals
if a trait is unknowable, but its super trait
is definitely not implemented, then the trait
itself is definitely also not implemented.
2024-07-10 16:16:48 +02:00

24 lines
827 B
Rust

//@ revisions: current next
//@ ignore-compare-mode-next-solver (explicit revisions)
//@[next] compile-flags: -Znext-solver
struct MyType;
trait MyTrait<S> {}
trait Mirror {
type Assoc;
}
impl<T> Mirror for T {
type Assoc = T;
}
impl<T: Copy, S: Iterator> MyTrait<S> for (T, S::Item) {}
//~^ NOTE first implementation here
impl<S: Iterator> MyTrait<S> for (Box<<(MyType,) as Mirror>::Assoc>, S::Item) {}
//~^ ERROR conflicting implementations of trait `MyTrait<_>` for type `(Box<(MyType,)>,
//~| NOTE conflicting implementation for `(Box<(MyType,)>,
//~| NOTE upstream crates may add a new impl of trait `std::marker::Copy` for type `std::boxed::Box<(MyType,)>` in future versions
//[next]~| NOTE upstream crates may add a new impl of trait `std::clone::Clone` for type `(MyType,)` in future versions
fn main() {}