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// compile-flags: -Ztrait-solver=next
// check-pass
trait Trait {
type Assoc: Sized;
}
impl Trait for &'static str {
type Assoc = &'static str;
}
// Wrapper is just here to get around stupid `Sized` obligations in mir typeck
struct Wrapper<T: ?Sized>(std::marker::PhantomData<T>);
fn mk<T: Trait>(x: T) -> Wrapper<<T as Trait>::Assoc> { todo!() }
trait IsStaticStr {}
impl IsStaticStr for (&'static str,) {}
fn define<T: IsStaticStr>(_: T) {}
fn foo<'a, T: Trait>() {
let y = Default::default();
// `<?0 as Trait>::Assoc <: &'a str`
// In the old solver, this would *equate* the LHS and RHS.
let _: Wrapper<&'a str> = mk(y);
// ... then later on, we constrain `?0 = &'static str`
// but that should not mean that `'a = 'static`, because
// we should use *sub* above.
define((y,));
}
fn main() {}
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