35 lines
845 B
Rust
35 lines
845 B
Rust
|
// 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() {}
|