rust/tests/ui/implied-bounds/normalization-placeholder-leak.rs
2024-02-16 20:02:50 +00:00

57 lines
1.4 KiB
Rust

// Because of #109628, when we compute the implied bounds from `Foo<X>`,
// we incorrectly get `X: placeholder('x)`.
// Make sure we ignore these bogus bounds and not use them for anything useful.
//
//@ revisions: fail pass
//@ [fail] check-fail
//@ [pass] check-pass
trait Trait {
type Ty<'a> where Self: 'a;
}
impl<T> Trait for T {
type Ty<'a> = () where Self: 'a;
}
struct Foo<T: Trait>(T)
where
for<'x> T::Ty<'x>: Sized;
trait AnotherTrait {
type Ty2<'a>: 'a;
}
#[cfg(fail)]
mod fail {
use super::*;
// implied_bound: `'lt: placeholder('x)`.
// don't use the bound to prove `'lt: 'static`.
fn test_lifetime<'lt, T: Trait>(_: Foo<&'lt u8>) {}
//[fail]~^ ERROR `&'lt u8` does not fulfill the required lifetime
// implied bound: `T::Ty2<'lt>: placeholder('x)`.
// don't use the bound to prove `T::Ty2<'lt>: 'static`.
fn test_alias<'lt, T: AnotherTrait>(_: Foo<T::Ty2::<'lt>>) {}
//[fail]~^ ERROR `<T as AnotherTrait>::Ty2<'lt>` does not fulfill the required lifetime
}
mod pass {
use super::*;
// implied_bound: 'static: placeholder('x).
// don't ice.
fn test_lifetime<T: Trait>(_: Foo<&'static u8>) {}
// implied bound: T::Ty2<'static>: placeholder('x).
// don't add the bound to the environment,
// otherwise we would fail to infer a value for `'_`.
fn test_alias<T: AnotherTrait>(_: Foo<T::Ty2::<'static>>) {
None::<&'static T::Ty2<'_>>;
}
}
fn main() {}