rust/tests/ui/type-alias-impl-trait/equal-lifetime-params-ok.rs

53 lines
1.3 KiB
Rust

// Normally we do not allow equal lifetimes in opaque type generic args at
// their defining sites. An exception to this rule, however, is when the bounds
// of the opaque type *require* the lifetimes to be equal.
// issue: #113916
//@ check-pass
#![feature(type_alias_impl_trait)]
#![feature(impl_trait_in_assoc_type)]
trait Trait<'a, 'b> {}
impl<T> Trait<'_, '_> for T {}
mod equal_params {
type Opaque<'a: 'b, 'b: 'a> = impl super::Trait<'a, 'b>;
fn test<'a: 'b, 'b: 'a>() -> Opaque<'a, 'b> {
let _ = None::<&'a &'b &'a ()>;
0u8
}
}
mod equal_static {
type Opaque<'a: 'static> = impl Sized + 'a;
fn test<'a: 'static>() -> Opaque<'a> {
let _ = None::<&'static &'a ()>;
0u8
}
}
mod implied_bounds {
trait Traitor {
type Assoc;
fn define(self) -> Self::Assoc;
}
impl<'a> Traitor for &'static &'a () {
type Assoc = impl Sized + 'a;
fn define(self) -> Self::Assoc {
let _ = None::<&'static &'a ()>;
0u8
}
}
impl<'a, 'b> Traitor for (&'a &'b (), &'b &'a ()) {
type Assoc = impl Sized + 'a + 'b;
fn define(self) -> Self::Assoc {
let _ = None::<(&'a &'b (), &'b &'a ())>;
0u8
}
}
}
fn main() {}