rust/tests/ui/variance/variance-contravariant-arg-trait-match.rs
2023-01-11 09:32:08 +00:00

29 lines
618 B
Rust

#![allow(dead_code)]
// Test that even when `T` is only used in contravariant position, it
// is treated as invariant.
trait Get<T> {
fn get(&self, t: T);
}
fn get_min_from_max<'min, 'max, G>()
where 'max : 'min, G : Get<&'max i32>
{
impls_get::<G,&'min i32>()
//~^ ERROR lifetime may not live long enough
}
fn get_max_from_min<'min, 'max, G>()
where 'max : 'min, G : Get<&'min i32>
{
// Previously OK, but now an error because traits are invariant:
impls_get::<G,&'max i32>()
//~^ ERROR lifetime may not live long enough
}
fn impls_get<G,T>() where G : Get<T> { }
fn main() { }