rust/tests/ui/traits/trait-upcasting/sub.rs

27 lines
591 B
Rust

//@ check-pass
//@ revisions: current next
//@ ignore-compare-mode-next-solver (explicit revisions)
//@[next] compile-flags: -Znext-solver
// Verify that the unsize goal can cast a higher-ranked trait goal to
// a non-higer-ranked instantiation.
#![feature(unsize)]
use std::marker::Unsize;
fn test<T: ?Sized, U: ?Sized>()
where
T: Unsize<U>,
{
}
fn main() {
test::<dyn for<'a> Fn(&'a ()) -> &'a (), dyn FnOnce(&'static ()) -> &'static ()>();
trait Foo: for<'a> Bar<'a> {}
trait Bar<'a> {}
test::<dyn Foo, dyn Bar<'static>>();
test::<dyn Foo, dyn Bar<'_>>();
}