#![feature(unsize)]

use std::fmt::Debug;
use std::marker::Unsize;
use std::rc::Rc;

fn convert<T>(x: T) -> Rc<dyn Debug>
where
    T: Into<Rc<T>>,
    T: Unsize<dyn Debug>,
{
    x.into()
}

fn foo() {
    convert(Rc::new(1) as Rc<Debug>);
    convert(1);
}