Code shared from the Rust Playground

playground.rs

use std::fmt::Display;

trait Bar<T: Display> {
    fn foo(&self, s: T) {
        println!("{}", s)
    }
}

struct Foo;

impl<'a> Bar<&'a str> for Foo {}

fn main() {
    let foo = Foo;
    foo.foo("hi");
}