How does AsRef work with str?

I want to write a trait that can take a string slice directly:

use std::path::Path;

trait Trait1 {}

impl Trait1 for str {}
// impl<'a> Trait1 for &'a str {}

fn run<T: Trait1>(_: T) {}
fn run1<T: AsRef<Path>>(_: T) {}

fn main() {
    // E0277: the trait bound `&str: Trait1` is not satisfied
    // run::<&str>("sf");
    run1::<&str>("sf");
}

      

        
        
        
      

    

note that

run::<&str>("sf");

      

        
        
        
      

    

will not compile unless Trait1

also used for &str

. However, it AsRef

works despite the fact that it only runs for str

. Is there something special about AsRef?