[the-slice-type] removed unnecessary prefixes

    let s = String::from("hello");

    let _s2: &String = &s;

    let _s3: &str = &s[..];

    println!("&String={} &str={}"

        std::mem::size_of::<&String>(),

        std::mem::size_of::<&str>()

    println!("&String={} &str={}",

        size_of::<&String>(), // std::mem::size_of::<&String>(),

        size_of::<&str>() // std::mem::size_of::<&str>()

    );

}