trait Hello {
    fn hello(&self);
}

impl <T: ToString> Hello for T {
    fn hello(&self) {
        println!("Hello {}!", self.to_string());
    }
}

impl Hello for Vec<u8> {
	fn hello(&self) {
	        println!("Hello {}!", self.to_string());
	}
}

fn main(){
	let a = vec!(5);
    a.hello();    
}