trait A {
   fn hello(&self) { println!("hello"); }
}

struct B<C: A> {
    pub c: Vec<C>
}

struct D;
struct E(usize);

impl A for D {}


fn main() {
    let x = B{c: vec![D, E(42)]};

    x.c[0].hello();
    x.c[1].hello();
}