use std::rc::Rc; union U { a: T } fn main() { let u = U { a: Rc::new(0u32) }; //~^ ERROR the trait bound `std::rc::Rc: std::marker::Copy` is not satisfied let u = U::> { a: Default::default() }; //~^ ERROR the trait bound `std::rc::Rc: std::marker::Copy` is not satisfied }