//! Test the behavior of moving out of non-`Copy` union fields. //! Avoid types that `Drop`, we want to focus on moving. #![feature(untagged_unions)] use std::cell::RefCell; fn move_out(x: T) {} union U1 { f1_nocopy: RefCell, f2_nocopy: RefCell, f3_copy: i32, } union U2 { f1_nocopy: RefCell, } impl Drop for U2 { fn drop(&mut self) {} } fn test1(x: U1) { // Moving out of a nocopy field prevents accessing other nocopy field. unsafe { move_out(x.f1_nocopy); move_out(x.f2_nocopy); //~ ERROR use of moved value: `x` } } fn test2(x: U1) { // "Moving" out of copy field doesn't prevent later field accesses. unsafe { move_out(x.f3_copy); move_out(x.f2_nocopy); // no error } } fn test3(x: U1) { // Moving out of a nocopy field prevents accessing other copy field. unsafe { move_out(x.f2_nocopy); move_out(x.f3_copy); //~ ERROR use of moved value: `x` } } fn test4(x: U2) { // Cannot move out of union that implements `Drop`. unsafe { move_out(x.f1_nocopy); //~ ERROR cannot move out of type `U2`, which implements the `Drop` trait } } fn main() {}