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//! Test the behavior of moving out of non-`Copy` union fields.
//! Avoid types that `Drop`, we want to focus on moving.
use std::cell::RefCell;
use std::mem::ManuallyDrop;
fn move_out<T>(x: T) {}
union U1 {
f1_nocopy: ManuallyDrop<RefCell<i32>>,
f2_nocopy: ManuallyDrop<RefCell<i32>>,
f3_copy: i32,
}
union U2 {
f1_nocopy: ManuallyDrop<RefCell<i32>>,
}
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`
}
}
fn main() {}
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