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