35 lines
1022 B
Rust
35 lines
1022 B
Rust
//@ run-pass
|
|
// Test when destructors run in a for loop. The intention is
|
|
// that the value for each iteration is dropped *after* the loop
|
|
// body has executed. This is true even when the value is assigned
|
|
// to a `_` pattern (and hence ignored).
|
|
|
|
use std::cell::Cell;
|
|
|
|
struct Flag<'a>(&'a Cell<bool>);
|
|
|
|
impl<'a> Drop for Flag<'a> {
|
|
fn drop(&mut self) {
|
|
self.0.set(false)
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
let alive2 = Cell::new(true);
|
|
for _i in std::iter::once(Flag(&alive2)) {
|
|
// The Flag value should be alive in the for loop body
|
|
assert_eq!(alive2.get(), true);
|
|
}
|
|
// The Flag value should be dead outside of the loop
|
|
assert_eq!(alive2.get(), false);
|
|
|
|
let alive = Cell::new(true);
|
|
for _ in std::iter::once(Flag(&alive)) {
|
|
// The Flag value should be alive in the for loop body even if it wasn't
|
|
// bound by the for loop
|
|
assert_eq!(alive.get(), true);
|
|
}
|
|
// The Flag value should be dead outside of the loop
|
|
assert_eq!(alive.get(), false);
|
|
}
|