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//@ 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);
}
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