28 lines
768 B
Rust
28 lines
768 B
Rust
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use std::cell::Cell;
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struct Flag<'a>(&'a Cell<bool>);
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impl<'a> Drop for Flag<'a> {
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fn drop(&mut self) {
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self.0.set(false)
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}
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}
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fn main() {
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let alive2 = Cell::new(true);
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for _i in std::iter::once(Flag(&alive2)) {
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// The Flag value should be alive in the for loop body
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assert_eq!(alive2.get(), true);
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}
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// The Flag value should be dead outside of the loop
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assert_eq!(alive2.get(), false);
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let alive = Cell::new(true);
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for _ in std::iter::once(Flag(&alive)) {
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// The Flag value should be alive in the for loop body even if it wasn't
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// bound by the for loop
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assert_eq!(alive.get(), true);
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}
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// The Flag value should be dead outside of the loop
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assert_eq!(alive.get(), false);
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}
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