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//@ check-pass
#![warn(clippy::significant_drop_tightening)]
use std::mem::ManuallyDrop;
use std::ops::{Deref, DerefMut};
trait Scopable: Sized {
type SubType: Scopable;
}
struct Subtree<T: Scopable>(ManuallyDrop<Box<Tree<T::SubType>>>);
impl<T: Scopable> Drop for Subtree<T> {
fn drop(&mut self) {
// SAFETY: The field cannot be used after we drop
unsafe { ManuallyDrop::drop(&mut self.0) }
}
}
impl<T: Scopable> Deref for Subtree<T> {
type Target = Tree<T::SubType>;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl<T: Scopable> DerefMut for Subtree<T> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0
}
}
enum Tree<T: Scopable> {
Group(Vec<Tree<T>>),
Subtree(Subtree<T>),
Leaf(T),
}
impl<T: Scopable> Tree<T> {
fn foo(self) -> Self {
self
}
}
fn main() {}
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