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|
enum DropOption<T> {
Some(T),
None,
}
impl<T> Drop for DropOption<T> {
fn drop(&mut self) {}
}
// Dropping opt could access the value behind the reference,
fn drop_enum(opt: DropOption<&mut i32>) -> Option<&mut i32> {
match opt {
DropOption::Some(&mut ref mut r) => { //~ ERROR
Some(r)
},
DropOption::None => None,
}
}
fn optional_drop_enum(opt: Option<DropOption<&mut i32>>) -> Option<&mut i32> {
match opt {
Some(DropOption::Some(&mut ref mut r)) => { //~ ERROR
Some(r)
},
Some(DropOption::None) | None => None,
}
}
// Ok, dropping opt doesn't access the reference
fn optional_tuple(opt: Option<(&mut i32, String)>) -> Option<&mut i32> {
match opt {
Some((&mut ref mut r, _)) => {
Some(r)
},
None => None,
}
}
// Ok, dropping res doesn't access the Ok case.
fn different_variants(res: Result<&mut i32, String>) -> Option<&mut i32> {
match res {
Ok(&mut ref mut r) => {
Some(r)
},
Err(_) => None,
}
}
fn main() {}
|
