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//@ run-pass
#![feature(deref_patterns)]
#![allow(incomplete_features)]
use std::rc::Rc;
struct NoCopy;
fn main() {
let b = Rc::new("aaa".to_string());
let f = || {
let deref!(ref s) = b;
assert_eq!(s.len(), 3);
};
assert_eq!(b.len(), 3);
f();
let v = vec![1, 2, 3];
let f = || {
// this should count as a borrow of `v` as a whole
let [.., x] = v else { unreachable!() };
assert_eq!(x, 3);
};
assert_eq!(v, [1, 2, 3]);
f();
let mut b = "aaa".to_string();
let mut f = || {
let deref!(ref mut s) = b;
s.make_ascii_uppercase();
};
f();
assert_eq!(b, "AAA");
let mut v = vec![1, 2, 3];
let mut f = || {
// this should count as a mutable borrow of `v` as a whole
let [.., ref mut x] = v else { unreachable!() };
*x = 4;
};
f();
assert_eq!(v, [1, 2, 4]);
let mut v = vec![1, 2, 3];
let mut f = || {
// here, `[.., x]` is adjusted by both an overloaded deref and a builtin deref
let [.., x] = &mut v else { unreachable!() };
*x = 4;
};
f();
assert_eq!(v, [1, 2, 4]);
let b = Box::new(NoCopy);
let f = || {
// this should move out of the box rather than borrow.
let deref!(x) = b;
drop::<NoCopy>(x);
};
f();
let b = Box::new((NoCopy,));
let f = || {
// this should move out of the box rather than borrow.
let (x,) = b;
drop::<NoCopy>(x);
};
f();
}
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