src/test/ui/issues/issue-33819.rs

   1 fn main() {
   2     let mut op = Some(2);
   3     match op {
   4         Some(ref v) => { let a = &mut v; },
   5         //~^ ERROR cannot borrow `v` as mutable, as it is not declared as mutable
   6         None => {},
   7     }
   8 }