1 error[E0658]: non-reference pattern used to match a reference (see issue #42640)
2 --> $DIR/dont-suggest-dereference-on-arg.rs:16:18
4 LL | .filter(|&(ref a, _)| foo(a))
5 | ^^^^^^^^^^^ help: consider using a reference: `&&(ref a, _)`
7 = help: add #![feature(match_default_bindings)] to the crate attributes to enable
9 error: aborting due to previous error
11 If you want more information on this error, try using "rustc --explain E0658"