The easiest* solution would be to do what rust does. You need to use & on both sides and error out on mismatch. Eg. fn foo(bar: &Bar) { ... } bar(&Baz) * Thi

The easiest* solution would be to do what rust does. You need to use & on both sides and error out on mismatch. Eg. fn foo(bar: &Bar) { ... } bar(&Baz) * This would be a breaking change, so a non-starter.