union Foo { bar: i8, zst: (), pizza: Pizza, } #[derive(Clone, Copy)] struct Pizza { topping: Option } #[allow(dead_code)] #[derive(Clone, Copy)] enum PizzaTopping { Cheese, Pineapple, } fn do_nothing(_x: &mut Foo) {} pub fn main() { let mut foo = Foo { bar: 5 }; do_nothing(&mut foo); // This is UB, so this test isn't run match foo { Foo { bar: _a } => {}, //~ ERROR access to union field is unsafe } match foo { Foo { pizza: Pizza { //~ ERROR access to union field is unsafe topping: Some(PizzaTopping::Cheese) | Some(PizzaTopping::Pineapple) | None } } => {}, } match foo { Foo { zst: () } => {} //~ ERROR access to union field is unsafe } match foo { Foo { pizza: Pizza { .. } } => {} //~ ERROR access to union field is unsafe } // binding to wildcard is okay match foo { Foo { bar: _ } => {}, } let Foo { bar: _ } = foo; }