//@ edition: 2021 //@ compile-flags: -Zunstable-options #![feature(ref_pat_eat_one_layer_2024)] #![allow(incomplete_features)] struct Foo(u8); fn main() { let Foo(mut a) = &Foo(0); a = &42; //~^ ERROR: mismatched types let Foo(mut a) = &mut Foo(0); a = &mut 42; //~^ ERROR: mismatched types }