rust/tests/ui/uninhabited/uninhabited-matches-feature...

39 lines
1.0 KiB
Rust

use std::mem::zeroed;
enum Void {}
fn main() {
let x: Result<u32, &'static Void> = Ok(23);
let _ = match x { //~ ERROR non-exhaustive
Ok(n) => n,
};
// This is pretty much instant UB. However, we have no choice -- we need to
// test matching on a reference to `&Void`; we cannot do anything other than
// just accept the fact that this is UB if `main` did run, but it doesn't;
// this test only checks that these are feature-gated.
let x: &Void = unsafe { zeroed() };
let _ = match x {}; //~ ERROR non-exhaustive
let x: (Void,) = unsafe { zeroed() };
let _ = match x {};
let x: [Void; 1] = unsafe { zeroed() };
let _ = match x {};
let x: &[Void] = unsafe { zeroed() };
let _ = match x { //~ ERROR non-exhaustive
&[] => (),
};
let x: Void = unsafe { zeroed() };
let _ = match x {}; // okay
let x: Result<u32, Void> = Ok(23);
let _ = match x {
Ok(x) => x,
};
let x: Result<u32, Void> = Ok(23);
let Ok(x) = x;
}