src/test/ui/binding/empty-types-in-patterns.rs

   1 // run-pass
   2 #![feature(never_type, never_type_fallback)]
   3 #![feature(exhaustive_patterns)]
   4 #![feature(slice_patterns)]
   5 #![allow(unreachable_patterns)]
   6 #![allow(unreachable_code)]
   7 #![allow(unused_variables)]
   8
   9 #[allow(dead_code)]
  10 fn foo(z: !) {
  11     let x: Result<!, !> = Ok(z);
  12
  13     let Ok(_y) = x;
  14     let Err(_y) = x;
  15
  16     let x = [z; 1];
  17
  18     match x {};
  19     match x {
  20         [q] => q,
  21     };
  22 }
  23
  24 fn bar(nevers: &[!]) {
  25     match nevers {
  26         &[]  => (),
  27     };
  28
  29     match nevers {
  30         &[]  => (),
  31         &[_]  => (),
  32         &[_, _, _, ..]  => (),
  33     };
  34 }
  35
  36 fn main() {
  37     let x: Result<u32, !> = Ok(123);
  38     let Ok(y) = x;
  39
  40     assert_eq!(123, y);
  41
  42     match x {
  43         Ok(y) => y,
  44     };
  45
  46     match x {
  47         Ok(y) => y,
  48         Err(e) => match e {},
  49     };
  50
  51     let x: Result<u32, &!> = Ok(123);
  52     match x {
  53         Ok(y) => y,
  54         Err(_) => unimplemented!(),
  55     };
  56
  57     bar(&[]);
  58 }