src/test/ui/pattern/usefulness/issue-57472.rs

   1 #![crate_type="lib"]
   2 #![deny(unreachable_patterns)]
   3
   4 mod test_struct {
   5     // Test the exact copy of the minimal example
   6     // posted in the issue.
   7     pub struct Punned {
   8         foo: [u8; 1],
   9         bar: [u8; 1],
  10     }
  11
  12     pub fn test(punned: Punned) {
  13         match punned {
  14             Punned { foo: [_], .. } => println!("foo"),
  15             Punned { bar: [_], .. } => println!("bar"),
  16             //~^ ERROR unreachable pattern [unreachable_patterns]
  17         }
  18     }
  19 }
  20
  21 mod test_union {
  22     // Test the same thing using a union.
  23     pub union Punned {
  24         foo: [u8; 1],
  25         bar: [u8; 1],
  26     }
  27
  28     pub fn test(punned: Punned) {
  29         match punned {
  30             Punned { foo: [_] } => println!("foo"),
  31             Punned { bar: [_] } => println!("bar"),
  32             //~^ ERROR unreachable pattern [unreachable_patterns]
  33         }
  34     }
  35 }