src/test/ui/or-patterns/search-via-bindings.rs

   1 // Check that we expand multiple or-patterns from left to right.
   2
   3 // run-pass
   4
   5 fn search(target: (bool, bool, bool)) -> u32 {
   6     let x = ((false, true), (false, true), (false, true));
   7     let mut guard_count = 0;
   8     match x {
   9         ((a, _) | (_, a), (b @ _, _) | (_, b @ _), (c @ false, _) | (_, c @ true))
  10             if {
  11                 guard_count += 1;
  12                 (a, b, c) == target
  13             } =>
  14         {
  15             guard_count
  16         }
  17         _ => unreachable!(),
  18     }
  19 }
  20
  21 // Equivalent to the above code, but hopefully easier to understand.
  22 fn search_old_style(target: (bool, bool, bool)) -> u32 {
  23     let x = ((false, true), (false, true), (false, true));
  24     let mut guard_count = 0;
  25     match x {
  26         ((a, _), (b @ _, _), (c @ false, _))
  27         | ((a, _), (b @ _, _), (_, c @ true))
  28         | ((a, _), (_, b @ _), (c @ false, _))
  29         | ((a, _), (_, b @ _), (_, c @ true))
  30         | ((_, a), (b @ _, _), (c @ false, _))
  31         | ((_, a), (b @ _, _), (_, c @ true))
  32         | ((_, a), (_, b @ _), (c @ false, _))
  33         | ((_, a), (_, b @ _), (_, c @ true))
  34             if {
  35                 guard_count += 1;
  36                 (a, b, c) == target
  37             } =>
  38         {
  39             guard_count
  40         }
  41         _ => unreachable!(),
  42     }
  43 }
  44
  45 fn main() {
  46     assert_eq!(search((false, false, false)), 1);
  47     assert_eq!(search((false, false, true)), 2);
  48     assert_eq!(search((false, true, false)), 3);
  49     assert_eq!(search((false, true, true)), 4);
  50     assert_eq!(search((true, false, false)), 5);
  51     assert_eq!(search((true, false, true)), 6);
  52     assert_eq!(search((true, true, false)), 7);
  53     assert_eq!(search((true, true, true)), 8);
  54
  55     assert_eq!(search_old_style((false, false, false)), 1);
  56     assert_eq!(search_old_style((false, false, true)), 2);
  57     assert_eq!(search_old_style((false, true, false)), 3);
  58     assert_eq!(search_old_style((false, true, true)), 4);
  59     assert_eq!(search_old_style((true, false, false)), 5);
  60     assert_eq!(search_old_style((true, false, true)), 6);
  61     assert_eq!(search_old_style((true, true, false)), 7);
  62     assert_eq!(search_old_style((true, true, true)), 8);
  63 }