Guards

A match guard can be added to filter the arm.

  1. fn main() {
  2.     let pair = (2, -2);
  3.     // TODO ^ Try different values for `pair`
  5.     println!("Tell me about {:?}", pair);
  6.     match pair {
  7.         (x, y) if x == y => println!("These are twins"),
  8.         // The ^ `if condition` part is a guard
  9.         (x, y) if x + y == 0 => println!("Antimatter, kaboom!"),
  10.         (x, _) if x % 2 == 1 => println!("The first one is odd"),
  11.         _ => println!("No correlation..."),
  12.     }
  13. }

See also:

Tuples