guards.rs

fn main() {
    let a = alt 10 {
      x when x < 7 { 1 }
      x when x < 11 { 2 }
      10 { 3 }
      _ { 4 }
    };
    assert a == 2;

    let b = alt {x: 10, y: 20} {
        x when x.x < 5 && x.y < 5 { 1 }
        {x, y} when x == 10 && y == 20 { 2 }
        {x, y} { 3 }
    };
    assert b == 2;
}