Invisible Bunnies That Power World of Warcraft (2017)(kotaku.com)

    fn complex_system(
      query: Query<(&Component1, &Component2, &Component3)>,
     ) {
      for (c1, c2, c3) in query.iter() {
         if condition(c1) {
           doSomethingTo(c2);
         } else {
           doSomethingTo(c3);
         }
      }
     }

    fn complex_system2(
      query: Query<&Component2, With<ConditionFullfiled>>,
     ) {
      for c2 in query.iter() {
           doSomethingTo(c2);
      }
     }
     fn complex_system3(
      query: Query<&Component3, Without<ConditionFullfiled>>,
     ) {
      for c3 in query.iter() {
           doSomethingTo(c3);
      }
     }