With current #47292 implementation, there is no way to check validity of unit counters. Neither there is a way to check validity of city counters specifically - we still just use generic counter_behaviour_is_valid() which works as long as there's no single unit counter (nor any other counter that has target other than city).
So, we need something like 'counter_is_valid(enum counter_target target, enum counter_behaviour cb)'
With current #47292 implementation, there is no way to check validity of unit counters. Neither there is a way to check validity of city counters specifically - we still just use generic counter_behaviour_is_valid() which works as long as there's no single unit counter (nor any other counter that has target other than city).
So, we need something like 'counter_is_valid(enum counter_target target, enum counter_behaviour cb)'