논리패턴 190page

class OrderItem
{
public int Amount { get; set; }
public int Price { get; set; }
}

static double GetPrice(OrderItem orderItem) => orderItem.switch
{
OrderItem { Amount: 0 } or OrderItem { Price: 0 }
=> 0.0,
OrderItem { Amount: >= 100 } and OrderItem { Price: >= 10_000 }
=> orderItem.Amount orderItem.Price 0.8,
not OrderItem { Amount: < 100 }
=> orderItem.Amout * orderItem.Price,
};