using System;

public class Program

{

    public static void Main()

    {

        ContractItemInventory item = new ContractItemInventory();

        item.SlotNumber = 5;

        var a = item.Cast<ContractItemWeapon>();

        Console.WriteLine(a.SlotNumber);

    }

}

​

public class ContractItemInventory<CItem> where CItem : ContractItem

    {

        public string CharInventoryIDRef { get; set; }

        public CItem Item { get; set; }

        public int SlotNumber { get; set; }

​

        public ContractItemInventory<T> Cast<T>() where T : ContractItem

        {

            if (typeof(CItem).IsSubclassOf(typeof(T)))

            {

                Console.WriteLine("boo");

                return this as ContractItemInventory<T>;

            }

            return new ContractItemInventory<T>()

            {

                CharInventoryIDRef = this.CharInventoryIDRef,

                Item = this.Item as T,

                SlotNumber = this.SlotNumber

            };

        }

        public T CastNew<T, U>() where T : ContractItemInventory<U> where U : ContractItem

        {

            return this as T;

        }

    }

    public class ContractItemInventory : ContractItemInventory<ContractItem> { }

    public class ContractItemEquippableInventory : ContractItemInventory<ContractItemEquippable> { }

    public class ContractItemWeaponInventory : ContractItemInventory<ContractItemWeapon> { }

    public class ContractItemArmorInventory : ContractItemInventory<ContractItemArmor> { }

​

public class ContractItem{}

​

public class ContractItemEquippable: ContractItem{}

public class ContractItemWeapon: ContractItemEquippable{}

public class ContractItemArmor: ContractItemEquippable{}