virtual -> override

VirtualToOverride.cs

class Base
	{
		public virtual void Test(){
			Debug.print("Base");
		}
	}
class Derived:Base
	{
		public override void Test(){
			Debug.print("Derived");
		}
	}
class VirtualTest
	{
	    public void M()
	    {
	         Base base1 = new Base();
	         base1.Test();//Base

	         Base base2 = new Derived();
	         base2.Test();//Derived

	         Derived derived1 = new Derived();
	         derived1.Test();//derived

	         /* これはどうなる？   */
	         //    Derived derived2 = new Base();
	         /*
	              error CS0266: Cannot implicitly
	              convert type `Base' to `Derived'.
	              An explicit conversion exists (are you missing a cast?)
	         */
	         //    derived2.Test();
	    }

	}