public static void CovariantGeneric()
{
ICovariantGeneric <MiddleClass> genericMiddle = new CovariantGeneric <MiddleClass>();
MiddleClass result = genericMiddle.Method();
ICovariantGeneric <BaseClass> genericMiddle1 = new CovariantGeneric <MiddleClass>();
ICovariantGeneric <BaseClass> genericMiddle2 = new CovariantGeneric <LastClass>();
var a = genericMiddle1.Method();
var b = genericMiddle2.Method();
ICovariantGeneric <MiddleClass> genericMiddle3 = new CovariantGeneric <LastClass>();
ICovariantGeneric <LastClass> genericMiddle4 = new CovariantGeneric <LastClass>();
// This is OK here:
ICovariantGeneric <BaseClass> genericBase = genericMiddle;
BaseClass baseResult = genericBase.Method();
// This will produce compile-time error:
// Cannot implicitly convert type 'ICovariantGeneric<MiddleClass>' to 'ICovariantGeneric<LastClass>'.
// An explicit conversion exists (are you missing a cast?)
//// ICovariantGeneric<LastClass> genericLast = genericMiddle;
}
private static void WithCovariantGeneric()
{
ICovariantGeneric <MIddleClass> covariantGeneric = new CovariantGeneric <LastClass>();
var result = covariantGeneric.Method();
}