interface iBase
{
iBase fooBase(iBase);
}
class cBase : iBase
{
cBase fooBase(cBase c) { return c; }
}
cBase.fooBase should be a valid override of iBase.fooBase because
they are the same type! cBase is a super type so it contains
everything iBase contains and maybe more.
There should be no reason why the compiler can't figure this out.
It's a very simple rule.
Any time the user calls iBase.fooBase it can be replaced with
cBase.fooBase so it should not compromise any code to go ahead
and accept it as a proper override.
