The Final(ize) Challenge

[Frits van Bommel]

Andrei Alexandrescu wrote:
> Good point! Now define Unfinalize that opens the final methods of a 
> class for method overriding.
> 
> class A
> {
>     final int foo(string) { ... }
> }
> 
> class UnfinalizeA : A
> {
>     int foo(string a) { return super.foo(a); }
> }

DMD rightly doesn't allow this:
---
test.d(8): Error: function test.UnfinalizeA.foo cannot override final function 
test.A.foo
---

There's a workaround though:
---
class UnfinalizeA : A
{
     int foo_(string a) { return super.foo(a); }
     alias foo_ foo;
}
---