On Saturday, 10 August 2019 at 17:28:32 UTC, Alex wrote:
´´´
void main(){}
interface A { void fun(); }
abstract class B{ void fun(); }
class C : A{ void fun(){} }
class D : B{ /*override*/ void fun(){} }
´´´
case 1:
interface A and class C implementing interface A:
You don't need to "override" anything. You are forced to
provide an implementation of the function inside the class.
case 2:
abstract class B and class D inheriting from it:
You can but not have to provide an implementation of a function
inside the abstract class.
If I don't and do not provide any implementation inside D I get
a linker error. Don't how this case behaves on your system.
If you provide an implementation inside the abstract class, you
don't have to provide any in the derived one.
In any case, if you want to provide an implementation inside
the derived class you have to literally "override", as in D
implicit overrides are not allowed.
I think there's some confusion here, because B.foo is not
abstract. abstract on a class is not inherited by its methods.
https://dlang.org/spec/attribute.html#abstract
