parent class get the subclass object

[rikki cattermole via Digitalmars-d]

On 17/01/2017 1:15 AM, Brian wrote:
> Dlang should support such coding. What should I do?
>
> import std.stdio : writeln;
>
> abstract class Base(T)
> {
>     this()
>     {
>         _this = this;
>     }
>
>     void hello()
>     {
>         _this.world();
>     }
>
>     private
>     {
>         T _this;
>     }
> }
>
>
> class Sub : Base!Sub
> {
>     void world()
>     {
>         writeln("Hello world");
>     }
> }
>
> void main()
> {
>     Sub sub = new Sub;
>     sub.hello();
> }
>

FYI, this would have been more appropriate in D.learn instead of the 
main forum.

import std.stdio;

abstract class Base {
	void hello() {
		world();
	}

	void world();
}

class Sub : Base {
	override void world() {
		writeln("Hello World");
	}
}

void main() {
	Sub sub = new Sub;
	sub.hello();
}