• Engine Machine (2/2) Aug 17 2016 https://en.wikipedia.org/wiki/Virtual_class
• Basile B. (24/26) Aug 17 2016 Not naturally. The ancestor must be specified for the inner
• Meta (3/5) Aug 17 2016 Yes, D's `alias this` feature supports this.
• Basile B. (3/10) Aug 17 2016 No read carefully, alias this does not the same thing,
• Meta (3/15) Aug 17 2016 How doesn't it? You define a member with the same name in the
• Basile B. (22/38) Aug 17 2016 You can't call the most derived from a variable that has a lesser

Engine Machine <EM EM.com> writes:

https://en.wikipedia.org/wiki/Virtual_class

Can D do stuff like this naturally?

Basile B. <b2.temp gmx.com> writes:

On Thursday, 18 August 2016 at 00:49:49 UTC, Engine Machine wrote:
 https://en.wikipedia.org/wiki/Virtual_class

 Can D do stuff like this naturally?

Not naturally. The ancestor must be specified for the inner 
"virtual class":

°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°
class Foo
{
     class Internal
     {
         void stuff() {}
     }
}

class Bar: Foo
{
     class Internal: Foo.Internal
     {
         override void stuff() {}
     }
}
°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°

However the ancestor inner class is well inherited (in the scope 
of a derived class Internal resolves to the parent definition or 
to the internal override when applicable).

Note that I find the wikipedia example very bad. "Parts" doesn't 
define anything to override.

Meta <jared771 gmail.com> writes:

On Thursday, 18 August 2016 at 00:49:49 UTC, Engine Machine wrote:
 https://en.wikipedia.org/wiki/Virtual_class

 Can D do stuff like this naturally?

Yes, D's `alias this` feature supports this.

https://dlang.org/spec/class.html#alias-this

Basile B. <b2.temp gmx.com> writes:

On Thursday, 18 August 2016 at 02:51:48 UTC, Meta wrote:
 On Thursday, 18 August 2016 at 00:49:49 UTC, Engine Machine 
 wrote:
 https://en.wikipedia.org/wiki/Virtual_class

 Can D do stuff like this naturally?

 Yes, D's `alias this` feature supports this.

 https://dlang.org/spec/class.html#alias-this

No read carefully, alias this does not the same thing, 
particularly when the time comes to override the inner type.

Meta <jared771 gmail.com> writes:

On Thursday, 18 August 2016 at 02:55:49 UTC, Basile B. wrote:
 On Thursday, 18 August 2016 at 02:51:48 UTC, Meta wrote:
 On Thursday, 18 August 2016 at 00:49:49 UTC, Engine Machine 
 wrote:
 https://en.wikipedia.org/wiki/Virtual_class

 Can D do stuff like this naturally?

 Yes, D's `alias this` feature supports this.

 https://dlang.org/spec/class.html#alias-this

 No read carefully, alias this does not the same thing, 
 particularly when the time comes to override the inner type.

How doesn't it? You define a member with the same name in the 
outer class and it'll override the inner one.

Basile B. <b2.temp gmx.com> writes:

On Thursday, 18 August 2016 at 03:58:00 UTC, Meta wrote:
 On Thursday, 18 August 2016 at 02:55:49 UTC, Basile B. wrote:
 On Thursday, 18 August 2016 at 02:51:48 UTC, Meta wrote:
 On Thursday, 18 August 2016 at 00:49:49 UTC, Engine Machine 
 wrote:
 https://en.wikipedia.org/wiki/Virtual_class

 Can D do stuff like this naturally?

 Yes, D's `alias this` feature supports this.

 https://dlang.org/spec/class.html#alias-this

 No read carefully, alias this does not the same thing, 
 particularly when the time comes to override the inner type.

 How doesn't it? You define a member with the same name in the 
 outer class and it'll override the inner one.

You can't call the most derived from a variable that has a lesser 
derived type:

°°°°°°°°°°°°°°°°°°°°°°°°
class Foo
{
     Internal internal;

     class Internal {void stuff() {"base".writeln;}}

     this() {internal = new Internal;}

     alias internal this;
}

class Bar: Foo
{
     void stuff() {"derived".writeln;}
}

void main(string[] args)
{
     Foo f = new Bar;
     f.stuff(); // "base", not "derived".
}
°°°°°°°°°°°°°°°°°°°°°°°°°

 From what i've read, "virtual classes" respect the OOP principles.