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();
}

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();
}

On Monday, 16 January 2017 at 12:20:47 UTC, rikki cattermole wrote:
> 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();
> }

No, you don't understand I want to express meaning.

other programing language is allow this.

Your code more like the old C++.

If a high-level programing language or need haevy like C++ impl code, It's very regret.

Can like rust / swift / php / java / C# ?

On Monday, 16 January 2017 at 16:31:41 UTC, Brian wrote:
> On Monday, 16 January 2017 at 12:20:47 UTC, rikki cattermole wrote:
>> 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();
>> }
>
> No, you don't understand I want to express meaning.
>
> other programing language is allow this.
>
> Your code more like the old C++.
>
> If a high-level programing language or need haevy like C++ impl code, It's very regret.
>
> Can like rust / swift / php / java / C# ?

You're missing a cast, since `this` is a reference to a superclass.

import std.stdio : writeln;

abstract class Base(T)
{
    this()
    {
        _this = cast(T)(this);
        assert(_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();
}

On Monday, 16 January 2017 at 16:31:41 UTC, Brian wrote:

> No, you don't understand I want to express meaning.
>
> other programing language is allow this.
>
> Your code more like the old C++.
>
> If a high-level programing language or need haevy like C++ impl code, It's very regret.
>
> Can like rust / swift / php / java / C# ?

Perhaps template this parameters [1]:

```
class Base {
    void hello(this C)() {
        (cast(C)this).world();
    }
}

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

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

[1] http://dlang.org/spec/template.html#TemplateThisParameter

On Monday, 16 January 2017 at 19:31:50 UTC, Mike Parker wrote:
> On Monday, 16 January 2017 at 16:31:41 UTC, Brian wrote:
>
>> No, you don't understand I want to express meaning.
>>
>> other programing language is allow this.
>>
>> Your code more like the old C++.
>>
>> If a high-level programing language or need haevy like C++ impl code, It's very regret.
>>
>> Can like rust / swift / php / java / C# ?
>
> Perhaps template this parameters [1]:
>
> ```
> class Base {
>     void hello(this C)() {
>         (cast(C)this).world();
>     }
> }
>
> class Sub:Base {
>     void world() { writeln("Hello world"); }
> }
>
> void main() {
>     auto sub = new Sub;
>     sub.hello();
> }
> ```
>
> [1] http://dlang.org/spec/template.html#TemplateThisParameter

That  Great!

On Monday, 16 January 2017 at 19:31:50 UTC, Mike Parker wrote:
> On Monday, 16 January 2017 at 16:31:41 UTC, Brian wrote:
>
>> No, you don't understand I want to express meaning.
>>
>> other programing language is allow this.
>>
>> Your code more like the old C++.
>>
>> If a high-level programing language or need haevy like C++ impl code, It's very regret.
>>
>> Can like rust / swift / php / java / C# ?
>
> Perhaps template this parameters [1]:
>
> ```
> class Base {
>     void hello(this C)() {
>         (cast(C)this).world();
>     }
> }
>
> class Sub:Base {
>     void world() { writeln("Hello world"); }
> }
>
> void main() {
>     auto sub = new Sub;
>     sub.hello();
> }
> ```
>
> [1] http://dlang.org/spec/template.html#TemplateThisParameter

Thanks, I think this is the best way!

On Monday, 16 January 2017 at 16:47:09 UTC, Nemanja Boric wrote:
> On Monday, 16 January 2017 at 16:31:41 UTC, Brian wrote:
>> [...]
>
> You're missing a cast, since `this` is a reference to a superclass.
>
> import std.stdio : writeln;
>
> abstract class Base(T)
> {
>     this()
>     {
>         _this = cast(T)(this);
>         assert(_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();
> }

Yes, it's possible, thank you!