Converting multiple inheritance code into C ++ for D language

[wiki via Digitalmars-d-learn]

On Saturday, 18 February 2017 at 09:33:25 UTC, biozic wrote:
> On Friday, 17 February 2017 at 23:35:33 UTC, Jean Cesar wrote:
>> On Friday, 17 February 2017 at 23:31:41 UTC, Adam D. Ruppe 
>> wrote:
>>> On Friday, 17 February 2017 at 23:11:25 UTC, Jean Cesar wrote:
>>>> so I changed the code to use interface but how would I do so 
>>>> I could use the constructor in the same way as such a C ++ 
>>>> code?
>>>
>>> Interfaces + mixin templates give you something very similar 
>>> to multiple inheritance. You can have named functions in the 
>>> mixin templates that do the work of the constructor, then 
>>> call them from the real constructor.
>>
>>
>> Yes I saw here that it uses interface to make multiple 
>> inheritance just like C#, but I did not understand what would 
>> this mixing?
>
> A mixin can be used to provide an base implementation for the 
> methods of an interface, along with data members, so that you 
> don't have to define it in every class that implements the 
> interface.
>
> An example : https://dpaste.dzfl.pl/b656851e5c51



I tried to use it in the same way but I did not understand 
correctly because to simulate, alias in this code I had already 
defined the classes as interfaces but I did not understand how 
these constructors should be declared for later use ..

import std.stdio;
import std.string;

/**************************************************************************
* Source: Digital MArs D                                          
         *
* Name: StringHerancaMulti.d                                      
         *
* Concept Aplied: Herança Multipla usando Classe com 4 variáveis 
string   *
* Autor: Jean Zonta                                               
         *
**************************************************************************/

class Test1
{
  protected string _msg1;

    this( string msg1 )
    {
      _msg1=msg1;
    }
};

interface Test2
{
    protected string _msg2;

  // Provide an overridable implementation
  mixin template Impl()
  {
    this( string msg2 )
    {
     _msg2=msg2;
    }
  }
};

interface Test3
{
  protected string _msg3;

  // Provide an overridable implementation
  mixin template Impl()
  {
    this( string msg3 )
    {
     _msg3=msg3;
    }
  }
};

class Test4: Test1, Test2, Test3
{
   mixin Test2.Impl;
   mixin Test3.Impl;

  string _msg4;

  this( string msg1, string msg2 , string msg3, string msg4 )
  {
   super(msg1,msg2,msg3);
   this._msg1 = msg1;
   this._msg2 = msg2;
   this._msg3 = msg3;
   this._msg4 = msg4;
  }

  override void show()
  {
   writeln(_msg1,_msg2,_msg3,_msg4);
  }
};

void main()
{
  Test4 teste = new Teste4("\n\tTeste1 ","Teste2 ","Teste3 
","Teste4");
  teste.show();
  return 0;
}