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digitalmars.D.learn - Without multiples inheritance, how is this done?

reply Jack <jckj33 gmail.com> writes:
let's say I have:

```d
class Base
{
     int f()
     {
         doSomething();
         return n * 5;
     }

     void doSomething() { }
}

class Foo : Base
{
     void myMethod() { /* ... */ }
}

class Baa : Base
{
     void myMethod2() { /* ... */ }
}
```

then I'd like to make a extended version(making those DRY 
routines a class itself) of Foo and Baa, like this:

```d
abstract class DRY : Base
{
     this(int n)
     {
         this.n = n;
     }

     override int f()
     {
         super.doSomething();
         return n;
     }

     private int n;
}
```

but the class ExtendFoo and ExtendedBaa  must inherit from Foo 
and Baa, respectively. But how can I make it inherit the routines 
from DRY class too without multiples inheritance? in C++ I'd just 
do:

```d
class ExtendedFoo : DRY, Base { /* ... */ }
class ExtendBaa : DRY, Base { /* ... */ }
```
May 08
next sibling parent matheus <matheus gmail.com> writes:
On Saturday, 8 May 2021 at 18:33:35 UTC, Jack wrote:
 ...
 but the class ExtendFoo and ExtendedBaa  must inherit from Foo 
 and Baa, respectively. But how can I make it inherit the 
 routines from DRY class too without multiples inheritance? in 
 C++ I'd just do:

 class ExtendedFoo : DRY, Base { /* ... */ }
 class ExtendBaa : DRY, Base { /* ... */ }
What about this model: class baseFoo{ // Implement foo stuff } class baseFooBar : baseFoo{ // Implement bar stuff } class FooBar : baseFooBar{ // Do your FooBar thing! } Matheus.
May 08
prev sibling parent Adam D. Ruppe <destructionator gmail.com> writes:
On Saturday, 8 May 2021 at 18:33:35 UTC, Jack wrote:
 ```d
 abstract class DRY : Base
 {
     this(int n)
     {
         this.n = n;
     }

     override int f()
     {
         super.doSomething();
         return n;
     }

     private int n;
 }
 ```
You can change that from abstract class to `mixin template`, make Foo and Baa be `interface`, then use `mixin DRY;` inside your child class.
May 08