I'm trying to move from Java to D, and i have some like this:

interface A
{
  public bool isCancelled();
  public void setCancelled(bool value);
}

class B
{
  public bool isCancelled();
  protected void setCancelled(bool value);
}

But when i do

class C : B, A
{}

I get

Engine/Main.d(6): Error: class Main.C interface function 'bool isCancelled()' is not implemented
Engine/Main.d(6): Error: class Main.C interface function 'void setCancelled(bool value)' is not implemented

On 11/26/2013 09:32 AM, Agustin wrote:
> I'm trying to move from Java to D, and i have some like this:
>
> interface A
> {
>    public bool isCancelled();
>    public void setCancelled(bool value);
> }
>
> class B
> {
>    public bool isCancelled();
>    protected void setCancelled(bool value);
> }
>
> But when i do
>
> class C : B, A
> {}
>
> I get
>
> Engine/Main.d(6): Error: class Main.C interface function 'bool
> isCancelled()' is not implemented
> Engine/Main.d(6): Error: class Main.C interface function 'void
> setCancelled(bool value)' is not implemented

You have to provide the implementations of the interface functions either in B or C. I think you actually tested with B implementations though:

class B
{
    public bool isCancelled()
    {
        // implemented
        return false;
    }

    protected void setCancelled(bool value)
    {
        // implemented
    }
}

Still the same error...

Unless you want to implement the functions on C as well, then C should not inherit from A. A is already inherited by B:

class C : B    // <-- no A
{}

Ali

On Tuesday, 26 November 2013 at 17:50:12 UTC, Ali Çehreli wrote:
> On 11/26/2013 09:32 AM, Agustin wrote:
>> I'm trying to move from Java to D, and i have some like this:
>>
>> interface A
>> {
>>   public bool isCancelled();
>>   public void setCancelled(bool value);
>> }
>>
>> class B
>> {
>>   public bool isCancelled();
>>   protected void setCancelled(bool value);
>> }
>>
>> But when i do
>>
>> class C : B, A
>> {}
>>
>> I get
>>
>> Engine/Main.d(6): Error: class Main.C interface function 'bool
>> isCancelled()' is not implemented
>> Engine/Main.d(6): Error: class Main.C interface function 'void
>> setCancelled(bool value)' is not implemented
>
> You have to provide the implementations of the interface functions either in B or C. I think you actually tested with B implementations though:
>
> class B
> {
>     public bool isCancelled()
>     {
>         // implemented
>         return false;
>     }
>
>     protected void setCancelled(bool value)
>     {
>         // implemented
>     }
> }
>
> Still the same error...
>
> Unless you want to implement the functions on C as well, then C should not inherit from A. A is already inherited by B:
>
> class C : B    // <-- no A
> {}
>
> Ali

Oh i forgot to add the implementation here, but its there, what i want to do is with an interface be able to change "protected" to "public", this is possible using Java but i don't know if possible using D.


class C : B, A -> setCancelled() is changed from protected to public
{
}

On 11/26/2013 09:52 AM, Agustin wrote:

> Oh i forgot to add the implementation here, but its there, what i want
> to do is with an interface be able to change "protected" to "public",
> this is possible using Java but i don't know if possible using D.
>
>
> class C : B, A -> setCancelled() is changed from protected to public
> {
> }
>
>

I don't know any other way than implementing in terms of B:

class C : B, A
{
    public override bool isCancelled()
    {
        return B.isCancelled();
    }

    protected override void setCancelled(bool value)
    {
        B.setCancelled(value);
    }
}

Ali

On Tuesday, 26 November 2013 at 17:52:28 UTC, Agustin wrote:
> Oh i forgot to add the implementation here, but its there, what i want to do is with an interface be able to change "protected" to "public", this is possible using Java but i don't know if possible using D.

Changing protection level like that seems very confusing.I'd expect a child to be able to expand visibility, not reduce it.