Hello

interface Int
{
    void coolFunc();
}

class C1
{
    void coolFunc()
    {
        return;
    }
}

class C2 : C1, Int
{

}

void main()
{
    auto c = new C2;
}

dmd says it's not Ok:
t.d(14): Error: class t.C2 interface function void coolFunc() is not implemented

how to make dmd happy?

On Saturday, 21 August 2021 at 20:35:43 UTC, Alexey wrote:

interface Int
{
    void coolFunc();
}

class C1
{
    void coolFunc()
    {
        return;
    }
}

class C2 : C1, Int
{

}

void main()
{
    auto c = new C2;
}

Not sure if this is the best way, but it does make dmd happy: https://run.dlang.io/is/44F3AE

class C2 : C1, Int
{
    override void coolFunc()
    {
        C1.coolFunc;
    }
}

It looks lame, I admit.

— Bastiaan.

On Saturday, 21 August 2021 at 22:56:40 UTC, Bastiaan Veelo wrote:

interface Int
{
    void coolFunc();
}

class C1
{
    void coolFunc()
    {
        return;
    }
}

class C2 : C1, Int
{

}

void main()
{
    auto c = new C2;
}

class C2 : C1, Int
{
    override void coolFunc()
    {
        C1.coolFunc;
    }
}

I want this inside of C1::coolFunc to return C2 if called as C2::coolFunc

so executing cast(C2) this !is null inside of C1::coolFunc would work

On Saturday, 21 August 2021 at 23:14:14 UTC, Alexey wrote:

If this would work, I'd farther used this like so

interface Int
{
    void coolFunc();
}

class C1
{
    void coolFunc()
    {
        {
            auto obj = (cast(C1)(cast(Int) this));
            if (obj !is null)
            {
                do_one_thing();
            }
        }
        {
            auto obj = (cast(C2)(cast(Int) this));
            if (obj !is null)
            {
                do_another_thing();
            }
        }
        {
            auto obj = (cast(C3)(cast(Int) this));
            if (obj !is null)
            {
                do_something_else();
            }
        }
        return;
    }
}

class C2 : C1, Int
{

}

class C3 : C1, Int
{

}

class C4 : C1, Int
{

}

void main()
{
    auto c = new C2;
    c.coolFunc();
}

On Saturday, 21 August 2021 at 20:35:43 UTC, Alexey wrote:

interface Int
{
    void coolFunc();
}

class C1
{
    void coolFunc()
    {
        return;
    }
}

class C2 : C1, Int
{

}

void main()
{
    auto c = new C2;
}

we're with friends tried similar thing with c++, java, groovy and go - worked ok.

interface Int
{
    public void coolFunc();
};

class C1
{
    public void coolFunc()
    {
        return;
    }
};

class C2 extends C1 implements Int
{

};


public class Main {

    public static void main(String args[])
    {
        Int c = new C2();
    }

}

interface Int
{
    void coolFunc()
}

class C1
{
    void coolFunc()
    {  print "hello" }
}

class C2 extends C1 implements Int
{ }

def printHello = { Int a -> a.coolFunc(); print " world: accept $Int" }

C2 a = new C2()
printHello(a)

class Int;
class C1;
class C2;

class Int
{
public:
    virtual void coolFunc() = delete;
};

class C1
{
public:
    virtual void coolFunc()
    {
        return;
    }
};

class C2 : public C1, public Int
{
public:
};

int main(int argc, char* argv[])
{
    auto c = new C2;
}

package main

import "fmt"

type Int interface {
  CoolFunc()
}

type C1 struct {
}

func (self *C1) CoolFunc() {
  fmt.Println("worked")
  return
}

type C2 struct {
  C1
}

func main() {

  var c Int

  c = new(C2)

  c.CoolFunc()

}

On Sunday, 22 August 2021 at 01:14:08 UTC, Alexey wrote:

interface Int
{
    void coolFunc();
}

class C1
{
    void coolFunc()
    {
        return;
    }
}

class C2 : C1, Int
{

}

void main()
{
    auto c = new C2;
}

interface Int
{
    public void coolFunc();
};

class C1
{
    public void coolFunc()
    {
        return;
    }
};

class C2 extends C1 implements Int
{

};


public class Main {

    public static void main(String args[])
    {
        Int c = new C2();
    }

}

interface Int
{
    void coolFunc()
}

class C1
{
    void coolFunc()
    {  print "hello" }
}

class C2 extends C1 implements Int
{ }

def printHello = { Int a -> a.coolFunc(); print " world: accept $Int" }

C2 a = new C2()
printHello(a)

class Int;
class C1;
class C2;

class Int
{
public:
    virtual void coolFunc() = delete;
};

class C1
{
public:
    virtual void coolFunc()
    {
        return;
    }
};

class C2 : public C1, public Int
{
public:
};

int main(int argc, char* argv[])
{
    auto c = new C2;
}

package main

import "fmt"

type Int interface {
  CoolFunc()
}

type C1 struct {
}

func (self *C1) CoolFunc() {
  fmt.Println("worked")
  return
}

type C2 struct {
  C1
}

func main() {

  var c Int

  c = new(C2)

  c.CoolFunc()

}

Sorry, Bastiaan's solution is the only that I know of as well.

Here's your desired behaviour:

import std.stdio:writeln;

interface Int
{
    void coolFunc();
}

class C1
{
    void coolFunc()
    {
        {
            auto obj = (cast(C1)(cast(Int) this));
            if (obj !is null)
            {
                do_one_thing();
            }
        }
        {
            auto obj = (cast(C2)(cast(Int) this));
            if (obj !is null)
            {
                obj.do_another_thing();
            }
        }
        {
            auto obj = (cast(C3)(cast(Int) this));
            if (obj !is null)
            {
                obj.do_something_else();
            }
        }
        return;
    }

    void do_one_thing(){
        writeln("one thing from C1");
    }
}

class C2 : C1, Int
{
    override void coolFunc(){
        typeof(super).coolFunc();
    }

    void do_another_thing(){
        writeln("did another thing from C2");
    }

}

class C3 : C1, Int
{
    override void coolFunc(){
        typeof(super).coolFunc();
    }

    void do_something_else(){
        writeln("doing something else from C3");
    }

}

class C4 : C1, Int
{
    override void coolFunc(){
        typeof(super).coolFunc();
    }

}

void main()
{
    auto c = new C2;
    c.coolFunc();
}

On Saturday, 21 August 2021 at 20:35:43 UTC, Alexey wrote:

interface Int
{
    void coolFunc();
}

class C1
{
    void coolFunc()
    {
        return;
    }
}

class C2 : C1, Int
{

}

void main()
{
    auto c = new C2;
}

so, Is this a bug in dmd or not?

On Sunday, 22 August 2021 at 12:20:56 UTC, Alexey wrote:

interface Int
{
    void coolFunc();
}

class C1
{
    void coolFunc()
    {
        return;
    }
}

class C2 : C1, Int
{

}

void main()
{
    auto c = new C2;
}

some answers have been given here and here
https://discord.com/channels/242094594181955585/242122752436338688/878996818904612864
https://issues.dlang.org/show_bug.cgi?id=22232