why seeples no interfaces?


#include<iostream>

using namespace std;

class A {
public:

  A() {
  }

  virtual ~A() {
  }

  void waka() {
    cout << "WakA!";
  }

};


class IWoopaWaka {
public:
  IWoopaWaka() {
  }

  virtual ~IWoopaWaka() {
  }

  virtual void waka() = 0;
  virtual void woopa() = 0;
};

class B : public IWoopaWaka, public A {
public:
  B() : A() {
  }

  virtual ~B() {
  }

  void woopa() {
    cout << "Woooopa!";
  }
};


int main(int argc, char** argv) {
  IWoopaWaka* wapa = new B();
  wapa->waka();
  wapa->woopa();
  delete wapa;
  return 0;
}

$g++ m.cpp
m.cpp: In function ‘int main(int, char**)’:
m.cpp:49: error: cannot allocate an object of abstract type ‘B’
m.cpp:34: note:   because the following virtual functions are pure within ‘B’:
m.cpp:30: note:         virtual void IWoopaWaka::waka()

#include<iostream>

using namespace std;

class A {
public:

  A() {
  }

  virtual ~A() {
  }

  void waka() {
    cout << "WakA!";
  }

};


class IWoopaWaka {
public:
  IWoopaWaka() {
  }

  virtual ~IWoopaWaka() {
  }

  virtual void waka() = 0;
  virtual void woopa() = 0;
};

class B : public IWoopaWaka, public A {
public:
  B() : A() {
  }

  virtual ~B() {
  }

  void waka() {
    A::waka();
  }

  void woopa() {
    cout << "Woooopa!";
  }
};


int main(int argc, char** argv) {
  IWoopaWaka* wapa = new B();
  wapa->waka();
  wapa->woopa();
  delete wapa;
  return 0;
}

$g++ m.cpp
$a.out
WakA!Woooopa!$

>>13

public interface i {
  public void faggot();
}

public class c{
  public void faggot() { }
}

public class ic implements i {
  public void faggot() { }
}


ic and c are exactly the same except for one feature: ic can be abstracted to an `i' object unlike `c' class

consider the following:

struct geometric_shape {
  int (*area)(struct geometric_shape);
}

struct square {
  int (*area)(struct geometric_shape);
  int (*anus)(struct square);
  int fuckmehard;
}

int main()
{
  struct sqaure sq;
  struct *geometric_shape gs = &sq;
  printf("%d\n",gs->area(gs));
}