diamond-problem

The Code is as follow : The Code : #include <iostream> using namespace std; class Animal{ int a; public: Animal(int a) : a(a){} int geta(){return a;} }; class Bird : virtual public Animal{ string b; public: Bird(int a , string b) : Animal(a) , b(b){} }; class Fish : virtual public Animal{ int f; public: Fish(int a , int f) : Animal(a) , f(f){} }; class Unknown : public Bird, public Fish{ char u; public: Unknown(int a , int f , string b , char u ) : Bird(a , b) , Fish(a , f) , u(u){} //Problem }; The Question : 1.)How am I going to initialize all the superclass if the Unknown class is

I have a diamond multiple inheritance scenario like this: A / \ B C \ / D The common parent, A, defines a virtual function fn(). Is it possible for both B and C to define fn() ? If it is, then the next question is - can D access both B and C's fn() without disambiguation? I'm assuming there is some syntax for this.. And is it possible for D to do that without knowing specifically who are B and C? B and C can be replaces by some other classes and I want the code in D to be generic. What I'm trying to do is to have D somehow enumerate all of the instances of fn() it has in its ancestry. Is this

Wikipedia on the diamond problem: "... the diamond problem is an ambiguity that arises when two classes B and C inherit from A, and class D inherits from both B and C. If a method in D calls a method defined in A (and does not override the method), and B and C have overridden that method differently, then from which class does it inherit: B, or C?" So the diamond looks like this: A / \ B C \ / D My question is, what happens if there is no such class A, but again B and C declare the same method, say foo(). Isn't this the same problem? Why is it then called diamond problem? Example: class B {

I know that having diamond inheritance is considered bad practice. However, I have 2 cases in which I feel that diamond inheritance could fit very nicely. I want to ask, would you recommend me to use diamond inheritance in these cases, or is there another design that could be better. Case 1: I want to create classes that represent different kinds of "Actions" in my system. The actions are classified by several parameters: The action can be "Read" or "Write". The action can be with delay or without delay (It is not just 1 parameter. It changes the behavior significantly). The action's "flow

Java is not allowing inheritance from multiple classes (still it allows inheritance from multiple interfaces.), I know it is very much inline with classic diamond problem. But my questions is why java is not allowing multiple inheritance like C++ when there is no ambiguity (and hence no chances of diamond problem) while inheriting from multiple base class ? It was a design decision of Java. You'll never get it, so don't worry too much about it. Although MI might help you make Mixins, that's the only good MI will ever do you. I have read that most programmers don't use multiple inheritance in a

In Java there used to be a subtle but important difference between abstract classes and interfaces: default implementations . Abstract classes could have them, interfaces could not. Java 8 though introduces default implementations for interfaces, meaning this is no longer the critical difference between an interface and an abstract class. So what is? As best as I can tell, the only remaining difference (besides perhaps some under the hood efficiency stuff) is that abstract classes follow traditional Java single-inheritance, whereas interfaces can have multiple-inheritance (or multiple