Greetings, currently I am refactoring one of my programs, and I found an interesting problem. I have Transitions in an automata. Transitions always have a start-state and an end-state. Some Transitions have a label, which encodes a certain Action that must be performed upon traversal. No label means no action. Some transitions have a co...
http://en.wikipedia.org/wiki/Diamond_problem I know what it means, but what steps can I take to avoid it? ...
Since multiple inheritance is bad (it makes the source more complicated) C# does not provide such a pattern directly. But sometimes it would be helpful to have this ability. For instance I'm able to implement the missing multiple inheritance pattern using interfaces and three classes like that: public interface IFirst { void FirstMetho...
I have come across numerous arguments against the inclusion of multiple inheritance in C#, some of which include (philosophical arguments aside): Multiple inheritance is too complicated and often ambiguous It is unnecessary because interfaces provide something similar Composition is a good substitute where interfaces are inappropriate ...
I can see people asking all the time whether multiple inheritance should be included into the next version of C# or Java. C++ folks, who are fortunate enough to have this ability, say that this is like giving someone a rope to eventually hang themselves. What’s the matter with multiple inheritance? Are there any concrete samples? ...
OK, I have a somewhat complicated system in C++. In a nutshell, I need to add a method to a third party abstract base class. The third party also provides a ton of derived classes that also need the new functionality. I'm using a library that provides a standard Shape interface, as well as some common shapes. class Shape { public: ...
I have an abstract base class which acts as an interface. I have two "sets" of derived classes, which implement half of the abstract class. ( one "set" defines the abstract virtual methods related to initialization, the other "set" defines those related to the actual "work". ) I then have derived classes which use multiple inheritance ...
Hi! The net is overflowing with explanations of the "dreaded diamond problem". So is StackOverflow. I think I understand that bit, but I fail to translate that knowledge into comprehending something similar yet different. My question begins as a pure C++ question, but the answer might well branch over into MS-COM specifics. The genera...
I got the following class : class ConstraintFailureSet(dict, Exception) : """ Container for constraint failures. It act as a constraint failure itself but can contain other constraint failures that can be accessed with a dict syntax. """ def __init__(self, **failures) : dict.__init__(self, failures) ...
Hi, I read about this ages ago but never tried it now I can't remember if this is possible or not. Is it possible to extend a class from two parents on php5 e.g. class_d extends class_c and class_b moreover can you do this if class_c and class_b are themselves extended from class_a ... so you get something like this ...
How to solve "Must be MarshalByRefObject" in a good but multiple-inheritance amputated language like C#? The problem is very simple, in several cases you just have to inherit from this class (infrastructure requirements). It does not matter here really, which cases. So, what do you do if you've already inherited from some other class (y...
Is multiple inheritance possible in VB .Net? If so, what is the syntax? ...
Does anyone have any good suggestions for creating a Pipe object in Java which is both an InputStream and and OutputStream since Java does not have multiple inheritance and both of the streams are abstract classes instead of interfaces? The underlying need is to have a single object that can be passed to things which need either an Inpu...
Why is multiple inheritance considered to be evil while implementing multiple interfaces is not? Especially when once considers that interfaces are simply pure abstract classes? (More or less) duplicate of What is the exact problem with multiple inheritance?, Multiple Inheritance in C#, and some others... ...
I have a database structure that has a Person table which contains fields such as name, email, company_id, personType and the like. Because not all Person's are necessarily system user's, I have a separate table User that defines userName and password for those Person's that are User's in the system. I have the following code to define ...
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 diffe...
#include<iostream> using namespace std; class A { int a; int b; public: void eat() { cout<<"A::eat()"<<endl; } }; class B: public A { public: void eat() { cout<<"B::eat()"<<endl; } }; class C: public A { public: void eat() { cout<<"C::eat()"<<endl; } }; class D: pub...
Say I have three classes: class X{}; class Y{}; class Both : public X, public Y {}; I mean to say I have two classes, and then a third class which extends both (multiple-inheritance). Now say I have a function defined in another class: void doIt(X *arg) { } void doIt(Y *arg) { } and I call this function with an instance of both: ...
Whats the other option we can use for multiple inheritance other than implementing interface ...
The following code prints 20, i.e. sizeof(z) is 20. #include <iostream.h> class Base { public: int a; }; class X:virtual public Base { public: int x; }; class Y:virtual public Base { public: int y; }; class Z:public X,public Y { }; int main() { Z z; cout << sizeof(z) <<endl; } ...