inheritance

C++: Inheritance and Operator Overloading

I have two structs: template <typename T> struct Odp { T m_t; T operator=(const T rhs) { return m_t = rhs; } }; struct Ftw : public Odp<int> { bool operator==(const Ftw& rhs) { return m_t == rhs.m_t; } }; I would like the following to compile: int main() { Odp<int> odp; odp = 2; ...

C++: Using base class's private members in equality test

I would like the following to compile, but it does not: template <typename T> struct Odp { public: operator*() const { return m_p; } T* operator->() const { return m_p; } T** operator&() { return &m_p; } private: T* m_p; }; struct Ftw : public Odp<int> { bool o...

Php inheritance superclass variables

Hi! I try to load an entity with some details and there is a resellerId in the entity. Now I inherit a subclass from it, and try to access the resellerId but it's not there. How to pass the attributes to the subclasses? I really need it loaded. Thanks! edit: class Crm_Entity extends Crm_Abstract { protected $_mapper = 'Crm_Mapp...

Inheriting an already instantiated base object

Is it possible to do something like the following: public class ChildClass : BaseClass { public ChildClass(BaseClass o) { base = o; } } Basically, I want a transparent way to wrap a base class inside of other functionality. One example I've thought of is a custom Settings Provider which transparently audits the set...

What are some easy to understand *bad* examples of using inheritance?

I'm looking for bad examples of using inheritance. I'm not very creative so this was the best I could think of: class Car : public Engine {} A car has an engine, but it is not an engine. This would probably work to explain the concept, but I believe there are more illustrative examples? ...

Native Javascript Class implementation

Hi, I am involved in a web application project at the moment and we are not going to be using a framework. I am looking for the 'best' javascript inheritance implementation. I have worked with prototypal style classes as follows: function animal(options) { self = this; //properties this.name = options.name; //eve...

Interface Inheritance and Casting

I have created an interface which I am inheriting from another (COM) interface: public interface IDTSComponentMetaData : IDTSComponentMetaData90 { } That's all it does. The reason behind this is, depending on which version of SQL Server I am working with, the base may be IDTSComponentMetaData90 (2005) or IDTSComponentMetaData100 (20...

VB.NET: Declaring a function inside a base class non-overridable

I have a base class foo that will be used in multiple child classes of similar but slightly different function: Public MustInherit Class foo Public Function bar1() as Something ''// Perfectly OK to change what this method does End Function Public Function bar2() as Something ''// Does a very specific thing I...

Self type inheritance in scala

Say I have the following traits: trait A trait B { this: A => } trait C extends B // { this: A => } Compiler error: illegal inheritance; self-type C does not conform to B's selftype B with A As expected if I uncomment the self type annotation, the compiler is happy. I think it's quite obvious why C also needs this self type. What ...

Maven Site Plugin: How does menu inheritance work?

If I have a multi-module project, how can I inherit a menu from my parent POM? The project layout is: main <-- main project which just contains modules parent <-- parent POM ext <-- 3rd party code I tried this in my parent's site.xml: <menu name="Projects"> <item name="Main Project" href="${web-root}/" collapse="false...

WCF service inheritance

I have a VERY complex service host which consists of multiple DUPLEX services here. They provide a bit of common functionality (Connect, Disconnect, KeepAlive, etc...) but besides that they provide very specific functionality each. All my services inherit from a common base class (abstract). So, I'm also responsible for a part of the c...

Ruby on Rails: how do I check if a variable in an instance of a class?

In Java, you can do instanceof. Is there a Ruby equivalent? ...

C# Form inheritance and generic constraints

I'm working with .NET Compact Framework and just started to refactor some UI code. I'm defining a base user control to encapsulate common functionality, the project compiles OK but when I try to open a child user control in design mode I'm getting an error. I made my class hierarchy taking into account this question. My classes are like...

Why isn't the vtable created?

I'm making a memory patcher for a game but when compiling it with only a single patch implemented, no vtable was created (Using mingw). Could someone tell me what is the problem and how I can fix it? a_patch.cpp (Compile this) #include "a_patch.h" void a_patch::init_patch() { /* example initilisation */ init_var(); vector...

WCF and Inheritance

Hi experts! I'm working on a project where I have an abstract class of Appointment. There are Workouts, Meals and Measurements that all derived from Appointment. My architecture looks like this so far: Dao - with data access layer being entity framework 4 right now POCO classes using the T4 templates WCF Silverlight Client, ASP.net MVP...

Adding static member variable to third-party class

I'm using Boost.Property_Tree for a project and I want to add a small bit of functionality to it. I want to add a "fromFile" static member variable that will figure out the file type and then use the proper parser. In my project, this is currently how I've got it. typedef boost::property_tree::ptree ConfigNode; Then I have another cla...

Baffling JavaScript Inheritance Behavior

<disclaimer> What follows is the fruits of a thought experiment. What I'm doing isn't the issue; the symptoms are. Thank you. </disclaimer> I've finally wrapped my head around constructors, prototypes, and prototypal inheritance in JavaScript. But the SomethingSpectactular method in the sample below bugs me: function FinalClass() { ...

Multiple inheritance is not supported in dotnet. But multiple interface supports?

Multiple inheritance is not supported in dotnet. But multiple interface supports. Why this kind of behaviour exists. Any specific reasons?? ...

Visual Inheritance

Hi. I have same settings for all of my forms for example color , font , align, etc How can i do these settings for one form and inheriting it on all forms. thanks. Edition 1 : i am using Windows Forms. ...

DHTML: Css inheritance problem.

Hello I would like to use in my css simple inheritance from the browsers default values: .myfromh1{ font-weight: bold; } Can I tell css that .myfromh1 class is owning all properties of the h1 default class? thanks Arman. ...