Possible Duplicate: C++ Virtual/Pure Virtual Explained For example i have: class A { private: int i; int j; public: void k (int l, int m) { i=l; j=m; } virtual int n (void); }; class B : public A { public: int n (void); }; What good is this virtual ? ...
One of my C++ classes derives from std::vector so that it can act as a container that also perform custom actions on its content. Unfortunately, the compiler complains about the destructor not to be virtual, which I cannot change, since its in the standard library. Am I doing the whole thing wrong (thou shall not derive from STL) or is ...
Just finding my way around templates so was trying out a few stuff. Let me know what I am doing wrong here. I am trying to overload a inherited templates virtual method. // class templates #include <iostream> using namespace std; template <class T, class A> class mypair { T a, b; public: mypair (T first, T second) {a...
Hi. I have a derived class called NumericTextBox that is derived from TextBox.This has all the validationsf for the data to be numeric. Now, i have a popup attached to this textbox in my window. the popup is a virtual keyboard. this lets the user input from both Keyboard and Mouse. but whenever i click a button on the popup, the PreivewT...
I'm extending a class provided by a third part library. The class, let's call it Foo, has a reset() method which can be called in order to restart Foo's behavior. The reset() method is also used internally by the class. class Foo { public: void reset () { /* ... */ } void something () { reset(); } }; ...
C# methods in interfaces are declared without using the virtual keyword, and overridden in the derived class without using the override keyword. Is there a reason for this? I assume that it is just a language convenience, and obviously the CLR knows how to handle this under the covers (methods are not virtual by default), but are there...
I want to do my best on a cool personal project I have in mind, and I need to choose between an interpreter (slow and lightweight in memory) and a virtual machine (faster and heavy). Is true that interpreters are much slower than virtual machines, at a point which it is visible to the user? Somebody have done a comparison? Thanks! ...
Hi all Why is new/override required on abstract methods but not on virtual methods? Sample 1: abstract class ShapesClass { abstract public int Area(); // abstract! } class Square : ShapesClass { int x, y; public int Area() // Error: missing 'override' or 'new' { return x * y; } } The compiler will show ...
Hi all, I have two classes that are almost identical, besides one method. The classes have the same data part and all the member functions but one: class A { private: double data; public: double calc(){ return data*data; } double especific(){ return 2.0*data; } } and the second class is identical, besides the es...
i tried to look up whether virtual function determine during compilation or while running. while looking i found something as dynamic linking/late binding but i didn't understand if it means that the function itself determine during compilation before the executable or during the executable. can someone please explain? ...
Hello, I want to use the java.awt.Robot class to implement a virtual keyboard. I am wondering if there is a way to send the keycode WITH the key location (left or right) using the keyPress(int) method. If you add a KeyListener to an awt Element, a KeyEvent triggered by ctrl or shift has an information if it was the left or right button....
I'm attempting to programatically locate the virtual hostname for a J2EE servlet container. In this enterprise environment, the logical URL consists of protocol://application.company.com/, which is translated to protocol://virtualhost.datacenter.company.com:port/context/. Using ServletRequest.getServerName() gives me "application.compa...
I've got a situation where it seems like the compiler isn't finding the base class definition/implementation of a virtual function with the same name as another member function. struct One {}; struct Two {}; struct Base { virtual void func( One & ); virtual void func( Two & ) = 0; }; struct Derived : public Base { virtual...
Hello! I want to make a virtual tour of a room in Flash / Flex. How can this be achieved? Firstly, is it enough to have pictures taken from a still point? If yes, how can I turn them into a real tour? Also, is there a library for this kind of thing for AS3? Thank you. ...
I need to create a virtual machine appliance (guest: linux, host: win xp/vista/7). I would like to minimize the install process as much as possible. For example, installing VirtualBox + my VM is too much for the end user. I would ideally like a single EXE, "zero-install" solution, but don't know if it exists. I can use qemu or virtua...
I didnt see it in the C++ Faq lite How do i define a base class so every class inheriting it is required to define a destructor? I tried running this program struct VDtor { virtual ~VDtor()=0; }; struct Test:VDtor { virtual ~Test(){} }; int main() { delete new Test; return 0; } http://codepad.org/wFcE71w3 With the error In functi...
I know that virtual and static methods are opposing concepts, but I think that it could make sense sometimes to use them together. There have been quite a bunch of similiar question on SO on this topic, but the following scenario has not been covered yet. There's a C# interface that looks like this: interface IVertexMeshLoader { Ve...
I am extending an existing C++ project. I have a base class that derives from two parent classes. One of the parents has a pure virtual function. I want that pure virtual function to be defined by a function implemented in the other parent. So, I want another parent to satisfy the base class's obligation to define a parent's pure vir...
I have the following class hierarchy: class Base { public: virtual ~Base(); }; class Derived : public Base { public: virtual ~Derived(); }; class MoreDerived : public Derived { public: virtual ~MoreDerived(); }; along with an objects Base* base = new Base(); MoreDerived* obj = new MoreDer...
I have an existing application in C++ with a custom ArrayBase class that manages storage and access to a contiguously allocated region of memory. I have a separate ItrBase class that is used to access data in that ArrayBase. ArrayBase has a createItr() function that currently returns an ItrBase object. I need to extend ArrayBase to us...