The virtual keyword is used to modify a method, property, indexer or event declaration, and allow it to be overridden in a derived class. For example, this method can be overridden by any class that inherits it: Use the new modifier to explicitly hide a member inherited from a base class. To hide an inherited … Read more
The Virtual Modifier is used to mark that a method\property(ect) can be modified in a derived class by using the override modifier. Example: class A { public virtual void Foo() //DoStuff For A } class B : A { public override void Foo() //DoStuff For B //now call the base to do the stuff for … Read more
Virtual inheritance is used to solve the DDD problem (Dreadful Diamond on Derivation). Look at the following example, where you have two classes that inherit from the same base class: class Base { public: virtual void Ambig(); }; class C : public Base { public: //… }; class D : public Base { public: //… … Read more
Did exactly what you are asking using the Github project: Microsoft/Windows-driver-samples/print/XPSDrvSmpl https://github.com/Microsoft/Windows-driver-samples/tree/master/print/XPSDrvSmpl Installer: http://wixtoolset.org/ Application: Listen to internal port Flow: Install printer and application from a single installer. User prints something with your driver while the application listens to the internal port. When data is sent the application picks it up. This is for XPS, … Read more
A function overrides a virtual function of a base class based on the name and parameter types (see below). Therefore, your class C has two virtual functions foo, one inherited from each A and B. But a function void C::foo() overrides both: [class.virtual]/2 If a virtual member function vf is declared in a class Base … Read more
Through virtual tables. Read this article, http://en.wikipedia.org/wiki/Virtual_table. I could explain it here, but the wikipedia does a better job than I could.
Multiple purposes depending on what you cast Marking your intention to the compiler that an expression that is entirely a no-op is intended as written (for inhibiting warnings, for example) Marking your intention to to the compiler and programmer that the result of something is ignored (the result of a function call, for example) In … Read more
This code demonstrates why you should never call an abstract method, or any other overridable method, from a constructor: abstract class Super { Super() { doSubStuff(); } abstract void doSubStuff(); } class Sub extends Super { String s = “Hello world”; void doSubStuff() { System.out.println(s); } } public static void main(String[] args) { new Sub(); … Read more
After some thinking I recognized this as the classic multi-method requirement, i.e. a method that dispatches based on the runtime type of more than one parameter. Usual virtual functions are single dispatch in comparison (and they dispatch on the type of this only). Refer to the following: Andrei Alexandrescu has written (the seminal bits for … Read more
I am going to go against the flow here… but first, I must assume that your PublicBase destructor is virtual, as otherwise the Derived destructor will never be called. It is usually not a good idea to call a virtual function from a constructor/destructor The reason for this is that dynamic dispatch is strange during … Read more