virtual

Is it possible to write virtual methods in Java, as one would do in C++? Or, is there a proper Java approach which you can implement that produces similar behavior? Could I please have some examples? Klaus Byskov Pedersen From wikipedia In Java , all non-static methods are by default " virtual functions. " Only methods marked with the keyword final , which cannot be overridden, along with private methods , which are not inherited, are non-virtual . Eric Leschinski Can you write virtual functions in Java? Yes. In fact, all instance methods in Java are virtual by default. Only certain methods

I have an abstract class (I know that it will not compile this way, but it's for comprehension of what I want to do) : class AbstractComputation { public: template <class T> virtual void setData(std::string id, T data); template <class T> virtual T getData(std::string id); }; class Computation : public AbstractComputation { public: template <class T> void setData(std::string id, T data); template <class T> T getData(std::string id, T data); }; So when I call setData<double>("foodouble", data) I want the double identified by foodouble (internal mechanism which is not the main concern here) to

I need to use a virtual << operator. However, when I try to write: virtual friend ostream & operator<<(ostream& os,const Advertising& add); I get the compiler error Error 1 error C2575: 'operator <<' : only member functions and bases can be virtual How can I turn this operator virtual? The problem with this setup is that the operator<< you defined above is a free function, which can't be virtual (it has no receiver object). In order to make the function virtual, it must be defined as a member of some class, which is problematic here because if you define operator<< as a member of a class then

How can I use CRTP in C++ to avoid the overhead of virtual member functions? There are two ways. The first one is by specifying the interface statically for the structure of types: template <class Derived> struct base { void foo() { static_cast<Derived *>(this)->foo(); }; }; struct my_type : base<my_type> { void foo(); // required to compile. }; struct your_type : base<your_type> { void foo(); // required to compile. }; The second one is by avoiding the use of the reference-to-base or pointer-to-base idiom and do the wiring at compile-time. Using the above definition, you can have template

C++ supports dynamic binding through virtual mechanism. But as I understand the virtual mechanism is an implementation detail of the compiler and the standard just specifies the behaviors of what should happen under specific scenarios. Most compilers implement the virtual mechanism through the virtual table and virtual pointer. And yes I am aware of how this works, So my question is not about implementation detail of virtual pointers and table. My questions are: Are there any compilers which implement Virtual Mechanism in any other way other than the virtual pointer and virtual table mechanism

In the following blog: http://weblogs.asp.net/scottgu/archive/2010/07/16/code-first-development-with-entity-framework-4.aspx The blog contains the following code sample: public class Dinner { public int DinnerID { get; set; } public string Title { get; set; } public DateTime EventDate { get; set; } public string Address { get; set; } public string HostedBy { get; set; } public virtual ICollection<RSVP> RSVPs { get; set; } } public class RSVP { public int RsvpID { get; set; } public int DinnerID { get; set; } public string AttendeeEmail { get; set; } public virtual Dinner Dinner { get; set; } }