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Why Static Functions Cannot Be Virtual


Unless you have a singleton, that's questionable. Why is the 'You talking to me' speech from the movie 'Taxi Driver' so famous? asked 8 years ago viewed 30687 times active 13 days ago Upcoming Events 2016 Community Moderator Election ends Nov 22 Visit Chat Linked 1 Redefine static fields in derived / nested Good luck in your journey in a C++ land. http://bovbjerg.net/cannot-be/why-virtual-functions-cannot-be-static.php

Can we have a static virtual functions? Without a "live" object, you have no way to access any virtual function. Since no one responds my question on stack overflow, I hope somebody here may help. It would be possible to define interface classes and include static methods that have to be implemented in derived class. –bkausbk Jan 24 '13 at 7:43 12 It's not so

Static Virtual C#

When does TNG take place in relation to DS9? One solution is to create two functions like I has presented in my last answer. Virtual functions are invoked when you have a pointer/reference to an instance of a class. Cause duplication of code is a bad thing.

The only ways I can think of involves writing two functions / a function and a constant, per class, or use macros. Think of a getInstance() function for example for making singleton. Thank you. Why Static Member Function Cannot Have This Pointer since you return a constant value in your functions, using no static data member, you can drop the static modifier and leave it virtual.

Tweet Thread Tools Show Printable Version Email this Page… Subscribe to this Thread… Display Linear Mode Switch to Hybrid Mode Switch to Threaded Mode December 16th, 1999,04:56 AM #1 Guest The C++ Override Static Method The virtual function-call mechanism can be suppressed by explicitly qualifying the function name using the scope-resolution operator (: to call specific version. current community chat Stack Overflow Meta Stack Overflow your communities Sign up or log in to customize your list. Solving a discrete equation Is it possible to sheathe a katana as a free action?

Delphi has that, and also has "static virtual" methods. –Pavel Minaev Nov 30 '09 at 16:04 4 Exactly. Why Virtual Function Cannot Be Friend I think the Visitor Pattern can give you what you want. On the other hand, static functions are not related to any instances and are rather a property of the class. more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed

C++ Override Static Method

Last Post 1 Day Ago Hi! share|improve this answer answered Aug 29 '11 at 7:26 RvdK 14.7k23276 3 Aha , then static means that *this doesn't exists , virtual means that the method has a this Static Virtual C# class X { public: virtual static void fun(){} // Why we cant have static virtual function in C++? }; c++ share|improve this question edited Nov 28 '12 at 15:23 Bill the Why Static Member Function Cannot Be Const Find a mistake in the following bogus proof Professor Lewin: "Which string will break?" / Me: "That one." / Professor Lewin: "Wrong!" Polyglot Anagrams Robbers' Thread Why hippopotamus instead of potamohippus?

so class D1 : public Base ...; class D2 : public Base ...; ...; D1* pd1 = new D1(); D2* pd2 = new D2(); pd1->MyStaticFun(); /* calls D2::MyVirtualFun() */ delete pd2; http://bovbjerg.net/cannot-be/virtual-path-cannot-be-null.php So there is a wide gap between the two concepts hence it is not possible" I know the reasoning above looks stupid but can you provide some solid grounds to it Each object (having virtual function/s) has an inner pointer to his class's virtual table. Why is this download progress bar worded in the past tense? Static Member Function Cannot Be Const And Volatile

Virtaul functions is how run time polymorphism is implemented. So pure virtual static functions are indeed in contradiction with themselves. If this is your first visit, be sure to check out the FAQ by clicking the link above. http://bovbjerg.net/cannot-be/variable-cannot-be-referenced-from-a-static-context.php Linked 101 C++ static virtual members? 1614 What is the difference between @staticmethod and @classmethod in Python? 195 What are Class methods in Python for?

Can a president win the electoral college and lose the popular vote What is the reasoning behind why the ratio test works? C++ Static Abstract Method And theses functions can't have the same name... To start viewing messages, select the forum that you want to visit from the selection below.

TSA broke a lock for which they have a master key.

You're probably thinking of the usual way of accessing a static member function: MyClass::my_static_function(); Expecting polymorphic behavior in this case is silly unless you use templates for compile-time polymorphism: #include The class calling mechanism ( MyClass::my_static_function(); ) would work the same and an extra rule could be added so that obj->my_static_function(); calls the most derived static member function. Build me a brick wall! C++ Virtual Static Variable Advanced Search Forum Visual C++ & C++ Programming Visual C++ Programming The difference between virtual and static functions?

The columns in the dataset are expected to vary, for example, sometimes it ... HelperClass.Instance.HelperMethod() isn't so much worse than HelperClass.HelperMethod(). So a static function is determined at compile time. Get More Info The method that is overridden by an override declaration is known as the overridden base method.

Well... Thus it makes no sense for them to be virtual. more hot questions question feed lang-cs about us tour help blog chat data legal privacy policy work here advertising info mobile contact us feedback Technology Life / Arts Culture / Recreation In particular allowing run time determination of meta data.

Related 205C++ Virtual/Pure Virtual Explained298C++ static constant string (class member)101C++ static virtual members?27Alternative to c++ static virtual methods5Calling a virtual function statically through a function pointer4Static Virtual workaround in GSL1can we Popular Posts Top 10 Algorithms and Data Structures for Competitive Programming Top 10 algorithms in Interview Questions How to begin with Competitive Programming? I've not seen it work, so I'm not sure that it works, or what's the point for that. How to prove that authentication system works, and that the customer is using the wrong password?

Make two functions: static and virtual struct Object{ struct TypeInformation; static const TypeInformation &GetTypeInformationStatic() const { return GetTypeInformationMain1(); } virtual const TypeInformation &GetTypeInformation() const { return GetTypeInformationMain1(); } protected: static const It can't know which derived class version to call since there's no object associated with it. How do unlimited vacation days work? In what context would you ever be in a position to virtually invoke a static function? –Oliver Charlesworth Mar 25 '12 at 19:03 1 Given the constraints of C++ it's

The point of virtual member functions is that they are dispatched based on the dynamic type of the object instance on which they are called. Because in Telegram you must enumerate each type of derived classes. You'll have to make it a non-static virtual function to work properly; if you also want to be able to call a specific derived class's version non-virtually without an object instance, Well...there is no problem at the end.

One could imagine C++ allowing calling statics from an instance (e.g., Foo foo; ... Please use code.geeksforgeeks.org, generate link and share the link here. [V] The static member function can't access non-static data members/functions of a class. after … ACE: Sharing Dynamically Allocated Memory Across Threads 8 replies Hello, I have dynamically allocated memory that I would like to share across threads.