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Re: Inheritance 10 Years Ago by mike_2000_17 … specific problem, just ask. The types of inheritance in C++... well, that depends a bit.…you can do public inheritance, private inheritance, [multiple inheritance](http://en.wikipedia.org/wiki/Multiple_inheritance), [virtual inheritance](http://en.wikipedia.org…for now). Of course, only "public inheritance" is what is generally meant by … Re: virtual inheritance 14 Years Ago by mrnutty … from the same base class. Its called the diamond shape inheritance. Here is an example : [code] struct Base{ }; … needs. So to solve this problem, we need to use virtual inheritance. So : [code] struct Base{ }; struct A : Base{ }; struct…Thats the overview of why one would use virtual inheritance. Google it up for more info. virtual inheritance? 15 Years Ago by serkan sendur can you guys provide me with an example as to when do i need to use virtual inheritance? Re: virtual inheritance? 15 Years Ago by cikara21 [URL="http://en.allexperts.com/q/C-1040/virtual-inheritance.htm"]ask the expert[/URL] virtual inheritance 14 Years Ago by thileep i want more details abt virtual inheritance in c++ Re: Virtual Inheritance Doubt 14 Years Ago by Tom Gunn … avoid ambiguity while inheriting from multiple base classes[/QUOTE] Right. Virtual inheritance is kind of like inheriting a reference to a class… Re: Virtual Inheritance Doubt 14 Years Ago by nalasimbha … it causes an ambiguity.[/QUOTE] But the purpose of using virtual inheritance is to avoid ambiguity while inheriting from multiple base classes… Re: A question about virtual inheritance 12 Years Ago by alwaysLearning0 …;]http://www.cplusplus.com/doc/tutorial/polymorphism/[/URL] Virtual inheritance is used to answer the problem of memory of…for B and C to avoid this you need virtual inheritance, then it will share memory for A. see … for vtable pointer. I hope it helps to understand virtual inheritance. For further reading: [URL="http://en.wikipedia… Re: Unexpected size of class in case of Virtual Inheritance 9 Years Ago by mike_2000_17 … because that's all it contains and there is no virtual inheritance there. Then, the D2 class has the size of … 4 of these bytes. If you change the inheritance in D1 to use virtual inheritance, you will get a `sizeof(D1) == 4`, but…issue you might raise is the fact that D1, without virtual inheritance, and with an empty base class, is an empty class… Unexpected size of class in case of Virtual Inheritance 9 Years Ago by tapananand …that in case of virtual inheritance, a vptr is… at a program that involved virtual inheritance but I was amazed at …public: }; class D1:public Base { }; class D2:virtual public Base { }; class DD: public D1, public…usual Dreaded Diamond virtual inheritance. If I make D1 use virtual inheritance the size … Re: A question about virtual inheritance 12 Years Ago by mike_2000_17 … of memory allocation. None of the classes have virtual functions, so they will not have vtable pointers.… 4032 bytes in total. In order to implement virtual inheritance, all the classes that are virtually derived from a…"this" pointer depending on the overall inheritance hierarchy. I also recommend Marshall Cline's explanations of… A question about virtual inheritance 12 Years Ago by ChaseRLewis …believe it means. [CODE] class A { protected: int a; public: virtual int get_a(); A(void); ~A(void); }; [/CODE] With an …a function to do so. If I do a non-virtual inheritance my assumption is that it grabs get_a() function from the… I'm not aware. Like maybe a virtual static member so each virtual inherited member gets it's own copy because… multiple inheritance ambiguity problem 7 Years Ago by can-mohan …'s constructor in below programme. below is example of multiple inheritance. As construction always happens from right to left so it… value 10 it is not happening. so how does this virtual inheritance solve this problem here. #include<iostream> using namespace… Re: working of virtual function in Polymorphism 9 Years Ago by mike_2000_17 … aSomeValue, int aSomeOtherValue) : Base(aSomeValue), some_other_value(aSomeOtherValue) { }; virtual ~Derived() { }; virtual void print() const { std::cout << "Some value… also, if you start talking about multiple and virtual inheritance, things could get a lot more complicated. Re: Memory allocation difference between virtual and non virtual class 12 Years Ago by Narue Given the size difference, I'd say that your compiler implements virtual bases using a virtual base pointer (much like the better known virtual table pointer for polymorphism). Extra bookkeeping is required to maintain the shared instance, because the compiler can't simply stack the instances as in non-virtual inheritance. Re: Multiple Inheritance 12 Years Ago by mike_2000_17 …two separate data members as was the case without virtual inheritance). Think of it as a way to merge …But then that goes against the idea of virtual inheritance The purpose of virtual inheritance is to allow for base-classes to,…any C++ learning path. But, luckily, multiple and virtual inheritance is much less common than you might think (but they… Re: Multiple Inheritance: Ambiguous Function 15 Years Ago by Clockowl … I know the solution to this is to use virtual inheritance, but I was wondering why C++ works like it… does. The correct solution is to virtual inherit the class cars in race and tank class. … most cases, is to go by virtual inheritance. This was helpful research. Multiple Virtual Inheritance seems a nice and powerful tool, albeit… Re: Multiple Inheritance 12 Years Ago by rubberman … out for in more complex scenarios. Dealing cleanly with virtual base classes is really gnarly at times, which is…. When I utilize multiple inheritance, I always make sure the base classes are 1) not virtual, and 2) don't…There are other techniques to get the benefits of multiple virtual inheritance, that are generally safer, such as using the PImpl … Re: Multiple Inheritance 12 Years Ago by rubberman …constructor was already invoked before the constructors of the non-virtual bases (Teacher and Student). And, of course, … has been so long since I did any virtual inheritance like this that I forgot the fact that the…(TeachingStudent <- Student and Teacher) directly derived from the virtual base (Student and Teacher <- Person). As you so… Multiple Inheritance 12 Years Ago by jimmymack …the Teacher class. // Teacher inherits Person. class Teacher: virtual public Person { public: Teacher(std::string theName, std::…the Student class. // Student inherits Person. class Student: virtual public Person { public: Student(std::string theName, std::string…goes against the idea of virtual inheritance...this is so confuseing!! help lol Re: Multiple Inheritance: Ambiguous Function 15 Years Ago by Clockowl …} return speed; } private: float speed; }; class racer : virtual public car { public: void boost(float power) { cout <… cruise(getSpeed() + power*power/3); } }; class tank : virtual public car { public: bool shoot(float aimTime) { cout <…base object car, not two. Virtual Inheritance :D Multiple Inheritance: Ambiguous Function 15 Years Ago by Clockowl … function is not overloaded (?) It knows the function is not virtual. Can't the compiler be sure that when I call…, PS: I know the solution to this is to use virtual inheritance, but I was wondering why C++ works like it does… dreaded diamond 13 Years Ago by jagan605 …dreaded diamond.And I wrote a program using virtual inheritance to overcome the problems.I use g++…nme moves"; } }; class car :public virtual vehicle { public: virtual void move() { cout<<"\n…screeching speed"; } }; class boat :public virtual vehicle { public: virtual void move() { cout<<"\n… Re: abstract class and inheritance 13 Years Ago by Narue You've introduced a virtual inheritance ambiguity. Since those member functions are virtual from the base, and both sides of this triangle you'… derive: [code] class derive : public derive2, protected derive3 { public: derive(){}; virtual ~derive(){}; virtual void foo() {} virtual void boo() {} }; [/code] Re: abstract class and inheritance 13 Years Ago by dophine [QUOTE=Narue;1531694]You've introduced a virtual inheritance ambiguity. Since those member functions are virtual from the base, and both sides of …] class derive : public derive2, protected derive3 { public: derive(){}; virtual ~derive(){}; virtual void foo() {} virtual void boo() {} }; [/code][/QUOTE] Thank you Narue. I… Re: Vtable in case of Virtual Base class 14 Years Ago by Narue … [list=1] [*]Objects store data members. [*]Non-virtual inheritance merges data members of every involved class to create an… object. [*]Virtual inheritance merges only a single copy of each virtual base into an object. [*]A…corresponding to the dynamic type of an object. [*]Virtual member functions may incur both a size and … Re: What is pure virtual destructor in c++? 13 Years Ago by mike_2000_17 …sense to have a pure virtual destructor. Because virtual destructors are not like normal virtual functions, they don't get… is true whether the destructor is virtual or not. The reason for virtual destructors is to make sure that,… derived class constructor. The only exception is multiple virtual inheritance in which the order is a bit different. … Re: again having problem about inheritance please help 14 Years Ago by StuXYZ … what you have then change your model to a pure virtual inheritance. (vi) Validate input. Re: A quick multiple inheritance question 15 Years Ago by Narue >Is C++ going to barf on that Possibly. It depends on whether A contains data members and if having multiple copies of the A subobject within a C object would cause problems in your code. Virtual inheritance was introduced to alleviate these kinds of problems. Re: Ambiguous bases 10 Years Ago by rubberman Is there a reason why you are using virtual inheritance for Student and Employee? That should only be necessary if… classes that have a common root, so it should use virtual inheritance so it only has one instance of the root (Person…you might want to define Student and Staff to have virtual inheritence of Person just to be clear. Compilers are picky…