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Re: virtual inheritance 15 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? 16 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? 16 Years Ago by cikara21 [URL="http://en.allexperts.com/q/C-1040/virtual-inheritance.htm"]ask the expert[/URL] virtual inheritance 15 Years Ago by thileep i want more details abt virtual inheritance in c++ Re: Virtual Inheritance Doubt 15 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 15 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 13 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 11 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 11 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 13 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 13 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… virtual inheritance 15 Years Ago by bil050 …) : x(i) {} virtual void a() {}; }; struct B: virtual A { B() : A(0) {} virtual void a(){} }; struct C: A, virtual B { virtual void a(){} virtual void c… Re: virtual inheritance 15 Years Ago by kvprajapati Welcome bel050, It would be [B]virtual A[/B]. [CODE=C++] struct C: virtual A, virtual B { C(): A(1) {} virtual void a(){} virtual void c(){} }; [/CODE] Use code tags. Source code must be surrounded with code tags. For example, [noparse] [CODE=C++] ... statements.. [/CODE] [/noparse] Re: virtual inheritance 15 Years Ago by bil050 I want the A to be non-virtual Base! Re: virtual inheritance 15 Years Ago by CppBuilder2006 why don't you search for a C++ tutorial?! Virtual Inheritance Doubt 15 Years Ago by nalasimbha … would like to know in particular what happens internally during inheritance. The classes that i use and the way they are… D: public B, public C { public: double d; }; class E:virtual public A { public: double e; void c1(); }; class F:public…of class H do i need to use the keyword 'virtual' before classes D and F? What are the variables contained… Re: Virtual Inheritance Question 16 Years Ago by Alex Edwards … classes are constructed before any Non-virtual Base class. "virtual base classes and inheritance offer a set of rules which every c…++ programmar should be aware of. Specifically: virtual base classes… Virtual Inheritance Question 16 Years Ago by Agni … std; class Lock { friend class First; private: Lock() { } }; class First : virtual public Lock { public: void function() { cout << "function1… Re: Virtual Inheritance Question 16 Years Ago by Alex Edwards … { friend class First; friend class Second; private: Lock() { } }; class First : virtual public Lock { public: void function() { cout << "function1… Re: Virtual Inheritance Question 16 Years Ago by Agni i think its more because of the keyword 'virtual', just try and remove that and it compiles and excutes fine. Normally the class Second wil call the ctor of class First and then class First will call the ctor of Lock so i dont need to make 'Second' a friend of 'Lock'. but when i derive from the class 'Lock' virtually this doesnt happen. Re: Virtual Inheritance Question 16 Years Ago by Agni thanks Edwards, that makes sense. Need to understand the virtual base classes more. >Change the private constructor into a public constructor.. yes but then we wouldn't have faced the problem and wouldn't have come to know all this. it was just something i was trying to do. Re: Inheritance 12 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 15 Years Ago by kvprajapati [CODE=C++] struct C: B {} [/CODE] Re: virtual inheritance 15 Years Ago by Nick Evan [QUOTE=adatapost;920786] Use code tags. Source code must be surrounded with code tags. For example, [noparse] [CODE=C++] ... statements.. [/CODE] [/noparse][/QUOTE] You're wrong, it should be: [noparse] [CODE=cplusplus] ... statements.. [/CODE] [/noparse] Here's the difference: [code=c++] #include <iostream> … Re: virtual inheritance 15 Years Ago by kvprajapati Thanks niek_e, Yes, I got it. Thanks a lot for your cooperation. Re: Multiple Inheritance 14 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 16 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… multiple inheritance ambiguity problem 8 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: Multiple Inheritance 14 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 14 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…