Full Marks, I got it, I was thinking, there is something wrong in my code, for that reason, only the size is being retrieved and not the data. I have an explanation now for using the boost/interprocess/map.hpp Thanks alot. :) :thumbsup: Thanks and Regards, Neelesh K J Jain.

Yes, its implied.

Neelesh K J Jain wrote: for e.g., xFFFF should utilize only 2 bytes, instead of 4 bytes. What? How the hell is that going to happen? Run the following code and see if you get a clue. char buf[5]; itoa( 0xf, buf, 16); cout << buf << endl; itoa( 0xff, buf, 16); cout << buf << endl; itoa( 0xfff, buf, 16); cout << buf << endl; itoa( 0xffff, buf, 16); cout << buf << endl;

Well,to be included, the sentence must be really memorable, I suppose the OP should try harder, the next time.. :rolleyes: If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile. This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke [My articles]

If you're using VC++2003, 2005 or 2008, it's very easy. If you #include , you have various string conversion macros[^] available. If you're using Visual C++ 6, you have similar macros[^] available. Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

As someone else said, iostream.h is not standard C++. You also need to put using namespace std; at the top of the code, as standard C++ libraries use the std namespace. Christian Graus - Microsoft MVP - C++

It sounds like you are just redrawing the control in a new color and not setting it to the new color. In orther words, you should be calling a function that changes the drawing color of the control so that when it is being repainted it uses the new color. You should not need to define your own OnPaint() function to accomplish this. The flickering is noramaly caused by the OnEraseBkgnd(). INTP "The more help VB provides VB programmers, the more miserable your life as a C++ programmer becomes." Andrew W. Troelsen

You are in the right forum . But minutes away from the tutorial .. Search it !!! here itself redindian

They are one and the same thing! You probably wanted to ask this: What is the difference between ActiveX Control and COM Component? A Control is a COM object with a set of standard interfaces as defined by COM standard for a Control. If a COM object supports all the required interfaces as defined by Microsoft for a Control, then it is a Control.

Hi Neelesh , TO start with COM the best resources are books and online MSDN. Here are some good books. Essential COM by-Don Box Inside COM by-Dale Rogerson Have fun ! Cheers, Vishal

Neelesh K J Jain wrote: I want to know at the runtime for this dependency. I cann't expect the user to use the dependency walker tool to know whether to include another dll or not. there's a non sense in your sentence... when the program is running (and so, when the user is on your program), it is run-time !!! TOXCCT >>> GEII power [toxcct][VisualCalc]

__declspec(novtable) e.g. class __declspec(novtable) MyVBase { ... }; ...cmk Save the whales - collect the whole set

It usually is in the same order as you declare, but it's not required to by the C++ standard. In fact, the standard doesn't talk about object layout at all. AFAIK, COM relies on the ordering of functions in the vtable, so I guess the VC++ compiler must put them in the same order as you declare. Regards Senthil _____________________________ My Blog | My Articles | WinMacro

Davin's collection of Unix programming links[^]

Neelesh K J Jain wrote: What is the main advantage of Virtual destructor? Imagine you have one base class (CBase) and one derived class (CChild that inherits from CBase). Now look at this piece of code: CBase* pPtr = new CChild; .... // Do things with pPtr.. ... delete pPtr; Now, what would happens if the destructor wasn't virtual ? The only destructor that will be called is the destructor of the base class (pPtr is a pointer of type CBase*) and so your object may be not completelly cleaned. So, if you make your destructor virtual, the destructor of CChild will be called. Neelesh K J Jain wrote: Why don't we have virtual constructor when virtual destructor's are present? Because when you create an instance of an object (like in the piece of code before), you know exactly which kind of class (CChild or CBase) you want to create. In fact this line: CBase* pPtr = new CChild can be explained as: first create an object of type CChild (the compiler knows exactly that he will need to call the constructor of CChild) and then store this pointer in pPtr. So, here, no need for virtual constructors... Hope this helps

...Additionally callback functions can be very useful in event notification purposes. Ant. I'm hard, yet soft. I'm coloured, yet clear. I'm fruity and sweet. I'm jelly, what am I? Muse on it further, I shall return! - David Walliams (Little Britain)

I like this question. The other posting did a good job of explaining why the virtual destructor is needed. The reason you don't need a virtual constructor is that you are specifically telling the compiler what you want to instantiate. You write int i = 10; CBase* pPointer; pPointer = new CChild(i); The concept of virtual functions is also described as dynamic run time binding. So the idea is that you call a function on the fully instantiated object and the system is smart enough to realize that since a function is virtual, the child class version of the function is called first. Then the child class can execute it's own code and may or may not ivoke the base class version of the function as well. So virtual functions don't make sense during the construction process. The child class has to call the constructor for the base class from within it's own constructor. Once the construction of the class is complete, you can use the base class pointer to call virtual functions. If you tried to call any virtual functions from either of the constructors, I'm not sure what would really happen. I wouldn't recommend trying this as it really makes no sense. Seems like it would be an undefined operation that may or may not cause a crash. Shawn