View Full Version : Doubt ?

19th January 2007, 07:31
Hi Aces,

"Members" is one of the TAB in "Object Explorer" Window of "Qt Designer".

In that there are some items called 'Forward Declaration", "Includes(in Declaration)" and "Includes(in Implemetation)".

My doubt is, what are the general and functionality difference between them in a program.?

Plz any one give explanation or some useful links regarding my doubt.

Thanks in Advance.

19th January 2007, 08:07
When you just use a pointer to a class you can forward declare it in your header file, i.e. tell the compiler that there will be a class called Xxx. Then you need to include the actual class header file <xxx.h> in your implementation.

The point of this is that the compiler does not have to look into the <xxx.h> when parsing your header file. This saves compilation time.

3rd March 2007, 09:45
If you want to know what is forward declaration, includes etc, then these are C++ implementation and you need to brush up C++. But if you want to know what they actually do in QtDesigner then Open QtAssistance->QtDesigner Manual->Creating a Main Window Application

Read and follow the steps you will get to know what is actually happening and how you can use those variables. I too learned like that.