Solved

Renaming classes, handling header guard GUIDs

Posted on 2004-09-02
2
264 Views
Last Modified: 2012-05-05
When I create a new class in VC++ 6.0, an MFC class for example, Visual Studio will generate a header and implementation file, and within that header is a header guard, something along the lines of

#IFDEF  __MYCLASSNAME_H_GUID

Anyway - say I want to later rename the class, either before or after it is actually in use elsewhere in the codebase. I would first change the names of the .H and .CPP files, and change all instances of CMyClassName throughout the code to CMyNewName as well as all include references etc. What, if anything do I have to do to the header guard, specifically, the GUID portion of it? Is that value installed in the registry or anything and further used by the compiler, or is purely a long random number used only to insure a unique identifier?

thanks
-Paul
0
Comment
Question by:PMH4514
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 3

Accepted Solution

by:
teratoma earned 30 total points
ID: 11970339
Rest assured, the header guard is only there to prevent the header from being included twice in the same compilation unit.  This is the basic C workaround to the multiple inclusion problem.  Changing the filename or the name of the class will not cause a problem unless __MYCLASSNAME_H_GUID somehow gets defined elsewhere.  The only true guideline is that each header has a unique guard.  Well, underscores in front are discouraged, but that was MS's decision not yours :)
0
 
LVL 39

Assisted Solution

by:itsmeandnobodyelse
itsmeandnobodyelse earned 20 total points
ID: 11971165
It's good practice to use the filename as guard. e. g. header.h  gives

#ifdef HEADER_H
#define HEADER_H

#endif // HEADER_H

That GUID thing of MFC wizard is some kind of stupidity i always remove from my projects. It's the same as you would use a loop counter variables having a 40 character long name.

Regards, Alex

0

Featured Post

Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Templates For Beginners Or How To Encourage The Compiler To Work For You Introduction This tutorial is targeted at the reader who is, perhaps, familiar with the basics of C++ but would prefer a little slower introduction to the more ad…
IntroductionThis article is the second in a three part article series on the Visual Studio 2008 Debugger.  It provides tips in setting and using breakpoints. If not familiar with this debugger, you can find a basic introduction in the EE article loc…
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.
The viewer will be introduced to the member functions push_back and pop_back of the vector class. The video will teach the difference between the two as well as how to use each one along with its functionality.

726 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question