Solved

header file confusion

Posted on 1998-08-10
2
172 Views
Last Modified: 2010-04-02
Hi,

  I want to create two classes, say class A and class B. For each class, I have a header file(A.h and B.h) as well as implementation file(A.cpp and B.cpp).  My class A has a member variable which is of the type class B. Also, in my class B, there is a member variable of type class A. i.e. the class definition looks like this:

class A {
B testMember;
...
};

class B {
A testMember;
...
};

I have "include A.h" in the B.h file and also, I "include B.h" in the A.h file. Initially i got error saying some kind of recursion definition too deep. I realized this error and added #ifdef and #endif to my program to avoid the recursion. But then I got some error saying missing decl-specifiers. I wonder what is the proper way of doing this? I am using MSVC 5.0.

Any help is appreciated!

sunjian
0
Comment
Question by:sunjian061197
[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 5

Accepted Solution

by:
yonat earned 200 total points
ID: 1169901
You can't have both A containing B and B containing A - consider the size of A, for example:
    sizeof(A) == sizeof(B) + size of the rest of A > sizeof(B)
But also:
    sizeof(B) == sizeof(A) + size of the rest of B > sizeof(A)

What you *can* do, is have A contain a pointer to B. So in A.h you should write:

class B; // forward declaration

class A
{
   B* testMember;
   ...
};

You don't need to #include B.h in A.h, only in A.cpp.

0
 

Author Comment

by:sunjian061197
ID: 1169902
Hi yonat,

   Thank you very much for your answer! You really saved me a lot of frustration...

sunjian
0

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

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

This article shows you how to optimize memory allocations in C++ using placement new. Applicable especially to usecases dealing with creation of large number of objects. A brief on problem: Lets take example problem for simplicity: - I have a G…
Basic understanding on "OO- Object Orientation" is needed for designing a logical solution to solve a problem. Basic OOAD is a prerequisite for a coder to ensure that they follow the basic design of OO. This would help developers to understand the b…
The viewer will learn how to user default arguments when defining functions. This method of defining functions will be contrasted with the non-default-argument of defining functions.
The viewer will learn additional member functions of the vector class. Specifically, the capacity and swap member functions will be introduced.

730 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