Visual C++ and include order.

**Gianni Mariani** · Jul 19 '05, 05:33 PM

Re: Visual C++ and include order.

Holden wrote:[color=blue]
> Hello,
> I am using Visual C++ 6.0 with Service Pack 5 installed and I have run
> into a problem that I haven't been able to figure out. I have written
> two classes and I want them to have pointers to each other. So class
> One has a private class variable of type Two and class Two has a
> private class variable of type One. I #include the header file of the
> other class in each file. When I try to build the project it gives me
> three errors, all in regards to the line that the variable is declared
> (ex: 'One' : missing storage-class or type specifiers). If I change
> the order that the classes are included in Main.cpp from:
> #include "One.h"
> #include "Two.h"
>
> to:
> #include "Two.h"
> #include "One.h"
>
> then I get errors on the opposite classes (ex: 'Two' : missing
> storage-class or type specifiers).
> Is this something that I can't do in C++? Is there a problem with
> Visual C++? Do I need to change my code or a setting somewhere?
> Thanks in advance,
> Holden.[/color]

You can forward declare the other class ...

// file one.h
class B; // incomplete class decl.

class A
{
public:
B * b;

};

// file two.h
class A; // incomplete class decl

class B
{
public:
A * a;
};

It won't matter which order they are included.

Visual C++ and include order.

Visual C++ and include order.

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