Re: Forward declaration vs including a header file

From:

"Heinz Ozwirk" <hozwirk.SPAM@arcor.de>

Newsgroups:

microsoft.public.vc.language

Date:

Sat, 29 Apr 2006 19:03:53 +0200

Message-ID:

<44539c73$0$4494$9b4e6d93@newsread2.arcor-online.net>

"Daniel Ranger" <dranger003@gmail.com> schrieb im Newsbeitrag =
news:1146328499.034351.171590@j33g2000cwa.googlegroups.com...

Hi, I have an issue where I have two classes that require a complete
declaration of each other in order to compile and I can't get it to
work. Here's my code:

// IncludeFile1.h

#pragma once
#include "IncludeFile2.h"

using namespace NameSpace2;

namespace NameSpace1 {
class Obj1 {
public:
   Obj2 m_obj2;

   inline void method() { }
   inline void ObjMethod() { m_obj2.method(); }
};
}

// IncludeFile2.h

#pragma once
#include "IncludeFile1.h"

using namespace NameSpace1;

namespace NameSpace2 {
class Obj2 {
public:
   Obj1 m_obj1;

   inline void method() { }
   inline void ObjMethod() { m_obj1.method(); }
};
}

The above doesn't compile. I can't forward declare because of the
namespace & because of the ObjMethod() being defined in the header =

file

and I can't include each other's header file because they require each
other...

There must be a simple answer...

Think about your design. If your namespaces are so closely related that =
one cannot be defined without the other, they probably should be only =
one namespace. And for the classes -- forget it! Any instance of Obj1 =
would containe an instance of Obj2, which containes an instance of Obj1, =
which contains an instance of Obj2, which ...

That would result in a really large object, and your computer has not =
enough memory to hold such an object (and you don't have enough money to =
by enough memory). And of cause, calling, say, Obj1::ObjMethod would =
take a really long time.

Heinz