Re: forward declaration of class from another namespace

From:

=?ISO-8859-1?Q?Daniel_Kr=FCgler?= <daniel.kruegler@googlemail.com>

Newsgroups:

comp.lang.c++.moderated

Date:

Sat, 24 Oct 2009 13:55:30 CST

Message-ID:

<fdb1c9a8-e2e8-4f18-bbe3-463ec5ba75ab@b18g2000vbl.googlegroups.com>

On 23 Okt., 23:34, Sergey Lukoshkin <sergey....@gmail.com> wrote:

Hello, dear community!

I've faced such a problem:

1. I got header "headerA.h" with the following code:

----------------------------------------
#include "headerB.h"

namespace A
{
       class A
       {
            public:

               create_b_ojects()
               {
                    B* pB = new B( this );
               }
       };

}

-------------------------------------

2. And I got header "headerB.h" with the following code:
-------------------------------------------
namespace B
{

     class B
     {
           public:
             B(){}
             B( /* here I need to use pointer to object of type A::A
*/ ){....}
     };

}

-------------------------------------------
Question:
what is the correct way to make forward declaration of class A::A in
module B?
Thanks in advance!!

To begin with, You need to open namespace A. The complete
code would look like the following:

namespace A
{
   class A;
}

namespace B
{
      class B
      {
            A::A* p;
            public:
              B(){}
              B(A::A* p) : p(p) {}
      };
}

HTH & Greetings from Bremen,

Daniel Kr?gler

--
      [ See http://www.gotw.ca/resources/clcm.htm for info about ]
      [ comp.lang.c++.moderated. First time posters: Do this! ]