Re: Can Class be Inter-refferenced?

From:

David Wilkinson <no-reply@effisols.com>

Newsgroups:

microsoft.public.vc.language

Date:

Sat, 11 Nov 2006 06:57:49 -0500

Message-ID:

<#zB5UiYBHHA.4256@TK2MSFTNGP04.phx.gbl>

John Carson wrote:

"Mark Randall" <markyr@gEEEEEmail.com> wrote in message
news:eSD73FYBHHA.2304@TK2MSFTNGP02.phx.gbl

"William DePalo [MVP VC++]" wrote:

Hello Everone,
  I am new to cpp, I wonder how can I do something below,
  class ClassA
  {
      public:
          ClassA(ClassB aB);
  }
  class ClassB
  {
      public:
          ClassB(ClassA aA);
  }

class B;

class ClassA
{
public:
ClassA(ClassB& aB);
};

Note the reference.

Test it and you will see that it also works in the form Will gave.

If we were talking about a member variable of ClassA, then a pointer or
reference to a ClassB object would be needed. When talking about function
parameters, however, a ClassB object itself is acceptable.

Of course, a reference may be preferred on other grounds.

Gotta say, when I saw Will's code I thought it was wrong also, but when
I checked it I found that it worked! I'm so used to using forward
declaration with pointers or references, I guess.

But to the OP: almost certainly you want to pass these constructor
parameters by const reference.

David Wilkinson