Re: mutual dependency

From:
Saeed Amrollahi <amrollahi.saeed@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Fri, 30 Oct 2009 03:00:36 -0700 (PDT)
Message-ID:
<55068fdb-99f3-487a-a51d-65fef948bc23@c3g2000yqd.googlegroups.com>
On Oct 30, 11:47 am, thomas <freshtho...@gmail.com> wrote:

-------------code------------
class A{
public:
     A(){}
     void f(){
           B *b = new B();
     }

};

class B{
public:
      B(){}
      void f(){
          A *a = new A();
      }};

---------------code------------
for the above sample code, there's compile error.
if I put a declaration "class B;" at the begining, it says that no
default constructor.
how to declare a default constructor to avoid the compile error?


Hi Thomas

Put the definition of A::f() after the the defintion of B:

class A{
public:
     A(){}
     void f();
};

class B{
public:
      B(){}
      void f() {
          A *a = new A();
      }

};

void A::f()
{
       B *b = new class B();
}

it compiles and works.

FYI, such mutual dependency isn't good sign of object-oriented design.

Regards,
  -- Saeed Amrollahi

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