Question

Would someone explain the below code?

A{}

C{public: begin(&a); private: A *a;}

begin(&a)
{
   a = &a;
}

B{private: A *a; C *c; start(); }

start(){
   c->begin(&a);
}

=> In B, the object A is created and in C the object A is referenced to the object a in B.

then I got this problem:

no matching function for call to: begin(a**), candidate: begin(&a)

Otherwise, I can write this in C# and I am not sure how to implement this in C++:

public class A
{
   public A(){}
}

public class B
{
   A a;
   C c;
   public B()
   {
      c = new C();
   } 

   void start()
   {
       a = new A();
       c.begin(a);
   }
}

public class C
{
    A a;
    public C(){}

    public void begin(A a)
    {
      this.a = a;
    }
}

Answer 1

Are you just trying to get the syntax correct?

class A
{};

class B
{
   std::auto_ptr<A> a;  // This object owns A so use a smart pointer to indicate ownership.
   C                c;

   B(B const&);           // Disable copying. If you want copying use boost::shared_ptr
   B& operator=(B const&);// Disable copying.

   public:   
     void start()
     {
       a.reset(new A());
       c.begin(a.get());
     }
};

class C
{
    A* a;
    public:
      C()
       : a(NULL)
      {}

    void begin(A* pA)
    {
      a = pA;
    }
};