Question

I have class B and class A. In method of class B (let name it foo()) I have defined local object of class A. In class A I have method taking B object. How to pass B object to this method of class A when A object is local in method of class B. ?

class B {
public:
  void foo()
  {
     A a;
     a.bar(???); // want to pass B object?
  }
};

class A {
public:
  void bar(B& b)
  {
     ...
  }
};

Answer 1

If you want to pass the current instance of B:

a.bar(*this);

If you want a different instance:

B b;
a.bar(b);

If you want to pass a temporary, you need to modify A::foo to:

void bar(const B& b)

and then directly pass it:

a.bar(B());