source: DMM/applications/test1.cxx@ 386

#include <iostream>
#include "boost/shared_ptr.hpp"
#include "boost/weak_ptr.hpp"

class A;
class B;
typedef boost::shared_ptr<A> AStrongPtr;
typedef boost::weak_ptr<A>   AWeakPtr;
typedef boost::shared_ptr<B> BStrongPtr;
typedef boost::weak_ptr<B>   BWeakPtr;


class A {
 public:
  A() { std::cout << "Ctor A<"<<this<<">" << std::endl;}
  virtual ~A() { std::cout << "Dtor A<"<<this<<">" << std::endl;}
  
  A(const A& aA) : b(aA.b) {std::cout << "CCtor A<"<<this<<">" << std::endl;}
  A& operator=(const A& aA) {
    std::cout << "opr= A<"<<this<<">" << std::endl;
    if(&aA != this){
      b = aA.b;
    }
    return *this;
  }

  void setB(const BStrongPtr& aB) {b = aB;}
//   BWeakPtr& getB() { 
//     std::cout << "Use non-const getB" << std::endl;
//     return b;
//   }
  const BWeakPtr& getB() const { 
    std::cout << "Use const getB" << std::endl;
    return b;
  }

 private:
  BWeakPtr b;
};

class B {
 public:
  B() { std::cout << "Ctor B<"<<this<<">" << std::endl;}
  virtual ~B() { std::cout << "Dtor B<"<<this<<">" << std::endl;}
  
  B(const B& aB) : a(aB.a) {std::cout << "CCtor B<"<<this<<">" << std::endl;}
  B& operator=(const B& aB) {
    std::cout << "opr= B<"<<this<<">" << std::endl;
    if(&aB != this){
      a = aB.a;
    }
    return *this;
  }

  void setA(const AStrongPtr& aA) {a = aA;}
  AWeakPtr& getA() { 
    std::cout << "Use non-const getA" << std::endl;
    return a;
  }
  const AWeakPtr& getA() const { 
    std::cout << "Use const getA" << std::endl;
    return a;
  }

 private:
  AWeakPtr a;
};


int main() {

  std::cout << "Create A & B" << std::endl;
  AStrongPtr aA(new A);
  BStrongPtr aB(new B);
  
  std::cout << "Make the association A <-> B" << std::endl;
  aA->setB(aB);
  aB->setA(aA);

  if(BStrongPtr aB = aA->getB().lock()) {
    std::cout << "Use a B given by A->getB().lock() " << std::endl;
  }



  std::cout << "return" << std::endl;

  return 0;

}