title: Composition vs. Delegation
body: <p>Is there any difference in terms of implementation as how a composition design can be different from delegation. For example the code below seems to be doing delegation since the user cannot access the composed object (i.e "a") without using b. Hence, the user would need to invoke interfaces of class b and then "class b" invoke appropriate interfaces of "class a" making it delegation. Does this make sense ?</p>
  
  <pre><code>Class A {
  friend class B;
  private: 
  A(){}; //dont want user to instantiate this class object since it wont sense without any context. Just like a room with no house.
  void PrintStructure(){};
  };
  
  Class B{
  public:
  void PrintStructure(){a.PrintStructure();} //delegate
  
  private:
  A a; //composition
  };
  </code></pre>