title: C++ calling multiple constructors
body: <p>I am trying to accomplish the following: I have 4 classes(lets call one primary, other 3 secondary ones) within one namespace, I want to store instances of secondary classes as private members of <code>primary</code>, to do this I need to call <code>secondary</code> constructors from <code>primary</code>'s one and then store instances. But Unfortunately I do not completely understand how to do it (not really experienced with c++): here is what I have in header file:</p>
  
  <pre><code>    class secondary_one
      {
      private:
          int number1;
      public:
          secondary_one(int);
          int get_number1() const;
      };
  
      class secondary_two
      {
      private:
          int number2;
      public:
          secondary_two(int);
          int get_number2() const;
      };
  
      class secondary_three
      {
      private:
          int number3;
      public:
          secondary_three(int);
          int get_number3() const;
      };
  </code></pre>
  
  <p>And 'primary' class is:</p>
  
  <pre><code>class primary
  {
  private:
      secondary_one one;
      secondary_two two;
      secondary_three three;
  public:
      primary(int,int,int);
  };
  </code></pre>
  
  <p>Upon calling <code>primary</code> constructor I want first argument to be send to constructor of <code>secondary_one</code>, second argument to constructor of <code>secondary_two</code> and so on.
  And then store instances as private members. Is it even possible or I am just wasting time? If it is, can you give a short example what should I have in header and source file?</p>