/* The following code example is taken from the book * "C++ Templates - The Complete Guide" * by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002 * * (C) Copyright David Vandevoorde and Nicolai M. Josuttis 2002. * Permission to copy, use, modify, sell and distribute this software * is granted provided this copyright notice appears in all copies. * This software is provided "as is" without express or implied * warranty, and with no claim as to its suitability for any purpose. */#include "holder.hpp"class RefMembers {  private:    Holder<MemType> ptr1;       // referenced members    Holder<MemType> ptr2;  public:    // default constructor    // - no resource leak possible    RefMembers ()     : ptr1(new MemType), ptr2(new MemType) {    }    // copy constructor    // - no resource leak possible    RefMembers (RefMembers const& x)     : ptr1(new MemType(*x.ptr1)), ptr2(new MemType(*x.ptr2)) {    }    // assignment operator    const RefMembers& operator= (RefMembers const& x) {       *ptr1 = *x.ptr1;       *ptr2 = *x.ptr2;       return *this;    }    // no destructor necessary    // (default destructor lets ptr1 and ptr2 delete their objects)    //...};