Re: operator overloading question

none <mikem891@hotmail.com> wrote in news:eecdc33b-dbfe-4f93-b2af-
e4dee0475b6e@c4g2000hsg.googlegroups.com:


You can do that by declaring your binary operators outside your class.
In the 'a picture is worth a thousand words category', here is a small
sample program.

#include <iostream>
#include <ostream>

class foo
{
public:
   foo(int a) : m_a(a) {}
   foo & operator+=(foo const & a)
   {
      m_a += a.m_a;
      return *this;
   }
   void print(std::ostream & o) const
   {
      o << m_a;
   }
private:
   int m_a;
};

std::ostream & operator<<(std::ostream & o, foo const & f)
{
   f.print(o);
   return o;
}

foo operator+(int a, foo const & f)
{
   foo aFoo(a); // convert the int to a foo
   aFoo += f;
   return aFoo;
}

foo operator+(foo const & f, int a)
{
   foo aFoo(a); // convert the int to a foo
   aFoo += f;
   return aFoo;
}

int main()
{
   foo a(2);
   foo b(0);

   b = a + 4;
   std::cout << "b = " << b << std::endl;
   b = 4 + a;
   std::cout << "b = " << b << std::endl;
}

Hope that helps,
joe