🚀 go-pugleaf

When attempted to compile the following code using GNU's g++ (ver. 2.7.1)
on HP-UX, I got the following error :

news.cc: In function `int equal(const class abc &, const class abc &)':
news.cc:23: no match for `operator ==(class abc, class abc)'


#include <iostream.h>

class abc {
    public : 
       abc( int x )
	  {
	  a = x;
	  b = 0;
	  }
       int a;
       int b;
       inline int operator ==(abc x)
           {
              return ((a==x.a) && (b==x.b));
           }
    };



template < class Element>
inline int equal (Element const& e1, Element const& e2) 
{
  return e1 == e2;

}

main()
{
abc a1(5), a2(5);

cout << "Return value is = " << equal(a1, a2) << endl;
}


Even though the 'operator ==' is overloaded in class abc, compiler is
reporting match not found. By making the overloaded function 'operator =='
as friend to 'class abc' I could resolve the problem, because in this case,
this overloaded function becomes outsider function.

As far as I know, template instantiation for function 'equal will be done
for 'class abc'(because the passed parameters are of type class abc), 
and so the corresponding member function 'operator ==' can be used for 
template variables e1 and e2.

Could any one explain why this error happens.  Please send 
your response via mail to 'seedy@trigent.com' or post it here.

Cheers,

Praveen.